1.. SPDX-License-Identifier: GPL-2.0 2 3=================================================================== 4The Definitive KVM (Kernel-based Virtual Machine) API Documentation 5=================================================================== 6 71. General description 8====================== 9 10The kvm API is a set of ioctls that are issued to control various aspects 11of a virtual machine. The ioctls belong to the following classes: 12 13 - System ioctls: These query and set global attributes which affect the 14 whole kvm subsystem. In addition a system ioctl is used to create 15 virtual machines. 16 17 - VM ioctls: These query and set attributes that affect an entire virtual 18 machine, for example memory layout. In addition a VM ioctl is used to 19 create virtual cpus (vcpus) and devices. 20 21 VM ioctls must be issued from the same process (address space) that was 22 used to create the VM. 23 24 - vcpu ioctls: These query and set attributes that control the operation 25 of a single virtual cpu. 26 27 vcpu ioctls should be issued from the same thread that was used to create 28 the vcpu, except for asynchronous vcpu ioctl that are marked as such in 29 the documentation. Otherwise, the first ioctl after switching threads 30 could see a performance impact. 31 32 - device ioctls: These query and set attributes that control the operation 33 of a single device. 34 35 device ioctls must be issued from the same process (address space) that 36 was used to create the VM. 37 382. File descriptors 39=================== 40 41The kvm API is centered around file descriptors. An initial 42open("/dev/kvm") obtains a handle to the kvm subsystem; this handle 43can be used to issue system ioctls. A KVM_CREATE_VM ioctl on this 44handle will create a VM file descriptor which can be used to issue VM 45ioctls. A KVM_CREATE_VCPU or KVM_CREATE_DEVICE ioctl on a VM fd will 46create a virtual cpu or device and return a file descriptor pointing to 47the new resource. Finally, ioctls on a vcpu or device fd can be used 48to control the vcpu or device. For vcpus, this includes the important 49task of actually running guest code. 50 51In general file descriptors can be migrated among processes by means 52of fork() and the SCM_RIGHTS facility of unix domain socket. These 53kinds of tricks are explicitly not supported by kvm. While they will 54not cause harm to the host, their actual behavior is not guaranteed by 55the API. See "General description" for details on the ioctl usage 56model that is supported by KVM. 57 58It is important to note that althought VM ioctls may only be issued from 59the process that created the VM, a VM's lifecycle is associated with its 60file descriptor, not its creator (process). In other words, the VM and 61its resources, *including the associated address space*, are not freed 62until the last reference to the VM's file descriptor has been released. 63For example, if fork() is issued after ioctl(KVM_CREATE_VM), the VM will 64not be freed until both the parent (original) process and its child have 65put their references to the VM's file descriptor. 66 67Because a VM's resources are not freed until the last reference to its 68file descriptor is released, creating additional references to a VM 69via fork(), dup(), etc... without careful consideration is strongly 70discouraged and may have unwanted side effects, e.g. memory allocated 71by and on behalf of the VM's process may not be freed/unaccounted when 72the VM is shut down. 73 74 753. Extensions 76============= 77 78As of Linux 2.6.22, the KVM ABI has been stabilized: no backward 79incompatible change are allowed. However, there is an extension 80facility that allows backward-compatible extensions to the API to be 81queried and used. 82 83The extension mechanism is not based on the Linux version number. 84Instead, kvm defines extension identifiers and a facility to query 85whether a particular extension identifier is available. If it is, a 86set of ioctls is available for application use. 87 88 894. API description 90================== 91 92This section describes ioctls that can be used to control kvm guests. 93For each ioctl, the following information is provided along with a 94description: 95 96 Capability: 97 which KVM extension provides this ioctl. Can be 'basic', 98 which means that is will be provided by any kernel that supports 99 API version 12 (see section 4.1), a KVM_CAP_xyz constant, which 100 means availability needs to be checked with KVM_CHECK_EXTENSION 101 (see section 4.4), or 'none' which means that while not all kernels 102 support this ioctl, there's no capability bit to check its 103 availability: for kernels that don't support the ioctl, 104 the ioctl returns -ENOTTY. 105 106 Architectures: 107 which instruction set architectures provide this ioctl. 108 x86 includes both i386 and x86_64. 109 110 Type: 111 system, vm, or vcpu. 112 113 Parameters: 114 what parameters are accepted by the ioctl. 115 116 Returns: 117 the return value. General error numbers (EBADF, ENOMEM, EINVAL) 118 are not detailed, but errors with specific meanings are. 119 120 1214.1 KVM_GET_API_VERSION 122----------------------- 123 124:Capability: basic 125:Architectures: all 126:Type: system ioctl 127:Parameters: none 128:Returns: the constant KVM_API_VERSION (=12) 129 130This identifies the API version as the stable kvm API. It is not 131expected that this number will change. However, Linux 2.6.20 and 1322.6.21 report earlier versions; these are not documented and not 133supported. Applications should refuse to run if KVM_GET_API_VERSION 134returns a value other than 12. If this check passes, all ioctls 135described as 'basic' will be available. 136 137 1384.2 KVM_CREATE_VM 139----------------- 140 141:Capability: basic 142:Architectures: all 143:Type: system ioctl 144:Parameters: machine type identifier (KVM_VM_*) 145:Returns: a VM fd that can be used to control the new virtual machine. 146 147The new VM has no virtual cpus and no memory. 148You probably want to use 0 as machine type. 149 150In order to create user controlled virtual machines on S390, check 151KVM_CAP_S390_UCONTROL and use the flag KVM_VM_S390_UCONTROL as 152privileged user (CAP_SYS_ADMIN). 153 154To use hardware assisted virtualization on MIPS (VZ ASE) rather than 155the default trap & emulate implementation (which changes the virtual 156memory layout to fit in user mode), check KVM_CAP_MIPS_VZ and use the 157flag KVM_VM_MIPS_VZ. 158 159 160On arm64, the physical address size for a VM (IPA Size limit) is limited 161to 40bits by default. The limit can be configured if the host supports the 162extension KVM_CAP_ARM_VM_IPA_SIZE. When supported, use 163KVM_VM_TYPE_ARM_IPA_SIZE(IPA_Bits) to set the size in the machine type 164identifier, where IPA_Bits is the maximum width of any physical 165address used by the VM. The IPA_Bits is encoded in bits[7-0] of the 166machine type identifier. 167 168e.g, to configure a guest to use 48bit physical address size:: 169 170 vm_fd = ioctl(dev_fd, KVM_CREATE_VM, KVM_VM_TYPE_ARM_IPA_SIZE(48)); 171 172The requested size (IPA_Bits) must be: 173 174 == ========================================================= 175 0 Implies default size, 40bits (for backward compatibility) 176 N Implies N bits, where N is a positive integer such that, 177 32 <= N <= Host_IPA_Limit 178 == ========================================================= 179 180Host_IPA_Limit is the maximum possible value for IPA_Bits on the host and 181is dependent on the CPU capability and the kernel configuration. The limit can 182be retrieved using KVM_CAP_ARM_VM_IPA_SIZE of the KVM_CHECK_EXTENSION 183ioctl() at run-time. 184 185Creation of the VM will fail if the requested IPA size (whether it is 186implicit or explicit) is unsupported on the host. 187 188Please note that configuring the IPA size does not affect the capability 189exposed by the guest CPUs in ID_AA64MMFR0_EL1[PARange]. It only affects 190size of the address translated by the stage2 level (guest physical to 191host physical address translations). 192 193 1944.3 KVM_GET_MSR_INDEX_LIST, KVM_GET_MSR_FEATURE_INDEX_LIST 195---------------------------------------------------------- 196 197:Capability: basic, KVM_CAP_GET_MSR_FEATURES for KVM_GET_MSR_FEATURE_INDEX_LIST 198:Architectures: x86 199:Type: system ioctl 200:Parameters: struct kvm_msr_list (in/out) 201:Returns: 0 on success; -1 on error 202 203Errors: 204 205 ====== ============================================================ 206 EFAULT the msr index list cannot be read from or written to 207 E2BIG the msr index list is to be to fit in the array specified by 208 the user. 209 ====== ============================================================ 210 211:: 212 213 struct kvm_msr_list { 214 __u32 nmsrs; /* number of msrs in entries */ 215 __u32 indices[0]; 216 }; 217 218The user fills in the size of the indices array in nmsrs, and in return 219kvm adjusts nmsrs to reflect the actual number of msrs and fills in the 220indices array with their numbers. 221 222KVM_GET_MSR_INDEX_LIST returns the guest msrs that are supported. The list 223varies by kvm version and host processor, but does not change otherwise. 224 225Note: if kvm indicates supports MCE (KVM_CAP_MCE), then the MCE bank MSRs are 226not returned in the MSR list, as different vcpus can have a different number 227of banks, as set via the KVM_X86_SETUP_MCE ioctl. 228 229KVM_GET_MSR_FEATURE_INDEX_LIST returns the list of MSRs that can be passed 230to the KVM_GET_MSRS system ioctl. This lets userspace probe host capabilities 231and processor features that are exposed via MSRs (e.g., VMX capabilities). 232This list also varies by kvm version and host processor, but does not change 233otherwise. 234 235 2364.4 KVM_CHECK_EXTENSION 237----------------------- 238 239:Capability: basic, KVM_CAP_CHECK_EXTENSION_VM for vm ioctl 240:Architectures: all 241:Type: system ioctl, vm ioctl 242:Parameters: extension identifier (KVM_CAP_*) 243:Returns: 0 if unsupported; 1 (or some other positive integer) if supported 244 245The API allows the application to query about extensions to the core 246kvm API. Userspace passes an extension identifier (an integer) and 247receives an integer that describes the extension availability. 248Generally 0 means no and 1 means yes, but some extensions may report 249additional information in the integer return value. 250 251Based on their initialization different VMs may have different capabilities. 252It is thus encouraged to use the vm ioctl to query for capabilities (available 253with KVM_CAP_CHECK_EXTENSION_VM on the vm fd) 254 2554.5 KVM_GET_VCPU_MMAP_SIZE 256-------------------------- 257 258:Capability: basic 259:Architectures: all 260:Type: system ioctl 261:Parameters: none 262:Returns: size of vcpu mmap area, in bytes 263 264The KVM_RUN ioctl (cf.) communicates with userspace via a shared 265memory region. This ioctl returns the size of that region. See the 266KVM_RUN documentation for details. 267 268 2694.6 KVM_SET_MEMORY_REGION 270------------------------- 271 272:Capability: basic 273:Architectures: all 274:Type: vm ioctl 275:Parameters: struct kvm_memory_region (in) 276:Returns: 0 on success, -1 on error 277 278This ioctl is obsolete and has been removed. 279 280 2814.7 KVM_CREATE_VCPU 282------------------- 283 284:Capability: basic 285:Architectures: all 286:Type: vm ioctl 287:Parameters: vcpu id (apic id on x86) 288:Returns: vcpu fd on success, -1 on error 289 290This API adds a vcpu to a virtual machine. No more than max_vcpus may be added. 291The vcpu id is an integer in the range [0, max_vcpu_id). 292 293The recommended max_vcpus value can be retrieved using the KVM_CAP_NR_VCPUS of 294the KVM_CHECK_EXTENSION ioctl() at run-time. 295The maximum possible value for max_vcpus can be retrieved using the 296KVM_CAP_MAX_VCPUS of the KVM_CHECK_EXTENSION ioctl() at run-time. 297 298If the KVM_CAP_NR_VCPUS does not exist, you should assume that max_vcpus is 4 299cpus max. 300If the KVM_CAP_MAX_VCPUS does not exist, you should assume that max_vcpus is 301same as the value returned from KVM_CAP_NR_VCPUS. 302 303The maximum possible value for max_vcpu_id can be retrieved using the 304KVM_CAP_MAX_VCPU_ID of the KVM_CHECK_EXTENSION ioctl() at run-time. 305 306If the KVM_CAP_MAX_VCPU_ID does not exist, you should assume that max_vcpu_id 307is the same as the value returned from KVM_CAP_MAX_VCPUS. 308 309On powerpc using book3s_hv mode, the vcpus are mapped onto virtual 310threads in one or more virtual CPU cores. (This is because the 311hardware requires all the hardware threads in a CPU core to be in the 312same partition.) The KVM_CAP_PPC_SMT capability indicates the number 313of vcpus per virtual core (vcore). The vcore id is obtained by 314dividing the vcpu id by the number of vcpus per vcore. The vcpus in a 315given vcore will always be in the same physical core as each other 316(though that might be a different physical core from time to time). 317Userspace can control the threading (SMT) mode of the guest by its 318allocation of vcpu ids. For example, if userspace wants 319single-threaded guest vcpus, it should make all vcpu ids be a multiple 320of the number of vcpus per vcore. 321 322For virtual cpus that have been created with S390 user controlled virtual 323machines, the resulting vcpu fd can be memory mapped at page offset 324KVM_S390_SIE_PAGE_OFFSET in order to obtain a memory map of the virtual 325cpu's hardware control block. 326 327 3284.8 KVM_GET_DIRTY_LOG (vm ioctl) 329-------------------------------- 330 331:Capability: basic 332:Architectures: all 333:Type: vm ioctl 334:Parameters: struct kvm_dirty_log (in/out) 335:Returns: 0 on success, -1 on error 336 337:: 338 339 /* for KVM_GET_DIRTY_LOG */ 340 struct kvm_dirty_log { 341 __u32 slot; 342 __u32 padding; 343 union { 344 void __user *dirty_bitmap; /* one bit per page */ 345 __u64 padding; 346 }; 347 }; 348 349Given a memory slot, return a bitmap containing any pages dirtied 350since the last call to this ioctl. Bit 0 is the first page in the 351memory slot. Ensure the entire structure is cleared to avoid padding 352issues. 353 354If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 specifies 355the address space for which you want to return the dirty bitmap. 356They must be less than the value that KVM_CHECK_EXTENSION returns for 357the KVM_CAP_MULTI_ADDRESS_SPACE capability. 358 359The bits in the dirty bitmap are cleared before the ioctl returns, unless 360KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 is enabled. For more information, 361see the description of the capability. 362 3634.9 KVM_SET_MEMORY_ALIAS 364------------------------ 365 366:Capability: basic 367:Architectures: x86 368:Type: vm ioctl 369:Parameters: struct kvm_memory_alias (in) 370:Returns: 0 (success), -1 (error) 371 372This ioctl is obsolete and has been removed. 373 374 3754.10 KVM_RUN 376------------ 377 378:Capability: basic 379:Architectures: all 380:Type: vcpu ioctl 381:Parameters: none 382:Returns: 0 on success, -1 on error 383 384Errors: 385 386 ===== ============================= 387 EINTR an unmasked signal is pending 388 ===== ============================= 389 390This ioctl is used to run a guest virtual cpu. While there are no 391explicit parameters, there is an implicit parameter block that can be 392obtained by mmap()ing the vcpu fd at offset 0, with the size given by 393KVM_GET_VCPU_MMAP_SIZE. The parameter block is formatted as a 'struct 394kvm_run' (see below). 395 396 3974.11 KVM_GET_REGS 398----------------- 399 400:Capability: basic 401:Architectures: all except ARM, arm64 402:Type: vcpu ioctl 403:Parameters: struct kvm_regs (out) 404:Returns: 0 on success, -1 on error 405 406Reads the general purpose registers from the vcpu. 407 408:: 409 410 /* x86 */ 411 struct kvm_regs { 412 /* out (KVM_GET_REGS) / in (KVM_SET_REGS) */ 413 __u64 rax, rbx, rcx, rdx; 414 __u64 rsi, rdi, rsp, rbp; 415 __u64 r8, r9, r10, r11; 416 __u64 r12, r13, r14, r15; 417 __u64 rip, rflags; 418 }; 419 420 /* mips */ 421 struct kvm_regs { 422 /* out (KVM_GET_REGS) / in (KVM_SET_REGS) */ 423 __u64 gpr[32]; 424 __u64 hi; 425 __u64 lo; 426 __u64 pc; 427 }; 428 429 4304.12 KVM_SET_REGS 431----------------- 432 433:Capability: basic 434:Architectures: all except ARM, arm64 435:Type: vcpu ioctl 436:Parameters: struct kvm_regs (in) 437:Returns: 0 on success, -1 on error 438 439Writes the general purpose registers into the vcpu. 440 441See KVM_GET_REGS for the data structure. 442 443 4444.13 KVM_GET_SREGS 445------------------ 446 447:Capability: basic 448:Architectures: x86, ppc 449:Type: vcpu ioctl 450:Parameters: struct kvm_sregs (out) 451:Returns: 0 on success, -1 on error 452 453Reads special registers from the vcpu. 454 455:: 456 457 /* x86 */ 458 struct kvm_sregs { 459 struct kvm_segment cs, ds, es, fs, gs, ss; 460 struct kvm_segment tr, ldt; 461 struct kvm_dtable gdt, idt; 462 __u64 cr0, cr2, cr3, cr4, cr8; 463 __u64 efer; 464 __u64 apic_base; 465 __u64 interrupt_bitmap[(KVM_NR_INTERRUPTS + 63) / 64]; 466 }; 467 468 /* ppc -- see arch/powerpc/include/uapi/asm/kvm.h */ 469 470interrupt_bitmap is a bitmap of pending external interrupts. At most 471one bit may be set. This interrupt has been acknowledged by the APIC 472but not yet injected into the cpu core. 473 474 4754.14 KVM_SET_SREGS 476------------------ 477 478:Capability: basic 479:Architectures: x86, ppc 480:Type: vcpu ioctl 481:Parameters: struct kvm_sregs (in) 482:Returns: 0 on success, -1 on error 483 484Writes special registers into the vcpu. See KVM_GET_SREGS for the 485data structures. 486 487 4884.15 KVM_TRANSLATE 489------------------ 490 491:Capability: basic 492:Architectures: x86 493:Type: vcpu ioctl 494:Parameters: struct kvm_translation (in/out) 495:Returns: 0 on success, -1 on error 496 497Translates a virtual address according to the vcpu's current address 498translation mode. 499 500:: 501 502 struct kvm_translation { 503 /* in */ 504 __u64 linear_address; 505 506 /* out */ 507 __u64 physical_address; 508 __u8 valid; 509 __u8 writeable; 510 __u8 usermode; 511 __u8 pad[5]; 512 }; 513 514 5154.16 KVM_INTERRUPT 516------------------ 517 518:Capability: basic 519:Architectures: x86, ppc, mips 520:Type: vcpu ioctl 521:Parameters: struct kvm_interrupt (in) 522:Returns: 0 on success, negative on failure. 523 524Queues a hardware interrupt vector to be injected. 525 526:: 527 528 /* for KVM_INTERRUPT */ 529 struct kvm_interrupt { 530 /* in */ 531 __u32 irq; 532 }; 533 534X86: 535^^^^ 536 537:Returns: 538 539 ========= =================================== 540 0 on success, 541 -EEXIST if an interrupt is already enqueued 542 -EINVAL the irq number is invalid 543 -ENXIO if the PIC is in the kernel 544 -EFAULT if the pointer is invalid 545 ========= =================================== 546 547Note 'irq' is an interrupt vector, not an interrupt pin or line. This 548ioctl is useful if the in-kernel PIC is not used. 549 550PPC: 551^^^^ 552 553Queues an external interrupt to be injected. This ioctl is overleaded 554with 3 different irq values: 555 556a) KVM_INTERRUPT_SET 557 558 This injects an edge type external interrupt into the guest once it's ready 559 to receive interrupts. When injected, the interrupt is done. 560 561b) KVM_INTERRUPT_UNSET 562 563 This unsets any pending interrupt. 564 565 Only available with KVM_CAP_PPC_UNSET_IRQ. 566 567c) KVM_INTERRUPT_SET_LEVEL 568 569 This injects a level type external interrupt into the guest context. The 570 interrupt stays pending until a specific ioctl with KVM_INTERRUPT_UNSET 571 is triggered. 572 573 Only available with KVM_CAP_PPC_IRQ_LEVEL. 574 575Note that any value for 'irq' other than the ones stated above is invalid 576and incurs unexpected behavior. 577 578This is an asynchronous vcpu ioctl and can be invoked from any thread. 579 580MIPS: 581^^^^^ 582 583Queues an external interrupt to be injected into the virtual CPU. A negative 584interrupt number dequeues the interrupt. 585 586This is an asynchronous vcpu ioctl and can be invoked from any thread. 587 588 5894.17 KVM_DEBUG_GUEST 590-------------------- 591 592:Capability: basic 593:Architectures: none 594:Type: vcpu ioctl 595:Parameters: none) 596:Returns: -1 on error 597 598Support for this has been removed. Use KVM_SET_GUEST_DEBUG instead. 599 600 6014.18 KVM_GET_MSRS 602----------------- 603 604:Capability: basic (vcpu), KVM_CAP_GET_MSR_FEATURES (system) 605:Architectures: x86 606:Type: system ioctl, vcpu ioctl 607:Parameters: struct kvm_msrs (in/out) 608:Returns: number of msrs successfully returned; 609 -1 on error 610 611When used as a system ioctl: 612Reads the values of MSR-based features that are available for the VM. This 613is similar to KVM_GET_SUPPORTED_CPUID, but it returns MSR indices and values. 614The list of msr-based features can be obtained using KVM_GET_MSR_FEATURE_INDEX_LIST 615in a system ioctl. 616 617When used as a vcpu ioctl: 618Reads model-specific registers from the vcpu. Supported msr indices can 619be obtained using KVM_GET_MSR_INDEX_LIST in a system ioctl. 620 621:: 622 623 struct kvm_msrs { 624 __u32 nmsrs; /* number of msrs in entries */ 625 __u32 pad; 626 627 struct kvm_msr_entry entries[0]; 628 }; 629 630 struct kvm_msr_entry { 631 __u32 index; 632 __u32 reserved; 633 __u64 data; 634 }; 635 636Application code should set the 'nmsrs' member (which indicates the 637size of the entries array) and the 'index' member of each array entry. 638kvm will fill in the 'data' member. 639 640 6414.19 KVM_SET_MSRS 642----------------- 643 644:Capability: basic 645:Architectures: x86 646:Type: vcpu ioctl 647:Parameters: struct kvm_msrs (in) 648:Returns: number of msrs successfully set (see below), -1 on error 649 650Writes model-specific registers to the vcpu. See KVM_GET_MSRS for the 651data structures. 652 653Application code should set the 'nmsrs' member (which indicates the 654size of the entries array), and the 'index' and 'data' members of each 655array entry. 656 657It tries to set the MSRs in array entries[] one by one. If setting an MSR 658fails, e.g., due to setting reserved bits, the MSR isn't supported/emulated 659by KVM, etc..., it stops processing the MSR list and returns the number of 660MSRs that have been set successfully. 661 662 6634.20 KVM_SET_CPUID 664------------------ 665 666:Capability: basic 667:Architectures: x86 668:Type: vcpu ioctl 669:Parameters: struct kvm_cpuid (in) 670:Returns: 0 on success, -1 on error 671 672Defines the vcpu responses to the cpuid instruction. Applications 673should use the KVM_SET_CPUID2 ioctl if available. 674 675Note, when this IOCTL fails, KVM gives no guarantees that previous valid CPUID 676configuration (if there is) is not corrupted. Userspace can get a copy of the 677resulting CPUID configuration through KVM_GET_CPUID2 in case. 678 679:: 680 681 struct kvm_cpuid_entry { 682 __u32 function; 683 __u32 eax; 684 __u32 ebx; 685 __u32 ecx; 686 __u32 edx; 687 __u32 padding; 688 }; 689 690 /* for KVM_SET_CPUID */ 691 struct kvm_cpuid { 692 __u32 nent; 693 __u32 padding; 694 struct kvm_cpuid_entry entries[0]; 695 }; 696 697 6984.21 KVM_SET_SIGNAL_MASK 699------------------------ 700 701:Capability: basic 702:Architectures: all 703:Type: vcpu ioctl 704:Parameters: struct kvm_signal_mask (in) 705:Returns: 0 on success, -1 on error 706 707Defines which signals are blocked during execution of KVM_RUN. This 708signal mask temporarily overrides the threads signal mask. Any 709unblocked signal received (except SIGKILL and SIGSTOP, which retain 710their traditional behaviour) will cause KVM_RUN to return with -EINTR. 711 712Note the signal will only be delivered if not blocked by the original 713signal mask. 714 715:: 716 717 /* for KVM_SET_SIGNAL_MASK */ 718 struct kvm_signal_mask { 719 __u32 len; 720 __u8 sigset[0]; 721 }; 722 723 7244.22 KVM_GET_FPU 725---------------- 726 727:Capability: basic 728:Architectures: x86 729:Type: vcpu ioctl 730:Parameters: struct kvm_fpu (out) 731:Returns: 0 on success, -1 on error 732 733Reads the floating point state from the vcpu. 734 735:: 736 737 /* for KVM_GET_FPU and KVM_SET_FPU */ 738 struct kvm_fpu { 739 __u8 fpr[8][16]; 740 __u16 fcw; 741 __u16 fsw; 742 __u8 ftwx; /* in fxsave format */ 743 __u8 pad1; 744 __u16 last_opcode; 745 __u64 last_ip; 746 __u64 last_dp; 747 __u8 xmm[16][16]; 748 __u32 mxcsr; 749 __u32 pad2; 750 }; 751 752 7534.23 KVM_SET_FPU 754---------------- 755 756:Capability: basic 757:Architectures: x86 758:Type: vcpu ioctl 759:Parameters: struct kvm_fpu (in) 760:Returns: 0 on success, -1 on error 761 762Writes the floating point state to the vcpu. 763 764:: 765 766 /* for KVM_GET_FPU and KVM_SET_FPU */ 767 struct kvm_fpu { 768 __u8 fpr[8][16]; 769 __u16 fcw; 770 __u16 fsw; 771 __u8 ftwx; /* in fxsave format */ 772 __u8 pad1; 773 __u16 last_opcode; 774 __u64 last_ip; 775 __u64 last_dp; 776 __u8 xmm[16][16]; 777 __u32 mxcsr; 778 __u32 pad2; 779 }; 780 781 7824.24 KVM_CREATE_IRQCHIP 783----------------------- 784 785:Capability: KVM_CAP_IRQCHIP, KVM_CAP_S390_IRQCHIP (s390) 786:Architectures: x86, ARM, arm64, s390 787:Type: vm ioctl 788:Parameters: none 789:Returns: 0 on success, -1 on error 790 791Creates an interrupt controller model in the kernel. 792On x86, creates a virtual ioapic, a virtual PIC (two PICs, nested), and sets up 793future vcpus to have a local APIC. IRQ routing for GSIs 0-15 is set to both 794PIC and IOAPIC; GSI 16-23 only go to the IOAPIC. 795On ARM/arm64, a GICv2 is created. Any other GIC versions require the usage of 796KVM_CREATE_DEVICE, which also supports creating a GICv2. Using 797KVM_CREATE_DEVICE is preferred over KVM_CREATE_IRQCHIP for GICv2. 798On s390, a dummy irq routing table is created. 799 800Note that on s390 the KVM_CAP_S390_IRQCHIP vm capability needs to be enabled 801before KVM_CREATE_IRQCHIP can be used. 802 803 8044.25 KVM_IRQ_LINE 805----------------- 806 807:Capability: KVM_CAP_IRQCHIP 808:Architectures: x86, arm, arm64 809:Type: vm ioctl 810:Parameters: struct kvm_irq_level 811:Returns: 0 on success, -1 on error 812 813Sets the level of a GSI input to the interrupt controller model in the kernel. 814On some architectures it is required that an interrupt controller model has 815been previously created with KVM_CREATE_IRQCHIP. Note that edge-triggered 816interrupts require the level to be set to 1 and then back to 0. 817 818On real hardware, interrupt pins can be active-low or active-high. This 819does not matter for the level field of struct kvm_irq_level: 1 always 820means active (asserted), 0 means inactive (deasserted). 821 822x86 allows the operating system to program the interrupt polarity 823(active-low/active-high) for level-triggered interrupts, and KVM used 824to consider the polarity. However, due to bitrot in the handling of 825active-low interrupts, the above convention is now valid on x86 too. 826This is signaled by KVM_CAP_X86_IOAPIC_POLARITY_IGNORED. Userspace 827should not present interrupts to the guest as active-low unless this 828capability is present (or unless it is not using the in-kernel irqchip, 829of course). 830 831 832ARM/arm64 can signal an interrupt either at the CPU level, or at the 833in-kernel irqchip (GIC), and for in-kernel irqchip can tell the GIC to 834use PPIs designated for specific cpus. The irq field is interpreted 835like this:: 836 837 bits: | 31 ... 28 | 27 ... 24 | 23 ... 16 | 15 ... 0 | 838 field: | vcpu2_index | irq_type | vcpu_index | irq_id | 839 840The irq_type field has the following values: 841 842- irq_type[0]: 843 out-of-kernel GIC: irq_id 0 is IRQ, irq_id 1 is FIQ 844- irq_type[1]: 845 in-kernel GIC: SPI, irq_id between 32 and 1019 (incl.) 846 (the vcpu_index field is ignored) 847- irq_type[2]: 848 in-kernel GIC: PPI, irq_id between 16 and 31 (incl.) 849 850(The irq_id field thus corresponds nicely to the IRQ ID in the ARM GIC specs) 851 852In both cases, level is used to assert/deassert the line. 853 854When KVM_CAP_ARM_IRQ_LINE_LAYOUT_2 is supported, the target vcpu is 855identified as (256 * vcpu2_index + vcpu_index). Otherwise, vcpu2_index 856must be zero. 857 858Note that on arm/arm64, the KVM_CAP_IRQCHIP capability only conditions 859injection of interrupts for the in-kernel irqchip. KVM_IRQ_LINE can always 860be used for a userspace interrupt controller. 861 862:: 863 864 struct kvm_irq_level { 865 union { 866 __u32 irq; /* GSI */ 867 __s32 status; /* not used for KVM_IRQ_LEVEL */ 868 }; 869 __u32 level; /* 0 or 1 */ 870 }; 871 872 8734.26 KVM_GET_IRQCHIP 874-------------------- 875 876:Capability: KVM_CAP_IRQCHIP 877:Architectures: x86 878:Type: vm ioctl 879:Parameters: struct kvm_irqchip (in/out) 880:Returns: 0 on success, -1 on error 881 882Reads the state of a kernel interrupt controller created with 883KVM_CREATE_IRQCHIP into a buffer provided by the caller. 884 885:: 886 887 struct kvm_irqchip { 888 __u32 chip_id; /* 0 = PIC1, 1 = PIC2, 2 = IOAPIC */ 889 __u32 pad; 890 union { 891 char dummy[512]; /* reserving space */ 892 struct kvm_pic_state pic; 893 struct kvm_ioapic_state ioapic; 894 } chip; 895 }; 896 897 8984.27 KVM_SET_IRQCHIP 899-------------------- 900 901:Capability: KVM_CAP_IRQCHIP 902:Architectures: x86 903:Type: vm ioctl 904:Parameters: struct kvm_irqchip (in) 905:Returns: 0 on success, -1 on error 906 907Sets the state of a kernel interrupt controller created with 908KVM_CREATE_IRQCHIP from a buffer provided by the caller. 909 910:: 911 912 struct kvm_irqchip { 913 __u32 chip_id; /* 0 = PIC1, 1 = PIC2, 2 = IOAPIC */ 914 __u32 pad; 915 union { 916 char dummy[512]; /* reserving space */ 917 struct kvm_pic_state pic; 918 struct kvm_ioapic_state ioapic; 919 } chip; 920 }; 921 922 9234.28 KVM_XEN_HVM_CONFIG 924----------------------- 925 926:Capability: KVM_CAP_XEN_HVM 927:Architectures: x86 928:Type: vm ioctl 929:Parameters: struct kvm_xen_hvm_config (in) 930:Returns: 0 on success, -1 on error 931 932Sets the MSR that the Xen HVM guest uses to initialize its hypercall 933page, and provides the starting address and size of the hypercall 934blobs in userspace. When the guest writes the MSR, kvm copies one 935page of a blob (32- or 64-bit, depending on the vcpu mode) to guest 936memory. 937 938:: 939 940 struct kvm_xen_hvm_config { 941 __u32 flags; 942 __u32 msr; 943 __u64 blob_addr_32; 944 __u64 blob_addr_64; 945 __u8 blob_size_32; 946 __u8 blob_size_64; 947 __u8 pad2[30]; 948 }; 949 950 9514.29 KVM_GET_CLOCK 952------------------ 953 954:Capability: KVM_CAP_ADJUST_CLOCK 955:Architectures: x86 956:Type: vm ioctl 957:Parameters: struct kvm_clock_data (out) 958:Returns: 0 on success, -1 on error 959 960Gets the current timestamp of kvmclock as seen by the current guest. In 961conjunction with KVM_SET_CLOCK, it is used to ensure monotonicity on scenarios 962such as migration. 963 964When KVM_CAP_ADJUST_CLOCK is passed to KVM_CHECK_EXTENSION, it returns the 965set of bits that KVM can return in struct kvm_clock_data's flag member. 966 967The only flag defined now is KVM_CLOCK_TSC_STABLE. If set, the returned 968value is the exact kvmclock value seen by all VCPUs at the instant 969when KVM_GET_CLOCK was called. If clear, the returned value is simply 970CLOCK_MONOTONIC plus a constant offset; the offset can be modified 971with KVM_SET_CLOCK. KVM will try to make all VCPUs follow this clock, 972but the exact value read by each VCPU could differ, because the host 973TSC is not stable. 974 975:: 976 977 struct kvm_clock_data { 978 __u64 clock; /* kvmclock current value */ 979 __u32 flags; 980 __u32 pad[9]; 981 }; 982 983 9844.30 KVM_SET_CLOCK 985------------------ 986 987:Capability: KVM_CAP_ADJUST_CLOCK 988:Architectures: x86 989:Type: vm ioctl 990:Parameters: struct kvm_clock_data (in) 991:Returns: 0 on success, -1 on error 992 993Sets the current timestamp of kvmclock to the value specified in its parameter. 994In conjunction with KVM_GET_CLOCK, it is used to ensure monotonicity on scenarios 995such as migration. 996 997:: 998 999 struct kvm_clock_data { 1000 __u64 clock; /* kvmclock current value */ 1001 __u32 flags; 1002 __u32 pad[9]; 1003 }; 1004 1005 10064.31 KVM_GET_VCPU_EVENTS 1007------------------------ 1008 1009:Capability: KVM_CAP_VCPU_EVENTS 1010:Extended by: KVM_CAP_INTR_SHADOW 1011:Architectures: x86, arm, arm64 1012:Type: vcpu ioctl 1013:Parameters: struct kvm_vcpu_event (out) 1014:Returns: 0 on success, -1 on error 1015 1016X86: 1017^^^^ 1018 1019Gets currently pending exceptions, interrupts, and NMIs as well as related 1020states of the vcpu. 1021 1022:: 1023 1024 struct kvm_vcpu_events { 1025 struct { 1026 __u8 injected; 1027 __u8 nr; 1028 __u8 has_error_code; 1029 __u8 pending; 1030 __u32 error_code; 1031 } exception; 1032 struct { 1033 __u8 injected; 1034 __u8 nr; 1035 __u8 soft; 1036 __u8 shadow; 1037 } interrupt; 1038 struct { 1039 __u8 injected; 1040 __u8 pending; 1041 __u8 masked; 1042 __u8 pad; 1043 } nmi; 1044 __u32 sipi_vector; 1045 __u32 flags; 1046 struct { 1047 __u8 smm; 1048 __u8 pending; 1049 __u8 smm_inside_nmi; 1050 __u8 latched_init; 1051 } smi; 1052 __u8 reserved[27]; 1053 __u8 exception_has_payload; 1054 __u64 exception_payload; 1055 }; 1056 1057The following bits are defined in the flags field: 1058 1059- KVM_VCPUEVENT_VALID_SHADOW may be set to signal that 1060 interrupt.shadow contains a valid state. 1061 1062- KVM_VCPUEVENT_VALID_SMM may be set to signal that smi contains a 1063 valid state. 1064 1065- KVM_VCPUEVENT_VALID_PAYLOAD may be set to signal that the 1066 exception_has_payload, exception_payload, and exception.pending 1067 fields contain a valid state. This bit will be set whenever 1068 KVM_CAP_EXCEPTION_PAYLOAD is enabled. 1069 1070ARM/ARM64: 1071^^^^^^^^^^ 1072 1073If the guest accesses a device that is being emulated by the host kernel in 1074such a way that a real device would generate a physical SError, KVM may make 1075a virtual SError pending for that VCPU. This system error interrupt remains 1076pending until the guest takes the exception by unmasking PSTATE.A. 1077 1078Running the VCPU may cause it to take a pending SError, or make an access that 1079causes an SError to become pending. The event's description is only valid while 1080the VPCU is not running. 1081 1082This API provides a way to read and write the pending 'event' state that is not 1083visible to the guest. To save, restore or migrate a VCPU the struct representing 1084the state can be read then written using this GET/SET API, along with the other 1085guest-visible registers. It is not possible to 'cancel' an SError that has been 1086made pending. 1087 1088A device being emulated in user-space may also wish to generate an SError. To do 1089this the events structure can be populated by user-space. The current state 1090should be read first, to ensure no existing SError is pending. If an existing 1091SError is pending, the architecture's 'Multiple SError interrupts' rules should 1092be followed. (2.5.3 of DDI0587.a "ARM Reliability, Availability, and 1093Serviceability (RAS) Specification"). 1094 1095SError exceptions always have an ESR value. Some CPUs have the ability to 1096specify what the virtual SError's ESR value should be. These systems will 1097advertise KVM_CAP_ARM_INJECT_SERROR_ESR. In this case exception.has_esr will 1098always have a non-zero value when read, and the agent making an SError pending 1099should specify the ISS field in the lower 24 bits of exception.serror_esr. If 1100the system supports KVM_CAP_ARM_INJECT_SERROR_ESR, but user-space sets the events 1101with exception.has_esr as zero, KVM will choose an ESR. 1102 1103Specifying exception.has_esr on a system that does not support it will return 1104-EINVAL. Setting anything other than the lower 24bits of exception.serror_esr 1105will return -EINVAL. 1106 1107It is not possible to read back a pending external abort (injected via 1108KVM_SET_VCPU_EVENTS or otherwise) because such an exception is always delivered 1109directly to the virtual CPU). 1110 1111:: 1112 1113 struct kvm_vcpu_events { 1114 struct { 1115 __u8 serror_pending; 1116 __u8 serror_has_esr; 1117 __u8 ext_dabt_pending; 1118 /* Align it to 8 bytes */ 1119 __u8 pad[5]; 1120 __u64 serror_esr; 1121 } exception; 1122 __u32 reserved[12]; 1123 }; 1124 11254.32 KVM_SET_VCPU_EVENTS 1126------------------------ 1127 1128:Capability: KVM_CAP_VCPU_EVENTS 1129:Extended by: KVM_CAP_INTR_SHADOW 1130:Architectures: x86, arm, arm64 1131:Type: vcpu ioctl 1132:Parameters: struct kvm_vcpu_event (in) 1133:Returns: 0 on success, -1 on error 1134 1135X86: 1136^^^^ 1137 1138Set pending exceptions, interrupts, and NMIs as well as related states of the 1139vcpu. 1140 1141See KVM_GET_VCPU_EVENTS for the data structure. 1142 1143Fields that may be modified asynchronously by running VCPUs can be excluded 1144from the update. These fields are nmi.pending, sipi_vector, smi.smm, 1145smi.pending. Keep the corresponding bits in the flags field cleared to 1146suppress overwriting the current in-kernel state. The bits are: 1147 1148=============================== ================================== 1149KVM_VCPUEVENT_VALID_NMI_PENDING transfer nmi.pending to the kernel 1150KVM_VCPUEVENT_VALID_SIPI_VECTOR transfer sipi_vector 1151KVM_VCPUEVENT_VALID_SMM transfer the smi sub-struct. 1152=============================== ================================== 1153 1154If KVM_CAP_INTR_SHADOW is available, KVM_VCPUEVENT_VALID_SHADOW can be set in 1155the flags field to signal that interrupt.shadow contains a valid state and 1156shall be written into the VCPU. 1157 1158KVM_VCPUEVENT_VALID_SMM can only be set if KVM_CAP_X86_SMM is available. 1159 1160If KVM_CAP_EXCEPTION_PAYLOAD is enabled, KVM_VCPUEVENT_VALID_PAYLOAD 1161can be set in the flags field to signal that the 1162exception_has_payload, exception_payload, and exception.pending fields 1163contain a valid state and shall be written into the VCPU. 1164 1165ARM/ARM64: 1166^^^^^^^^^^ 1167 1168User space may need to inject several types of events to the guest. 1169 1170Set the pending SError exception state for this VCPU. It is not possible to 1171'cancel' an Serror that has been made pending. 1172 1173If the guest performed an access to I/O memory which could not be handled by 1174userspace, for example because of missing instruction syndrome decode 1175information or because there is no device mapped at the accessed IPA, then 1176userspace can ask the kernel to inject an external abort using the address 1177from the exiting fault on the VCPU. It is a programming error to set 1178ext_dabt_pending after an exit which was not either KVM_EXIT_MMIO or 1179KVM_EXIT_ARM_NISV. This feature is only available if the system supports 1180KVM_CAP_ARM_INJECT_EXT_DABT. This is a helper which provides commonality in 1181how userspace reports accesses for the above cases to guests, across different 1182userspace implementations. Nevertheless, userspace can still emulate all Arm 1183exceptions by manipulating individual registers using the KVM_SET_ONE_REG API. 1184 1185See KVM_GET_VCPU_EVENTS for the data structure. 1186 1187 11884.33 KVM_GET_DEBUGREGS 1189---------------------- 1190 1191:Capability: KVM_CAP_DEBUGREGS 1192:Architectures: x86 1193:Type: vm ioctl 1194:Parameters: struct kvm_debugregs (out) 1195:Returns: 0 on success, -1 on error 1196 1197Reads debug registers from the vcpu. 1198 1199:: 1200 1201 struct kvm_debugregs { 1202 __u64 db[4]; 1203 __u64 dr6; 1204 __u64 dr7; 1205 __u64 flags; 1206 __u64 reserved[9]; 1207 }; 1208 1209 12104.34 KVM_SET_DEBUGREGS 1211---------------------- 1212 1213:Capability: KVM_CAP_DEBUGREGS 1214:Architectures: x86 1215:Type: vm ioctl 1216:Parameters: struct kvm_debugregs (in) 1217:Returns: 0 on success, -1 on error 1218 1219Writes debug registers into the vcpu. 1220 1221See KVM_GET_DEBUGREGS for the data structure. The flags field is unused 1222yet and must be cleared on entry. 1223 1224 12254.35 KVM_SET_USER_MEMORY_REGION 1226------------------------------- 1227 1228:Capability: KVM_CAP_USER_MEMORY 1229:Architectures: all 1230:Type: vm ioctl 1231:Parameters: struct kvm_userspace_memory_region (in) 1232:Returns: 0 on success, -1 on error 1233 1234:: 1235 1236 struct kvm_userspace_memory_region { 1237 __u32 slot; 1238 __u32 flags; 1239 __u64 guest_phys_addr; 1240 __u64 memory_size; /* bytes */ 1241 __u64 userspace_addr; /* start of the userspace allocated memory */ 1242 }; 1243 1244 /* for kvm_memory_region::flags */ 1245 #define KVM_MEM_LOG_DIRTY_PAGES (1UL << 0) 1246 #define KVM_MEM_READONLY (1UL << 1) 1247 1248This ioctl allows the user to create, modify or delete a guest physical 1249memory slot. Bits 0-15 of "slot" specify the slot id and this value 1250should be less than the maximum number of user memory slots supported per 1251VM. The maximum allowed slots can be queried using KVM_CAP_NR_MEMSLOTS. 1252Slots may not overlap in guest physical address space. 1253 1254If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 of "slot" 1255specifies the address space which is being modified. They must be 1256less than the value that KVM_CHECK_EXTENSION returns for the 1257KVM_CAP_MULTI_ADDRESS_SPACE capability. Slots in separate address spaces 1258are unrelated; the restriction on overlapping slots only applies within 1259each address space. 1260 1261Deleting a slot is done by passing zero for memory_size. When changing 1262an existing slot, it may be moved in the guest physical memory space, 1263or its flags may be modified, but it may not be resized. 1264 1265Memory for the region is taken starting at the address denoted by the 1266field userspace_addr, which must point at user addressable memory for 1267the entire memory slot size. Any object may back this memory, including 1268anonymous memory, ordinary files, and hugetlbfs. 1269 1270On architectures that support a form of address tagging, userspace_addr must 1271be an untagged address. 1272 1273It is recommended that the lower 21 bits of guest_phys_addr and userspace_addr 1274be identical. This allows large pages in the guest to be backed by large 1275pages in the host. 1276 1277The flags field supports two flags: KVM_MEM_LOG_DIRTY_PAGES and 1278KVM_MEM_READONLY. The former can be set to instruct KVM to keep track of 1279writes to memory within the slot. See KVM_GET_DIRTY_LOG ioctl to know how to 1280use it. The latter can be set, if KVM_CAP_READONLY_MEM capability allows it, 1281to make a new slot read-only. In this case, writes to this memory will be 1282posted to userspace as KVM_EXIT_MMIO exits. 1283 1284When the KVM_CAP_SYNC_MMU capability is available, changes in the backing of 1285the memory region are automatically reflected into the guest. For example, an 1286mmap() that affects the region will be made visible immediately. Another 1287example is madvise(MADV_DROP). 1288 1289It is recommended to use this API instead of the KVM_SET_MEMORY_REGION ioctl. 1290The KVM_SET_MEMORY_REGION does not allow fine grained control over memory 1291allocation and is deprecated. 1292 1293 12944.36 KVM_SET_TSS_ADDR 1295--------------------- 1296 1297:Capability: KVM_CAP_SET_TSS_ADDR 1298:Architectures: x86 1299:Type: vm ioctl 1300:Parameters: unsigned long tss_address (in) 1301:Returns: 0 on success, -1 on error 1302 1303This ioctl defines the physical address of a three-page region in the guest 1304physical address space. The region must be within the first 4GB of the 1305guest physical address space and must not conflict with any memory slot 1306or any mmio address. The guest may malfunction if it accesses this memory 1307region. 1308 1309This ioctl is required on Intel-based hosts. This is needed on Intel hardware 1310because of a quirk in the virtualization implementation (see the internals 1311documentation when it pops into existence). 1312 1313 13144.37 KVM_ENABLE_CAP 1315------------------- 1316 1317:Capability: KVM_CAP_ENABLE_CAP 1318:Architectures: mips, ppc, s390 1319:Type: vcpu ioctl 1320:Parameters: struct kvm_enable_cap (in) 1321:Returns: 0 on success; -1 on error 1322 1323:Capability: KVM_CAP_ENABLE_CAP_VM 1324:Architectures: all 1325:Type: vm ioctl 1326:Parameters: struct kvm_enable_cap (in) 1327:Returns: 0 on success; -1 on error 1328 1329.. note:: 1330 1331 Not all extensions are enabled by default. Using this ioctl the application 1332 can enable an extension, making it available to the guest. 1333 1334On systems that do not support this ioctl, it always fails. On systems that 1335do support it, it only works for extensions that are supported for enablement. 1336 1337To check if a capability can be enabled, the KVM_CHECK_EXTENSION ioctl should 1338be used. 1339 1340:: 1341 1342 struct kvm_enable_cap { 1343 /* in */ 1344 __u32 cap; 1345 1346The capability that is supposed to get enabled. 1347 1348:: 1349 1350 __u32 flags; 1351 1352A bitfield indicating future enhancements. Has to be 0 for now. 1353 1354:: 1355 1356 __u64 args[4]; 1357 1358Arguments for enabling a feature. If a feature needs initial values to 1359function properly, this is the place to put them. 1360 1361:: 1362 1363 __u8 pad[64]; 1364 }; 1365 1366The vcpu ioctl should be used for vcpu-specific capabilities, the vm ioctl 1367for vm-wide capabilities. 1368 13694.38 KVM_GET_MP_STATE 1370--------------------- 1371 1372:Capability: KVM_CAP_MP_STATE 1373:Architectures: x86, s390, arm, arm64 1374:Type: vcpu ioctl 1375:Parameters: struct kvm_mp_state (out) 1376:Returns: 0 on success; -1 on error 1377 1378:: 1379 1380 struct kvm_mp_state { 1381 __u32 mp_state; 1382 }; 1383 1384Returns the vcpu's current "multiprocessing state" (though also valid on 1385uniprocessor guests). 1386 1387Possible values are: 1388 1389 ========================== =============================================== 1390 KVM_MP_STATE_RUNNABLE the vcpu is currently running [x86,arm/arm64] 1391 KVM_MP_STATE_UNINITIALIZED the vcpu is an application processor (AP) 1392 which has not yet received an INIT signal [x86] 1393 KVM_MP_STATE_INIT_RECEIVED the vcpu has received an INIT signal, and is 1394 now ready for a SIPI [x86] 1395 KVM_MP_STATE_HALTED the vcpu has executed a HLT instruction and 1396 is waiting for an interrupt [x86] 1397 KVM_MP_STATE_SIPI_RECEIVED the vcpu has just received a SIPI (vector 1398 accessible via KVM_GET_VCPU_EVENTS) [x86] 1399 KVM_MP_STATE_STOPPED the vcpu is stopped [s390,arm/arm64] 1400 KVM_MP_STATE_CHECK_STOP the vcpu is in a special error state [s390] 1401 KVM_MP_STATE_OPERATING the vcpu is operating (running or halted) 1402 [s390] 1403 KVM_MP_STATE_LOAD the vcpu is in a special load/startup state 1404 [s390] 1405 ========================== =============================================== 1406 1407On x86, this ioctl is only useful after KVM_CREATE_IRQCHIP. Without an 1408in-kernel irqchip, the multiprocessing state must be maintained by userspace on 1409these architectures. 1410 1411For arm/arm64: 1412^^^^^^^^^^^^^^ 1413 1414The only states that are valid are KVM_MP_STATE_STOPPED and 1415KVM_MP_STATE_RUNNABLE which reflect if the vcpu is paused or not. 1416 14174.39 KVM_SET_MP_STATE 1418--------------------- 1419 1420:Capability: KVM_CAP_MP_STATE 1421:Architectures: x86, s390, arm, arm64 1422:Type: vcpu ioctl 1423:Parameters: struct kvm_mp_state (in) 1424:Returns: 0 on success; -1 on error 1425 1426Sets the vcpu's current "multiprocessing state"; see KVM_GET_MP_STATE for 1427arguments. 1428 1429On x86, this ioctl is only useful after KVM_CREATE_IRQCHIP. Without an 1430in-kernel irqchip, the multiprocessing state must be maintained by userspace on 1431these architectures. 1432 1433For arm/arm64: 1434^^^^^^^^^^^^^^ 1435 1436The only states that are valid are KVM_MP_STATE_STOPPED and 1437KVM_MP_STATE_RUNNABLE which reflect if the vcpu should be paused or not. 1438 14394.40 KVM_SET_IDENTITY_MAP_ADDR 1440------------------------------ 1441 1442:Capability: KVM_CAP_SET_IDENTITY_MAP_ADDR 1443:Architectures: x86 1444:Type: vm ioctl 1445:Parameters: unsigned long identity (in) 1446:Returns: 0 on success, -1 on error 1447 1448This ioctl defines the physical address of a one-page region in the guest 1449physical address space. The region must be within the first 4GB of the 1450guest physical address space and must not conflict with any memory slot 1451or any mmio address. The guest may malfunction if it accesses this memory 1452region. 1453 1454Setting the address to 0 will result in resetting the address to its default 1455(0xfffbc000). 1456 1457This ioctl is required on Intel-based hosts. This is needed on Intel hardware 1458because of a quirk in the virtualization implementation (see the internals 1459documentation when it pops into existence). 1460 1461Fails if any VCPU has already been created. 1462 14634.41 KVM_SET_BOOT_CPU_ID 1464------------------------ 1465 1466:Capability: KVM_CAP_SET_BOOT_CPU_ID 1467:Architectures: x86 1468:Type: vm ioctl 1469:Parameters: unsigned long vcpu_id 1470:Returns: 0 on success, -1 on error 1471 1472Define which vcpu is the Bootstrap Processor (BSP). Values are the same 1473as the vcpu id in KVM_CREATE_VCPU. If this ioctl is not called, the default 1474is vcpu 0. 1475 1476 14774.42 KVM_GET_XSAVE 1478------------------ 1479 1480:Capability: KVM_CAP_XSAVE 1481:Architectures: x86 1482:Type: vcpu ioctl 1483:Parameters: struct kvm_xsave (out) 1484:Returns: 0 on success, -1 on error 1485 1486 1487:: 1488 1489 struct kvm_xsave { 1490 __u32 region[1024]; 1491 }; 1492 1493This ioctl would copy current vcpu's xsave struct to the userspace. 1494 1495 14964.43 KVM_SET_XSAVE 1497------------------ 1498 1499:Capability: KVM_CAP_XSAVE 1500:Architectures: x86 1501:Type: vcpu ioctl 1502:Parameters: struct kvm_xsave (in) 1503:Returns: 0 on success, -1 on error 1504 1505:: 1506 1507 1508 struct kvm_xsave { 1509 __u32 region[1024]; 1510 }; 1511 1512This ioctl would copy userspace's xsave struct to the kernel. 1513 1514 15154.44 KVM_GET_XCRS 1516----------------- 1517 1518:Capability: KVM_CAP_XCRS 1519:Architectures: x86 1520:Type: vcpu ioctl 1521:Parameters: struct kvm_xcrs (out) 1522:Returns: 0 on success, -1 on error 1523 1524:: 1525 1526 struct kvm_xcr { 1527 __u32 xcr; 1528 __u32 reserved; 1529 __u64 value; 1530 }; 1531 1532 struct kvm_xcrs { 1533 __u32 nr_xcrs; 1534 __u32 flags; 1535 struct kvm_xcr xcrs[KVM_MAX_XCRS]; 1536 __u64 padding[16]; 1537 }; 1538 1539This ioctl would copy current vcpu's xcrs to the userspace. 1540 1541 15424.45 KVM_SET_XCRS 1543----------------- 1544 1545:Capability: KVM_CAP_XCRS 1546:Architectures: x86 1547:Type: vcpu ioctl 1548:Parameters: struct kvm_xcrs (in) 1549:Returns: 0 on success, -1 on error 1550 1551:: 1552 1553 struct kvm_xcr { 1554 __u32 xcr; 1555 __u32 reserved; 1556 __u64 value; 1557 }; 1558 1559 struct kvm_xcrs { 1560 __u32 nr_xcrs; 1561 __u32 flags; 1562 struct kvm_xcr xcrs[KVM_MAX_XCRS]; 1563 __u64 padding[16]; 1564 }; 1565 1566This ioctl would set vcpu's xcr to the value userspace specified. 1567 1568 15694.46 KVM_GET_SUPPORTED_CPUID 1570---------------------------- 1571 1572:Capability: KVM_CAP_EXT_CPUID 1573:Architectures: x86 1574:Type: system ioctl 1575:Parameters: struct kvm_cpuid2 (in/out) 1576:Returns: 0 on success, -1 on error 1577 1578:: 1579 1580 struct kvm_cpuid2 { 1581 __u32 nent; 1582 __u32 padding; 1583 struct kvm_cpuid_entry2 entries[0]; 1584 }; 1585 1586 #define KVM_CPUID_FLAG_SIGNIFCANT_INDEX BIT(0) 1587 #define KVM_CPUID_FLAG_STATEFUL_FUNC BIT(1) /* deprecated */ 1588 #define KVM_CPUID_FLAG_STATE_READ_NEXT BIT(2) /* deprecated */ 1589 1590 struct kvm_cpuid_entry2 { 1591 __u32 function; 1592 __u32 index; 1593 __u32 flags; 1594 __u32 eax; 1595 __u32 ebx; 1596 __u32 ecx; 1597 __u32 edx; 1598 __u32 padding[3]; 1599 }; 1600 1601This ioctl returns x86 cpuid features which are supported by both the 1602hardware and kvm in its default configuration. Userspace can use the 1603information returned by this ioctl to construct cpuid information (for 1604KVM_SET_CPUID2) that is consistent with hardware, kernel, and 1605userspace capabilities, and with user requirements (for example, the 1606user may wish to constrain cpuid to emulate older hardware, or for 1607feature consistency across a cluster). 1608 1609Note that certain capabilities, such as KVM_CAP_X86_DISABLE_EXITS, may 1610expose cpuid features (e.g. MONITOR) which are not supported by kvm in 1611its default configuration. If userspace enables such capabilities, it 1612is responsible for modifying the results of this ioctl appropriately. 1613 1614Userspace invokes KVM_GET_SUPPORTED_CPUID by passing a kvm_cpuid2 structure 1615with the 'nent' field indicating the number of entries in the variable-size 1616array 'entries'. If the number of entries is too low to describe the cpu 1617capabilities, an error (E2BIG) is returned. If the number is too high, 1618the 'nent' field is adjusted and an error (ENOMEM) is returned. If the 1619number is just right, the 'nent' field is adjusted to the number of valid 1620entries in the 'entries' array, which is then filled. 1621 1622The entries returned are the host cpuid as returned by the cpuid instruction, 1623with unknown or unsupported features masked out. Some features (for example, 1624x2apic), may not be present in the host cpu, but are exposed by kvm if it can 1625emulate them efficiently. The fields in each entry are defined as follows: 1626 1627 function: 1628 the eax value used to obtain the entry 1629 1630 index: 1631 the ecx value used to obtain the entry (for entries that are 1632 affected by ecx) 1633 1634 flags: 1635 an OR of zero or more of the following: 1636 1637 KVM_CPUID_FLAG_SIGNIFCANT_INDEX: 1638 if the index field is valid 1639 1640 eax, ebx, ecx, edx: 1641 the values returned by the cpuid instruction for 1642 this function/index combination 1643 1644The TSC deadline timer feature (CPUID leaf 1, ecx[24]) is always returned 1645as false, since the feature depends on KVM_CREATE_IRQCHIP for local APIC 1646support. Instead it is reported via:: 1647 1648 ioctl(KVM_CHECK_EXTENSION, KVM_CAP_TSC_DEADLINE_TIMER) 1649 1650if that returns true and you use KVM_CREATE_IRQCHIP, or if you emulate the 1651feature in userspace, then you can enable the feature for KVM_SET_CPUID2. 1652 1653 16544.47 KVM_PPC_GET_PVINFO 1655----------------------- 1656 1657:Capability: KVM_CAP_PPC_GET_PVINFO 1658:Architectures: ppc 1659:Type: vm ioctl 1660:Parameters: struct kvm_ppc_pvinfo (out) 1661:Returns: 0 on success, !0 on error 1662 1663:: 1664 1665 struct kvm_ppc_pvinfo { 1666 __u32 flags; 1667 __u32 hcall[4]; 1668 __u8 pad[108]; 1669 }; 1670 1671This ioctl fetches PV specific information that need to be passed to the guest 1672using the device tree or other means from vm context. 1673 1674The hcall array defines 4 instructions that make up a hypercall. 1675 1676If any additional field gets added to this structure later on, a bit for that 1677additional piece of information will be set in the flags bitmap. 1678 1679The flags bitmap is defined as:: 1680 1681 /* the host supports the ePAPR idle hcall 1682 #define KVM_PPC_PVINFO_FLAGS_EV_IDLE (1<<0) 1683 16844.52 KVM_SET_GSI_ROUTING 1685------------------------ 1686 1687:Capability: KVM_CAP_IRQ_ROUTING 1688:Architectures: x86 s390 arm arm64 1689:Type: vm ioctl 1690:Parameters: struct kvm_irq_routing (in) 1691:Returns: 0 on success, -1 on error 1692 1693Sets the GSI routing table entries, overwriting any previously set entries. 1694 1695On arm/arm64, GSI routing has the following limitation: 1696 1697- GSI routing does not apply to KVM_IRQ_LINE but only to KVM_IRQFD. 1698 1699:: 1700 1701 struct kvm_irq_routing { 1702 __u32 nr; 1703 __u32 flags; 1704 struct kvm_irq_routing_entry entries[0]; 1705 }; 1706 1707No flags are specified so far, the corresponding field must be set to zero. 1708 1709:: 1710 1711 struct kvm_irq_routing_entry { 1712 __u32 gsi; 1713 __u32 type; 1714 __u32 flags; 1715 __u32 pad; 1716 union { 1717 struct kvm_irq_routing_irqchip irqchip; 1718 struct kvm_irq_routing_msi msi; 1719 struct kvm_irq_routing_s390_adapter adapter; 1720 struct kvm_irq_routing_hv_sint hv_sint; 1721 __u32 pad[8]; 1722 } u; 1723 }; 1724 1725 /* gsi routing entry types */ 1726 #define KVM_IRQ_ROUTING_IRQCHIP 1 1727 #define KVM_IRQ_ROUTING_MSI 2 1728 #define KVM_IRQ_ROUTING_S390_ADAPTER 3 1729 #define KVM_IRQ_ROUTING_HV_SINT 4 1730 1731flags: 1732 1733- KVM_MSI_VALID_DEVID: used along with KVM_IRQ_ROUTING_MSI routing entry 1734 type, specifies that the devid field contains a valid value. The per-VM 1735 KVM_CAP_MSI_DEVID capability advertises the requirement to provide 1736 the device ID. If this capability is not available, userspace should 1737 never set the KVM_MSI_VALID_DEVID flag as the ioctl might fail. 1738- zero otherwise 1739 1740:: 1741 1742 struct kvm_irq_routing_irqchip { 1743 __u32 irqchip; 1744 __u32 pin; 1745 }; 1746 1747 struct kvm_irq_routing_msi { 1748 __u32 address_lo; 1749 __u32 address_hi; 1750 __u32 data; 1751 union { 1752 __u32 pad; 1753 __u32 devid; 1754 }; 1755 }; 1756 1757If KVM_MSI_VALID_DEVID is set, devid contains a unique device identifier 1758for the device that wrote the MSI message. For PCI, this is usually a 1759BFD identifier in the lower 16 bits. 1760 1761On x86, address_hi is ignored unless the KVM_X2APIC_API_USE_32BIT_IDS 1762feature of KVM_CAP_X2APIC_API capability is enabled. If it is enabled, 1763address_hi bits 31-8 provide bits 31-8 of the destination id. Bits 7-0 of 1764address_hi must be zero. 1765 1766:: 1767 1768 struct kvm_irq_routing_s390_adapter { 1769 __u64 ind_addr; 1770 __u64 summary_addr; 1771 __u64 ind_offset; 1772 __u32 summary_offset; 1773 __u32 adapter_id; 1774 }; 1775 1776 struct kvm_irq_routing_hv_sint { 1777 __u32 vcpu; 1778 __u32 sint; 1779 }; 1780 1781 17824.55 KVM_SET_TSC_KHZ 1783-------------------- 1784 1785:Capability: KVM_CAP_TSC_CONTROL 1786:Architectures: x86 1787:Type: vcpu ioctl 1788:Parameters: virtual tsc_khz 1789:Returns: 0 on success, -1 on error 1790 1791Specifies the tsc frequency for the virtual machine. The unit of the 1792frequency is KHz. 1793 1794 17954.56 KVM_GET_TSC_KHZ 1796-------------------- 1797 1798:Capability: KVM_CAP_GET_TSC_KHZ 1799:Architectures: x86 1800:Type: vcpu ioctl 1801:Parameters: none 1802:Returns: virtual tsc-khz on success, negative value on error 1803 1804Returns the tsc frequency of the guest. The unit of the return value is 1805KHz. If the host has unstable tsc this ioctl returns -EIO instead as an 1806error. 1807 1808 18094.57 KVM_GET_LAPIC 1810------------------ 1811 1812:Capability: KVM_CAP_IRQCHIP 1813:Architectures: x86 1814:Type: vcpu ioctl 1815:Parameters: struct kvm_lapic_state (out) 1816:Returns: 0 on success, -1 on error 1817 1818:: 1819 1820 #define KVM_APIC_REG_SIZE 0x400 1821 struct kvm_lapic_state { 1822 char regs[KVM_APIC_REG_SIZE]; 1823 }; 1824 1825Reads the Local APIC registers and copies them into the input argument. The 1826data format and layout are the same as documented in the architecture manual. 1827 1828If KVM_X2APIC_API_USE_32BIT_IDS feature of KVM_CAP_X2APIC_API is 1829enabled, then the format of APIC_ID register depends on the APIC mode 1830(reported by MSR_IA32_APICBASE) of its VCPU. x2APIC stores APIC ID in 1831the APIC_ID register (bytes 32-35). xAPIC only allows an 8-bit APIC ID 1832which is stored in bits 31-24 of the APIC register, or equivalently in 1833byte 35 of struct kvm_lapic_state's regs field. KVM_GET_LAPIC must then 1834be called after MSR_IA32_APICBASE has been set with KVM_SET_MSR. 1835 1836If KVM_X2APIC_API_USE_32BIT_IDS feature is disabled, struct kvm_lapic_state 1837always uses xAPIC format. 1838 1839 18404.58 KVM_SET_LAPIC 1841------------------ 1842 1843:Capability: KVM_CAP_IRQCHIP 1844:Architectures: x86 1845:Type: vcpu ioctl 1846:Parameters: struct kvm_lapic_state (in) 1847:Returns: 0 on success, -1 on error 1848 1849:: 1850 1851 #define KVM_APIC_REG_SIZE 0x400 1852 struct kvm_lapic_state { 1853 char regs[KVM_APIC_REG_SIZE]; 1854 }; 1855 1856Copies the input argument into the Local APIC registers. The data format 1857and layout are the same as documented in the architecture manual. 1858 1859The format of the APIC ID register (bytes 32-35 of struct kvm_lapic_state's 1860regs field) depends on the state of the KVM_CAP_X2APIC_API capability. 1861See the note in KVM_GET_LAPIC. 1862 1863 18644.59 KVM_IOEVENTFD 1865------------------ 1866 1867:Capability: KVM_CAP_IOEVENTFD 1868:Architectures: all 1869:Type: vm ioctl 1870:Parameters: struct kvm_ioeventfd (in) 1871:Returns: 0 on success, !0 on error 1872 1873This ioctl attaches or detaches an ioeventfd to a legal pio/mmio address 1874within the guest. A guest write in the registered address will signal the 1875provided event instead of triggering an exit. 1876 1877:: 1878 1879 struct kvm_ioeventfd { 1880 __u64 datamatch; 1881 __u64 addr; /* legal pio/mmio address */ 1882 __u32 len; /* 0, 1, 2, 4, or 8 bytes */ 1883 __s32 fd; 1884 __u32 flags; 1885 __u8 pad[36]; 1886 }; 1887 1888For the special case of virtio-ccw devices on s390, the ioevent is matched 1889to a subchannel/virtqueue tuple instead. 1890 1891The following flags are defined:: 1892 1893 #define KVM_IOEVENTFD_FLAG_DATAMATCH (1 << kvm_ioeventfd_flag_nr_datamatch) 1894 #define KVM_IOEVENTFD_FLAG_PIO (1 << kvm_ioeventfd_flag_nr_pio) 1895 #define KVM_IOEVENTFD_FLAG_DEASSIGN (1 << kvm_ioeventfd_flag_nr_deassign) 1896 #define KVM_IOEVENTFD_FLAG_VIRTIO_CCW_NOTIFY \ 1897 (1 << kvm_ioeventfd_flag_nr_virtio_ccw_notify) 1898 1899If datamatch flag is set, the event will be signaled only if the written value 1900to the registered address is equal to datamatch in struct kvm_ioeventfd. 1901 1902For virtio-ccw devices, addr contains the subchannel id and datamatch the 1903virtqueue index. 1904 1905With KVM_CAP_IOEVENTFD_ANY_LENGTH, a zero length ioeventfd is allowed, and 1906the kernel will ignore the length of guest write and may get a faster vmexit. 1907The speedup may only apply to specific architectures, but the ioeventfd will 1908work anyway. 1909 19104.60 KVM_DIRTY_TLB 1911------------------ 1912 1913:Capability: KVM_CAP_SW_TLB 1914:Architectures: ppc 1915:Type: vcpu ioctl 1916:Parameters: struct kvm_dirty_tlb (in) 1917:Returns: 0 on success, -1 on error 1918 1919:: 1920 1921 struct kvm_dirty_tlb { 1922 __u64 bitmap; 1923 __u32 num_dirty; 1924 }; 1925 1926This must be called whenever userspace has changed an entry in the shared 1927TLB, prior to calling KVM_RUN on the associated vcpu. 1928 1929The "bitmap" field is the userspace address of an array. This array 1930consists of a number of bits, equal to the total number of TLB entries as 1931determined by the last successful call to KVM_CONFIG_TLB, rounded up to the 1932nearest multiple of 64. 1933 1934Each bit corresponds to one TLB entry, ordered the same as in the shared TLB 1935array. 1936 1937The array is little-endian: the bit 0 is the least significant bit of the 1938first byte, bit 8 is the least significant bit of the second byte, etc. 1939This avoids any complications with differing word sizes. 1940 1941The "num_dirty" field is a performance hint for KVM to determine whether it 1942should skip processing the bitmap and just invalidate everything. It must 1943be set to the number of set bits in the bitmap. 1944 1945 19464.62 KVM_CREATE_SPAPR_TCE 1947------------------------- 1948 1949:Capability: KVM_CAP_SPAPR_TCE 1950:Architectures: powerpc 1951:Type: vm ioctl 1952:Parameters: struct kvm_create_spapr_tce (in) 1953:Returns: file descriptor for manipulating the created TCE table 1954 1955This creates a virtual TCE (translation control entry) table, which 1956is an IOMMU for PAPR-style virtual I/O. It is used to translate 1957logical addresses used in virtual I/O into guest physical addresses, 1958and provides a scatter/gather capability for PAPR virtual I/O. 1959 1960:: 1961 1962 /* for KVM_CAP_SPAPR_TCE */ 1963 struct kvm_create_spapr_tce { 1964 __u64 liobn; 1965 __u32 window_size; 1966 }; 1967 1968The liobn field gives the logical IO bus number for which to create a 1969TCE table. The window_size field specifies the size of the DMA window 1970which this TCE table will translate - the table will contain one 64 1971bit TCE entry for every 4kiB of the DMA window. 1972 1973When the guest issues an H_PUT_TCE hcall on a liobn for which a TCE 1974table has been created using this ioctl(), the kernel will handle it 1975in real mode, updating the TCE table. H_PUT_TCE calls for other 1976liobns will cause a vm exit and must be handled by userspace. 1977 1978The return value is a file descriptor which can be passed to mmap(2) 1979to map the created TCE table into userspace. This lets userspace read 1980the entries written by kernel-handled H_PUT_TCE calls, and also lets 1981userspace update the TCE table directly which is useful in some 1982circumstances. 1983 1984 19854.63 KVM_ALLOCATE_RMA 1986--------------------- 1987 1988:Capability: KVM_CAP_PPC_RMA 1989:Architectures: powerpc 1990:Type: vm ioctl 1991:Parameters: struct kvm_allocate_rma (out) 1992:Returns: file descriptor for mapping the allocated RMA 1993 1994This allocates a Real Mode Area (RMA) from the pool allocated at boot 1995time by the kernel. An RMA is a physically-contiguous, aligned region 1996of memory used on older POWER processors to provide the memory which 1997will be accessed by real-mode (MMU off) accesses in a KVM guest. 1998POWER processors support a set of sizes for the RMA that usually 1999includes 64MB, 128MB, 256MB and some larger powers of two. 2000 2001:: 2002 2003 /* for KVM_ALLOCATE_RMA */ 2004 struct kvm_allocate_rma { 2005 __u64 rma_size; 2006 }; 2007 2008The return value is a file descriptor which can be passed to mmap(2) 2009to map the allocated RMA into userspace. The mapped area can then be 2010passed to the KVM_SET_USER_MEMORY_REGION ioctl to establish it as the 2011RMA for a virtual machine. The size of the RMA in bytes (which is 2012fixed at host kernel boot time) is returned in the rma_size field of 2013the argument structure. 2014 2015The KVM_CAP_PPC_RMA capability is 1 or 2 if the KVM_ALLOCATE_RMA ioctl 2016is supported; 2 if the processor requires all virtual machines to have 2017an RMA, or 1 if the processor can use an RMA but doesn't require it, 2018because it supports the Virtual RMA (VRMA) facility. 2019 2020 20214.64 KVM_NMI 2022------------ 2023 2024:Capability: KVM_CAP_USER_NMI 2025:Architectures: x86 2026:Type: vcpu ioctl 2027:Parameters: none 2028:Returns: 0 on success, -1 on error 2029 2030Queues an NMI on the thread's vcpu. Note this is well defined only 2031when KVM_CREATE_IRQCHIP has not been called, since this is an interface 2032between the virtual cpu core and virtual local APIC. After KVM_CREATE_IRQCHIP 2033has been called, this interface is completely emulated within the kernel. 2034 2035To use this to emulate the LINT1 input with KVM_CREATE_IRQCHIP, use the 2036following algorithm: 2037 2038 - pause the vcpu 2039 - read the local APIC's state (KVM_GET_LAPIC) 2040 - check whether changing LINT1 will queue an NMI (see the LVT entry for LINT1) 2041 - if so, issue KVM_NMI 2042 - resume the vcpu 2043 2044Some guests configure the LINT1 NMI input to cause a panic, aiding in 2045debugging. 2046 2047 20484.65 KVM_S390_UCAS_MAP 2049---------------------- 2050 2051:Capability: KVM_CAP_S390_UCONTROL 2052:Architectures: s390 2053:Type: vcpu ioctl 2054:Parameters: struct kvm_s390_ucas_mapping (in) 2055:Returns: 0 in case of success 2056 2057The parameter is defined like this:: 2058 2059 struct kvm_s390_ucas_mapping { 2060 __u64 user_addr; 2061 __u64 vcpu_addr; 2062 __u64 length; 2063 }; 2064 2065This ioctl maps the memory at "user_addr" with the length "length" to 2066the vcpu's address space starting at "vcpu_addr". All parameters need to 2067be aligned by 1 megabyte. 2068 2069 20704.66 KVM_S390_UCAS_UNMAP 2071------------------------ 2072 2073:Capability: KVM_CAP_S390_UCONTROL 2074:Architectures: s390 2075:Type: vcpu ioctl 2076:Parameters: struct kvm_s390_ucas_mapping (in) 2077:Returns: 0 in case of success 2078 2079The parameter is defined like this:: 2080 2081 struct kvm_s390_ucas_mapping { 2082 __u64 user_addr; 2083 __u64 vcpu_addr; 2084 __u64 length; 2085 }; 2086 2087This ioctl unmaps the memory in the vcpu's address space starting at 2088"vcpu_addr" with the length "length". The field "user_addr" is ignored. 2089All parameters need to be aligned by 1 megabyte. 2090 2091 20924.67 KVM_S390_VCPU_FAULT 2093------------------------ 2094 2095:Capability: KVM_CAP_S390_UCONTROL 2096:Architectures: s390 2097:Type: vcpu ioctl 2098:Parameters: vcpu absolute address (in) 2099:Returns: 0 in case of success 2100 2101This call creates a page table entry on the virtual cpu's address space 2102(for user controlled virtual machines) or the virtual machine's address 2103space (for regular virtual machines). This only works for minor faults, 2104thus it's recommended to access subject memory page via the user page 2105table upfront. This is useful to handle validity intercepts for user 2106controlled virtual machines to fault in the virtual cpu's lowcore pages 2107prior to calling the KVM_RUN ioctl. 2108 2109 21104.68 KVM_SET_ONE_REG 2111-------------------- 2112 2113:Capability: KVM_CAP_ONE_REG 2114:Architectures: all 2115:Type: vcpu ioctl 2116:Parameters: struct kvm_one_reg (in) 2117:Returns: 0 on success, negative value on failure 2118 2119Errors: 2120 2121 ====== ============================================================ 2122 ENOENT no such register 2123 EINVAL invalid register ID, or no such register or used with VMs in 2124 protected virtualization mode on s390 2125 EPERM (arm64) register access not allowed before vcpu finalization 2126 ====== ============================================================ 2127 2128(These error codes are indicative only: do not rely on a specific error 2129code being returned in a specific situation.) 2130 2131:: 2132 2133 struct kvm_one_reg { 2134 __u64 id; 2135 __u64 addr; 2136 }; 2137 2138Using this ioctl, a single vcpu register can be set to a specific value 2139defined by user space with the passed in struct kvm_one_reg, where id 2140refers to the register identifier as described below and addr is a pointer 2141to a variable with the respective size. There can be architecture agnostic 2142and architecture specific registers. Each have their own range of operation 2143and their own constants and width. To keep track of the implemented 2144registers, find a list below: 2145 2146 ======= =============================== ============ 2147 Arch Register Width (bits) 2148 ======= =============================== ============ 2149 PPC KVM_REG_PPC_HIOR 64 2150 PPC KVM_REG_PPC_IAC1 64 2151 PPC KVM_REG_PPC_IAC2 64 2152 PPC KVM_REG_PPC_IAC3 64 2153 PPC KVM_REG_PPC_IAC4 64 2154 PPC KVM_REG_PPC_DAC1 64 2155 PPC KVM_REG_PPC_DAC2 64 2156 PPC KVM_REG_PPC_DABR 64 2157 PPC KVM_REG_PPC_DSCR 64 2158 PPC KVM_REG_PPC_PURR 64 2159 PPC KVM_REG_PPC_SPURR 64 2160 PPC KVM_REG_PPC_DAR 64 2161 PPC KVM_REG_PPC_DSISR 32 2162 PPC KVM_REG_PPC_AMR 64 2163 PPC KVM_REG_PPC_UAMOR 64 2164 PPC KVM_REG_PPC_MMCR0 64 2165 PPC KVM_REG_PPC_MMCR1 64 2166 PPC KVM_REG_PPC_MMCRA 64 2167 PPC KVM_REG_PPC_MMCR2 64 2168 PPC KVM_REG_PPC_MMCRS 64 2169 PPC KVM_REG_PPC_MMCR3 64 2170 PPC KVM_REG_PPC_SIAR 64 2171 PPC KVM_REG_PPC_SDAR 64 2172 PPC KVM_REG_PPC_SIER 64 2173 PPC KVM_REG_PPC_SIER2 64 2174 PPC KVM_REG_PPC_SIER3 64 2175 PPC KVM_REG_PPC_PMC1 32 2176 PPC KVM_REG_PPC_PMC2 32 2177 PPC KVM_REG_PPC_PMC3 32 2178 PPC KVM_REG_PPC_PMC4 32 2179 PPC KVM_REG_PPC_PMC5 32 2180 PPC KVM_REG_PPC_PMC6 32 2181 PPC KVM_REG_PPC_PMC7 32 2182 PPC KVM_REG_PPC_PMC8 32 2183 PPC KVM_REG_PPC_FPR0 64 2184 ... 2185 PPC KVM_REG_PPC_FPR31 64 2186 PPC KVM_REG_PPC_VR0 128 2187 ... 2188 PPC KVM_REG_PPC_VR31 128 2189 PPC KVM_REG_PPC_VSR0 128 2190 ... 2191 PPC KVM_REG_PPC_VSR31 128 2192 PPC KVM_REG_PPC_FPSCR 64 2193 PPC KVM_REG_PPC_VSCR 32 2194 PPC KVM_REG_PPC_VPA_ADDR 64 2195 PPC KVM_REG_PPC_VPA_SLB 128 2196 PPC KVM_REG_PPC_VPA_DTL 128 2197 PPC KVM_REG_PPC_EPCR 32 2198 PPC KVM_REG_PPC_EPR 32 2199 PPC KVM_REG_PPC_TCR 32 2200 PPC KVM_REG_PPC_TSR 32 2201 PPC KVM_REG_PPC_OR_TSR 32 2202 PPC KVM_REG_PPC_CLEAR_TSR 32 2203 PPC KVM_REG_PPC_MAS0 32 2204 PPC KVM_REG_PPC_MAS1 32 2205 PPC KVM_REG_PPC_MAS2 64 2206 PPC KVM_REG_PPC_MAS7_3 64 2207 PPC KVM_REG_PPC_MAS4 32 2208 PPC KVM_REG_PPC_MAS6 32 2209 PPC KVM_REG_PPC_MMUCFG 32 2210 PPC KVM_REG_PPC_TLB0CFG 32 2211 PPC KVM_REG_PPC_TLB1CFG 32 2212 PPC KVM_REG_PPC_TLB2CFG 32 2213 PPC KVM_REG_PPC_TLB3CFG 32 2214 PPC KVM_REG_PPC_TLB0PS 32 2215 PPC KVM_REG_PPC_TLB1PS 32 2216 PPC KVM_REG_PPC_TLB2PS 32 2217 PPC KVM_REG_PPC_TLB3PS 32 2218 PPC KVM_REG_PPC_EPTCFG 32 2219 PPC KVM_REG_PPC_ICP_STATE 64 2220 PPC KVM_REG_PPC_VP_STATE 128 2221 PPC KVM_REG_PPC_TB_OFFSET 64 2222 PPC KVM_REG_PPC_SPMC1 32 2223 PPC KVM_REG_PPC_SPMC2 32 2224 PPC KVM_REG_PPC_IAMR 64 2225 PPC KVM_REG_PPC_TFHAR 64 2226 PPC KVM_REG_PPC_TFIAR 64 2227 PPC KVM_REG_PPC_TEXASR 64 2228 PPC KVM_REG_PPC_FSCR 64 2229 PPC KVM_REG_PPC_PSPB 32 2230 PPC KVM_REG_PPC_EBBHR 64 2231 PPC KVM_REG_PPC_EBBRR 64 2232 PPC KVM_REG_PPC_BESCR 64 2233 PPC KVM_REG_PPC_TAR 64 2234 PPC KVM_REG_PPC_DPDES 64 2235 PPC KVM_REG_PPC_DAWR 64 2236 PPC KVM_REG_PPC_DAWRX 64 2237 PPC KVM_REG_PPC_CIABR 64 2238 PPC KVM_REG_PPC_IC 64 2239 PPC KVM_REG_PPC_VTB 64 2240 PPC KVM_REG_PPC_CSIGR 64 2241 PPC KVM_REG_PPC_TACR 64 2242 PPC KVM_REG_PPC_TCSCR 64 2243 PPC KVM_REG_PPC_PID 64 2244 PPC KVM_REG_PPC_ACOP 64 2245 PPC KVM_REG_PPC_VRSAVE 32 2246 PPC KVM_REG_PPC_LPCR 32 2247 PPC KVM_REG_PPC_LPCR_64 64 2248 PPC KVM_REG_PPC_PPR 64 2249 PPC KVM_REG_PPC_ARCH_COMPAT 32 2250 PPC KVM_REG_PPC_DABRX 32 2251 PPC KVM_REG_PPC_WORT 64 2252 PPC KVM_REG_PPC_SPRG9 64 2253 PPC KVM_REG_PPC_DBSR 32 2254 PPC KVM_REG_PPC_TIDR 64 2255 PPC KVM_REG_PPC_PSSCR 64 2256 PPC KVM_REG_PPC_DEC_EXPIRY 64 2257 PPC KVM_REG_PPC_PTCR 64 2258 PPC KVM_REG_PPC_TM_GPR0 64 2259 ... 2260 PPC KVM_REG_PPC_TM_GPR31 64 2261 PPC KVM_REG_PPC_TM_VSR0 128 2262 ... 2263 PPC KVM_REG_PPC_TM_VSR63 128 2264 PPC KVM_REG_PPC_TM_CR 64 2265 PPC KVM_REG_PPC_TM_LR 64 2266 PPC KVM_REG_PPC_TM_CTR 64 2267 PPC KVM_REG_PPC_TM_FPSCR 64 2268 PPC KVM_REG_PPC_TM_AMR 64 2269 PPC KVM_REG_PPC_TM_PPR 64 2270 PPC KVM_REG_PPC_TM_VRSAVE 64 2271 PPC KVM_REG_PPC_TM_VSCR 32 2272 PPC KVM_REG_PPC_TM_DSCR 64 2273 PPC KVM_REG_PPC_TM_TAR 64 2274 PPC KVM_REG_PPC_TM_XER 64 2275 2276 MIPS KVM_REG_MIPS_R0 64 2277 ... 2278 MIPS KVM_REG_MIPS_R31 64 2279 MIPS KVM_REG_MIPS_HI 64 2280 MIPS KVM_REG_MIPS_LO 64 2281 MIPS KVM_REG_MIPS_PC 64 2282 MIPS KVM_REG_MIPS_CP0_INDEX 32 2283 MIPS KVM_REG_MIPS_CP0_ENTRYLO0 64 2284 MIPS KVM_REG_MIPS_CP0_ENTRYLO1 64 2285 MIPS KVM_REG_MIPS_CP0_CONTEXT 64 2286 MIPS KVM_REG_MIPS_CP0_CONTEXTCONFIG 32 2287 MIPS KVM_REG_MIPS_CP0_USERLOCAL 64 2288 MIPS KVM_REG_MIPS_CP0_XCONTEXTCONFIG 64 2289 MIPS KVM_REG_MIPS_CP0_PAGEMASK 32 2290 MIPS KVM_REG_MIPS_CP0_PAGEGRAIN 32 2291 MIPS KVM_REG_MIPS_CP0_SEGCTL0 64 2292 MIPS KVM_REG_MIPS_CP0_SEGCTL1 64 2293 MIPS KVM_REG_MIPS_CP0_SEGCTL2 64 2294 MIPS KVM_REG_MIPS_CP0_PWBASE 64 2295 MIPS KVM_REG_MIPS_CP0_PWFIELD 64 2296 MIPS KVM_REG_MIPS_CP0_PWSIZE 64 2297 MIPS KVM_REG_MIPS_CP0_WIRED 32 2298 MIPS KVM_REG_MIPS_CP0_PWCTL 32 2299 MIPS KVM_REG_MIPS_CP0_HWRENA 32 2300 MIPS KVM_REG_MIPS_CP0_BADVADDR 64 2301 MIPS KVM_REG_MIPS_CP0_BADINSTR 32 2302 MIPS KVM_REG_MIPS_CP0_BADINSTRP 32 2303 MIPS KVM_REG_MIPS_CP0_COUNT 32 2304 MIPS KVM_REG_MIPS_CP0_ENTRYHI 64 2305 MIPS KVM_REG_MIPS_CP0_COMPARE 32 2306 MIPS KVM_REG_MIPS_CP0_STATUS 32 2307 MIPS KVM_REG_MIPS_CP0_INTCTL 32 2308 MIPS KVM_REG_MIPS_CP0_CAUSE 32 2309 MIPS KVM_REG_MIPS_CP0_EPC 64 2310 MIPS KVM_REG_MIPS_CP0_PRID 32 2311 MIPS KVM_REG_MIPS_CP0_EBASE 64 2312 MIPS KVM_REG_MIPS_CP0_CONFIG 32 2313 MIPS KVM_REG_MIPS_CP0_CONFIG1 32 2314 MIPS KVM_REG_MIPS_CP0_CONFIG2 32 2315 MIPS KVM_REG_MIPS_CP0_CONFIG3 32 2316 MIPS KVM_REG_MIPS_CP0_CONFIG4 32 2317 MIPS KVM_REG_MIPS_CP0_CONFIG5 32 2318 MIPS KVM_REG_MIPS_CP0_CONFIG7 32 2319 MIPS KVM_REG_MIPS_CP0_XCONTEXT 64 2320 MIPS KVM_REG_MIPS_CP0_ERROREPC 64 2321 MIPS KVM_REG_MIPS_CP0_KSCRATCH1 64 2322 MIPS KVM_REG_MIPS_CP0_KSCRATCH2 64 2323 MIPS KVM_REG_MIPS_CP0_KSCRATCH3 64 2324 MIPS KVM_REG_MIPS_CP0_KSCRATCH4 64 2325 MIPS KVM_REG_MIPS_CP0_KSCRATCH5 64 2326 MIPS KVM_REG_MIPS_CP0_KSCRATCH6 64 2327 MIPS KVM_REG_MIPS_CP0_MAAR(0..63) 64 2328 MIPS KVM_REG_MIPS_COUNT_CTL 64 2329 MIPS KVM_REG_MIPS_COUNT_RESUME 64 2330 MIPS KVM_REG_MIPS_COUNT_HZ 64 2331 MIPS KVM_REG_MIPS_FPR_32(0..31) 32 2332 MIPS KVM_REG_MIPS_FPR_64(0..31) 64 2333 MIPS KVM_REG_MIPS_VEC_128(0..31) 128 2334 MIPS KVM_REG_MIPS_FCR_IR 32 2335 MIPS KVM_REG_MIPS_FCR_CSR 32 2336 MIPS KVM_REG_MIPS_MSA_IR 32 2337 MIPS KVM_REG_MIPS_MSA_CSR 32 2338 ======= =============================== ============ 2339 2340ARM registers are mapped using the lower 32 bits. The upper 16 of that 2341is the register group type, or coprocessor number: 2342 2343ARM core registers have the following id bit patterns:: 2344 2345 0x4020 0000 0010 <index into the kvm_regs struct:16> 2346 2347ARM 32-bit CP15 registers have the following id bit patterns:: 2348 2349 0x4020 0000 000F <zero:1> <crn:4> <crm:4> <opc1:4> <opc2:3> 2350 2351ARM 64-bit CP15 registers have the following id bit patterns:: 2352 2353 0x4030 0000 000F <zero:1> <zero:4> <crm:4> <opc1:4> <zero:3> 2354 2355ARM CCSIDR registers are demultiplexed by CSSELR value:: 2356 2357 0x4020 0000 0011 00 <csselr:8> 2358 2359ARM 32-bit VFP control registers have the following id bit patterns:: 2360 2361 0x4020 0000 0012 1 <regno:12> 2362 2363ARM 64-bit FP registers have the following id bit patterns:: 2364 2365 0x4030 0000 0012 0 <regno:12> 2366 2367ARM firmware pseudo-registers have the following bit pattern:: 2368 2369 0x4030 0000 0014 <regno:16> 2370 2371 2372arm64 registers are mapped using the lower 32 bits. The upper 16 of 2373that is the register group type, or coprocessor number: 2374 2375arm64 core/FP-SIMD registers have the following id bit patterns. Note 2376that the size of the access is variable, as the kvm_regs structure 2377contains elements ranging from 32 to 128 bits. The index is a 32bit 2378value in the kvm_regs structure seen as a 32bit array:: 2379 2380 0x60x0 0000 0010 <index into the kvm_regs struct:16> 2381 2382Specifically: 2383 2384======================= ========= ===== ======================================= 2385 Encoding Register Bits kvm_regs member 2386======================= ========= ===== ======================================= 2387 0x6030 0000 0010 0000 X0 64 regs.regs[0] 2388 0x6030 0000 0010 0002 X1 64 regs.regs[1] 2389 ... 2390 0x6030 0000 0010 003c X30 64 regs.regs[30] 2391 0x6030 0000 0010 003e SP 64 regs.sp 2392 0x6030 0000 0010 0040 PC 64 regs.pc 2393 0x6030 0000 0010 0042 PSTATE 64 regs.pstate 2394 0x6030 0000 0010 0044 SP_EL1 64 sp_el1 2395 0x6030 0000 0010 0046 ELR_EL1 64 elr_el1 2396 0x6030 0000 0010 0048 SPSR_EL1 64 spsr[KVM_SPSR_EL1] (alias SPSR_SVC) 2397 0x6030 0000 0010 004a SPSR_ABT 64 spsr[KVM_SPSR_ABT] 2398 0x6030 0000 0010 004c SPSR_UND 64 spsr[KVM_SPSR_UND] 2399 0x6030 0000 0010 004e SPSR_IRQ 64 spsr[KVM_SPSR_IRQ] 2400 0x6060 0000 0010 0050 SPSR_FIQ 64 spsr[KVM_SPSR_FIQ] 2401 0x6040 0000 0010 0054 V0 128 fp_regs.vregs[0] [1]_ 2402 0x6040 0000 0010 0058 V1 128 fp_regs.vregs[1] [1]_ 2403 ... 2404 0x6040 0000 0010 00d0 V31 128 fp_regs.vregs[31] [1]_ 2405 0x6020 0000 0010 00d4 FPSR 32 fp_regs.fpsr 2406 0x6020 0000 0010 00d5 FPCR 32 fp_regs.fpcr 2407======================= ========= ===== ======================================= 2408 2409.. [1] These encodings are not accepted for SVE-enabled vcpus. See 2410 KVM_ARM_VCPU_INIT. 2411 2412 The equivalent register content can be accessed via bits [127:0] of 2413 the corresponding SVE Zn registers instead for vcpus that have SVE 2414 enabled (see below). 2415 2416arm64 CCSIDR registers are demultiplexed by CSSELR value:: 2417 2418 0x6020 0000 0011 00 <csselr:8> 2419 2420arm64 system registers have the following id bit patterns:: 2421 2422 0x6030 0000 0013 <op0:2> <op1:3> <crn:4> <crm:4> <op2:3> 2423 2424.. warning:: 2425 2426 Two system register IDs do not follow the specified pattern. These 2427 are KVM_REG_ARM_TIMER_CVAL and KVM_REG_ARM_TIMER_CNT, which map to 2428 system registers CNTV_CVAL_EL0 and CNTVCT_EL0 respectively. These 2429 two had their values accidentally swapped, which means TIMER_CVAL is 2430 derived from the register encoding for CNTVCT_EL0 and TIMER_CNT is 2431 derived from the register encoding for CNTV_CVAL_EL0. As this is 2432 API, it must remain this way. 2433 2434arm64 firmware pseudo-registers have the following bit pattern:: 2435 2436 0x6030 0000 0014 <regno:16> 2437 2438arm64 SVE registers have the following bit patterns:: 2439 2440 0x6080 0000 0015 00 <n:5> <slice:5> Zn bits[2048*slice + 2047 : 2048*slice] 2441 0x6050 0000 0015 04 <n:4> <slice:5> Pn bits[256*slice + 255 : 256*slice] 2442 0x6050 0000 0015 060 <slice:5> FFR bits[256*slice + 255 : 256*slice] 2443 0x6060 0000 0015 ffff KVM_REG_ARM64_SVE_VLS pseudo-register 2444 2445Access to register IDs where 2048 * slice >= 128 * max_vq will fail with 2446ENOENT. max_vq is the vcpu's maximum supported vector length in 128-bit 2447quadwords: see [2]_ below. 2448 2449These registers are only accessible on vcpus for which SVE is enabled. 2450See KVM_ARM_VCPU_INIT for details. 2451 2452In addition, except for KVM_REG_ARM64_SVE_VLS, these registers are not 2453accessible until the vcpu's SVE configuration has been finalized 2454using KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE). See KVM_ARM_VCPU_INIT 2455and KVM_ARM_VCPU_FINALIZE for more information about this procedure. 2456 2457KVM_REG_ARM64_SVE_VLS is a pseudo-register that allows the set of vector 2458lengths supported by the vcpu to be discovered and configured by 2459userspace. When transferred to or from user memory via KVM_GET_ONE_REG 2460or KVM_SET_ONE_REG, the value of this register is of type 2461__u64[KVM_ARM64_SVE_VLS_WORDS], and encodes the set of vector lengths as 2462follows:: 2463 2464 __u64 vector_lengths[KVM_ARM64_SVE_VLS_WORDS]; 2465 2466 if (vq >= SVE_VQ_MIN && vq <= SVE_VQ_MAX && 2467 ((vector_lengths[(vq - KVM_ARM64_SVE_VQ_MIN) / 64] >> 2468 ((vq - KVM_ARM64_SVE_VQ_MIN) % 64)) & 1)) 2469 /* Vector length vq * 16 bytes supported */ 2470 else 2471 /* Vector length vq * 16 bytes not supported */ 2472 2473.. [2] The maximum value vq for which the above condition is true is 2474 max_vq. This is the maximum vector length available to the guest on 2475 this vcpu, and determines which register slices are visible through 2476 this ioctl interface. 2477 2478(See Documentation/arm64/sve.rst for an explanation of the "vq" 2479nomenclature.) 2480 2481KVM_REG_ARM64_SVE_VLS is only accessible after KVM_ARM_VCPU_INIT. 2482KVM_ARM_VCPU_INIT initialises it to the best set of vector lengths that 2483the host supports. 2484 2485Userspace may subsequently modify it if desired until the vcpu's SVE 2486configuration is finalized using KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE). 2487 2488Apart from simply removing all vector lengths from the host set that 2489exceed some value, support for arbitrarily chosen sets of vector lengths 2490is hardware-dependent and may not be available. Attempting to configure 2491an invalid set of vector lengths via KVM_SET_ONE_REG will fail with 2492EINVAL. 2493 2494After the vcpu's SVE configuration is finalized, further attempts to 2495write this register will fail with EPERM. 2496 2497 2498MIPS registers are mapped using the lower 32 bits. The upper 16 of that is 2499the register group type: 2500 2501MIPS core registers (see above) have the following id bit patterns:: 2502 2503 0x7030 0000 0000 <reg:16> 2504 2505MIPS CP0 registers (see KVM_REG_MIPS_CP0_* above) have the following id bit 2506patterns depending on whether they're 32-bit or 64-bit registers:: 2507 2508 0x7020 0000 0001 00 <reg:5> <sel:3> (32-bit) 2509 0x7030 0000 0001 00 <reg:5> <sel:3> (64-bit) 2510 2511Note: KVM_REG_MIPS_CP0_ENTRYLO0 and KVM_REG_MIPS_CP0_ENTRYLO1 are the MIPS64 2512versions of the EntryLo registers regardless of the word size of the host 2513hardware, host kernel, guest, and whether XPA is present in the guest, i.e. 2514with the RI and XI bits (if they exist) in bits 63 and 62 respectively, and 2515the PFNX field starting at bit 30. 2516 2517MIPS MAARs (see KVM_REG_MIPS_CP0_MAAR(*) above) have the following id bit 2518patterns:: 2519 2520 0x7030 0000 0001 01 <reg:8> 2521 2522MIPS KVM control registers (see above) have the following id bit patterns:: 2523 2524 0x7030 0000 0002 <reg:16> 2525 2526MIPS FPU registers (see KVM_REG_MIPS_FPR_{32,64}() above) have the following 2527id bit patterns depending on the size of the register being accessed. They are 2528always accessed according to the current guest FPU mode (Status.FR and 2529Config5.FRE), i.e. as the guest would see them, and they become unpredictable 2530if the guest FPU mode is changed. MIPS SIMD Architecture (MSA) vector 2531registers (see KVM_REG_MIPS_VEC_128() above) have similar patterns as they 2532overlap the FPU registers:: 2533 2534 0x7020 0000 0003 00 <0:3> <reg:5> (32-bit FPU registers) 2535 0x7030 0000 0003 00 <0:3> <reg:5> (64-bit FPU registers) 2536 0x7040 0000 0003 00 <0:3> <reg:5> (128-bit MSA vector registers) 2537 2538MIPS FPU control registers (see KVM_REG_MIPS_FCR_{IR,CSR} above) have the 2539following id bit patterns:: 2540 2541 0x7020 0000 0003 01 <0:3> <reg:5> 2542 2543MIPS MSA control registers (see KVM_REG_MIPS_MSA_{IR,CSR} above) have the 2544following id bit patterns:: 2545 2546 0x7020 0000 0003 02 <0:3> <reg:5> 2547 2548 25494.69 KVM_GET_ONE_REG 2550-------------------- 2551 2552:Capability: KVM_CAP_ONE_REG 2553:Architectures: all 2554:Type: vcpu ioctl 2555:Parameters: struct kvm_one_reg (in and out) 2556:Returns: 0 on success, negative value on failure 2557 2558Errors include: 2559 2560 ======== ============================================================ 2561 ENOENT no such register 2562 EINVAL invalid register ID, or no such register or used with VMs in 2563 protected virtualization mode on s390 2564 EPERM (arm64) register access not allowed before vcpu finalization 2565 ======== ============================================================ 2566 2567(These error codes are indicative only: do not rely on a specific error 2568code being returned in a specific situation.) 2569 2570This ioctl allows to receive the value of a single register implemented 2571in a vcpu. The register to read is indicated by the "id" field of the 2572kvm_one_reg struct passed in. On success, the register value can be found 2573at the memory location pointed to by "addr". 2574 2575The list of registers accessible using this interface is identical to the 2576list in 4.68. 2577 2578 25794.70 KVM_KVMCLOCK_CTRL 2580---------------------- 2581 2582:Capability: KVM_CAP_KVMCLOCK_CTRL 2583:Architectures: Any that implement pvclocks (currently x86 only) 2584:Type: vcpu ioctl 2585:Parameters: None 2586:Returns: 0 on success, -1 on error 2587 2588This ioctl sets a flag accessible to the guest indicating that the specified 2589vCPU has been paused by the host userspace. 2590 2591The host will set a flag in the pvclock structure that is checked from the 2592soft lockup watchdog. The flag is part of the pvclock structure that is 2593shared between guest and host, specifically the second bit of the flags 2594field of the pvclock_vcpu_time_info structure. It will be set exclusively by 2595the host and read/cleared exclusively by the guest. The guest operation of 2596checking and clearing the flag must be an atomic operation so 2597load-link/store-conditional, or equivalent must be used. There are two cases 2598where the guest will clear the flag: when the soft lockup watchdog timer resets 2599itself or when a soft lockup is detected. This ioctl can be called any time 2600after pausing the vcpu, but before it is resumed. 2601 2602 26034.71 KVM_SIGNAL_MSI 2604------------------- 2605 2606:Capability: KVM_CAP_SIGNAL_MSI 2607:Architectures: x86 arm arm64 2608:Type: vm ioctl 2609:Parameters: struct kvm_msi (in) 2610:Returns: >0 on delivery, 0 if guest blocked the MSI, and -1 on error 2611 2612Directly inject a MSI message. Only valid with in-kernel irqchip that handles 2613MSI messages. 2614 2615:: 2616 2617 struct kvm_msi { 2618 __u32 address_lo; 2619 __u32 address_hi; 2620 __u32 data; 2621 __u32 flags; 2622 __u32 devid; 2623 __u8 pad[12]; 2624 }; 2625 2626flags: 2627 KVM_MSI_VALID_DEVID: devid contains a valid value. The per-VM 2628 KVM_CAP_MSI_DEVID capability advertises the requirement to provide 2629 the device ID. If this capability is not available, userspace 2630 should never set the KVM_MSI_VALID_DEVID flag as the ioctl might fail. 2631 2632If KVM_MSI_VALID_DEVID is set, devid contains a unique device identifier 2633for the device that wrote the MSI message. For PCI, this is usually a 2634BFD identifier in the lower 16 bits. 2635 2636On x86, address_hi is ignored unless the KVM_X2APIC_API_USE_32BIT_IDS 2637feature of KVM_CAP_X2APIC_API capability is enabled. If it is enabled, 2638address_hi bits 31-8 provide bits 31-8 of the destination id. Bits 7-0 of 2639address_hi must be zero. 2640 2641 26424.71 KVM_CREATE_PIT2 2643-------------------- 2644 2645:Capability: KVM_CAP_PIT2 2646:Architectures: x86 2647:Type: vm ioctl 2648:Parameters: struct kvm_pit_config (in) 2649:Returns: 0 on success, -1 on error 2650 2651Creates an in-kernel device model for the i8254 PIT. This call is only valid 2652after enabling in-kernel irqchip support via KVM_CREATE_IRQCHIP. The following 2653parameters have to be passed:: 2654 2655 struct kvm_pit_config { 2656 __u32 flags; 2657 __u32 pad[15]; 2658 }; 2659 2660Valid flags are:: 2661 2662 #define KVM_PIT_SPEAKER_DUMMY 1 /* emulate speaker port stub */ 2663 2664PIT timer interrupts may use a per-VM kernel thread for injection. If it 2665exists, this thread will have a name of the following pattern:: 2666 2667 kvm-pit/<owner-process-pid> 2668 2669When running a guest with elevated priorities, the scheduling parameters of 2670this thread may have to be adjusted accordingly. 2671 2672This IOCTL replaces the obsolete KVM_CREATE_PIT. 2673 2674 26754.72 KVM_GET_PIT2 2676----------------- 2677 2678:Capability: KVM_CAP_PIT_STATE2 2679:Architectures: x86 2680:Type: vm ioctl 2681:Parameters: struct kvm_pit_state2 (out) 2682:Returns: 0 on success, -1 on error 2683 2684Retrieves the state of the in-kernel PIT model. Only valid after 2685KVM_CREATE_PIT2. The state is returned in the following structure:: 2686 2687 struct kvm_pit_state2 { 2688 struct kvm_pit_channel_state channels[3]; 2689 __u32 flags; 2690 __u32 reserved[9]; 2691 }; 2692 2693Valid flags are:: 2694 2695 /* disable PIT in HPET legacy mode */ 2696 #define KVM_PIT_FLAGS_HPET_LEGACY 0x00000001 2697 2698This IOCTL replaces the obsolete KVM_GET_PIT. 2699 2700 27014.73 KVM_SET_PIT2 2702----------------- 2703 2704:Capability: KVM_CAP_PIT_STATE2 2705:Architectures: x86 2706:Type: vm ioctl 2707:Parameters: struct kvm_pit_state2 (in) 2708:Returns: 0 on success, -1 on error 2709 2710Sets the state of the in-kernel PIT model. Only valid after KVM_CREATE_PIT2. 2711See KVM_GET_PIT2 for details on struct kvm_pit_state2. 2712 2713This IOCTL replaces the obsolete KVM_SET_PIT. 2714 2715 27164.74 KVM_PPC_GET_SMMU_INFO 2717-------------------------- 2718 2719:Capability: KVM_CAP_PPC_GET_SMMU_INFO 2720:Architectures: powerpc 2721:Type: vm ioctl 2722:Parameters: None 2723:Returns: 0 on success, -1 on error 2724 2725This populates and returns a structure describing the features of 2726the "Server" class MMU emulation supported by KVM. 2727This can in turn be used by userspace to generate the appropriate 2728device-tree properties for the guest operating system. 2729 2730The structure contains some global information, followed by an 2731array of supported segment page sizes:: 2732 2733 struct kvm_ppc_smmu_info { 2734 __u64 flags; 2735 __u32 slb_size; 2736 __u32 pad; 2737 struct kvm_ppc_one_seg_page_size sps[KVM_PPC_PAGE_SIZES_MAX_SZ]; 2738 }; 2739 2740The supported flags are: 2741 2742 - KVM_PPC_PAGE_SIZES_REAL: 2743 When that flag is set, guest page sizes must "fit" the backing 2744 store page sizes. When not set, any page size in the list can 2745 be used regardless of how they are backed by userspace. 2746 2747 - KVM_PPC_1T_SEGMENTS 2748 The emulated MMU supports 1T segments in addition to the 2749 standard 256M ones. 2750 2751 - KVM_PPC_NO_HASH 2752 This flag indicates that HPT guests are not supported by KVM, 2753 thus all guests must use radix MMU mode. 2754 2755The "slb_size" field indicates how many SLB entries are supported 2756 2757The "sps" array contains 8 entries indicating the supported base 2758page sizes for a segment in increasing order. Each entry is defined 2759as follow:: 2760 2761 struct kvm_ppc_one_seg_page_size { 2762 __u32 page_shift; /* Base page shift of segment (or 0) */ 2763 __u32 slb_enc; /* SLB encoding for BookS */ 2764 struct kvm_ppc_one_page_size enc[KVM_PPC_PAGE_SIZES_MAX_SZ]; 2765 }; 2766 2767An entry with a "page_shift" of 0 is unused. Because the array is 2768organized in increasing order, a lookup can stop when encoutering 2769such an entry. 2770 2771The "slb_enc" field provides the encoding to use in the SLB for the 2772page size. The bits are in positions such as the value can directly 2773be OR'ed into the "vsid" argument of the slbmte instruction. 2774 2775The "enc" array is a list which for each of those segment base page 2776size provides the list of supported actual page sizes (which can be 2777only larger or equal to the base page size), along with the 2778corresponding encoding in the hash PTE. Similarly, the array is 27798 entries sorted by increasing sizes and an entry with a "0" shift 2780is an empty entry and a terminator:: 2781 2782 struct kvm_ppc_one_page_size { 2783 __u32 page_shift; /* Page shift (or 0) */ 2784 __u32 pte_enc; /* Encoding in the HPTE (>>12) */ 2785 }; 2786 2787The "pte_enc" field provides a value that can OR'ed into the hash 2788PTE's RPN field (ie, it needs to be shifted left by 12 to OR it 2789into the hash PTE second double word). 2790 27914.75 KVM_IRQFD 2792-------------- 2793 2794:Capability: KVM_CAP_IRQFD 2795:Architectures: x86 s390 arm arm64 2796:Type: vm ioctl 2797:Parameters: struct kvm_irqfd (in) 2798:Returns: 0 on success, -1 on error 2799 2800Allows setting an eventfd to directly trigger a guest interrupt. 2801kvm_irqfd.fd specifies the file descriptor to use as the eventfd and 2802kvm_irqfd.gsi specifies the irqchip pin toggled by this event. When 2803an event is triggered on the eventfd, an interrupt is injected into 2804the guest using the specified gsi pin. The irqfd is removed using 2805the KVM_IRQFD_FLAG_DEASSIGN flag, specifying both kvm_irqfd.fd 2806and kvm_irqfd.gsi. 2807 2808With KVM_CAP_IRQFD_RESAMPLE, KVM_IRQFD supports a de-assert and notify 2809mechanism allowing emulation of level-triggered, irqfd-based 2810interrupts. When KVM_IRQFD_FLAG_RESAMPLE is set the user must pass an 2811additional eventfd in the kvm_irqfd.resamplefd field. When operating 2812in resample mode, posting of an interrupt through kvm_irq.fd asserts 2813the specified gsi in the irqchip. When the irqchip is resampled, such 2814as from an EOI, the gsi is de-asserted and the user is notified via 2815kvm_irqfd.resamplefd. It is the user's responsibility to re-queue 2816the interrupt if the device making use of it still requires service. 2817Note that closing the resamplefd is not sufficient to disable the 2818irqfd. The KVM_IRQFD_FLAG_RESAMPLE is only necessary on assignment 2819and need not be specified with KVM_IRQFD_FLAG_DEASSIGN. 2820 2821On arm/arm64, gsi routing being supported, the following can happen: 2822 2823- in case no routing entry is associated to this gsi, injection fails 2824- in case the gsi is associated to an irqchip routing entry, 2825 irqchip.pin + 32 corresponds to the injected SPI ID. 2826- in case the gsi is associated to an MSI routing entry, the MSI 2827 message and device ID are translated into an LPI (support restricted 2828 to GICv3 ITS in-kernel emulation). 2829 28304.76 KVM_PPC_ALLOCATE_HTAB 2831-------------------------- 2832 2833:Capability: KVM_CAP_PPC_ALLOC_HTAB 2834:Architectures: powerpc 2835:Type: vm ioctl 2836:Parameters: Pointer to u32 containing hash table order (in/out) 2837:Returns: 0 on success, -1 on error 2838 2839This requests the host kernel to allocate an MMU hash table for a 2840guest using the PAPR paravirtualization interface. This only does 2841anything if the kernel is configured to use the Book 3S HV style of 2842virtualization. Otherwise the capability doesn't exist and the ioctl 2843returns an ENOTTY error. The rest of this description assumes Book 3S 2844HV. 2845 2846There must be no vcpus running when this ioctl is called; if there 2847are, it will do nothing and return an EBUSY error. 2848 2849The parameter is a pointer to a 32-bit unsigned integer variable 2850containing the order (log base 2) of the desired size of the hash 2851table, which must be between 18 and 46. On successful return from the 2852ioctl, the value will not be changed by the kernel. 2853 2854If no hash table has been allocated when any vcpu is asked to run 2855(with the KVM_RUN ioctl), the host kernel will allocate a 2856default-sized hash table (16 MB). 2857 2858If this ioctl is called when a hash table has already been allocated, 2859with a different order from the existing hash table, the existing hash 2860table will be freed and a new one allocated. If this is ioctl is 2861called when a hash table has already been allocated of the same order 2862as specified, the kernel will clear out the existing hash table (zero 2863all HPTEs). In either case, if the guest is using the virtualized 2864real-mode area (VRMA) facility, the kernel will re-create the VMRA 2865HPTEs on the next KVM_RUN of any vcpu. 2866 28674.77 KVM_S390_INTERRUPT 2868----------------------- 2869 2870:Capability: basic 2871:Architectures: s390 2872:Type: vm ioctl, vcpu ioctl 2873:Parameters: struct kvm_s390_interrupt (in) 2874:Returns: 0 on success, -1 on error 2875 2876Allows to inject an interrupt to the guest. Interrupts can be floating 2877(vm ioctl) or per cpu (vcpu ioctl), depending on the interrupt type. 2878 2879Interrupt parameters are passed via kvm_s390_interrupt:: 2880 2881 struct kvm_s390_interrupt { 2882 __u32 type; 2883 __u32 parm; 2884 __u64 parm64; 2885 }; 2886 2887type can be one of the following: 2888 2889KVM_S390_SIGP_STOP (vcpu) 2890 - sigp stop; optional flags in parm 2891KVM_S390_PROGRAM_INT (vcpu) 2892 - program check; code in parm 2893KVM_S390_SIGP_SET_PREFIX (vcpu) 2894 - sigp set prefix; prefix address in parm 2895KVM_S390_RESTART (vcpu) 2896 - restart 2897KVM_S390_INT_CLOCK_COMP (vcpu) 2898 - clock comparator interrupt 2899KVM_S390_INT_CPU_TIMER (vcpu) 2900 - CPU timer interrupt 2901KVM_S390_INT_VIRTIO (vm) 2902 - virtio external interrupt; external interrupt 2903 parameters in parm and parm64 2904KVM_S390_INT_SERVICE (vm) 2905 - sclp external interrupt; sclp parameter in parm 2906KVM_S390_INT_EMERGENCY (vcpu) 2907 - sigp emergency; source cpu in parm 2908KVM_S390_INT_EXTERNAL_CALL (vcpu) 2909 - sigp external call; source cpu in parm 2910KVM_S390_INT_IO(ai,cssid,ssid,schid) (vm) 2911 - compound value to indicate an 2912 I/O interrupt (ai - adapter interrupt; cssid,ssid,schid - subchannel); 2913 I/O interruption parameters in parm (subchannel) and parm64 (intparm, 2914 interruption subclass) 2915KVM_S390_MCHK (vm, vcpu) 2916 - machine check interrupt; cr 14 bits in parm, machine check interrupt 2917 code in parm64 (note that machine checks needing further payload are not 2918 supported by this ioctl) 2919 2920This is an asynchronous vcpu ioctl and can be invoked from any thread. 2921 29224.78 KVM_PPC_GET_HTAB_FD 2923------------------------ 2924 2925:Capability: KVM_CAP_PPC_HTAB_FD 2926:Architectures: powerpc 2927:Type: vm ioctl 2928:Parameters: Pointer to struct kvm_get_htab_fd (in) 2929:Returns: file descriptor number (>= 0) on success, -1 on error 2930 2931This returns a file descriptor that can be used either to read out the 2932entries in the guest's hashed page table (HPT), or to write entries to 2933initialize the HPT. The returned fd can only be written to if the 2934KVM_GET_HTAB_WRITE bit is set in the flags field of the argument, and 2935can only be read if that bit is clear. The argument struct looks like 2936this:: 2937 2938 /* For KVM_PPC_GET_HTAB_FD */ 2939 struct kvm_get_htab_fd { 2940 __u64 flags; 2941 __u64 start_index; 2942 __u64 reserved[2]; 2943 }; 2944 2945 /* Values for kvm_get_htab_fd.flags */ 2946 #define KVM_GET_HTAB_BOLTED_ONLY ((__u64)0x1) 2947 #define KVM_GET_HTAB_WRITE ((__u64)0x2) 2948 2949The 'start_index' field gives the index in the HPT of the entry at 2950which to start reading. It is ignored when writing. 2951 2952Reads on the fd will initially supply information about all 2953"interesting" HPT entries. Interesting entries are those with the 2954bolted bit set, if the KVM_GET_HTAB_BOLTED_ONLY bit is set, otherwise 2955all entries. When the end of the HPT is reached, the read() will 2956return. If read() is called again on the fd, it will start again from 2957the beginning of the HPT, but will only return HPT entries that have 2958changed since they were last read. 2959 2960Data read or written is structured as a header (8 bytes) followed by a 2961series of valid HPT entries (16 bytes) each. The header indicates how 2962many valid HPT entries there are and how many invalid entries follow 2963the valid entries. The invalid entries are not represented explicitly 2964in the stream. The header format is:: 2965 2966 struct kvm_get_htab_header { 2967 __u32 index; 2968 __u16 n_valid; 2969 __u16 n_invalid; 2970 }; 2971 2972Writes to the fd create HPT entries starting at the index given in the 2973header; first 'n_valid' valid entries with contents from the data 2974written, then 'n_invalid' invalid entries, invalidating any previously 2975valid entries found. 2976 29774.79 KVM_CREATE_DEVICE 2978---------------------- 2979 2980:Capability: KVM_CAP_DEVICE_CTRL 2981:Type: vm ioctl 2982:Parameters: struct kvm_create_device (in/out) 2983:Returns: 0 on success, -1 on error 2984 2985Errors: 2986 2987 ====== ======================================================= 2988 ENODEV The device type is unknown or unsupported 2989 EEXIST Device already created, and this type of device may not 2990 be instantiated multiple times 2991 ====== ======================================================= 2992 2993 Other error conditions may be defined by individual device types or 2994 have their standard meanings. 2995 2996Creates an emulated device in the kernel. The file descriptor returned 2997in fd can be used with KVM_SET/GET/HAS_DEVICE_ATTR. 2998 2999If the KVM_CREATE_DEVICE_TEST flag is set, only test whether the 3000device type is supported (not necessarily whether it can be created 3001in the current vm). 3002 3003Individual devices should not define flags. Attributes should be used 3004for specifying any behavior that is not implied by the device type 3005number. 3006 3007:: 3008 3009 struct kvm_create_device { 3010 __u32 type; /* in: KVM_DEV_TYPE_xxx */ 3011 __u32 fd; /* out: device handle */ 3012 __u32 flags; /* in: KVM_CREATE_DEVICE_xxx */ 3013 }; 3014 30154.80 KVM_SET_DEVICE_ATTR/KVM_GET_DEVICE_ATTR 3016-------------------------------------------- 3017 3018:Capability: KVM_CAP_DEVICE_CTRL, KVM_CAP_VM_ATTRIBUTES for vm device, 3019 KVM_CAP_VCPU_ATTRIBUTES for vcpu device 3020:Type: device ioctl, vm ioctl, vcpu ioctl 3021:Parameters: struct kvm_device_attr 3022:Returns: 0 on success, -1 on error 3023 3024Errors: 3025 3026 ===== ============================================================= 3027 ENXIO The group or attribute is unknown/unsupported for this device 3028 or hardware support is missing. 3029 EPERM The attribute cannot (currently) be accessed this way 3030 (e.g. read-only attribute, or attribute that only makes 3031 sense when the device is in a different state) 3032 ===== ============================================================= 3033 3034 Other error conditions may be defined by individual device types. 3035 3036Gets/sets a specified piece of device configuration and/or state. The 3037semantics are device-specific. See individual device documentation in 3038the "devices" directory. As with ONE_REG, the size of the data 3039transferred is defined by the particular attribute. 3040 3041:: 3042 3043 struct kvm_device_attr { 3044 __u32 flags; /* no flags currently defined */ 3045 __u32 group; /* device-defined */ 3046 __u64 attr; /* group-defined */ 3047 __u64 addr; /* userspace address of attr data */ 3048 }; 3049 30504.81 KVM_HAS_DEVICE_ATTR 3051------------------------ 3052 3053:Capability: KVM_CAP_DEVICE_CTRL, KVM_CAP_VM_ATTRIBUTES for vm device, 3054 KVM_CAP_VCPU_ATTRIBUTES for vcpu device 3055:Type: device ioctl, vm ioctl, vcpu ioctl 3056:Parameters: struct kvm_device_attr 3057:Returns: 0 on success, -1 on error 3058 3059Errors: 3060 3061 ===== ============================================================= 3062 ENXIO The group or attribute is unknown/unsupported for this device 3063 or hardware support is missing. 3064 ===== ============================================================= 3065 3066Tests whether a device supports a particular attribute. A successful 3067return indicates the attribute is implemented. It does not necessarily 3068indicate that the attribute can be read or written in the device's 3069current state. "addr" is ignored. 3070 30714.82 KVM_ARM_VCPU_INIT 3072---------------------- 3073 3074:Capability: basic 3075:Architectures: arm, arm64 3076:Type: vcpu ioctl 3077:Parameters: struct kvm_vcpu_init (in) 3078:Returns: 0 on success; -1 on error 3079 3080Errors: 3081 3082 ====== ================================================================= 3083 EINVAL the target is unknown, or the combination of features is invalid. 3084 ENOENT a features bit specified is unknown. 3085 ====== ================================================================= 3086 3087This tells KVM what type of CPU to present to the guest, and what 3088optional features it should have. This will cause a reset of the cpu 3089registers to their initial values. If this is not called, KVM_RUN will 3090return ENOEXEC for that vcpu. 3091 3092Note that because some registers reflect machine topology, all vcpus 3093should be created before this ioctl is invoked. 3094 3095Userspace can call this function multiple times for a given vcpu, including 3096after the vcpu has been run. This will reset the vcpu to its initial 3097state. All calls to this function after the initial call must use the same 3098target and same set of feature flags, otherwise EINVAL will be returned. 3099 3100Possible features: 3101 3102 - KVM_ARM_VCPU_POWER_OFF: Starts the CPU in a power-off state. 3103 Depends on KVM_CAP_ARM_PSCI. If not set, the CPU will be powered on 3104 and execute guest code when KVM_RUN is called. 3105 - KVM_ARM_VCPU_EL1_32BIT: Starts the CPU in a 32bit mode. 3106 Depends on KVM_CAP_ARM_EL1_32BIT (arm64 only). 3107 - KVM_ARM_VCPU_PSCI_0_2: Emulate PSCI v0.2 (or a future revision 3108 backward compatible with v0.2) for the CPU. 3109 Depends on KVM_CAP_ARM_PSCI_0_2. 3110 - KVM_ARM_VCPU_PMU_V3: Emulate PMUv3 for the CPU. 3111 Depends on KVM_CAP_ARM_PMU_V3. 3112 3113 - KVM_ARM_VCPU_PTRAUTH_ADDRESS: Enables Address Pointer authentication 3114 for arm64 only. 3115 Depends on KVM_CAP_ARM_PTRAUTH_ADDRESS. 3116 If KVM_CAP_ARM_PTRAUTH_ADDRESS and KVM_CAP_ARM_PTRAUTH_GENERIC are 3117 both present, then both KVM_ARM_VCPU_PTRAUTH_ADDRESS and 3118 KVM_ARM_VCPU_PTRAUTH_GENERIC must be requested or neither must be 3119 requested. 3120 3121 - KVM_ARM_VCPU_PTRAUTH_GENERIC: Enables Generic Pointer authentication 3122 for arm64 only. 3123 Depends on KVM_CAP_ARM_PTRAUTH_GENERIC. 3124 If KVM_CAP_ARM_PTRAUTH_ADDRESS and KVM_CAP_ARM_PTRAUTH_GENERIC are 3125 both present, then both KVM_ARM_VCPU_PTRAUTH_ADDRESS and 3126 KVM_ARM_VCPU_PTRAUTH_GENERIC must be requested or neither must be 3127 requested. 3128 3129 - KVM_ARM_VCPU_SVE: Enables SVE for the CPU (arm64 only). 3130 Depends on KVM_CAP_ARM_SVE. 3131 Requires KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE): 3132 3133 * After KVM_ARM_VCPU_INIT: 3134 3135 - KVM_REG_ARM64_SVE_VLS may be read using KVM_GET_ONE_REG: the 3136 initial value of this pseudo-register indicates the best set of 3137 vector lengths possible for a vcpu on this host. 3138 3139 * Before KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE): 3140 3141 - KVM_RUN and KVM_GET_REG_LIST are not available; 3142 3143 - KVM_GET_ONE_REG and KVM_SET_ONE_REG cannot be used to access 3144 the scalable archietctural SVE registers 3145 KVM_REG_ARM64_SVE_ZREG(), KVM_REG_ARM64_SVE_PREG() or 3146 KVM_REG_ARM64_SVE_FFR; 3147 3148 - KVM_REG_ARM64_SVE_VLS may optionally be written using 3149 KVM_SET_ONE_REG, to modify the set of vector lengths available 3150 for the vcpu. 3151 3152 * After KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE): 3153 3154 - the KVM_REG_ARM64_SVE_VLS pseudo-register is immutable, and can 3155 no longer be written using KVM_SET_ONE_REG. 3156 31574.83 KVM_ARM_PREFERRED_TARGET 3158----------------------------- 3159 3160:Capability: basic 3161:Architectures: arm, arm64 3162:Type: vm ioctl 3163:Parameters: struct kvm_vcpu_init (out) 3164:Returns: 0 on success; -1 on error 3165 3166Errors: 3167 3168 ====== ========================================== 3169 ENODEV no preferred target available for the host 3170 ====== ========================================== 3171 3172This queries KVM for preferred CPU target type which can be emulated 3173by KVM on underlying host. 3174 3175The ioctl returns struct kvm_vcpu_init instance containing information 3176about preferred CPU target type and recommended features for it. The 3177kvm_vcpu_init->features bitmap returned will have feature bits set if 3178the preferred target recommends setting these features, but this is 3179not mandatory. 3180 3181The information returned by this ioctl can be used to prepare an instance 3182of struct kvm_vcpu_init for KVM_ARM_VCPU_INIT ioctl which will result in 3183VCPU matching underlying host. 3184 3185 31864.84 KVM_GET_REG_LIST 3187--------------------- 3188 3189:Capability: basic 3190:Architectures: arm, arm64, mips 3191:Type: vcpu ioctl 3192:Parameters: struct kvm_reg_list (in/out) 3193:Returns: 0 on success; -1 on error 3194 3195Errors: 3196 3197 ===== ============================================================== 3198 E2BIG the reg index list is too big to fit in the array specified by 3199 the user (the number required will be written into n). 3200 ===== ============================================================== 3201 3202:: 3203 3204 struct kvm_reg_list { 3205 __u64 n; /* number of registers in reg[] */ 3206 __u64 reg[0]; 3207 }; 3208 3209This ioctl returns the guest registers that are supported for the 3210KVM_GET_ONE_REG/KVM_SET_ONE_REG calls. 3211 3212 32134.85 KVM_ARM_SET_DEVICE_ADDR (deprecated) 3214----------------------------------------- 3215 3216:Capability: KVM_CAP_ARM_SET_DEVICE_ADDR 3217:Architectures: arm, arm64 3218:Type: vm ioctl 3219:Parameters: struct kvm_arm_device_address (in) 3220:Returns: 0 on success, -1 on error 3221 3222Errors: 3223 3224 ====== ============================================ 3225 ENODEV The device id is unknown 3226 ENXIO Device not supported on current system 3227 EEXIST Address already set 3228 E2BIG Address outside guest physical address space 3229 EBUSY Address overlaps with other device range 3230 ====== ============================================ 3231 3232:: 3233 3234 struct kvm_arm_device_addr { 3235 __u64 id; 3236 __u64 addr; 3237 }; 3238 3239Specify a device address in the guest's physical address space where guests 3240can access emulated or directly exposed devices, which the host kernel needs 3241to know about. The id field is an architecture specific identifier for a 3242specific device. 3243 3244ARM/arm64 divides the id field into two parts, a device id and an 3245address type id specific to the individual device:: 3246 3247 bits: | 63 ... 32 | 31 ... 16 | 15 ... 0 | 3248 field: | 0x00000000 | device id | addr type id | 3249 3250ARM/arm64 currently only require this when using the in-kernel GIC 3251support for the hardware VGIC features, using KVM_ARM_DEVICE_VGIC_V2 3252as the device id. When setting the base address for the guest's 3253mapping of the VGIC virtual CPU and distributor interface, the ioctl 3254must be called after calling KVM_CREATE_IRQCHIP, but before calling 3255KVM_RUN on any of the VCPUs. Calling this ioctl twice for any of the 3256base addresses will return -EEXIST. 3257 3258Note, this IOCTL is deprecated and the more flexible SET/GET_DEVICE_ATTR API 3259should be used instead. 3260 3261 32624.86 KVM_PPC_RTAS_DEFINE_TOKEN 3263------------------------------ 3264 3265:Capability: KVM_CAP_PPC_RTAS 3266:Architectures: ppc 3267:Type: vm ioctl 3268:Parameters: struct kvm_rtas_token_args 3269:Returns: 0 on success, -1 on error 3270 3271Defines a token value for a RTAS (Run Time Abstraction Services) 3272service in order to allow it to be handled in the kernel. The 3273argument struct gives the name of the service, which must be the name 3274of a service that has a kernel-side implementation. If the token 3275value is non-zero, it will be associated with that service, and 3276subsequent RTAS calls by the guest specifying that token will be 3277handled by the kernel. If the token value is 0, then any token 3278associated with the service will be forgotten, and subsequent RTAS 3279calls by the guest for that service will be passed to userspace to be 3280handled. 3281 32824.87 KVM_SET_GUEST_DEBUG 3283------------------------ 3284 3285:Capability: KVM_CAP_SET_GUEST_DEBUG 3286:Architectures: x86, s390, ppc, arm64 3287:Type: vcpu ioctl 3288:Parameters: struct kvm_guest_debug (in) 3289:Returns: 0 on success; -1 on error 3290 3291:: 3292 3293 struct kvm_guest_debug { 3294 __u32 control; 3295 __u32 pad; 3296 struct kvm_guest_debug_arch arch; 3297 }; 3298 3299Set up the processor specific debug registers and configure vcpu for 3300handling guest debug events. There are two parts to the structure, the 3301first a control bitfield indicates the type of debug events to handle 3302when running. Common control bits are: 3303 3304 - KVM_GUESTDBG_ENABLE: guest debugging is enabled 3305 - KVM_GUESTDBG_SINGLESTEP: the next run should single-step 3306 3307The top 16 bits of the control field are architecture specific control 3308flags which can include the following: 3309 3310 - KVM_GUESTDBG_USE_SW_BP: using software breakpoints [x86, arm64] 3311 - KVM_GUESTDBG_USE_HW_BP: using hardware breakpoints [x86, s390, arm64] 3312 - KVM_GUESTDBG_INJECT_DB: inject DB type exception [x86] 3313 - KVM_GUESTDBG_INJECT_BP: inject BP type exception [x86] 3314 - KVM_GUESTDBG_EXIT_PENDING: trigger an immediate guest exit [s390] 3315 3316For example KVM_GUESTDBG_USE_SW_BP indicates that software breakpoints 3317are enabled in memory so we need to ensure breakpoint exceptions are 3318correctly trapped and the KVM run loop exits at the breakpoint and not 3319running off into the normal guest vector. For KVM_GUESTDBG_USE_HW_BP 3320we need to ensure the guest vCPUs architecture specific registers are 3321updated to the correct (supplied) values. 3322 3323The second part of the structure is architecture specific and 3324typically contains a set of debug registers. 3325 3326For arm64 the number of debug registers is implementation defined and 3327can be determined by querying the KVM_CAP_GUEST_DEBUG_HW_BPS and 3328KVM_CAP_GUEST_DEBUG_HW_WPS capabilities which return a positive number 3329indicating the number of supported registers. 3330 3331For ppc, the KVM_CAP_PPC_GUEST_DEBUG_SSTEP capability indicates whether 3332the single-step debug event (KVM_GUESTDBG_SINGLESTEP) is supported. 3333 3334When debug events exit the main run loop with the reason 3335KVM_EXIT_DEBUG with the kvm_debug_exit_arch part of the kvm_run 3336structure containing architecture specific debug information. 3337 33384.88 KVM_GET_EMULATED_CPUID 3339--------------------------- 3340 3341:Capability: KVM_CAP_EXT_EMUL_CPUID 3342:Architectures: x86 3343:Type: system ioctl 3344:Parameters: struct kvm_cpuid2 (in/out) 3345:Returns: 0 on success, -1 on error 3346 3347:: 3348 3349 struct kvm_cpuid2 { 3350 __u32 nent; 3351 __u32 flags; 3352 struct kvm_cpuid_entry2 entries[0]; 3353 }; 3354 3355The member 'flags' is used for passing flags from userspace. 3356 3357:: 3358 3359 #define KVM_CPUID_FLAG_SIGNIFCANT_INDEX BIT(0) 3360 #define KVM_CPUID_FLAG_STATEFUL_FUNC BIT(1) /* deprecated */ 3361 #define KVM_CPUID_FLAG_STATE_READ_NEXT BIT(2) /* deprecated */ 3362 3363 struct kvm_cpuid_entry2 { 3364 __u32 function; 3365 __u32 index; 3366 __u32 flags; 3367 __u32 eax; 3368 __u32 ebx; 3369 __u32 ecx; 3370 __u32 edx; 3371 __u32 padding[3]; 3372 }; 3373 3374This ioctl returns x86 cpuid features which are emulated by 3375kvm.Userspace can use the information returned by this ioctl to query 3376which features are emulated by kvm instead of being present natively. 3377 3378Userspace invokes KVM_GET_EMULATED_CPUID by passing a kvm_cpuid2 3379structure with the 'nent' field indicating the number of entries in 3380the variable-size array 'entries'. If the number of entries is too low 3381to describe the cpu capabilities, an error (E2BIG) is returned. If the 3382number is too high, the 'nent' field is adjusted and an error (ENOMEM) 3383is returned. If the number is just right, the 'nent' field is adjusted 3384to the number of valid entries in the 'entries' array, which is then 3385filled. 3386 3387The entries returned are the set CPUID bits of the respective features 3388which kvm emulates, as returned by the CPUID instruction, with unknown 3389or unsupported feature bits cleared. 3390 3391Features like x2apic, for example, may not be present in the host cpu 3392but are exposed by kvm in KVM_GET_SUPPORTED_CPUID because they can be 3393emulated efficiently and thus not included here. 3394 3395The fields in each entry are defined as follows: 3396 3397 function: 3398 the eax value used to obtain the entry 3399 index: 3400 the ecx value used to obtain the entry (for entries that are 3401 affected by ecx) 3402 flags: 3403 an OR of zero or more of the following: 3404 3405 KVM_CPUID_FLAG_SIGNIFCANT_INDEX: 3406 if the index field is valid 3407 3408 eax, ebx, ecx, edx: 3409 3410 the values returned by the cpuid instruction for 3411 this function/index combination 3412 34134.89 KVM_S390_MEM_OP 3414-------------------- 3415 3416:Capability: KVM_CAP_S390_MEM_OP 3417:Architectures: s390 3418:Type: vcpu ioctl 3419:Parameters: struct kvm_s390_mem_op (in) 3420:Returns: = 0 on success, 3421 < 0 on generic error (e.g. -EFAULT or -ENOMEM), 3422 > 0 if an exception occurred while walking the page tables 3423 3424Read or write data from/to the logical (virtual) memory of a VCPU. 3425 3426Parameters are specified via the following structure:: 3427 3428 struct kvm_s390_mem_op { 3429 __u64 gaddr; /* the guest address */ 3430 __u64 flags; /* flags */ 3431 __u32 size; /* amount of bytes */ 3432 __u32 op; /* type of operation */ 3433 __u64 buf; /* buffer in userspace */ 3434 __u8 ar; /* the access register number */ 3435 __u8 reserved[31]; /* should be set to 0 */ 3436 }; 3437 3438The type of operation is specified in the "op" field. It is either 3439KVM_S390_MEMOP_LOGICAL_READ for reading from logical memory space or 3440KVM_S390_MEMOP_LOGICAL_WRITE for writing to logical memory space. The 3441KVM_S390_MEMOP_F_CHECK_ONLY flag can be set in the "flags" field to check 3442whether the corresponding memory access would create an access exception 3443(without touching the data in the memory at the destination). In case an 3444access exception occurred while walking the MMU tables of the guest, the 3445ioctl returns a positive error number to indicate the type of exception. 3446This exception is also raised directly at the corresponding VCPU if the 3447flag KVM_S390_MEMOP_F_INJECT_EXCEPTION is set in the "flags" field. 3448 3449The start address of the memory region has to be specified in the "gaddr" 3450field, and the length of the region in the "size" field (which must not 3451be 0). The maximum value for "size" can be obtained by checking the 3452KVM_CAP_S390_MEM_OP capability. "buf" is the buffer supplied by the 3453userspace application where the read data should be written to for 3454KVM_S390_MEMOP_LOGICAL_READ, or where the data that should be written is 3455stored for a KVM_S390_MEMOP_LOGICAL_WRITE. When KVM_S390_MEMOP_F_CHECK_ONLY 3456is specified, "buf" is unused and can be NULL. "ar" designates the access 3457register number to be used; the valid range is 0..15. 3458 3459The "reserved" field is meant for future extensions. It is not used by 3460KVM with the currently defined set of flags. 3461 34624.90 KVM_S390_GET_SKEYS 3463----------------------- 3464 3465:Capability: KVM_CAP_S390_SKEYS 3466:Architectures: s390 3467:Type: vm ioctl 3468:Parameters: struct kvm_s390_skeys 3469:Returns: 0 on success, KVM_S390_GET_KEYS_NONE if guest is not using storage 3470 keys, negative value on error 3471 3472This ioctl is used to get guest storage key values on the s390 3473architecture. The ioctl takes parameters via the kvm_s390_skeys struct:: 3474 3475 struct kvm_s390_skeys { 3476 __u64 start_gfn; 3477 __u64 count; 3478 __u64 skeydata_addr; 3479 __u32 flags; 3480 __u32 reserved[9]; 3481 }; 3482 3483The start_gfn field is the number of the first guest frame whose storage keys 3484you want to get. 3485 3486The count field is the number of consecutive frames (starting from start_gfn) 3487whose storage keys to get. The count field must be at least 1 and the maximum 3488allowed value is defined as KVM_S390_SKEYS_ALLOC_MAX. Values outside this range 3489will cause the ioctl to return -EINVAL. 3490 3491The skeydata_addr field is the address to a buffer large enough to hold count 3492bytes. This buffer will be filled with storage key data by the ioctl. 3493 34944.91 KVM_S390_SET_SKEYS 3495----------------------- 3496 3497:Capability: KVM_CAP_S390_SKEYS 3498:Architectures: s390 3499:Type: vm ioctl 3500:Parameters: struct kvm_s390_skeys 3501:Returns: 0 on success, negative value on error 3502 3503This ioctl is used to set guest storage key values on the s390 3504architecture. The ioctl takes parameters via the kvm_s390_skeys struct. 3505See section on KVM_S390_GET_SKEYS for struct definition. 3506 3507The start_gfn field is the number of the first guest frame whose storage keys 3508you want to set. 3509 3510The count field is the number of consecutive frames (starting from start_gfn) 3511whose storage keys to get. The count field must be at least 1 and the maximum 3512allowed value is defined as KVM_S390_SKEYS_ALLOC_MAX. Values outside this range 3513will cause the ioctl to return -EINVAL. 3514 3515The skeydata_addr field is the address to a buffer containing count bytes of 3516storage keys. Each byte in the buffer will be set as the storage key for a 3517single frame starting at start_gfn for count frames. 3518 3519Note: If any architecturally invalid key value is found in the given data then 3520the ioctl will return -EINVAL. 3521 35224.92 KVM_S390_IRQ 3523----------------- 3524 3525:Capability: KVM_CAP_S390_INJECT_IRQ 3526:Architectures: s390 3527:Type: vcpu ioctl 3528:Parameters: struct kvm_s390_irq (in) 3529:Returns: 0 on success, -1 on error 3530 3531Errors: 3532 3533 3534 ====== ================================================================= 3535 EINVAL interrupt type is invalid 3536 type is KVM_S390_SIGP_STOP and flag parameter is invalid value, 3537 type is KVM_S390_INT_EXTERNAL_CALL and code is bigger 3538 than the maximum of VCPUs 3539 EBUSY type is KVM_S390_SIGP_SET_PREFIX and vcpu is not stopped, 3540 type is KVM_S390_SIGP_STOP and a stop irq is already pending, 3541 type is KVM_S390_INT_EXTERNAL_CALL and an external call interrupt 3542 is already pending 3543 ====== ================================================================= 3544 3545Allows to inject an interrupt to the guest. 3546 3547Using struct kvm_s390_irq as a parameter allows 3548to inject additional payload which is not 3549possible via KVM_S390_INTERRUPT. 3550 3551Interrupt parameters are passed via kvm_s390_irq:: 3552 3553 struct kvm_s390_irq { 3554 __u64 type; 3555 union { 3556 struct kvm_s390_io_info io; 3557 struct kvm_s390_ext_info ext; 3558 struct kvm_s390_pgm_info pgm; 3559 struct kvm_s390_emerg_info emerg; 3560 struct kvm_s390_extcall_info extcall; 3561 struct kvm_s390_prefix_info prefix; 3562 struct kvm_s390_stop_info stop; 3563 struct kvm_s390_mchk_info mchk; 3564 char reserved[64]; 3565 } u; 3566 }; 3567 3568type can be one of the following: 3569 3570- KVM_S390_SIGP_STOP - sigp stop; parameter in .stop 3571- KVM_S390_PROGRAM_INT - program check; parameters in .pgm 3572- KVM_S390_SIGP_SET_PREFIX - sigp set prefix; parameters in .prefix 3573- KVM_S390_RESTART - restart; no parameters 3574- KVM_S390_INT_CLOCK_COMP - clock comparator interrupt; no parameters 3575- KVM_S390_INT_CPU_TIMER - CPU timer interrupt; no parameters 3576- KVM_S390_INT_EMERGENCY - sigp emergency; parameters in .emerg 3577- KVM_S390_INT_EXTERNAL_CALL - sigp external call; parameters in .extcall 3578- KVM_S390_MCHK - machine check interrupt; parameters in .mchk 3579 3580This is an asynchronous vcpu ioctl and can be invoked from any thread. 3581 35824.94 KVM_S390_GET_IRQ_STATE 3583--------------------------- 3584 3585:Capability: KVM_CAP_S390_IRQ_STATE 3586:Architectures: s390 3587:Type: vcpu ioctl 3588:Parameters: struct kvm_s390_irq_state (out) 3589:Returns: >= number of bytes copied into buffer, 3590 -EINVAL if buffer size is 0, 3591 -ENOBUFS if buffer size is too small to fit all pending interrupts, 3592 -EFAULT if the buffer address was invalid 3593 3594This ioctl allows userspace to retrieve the complete state of all currently 3595pending interrupts in a single buffer. Use cases include migration 3596and introspection. The parameter structure contains the address of a 3597userspace buffer and its length:: 3598 3599 struct kvm_s390_irq_state { 3600 __u64 buf; 3601 __u32 flags; /* will stay unused for compatibility reasons */ 3602 __u32 len; 3603 __u32 reserved[4]; /* will stay unused for compatibility reasons */ 3604 }; 3605 3606Userspace passes in the above struct and for each pending interrupt a 3607struct kvm_s390_irq is copied to the provided buffer. 3608 3609The structure contains a flags and a reserved field for future extensions. As 3610the kernel never checked for flags == 0 and QEMU never pre-zeroed flags and 3611reserved, these fields can not be used in the future without breaking 3612compatibility. 3613 3614If -ENOBUFS is returned the buffer provided was too small and userspace 3615may retry with a bigger buffer. 3616 36174.95 KVM_S390_SET_IRQ_STATE 3618--------------------------- 3619 3620:Capability: KVM_CAP_S390_IRQ_STATE 3621:Architectures: s390 3622:Type: vcpu ioctl 3623:Parameters: struct kvm_s390_irq_state (in) 3624:Returns: 0 on success, 3625 -EFAULT if the buffer address was invalid, 3626 -EINVAL for an invalid buffer length (see below), 3627 -EBUSY if there were already interrupts pending, 3628 errors occurring when actually injecting the 3629 interrupt. See KVM_S390_IRQ. 3630 3631This ioctl allows userspace to set the complete state of all cpu-local 3632interrupts currently pending for the vcpu. It is intended for restoring 3633interrupt state after a migration. The input parameter is a userspace buffer 3634containing a struct kvm_s390_irq_state:: 3635 3636 struct kvm_s390_irq_state { 3637 __u64 buf; 3638 __u32 flags; /* will stay unused for compatibility reasons */ 3639 __u32 len; 3640 __u32 reserved[4]; /* will stay unused for compatibility reasons */ 3641 }; 3642 3643The restrictions for flags and reserved apply as well. 3644(see KVM_S390_GET_IRQ_STATE) 3645 3646The userspace memory referenced by buf contains a struct kvm_s390_irq 3647for each interrupt to be injected into the guest. 3648If one of the interrupts could not be injected for some reason the 3649ioctl aborts. 3650 3651len must be a multiple of sizeof(struct kvm_s390_irq). It must be > 0 3652and it must not exceed (max_vcpus + 32) * sizeof(struct kvm_s390_irq), 3653which is the maximum number of possibly pending cpu-local interrupts. 3654 36554.96 KVM_SMI 3656------------ 3657 3658:Capability: KVM_CAP_X86_SMM 3659:Architectures: x86 3660:Type: vcpu ioctl 3661:Parameters: none 3662:Returns: 0 on success, -1 on error 3663 3664Queues an SMI on the thread's vcpu. 3665 36664.97 KVM_CAP_PPC_MULTITCE 3667------------------------- 3668 3669:Capability: KVM_CAP_PPC_MULTITCE 3670:Architectures: ppc 3671:Type: vm 3672 3673This capability means the kernel is capable of handling hypercalls 3674H_PUT_TCE_INDIRECT and H_STUFF_TCE without passing those into the user 3675space. This significantly accelerates DMA operations for PPC KVM guests. 3676User space should expect that its handlers for these hypercalls 3677are not going to be called if user space previously registered LIOBN 3678in KVM (via KVM_CREATE_SPAPR_TCE or similar calls). 3679 3680In order to enable H_PUT_TCE_INDIRECT and H_STUFF_TCE use in the guest, 3681user space might have to advertise it for the guest. For example, 3682IBM pSeries (sPAPR) guest starts using them if "hcall-multi-tce" is 3683present in the "ibm,hypertas-functions" device-tree property. 3684 3685The hypercalls mentioned above may or may not be processed successfully 3686in the kernel based fast path. If they can not be handled by the kernel, 3687they will get passed on to user space. So user space still has to have 3688an implementation for these despite the in kernel acceleration. 3689 3690This capability is always enabled. 3691 36924.98 KVM_CREATE_SPAPR_TCE_64 3693---------------------------- 3694 3695:Capability: KVM_CAP_SPAPR_TCE_64 3696:Architectures: powerpc 3697:Type: vm ioctl 3698:Parameters: struct kvm_create_spapr_tce_64 (in) 3699:Returns: file descriptor for manipulating the created TCE table 3700 3701This is an extension for KVM_CAP_SPAPR_TCE which only supports 32bit 3702windows, described in 4.62 KVM_CREATE_SPAPR_TCE 3703 3704This capability uses extended struct in ioctl interface:: 3705 3706 /* for KVM_CAP_SPAPR_TCE_64 */ 3707 struct kvm_create_spapr_tce_64 { 3708 __u64 liobn; 3709 __u32 page_shift; 3710 __u32 flags; 3711 __u64 offset; /* in pages */ 3712 __u64 size; /* in pages */ 3713 }; 3714 3715The aim of extension is to support an additional bigger DMA window with 3716a variable page size. 3717KVM_CREATE_SPAPR_TCE_64 receives a 64bit window size, an IOMMU page shift and 3718a bus offset of the corresponding DMA window, @size and @offset are numbers 3719of IOMMU pages. 3720 3721@flags are not used at the moment. 3722 3723The rest of functionality is identical to KVM_CREATE_SPAPR_TCE. 3724 37254.99 KVM_REINJECT_CONTROL 3726------------------------- 3727 3728:Capability: KVM_CAP_REINJECT_CONTROL 3729:Architectures: x86 3730:Type: vm ioctl 3731:Parameters: struct kvm_reinject_control (in) 3732:Returns: 0 on success, 3733 -EFAULT if struct kvm_reinject_control cannot be read, 3734 -ENXIO if KVM_CREATE_PIT or KVM_CREATE_PIT2 didn't succeed earlier. 3735 3736i8254 (PIT) has two modes, reinject and !reinject. The default is reinject, 3737where KVM queues elapsed i8254 ticks and monitors completion of interrupt from 3738vector(s) that i8254 injects. Reinject mode dequeues a tick and injects its 3739interrupt whenever there isn't a pending interrupt from i8254. 3740!reinject mode injects an interrupt as soon as a tick arrives. 3741 3742:: 3743 3744 struct kvm_reinject_control { 3745 __u8 pit_reinject; 3746 __u8 reserved[31]; 3747 }; 3748 3749pit_reinject = 0 (!reinject mode) is recommended, unless running an old 3750operating system that uses the PIT for timing (e.g. Linux 2.4.x). 3751 37524.100 KVM_PPC_CONFIGURE_V3_MMU 3753------------------------------ 3754 3755:Capability: KVM_CAP_PPC_RADIX_MMU or KVM_CAP_PPC_HASH_MMU_V3 3756:Architectures: ppc 3757:Type: vm ioctl 3758:Parameters: struct kvm_ppc_mmuv3_cfg (in) 3759:Returns: 0 on success, 3760 -EFAULT if struct kvm_ppc_mmuv3_cfg cannot be read, 3761 -EINVAL if the configuration is invalid 3762 3763This ioctl controls whether the guest will use radix or HPT (hashed 3764page table) translation, and sets the pointer to the process table for 3765the guest. 3766 3767:: 3768 3769 struct kvm_ppc_mmuv3_cfg { 3770 __u64 flags; 3771 __u64 process_table; 3772 }; 3773 3774There are two bits that can be set in flags; KVM_PPC_MMUV3_RADIX and 3775KVM_PPC_MMUV3_GTSE. KVM_PPC_MMUV3_RADIX, if set, configures the guest 3776to use radix tree translation, and if clear, to use HPT translation. 3777KVM_PPC_MMUV3_GTSE, if set and if KVM permits it, configures the guest 3778to be able to use the global TLB and SLB invalidation instructions; 3779if clear, the guest may not use these instructions. 3780 3781The process_table field specifies the address and size of the guest 3782process table, which is in the guest's space. This field is formatted 3783as the second doubleword of the partition table entry, as defined in 3784the Power ISA V3.00, Book III section 5.7.6.1. 3785 37864.101 KVM_PPC_GET_RMMU_INFO 3787--------------------------- 3788 3789:Capability: KVM_CAP_PPC_RADIX_MMU 3790:Architectures: ppc 3791:Type: vm ioctl 3792:Parameters: struct kvm_ppc_rmmu_info (out) 3793:Returns: 0 on success, 3794 -EFAULT if struct kvm_ppc_rmmu_info cannot be written, 3795 -EINVAL if no useful information can be returned 3796 3797This ioctl returns a structure containing two things: (a) a list 3798containing supported radix tree geometries, and (b) a list that maps 3799page sizes to put in the "AP" (actual page size) field for the tlbie 3800(TLB invalidate entry) instruction. 3801 3802:: 3803 3804 struct kvm_ppc_rmmu_info { 3805 struct kvm_ppc_radix_geom { 3806 __u8 page_shift; 3807 __u8 level_bits[4]; 3808 __u8 pad[3]; 3809 } geometries[8]; 3810 __u32 ap_encodings[8]; 3811 }; 3812 3813The geometries[] field gives up to 8 supported geometries for the 3814radix page table, in terms of the log base 2 of the smallest page 3815size, and the number of bits indexed at each level of the tree, from 3816the PTE level up to the PGD level in that order. Any unused entries 3817will have 0 in the page_shift field. 3818 3819The ap_encodings gives the supported page sizes and their AP field 3820encodings, encoded with the AP value in the top 3 bits and the log 3821base 2 of the page size in the bottom 6 bits. 3822 38234.102 KVM_PPC_RESIZE_HPT_PREPARE 3824-------------------------------- 3825 3826:Capability: KVM_CAP_SPAPR_RESIZE_HPT 3827:Architectures: powerpc 3828:Type: vm ioctl 3829:Parameters: struct kvm_ppc_resize_hpt (in) 3830:Returns: 0 on successful completion, 3831 >0 if a new HPT is being prepared, the value is an estimated 3832 number of milliseconds until preparation is complete, 3833 -EFAULT if struct kvm_reinject_control cannot be read, 3834 -EINVAL if the supplied shift or flags are invalid, 3835 -ENOMEM if unable to allocate the new HPT, 3836 -ENOSPC if there was a hash collision 3837 3838:: 3839 3840 struct kvm_ppc_rmmu_info { 3841 struct kvm_ppc_radix_geom { 3842 __u8 page_shift; 3843 __u8 level_bits[4]; 3844 __u8 pad[3]; 3845 } geometries[8]; 3846 __u32 ap_encodings[8]; 3847 }; 3848 3849The geometries[] field gives up to 8 supported geometries for the 3850radix page table, in terms of the log base 2 of the smallest page 3851size, and the number of bits indexed at each level of the tree, from 3852the PTE level up to the PGD level in that order. Any unused entries 3853will have 0 in the page_shift field. 3854 3855The ap_encodings gives the supported page sizes and their AP field 3856encodings, encoded with the AP value in the top 3 bits and the log 3857base 2 of the page size in the bottom 6 bits. 3858 38594.102 KVM_PPC_RESIZE_HPT_PREPARE 3860-------------------------------- 3861 3862:Capability: KVM_CAP_SPAPR_RESIZE_HPT 3863:Architectures: powerpc 3864:Type: vm ioctl 3865:Parameters: struct kvm_ppc_resize_hpt (in) 3866:Returns: 0 on successful completion, 3867 >0 if a new HPT is being prepared, the value is an estimated 3868 number of milliseconds until preparation is complete, 3869 -EFAULT if struct kvm_reinject_control cannot be read, 3870 -EINVAL if the supplied shift or flags are invalid,when moving existing 3871 HPT entries to the new HPT, 3872 -EIO on other error conditions 3873 3874Used to implement the PAPR extension for runtime resizing of a guest's 3875Hashed Page Table (HPT). Specifically this starts, stops or monitors 3876the preparation of a new potential HPT for the guest, essentially 3877implementing the H_RESIZE_HPT_PREPARE hypercall. 3878 3879If called with shift > 0 when there is no pending HPT for the guest, 3880this begins preparation of a new pending HPT of size 2^(shift) bytes. 3881It then returns a positive integer with the estimated number of 3882milliseconds until preparation is complete. 3883 3884If called when there is a pending HPT whose size does not match that 3885requested in the parameters, discards the existing pending HPT and 3886creates a new one as above. 3887 3888If called when there is a pending HPT of the size requested, will: 3889 3890 * If preparation of the pending HPT is already complete, return 0 3891 * If preparation of the pending HPT has failed, return an error 3892 code, then discard the pending HPT. 3893 * If preparation of the pending HPT is still in progress, return an 3894 estimated number of milliseconds until preparation is complete. 3895 3896If called with shift == 0, discards any currently pending HPT and 3897returns 0 (i.e. cancels any in-progress preparation). 3898 3899flags is reserved for future expansion, currently setting any bits in 3900flags will result in an -EINVAL. 3901 3902Normally this will be called repeatedly with the same parameters until 3903it returns <= 0. The first call will initiate preparation, subsequent 3904ones will monitor preparation until it completes or fails. 3905 3906:: 3907 3908 struct kvm_ppc_resize_hpt { 3909 __u64 flags; 3910 __u32 shift; 3911 __u32 pad; 3912 }; 3913 39144.103 KVM_PPC_RESIZE_HPT_COMMIT 3915------------------------------- 3916 3917:Capability: KVM_CAP_SPAPR_RESIZE_HPT 3918:Architectures: powerpc 3919:Type: vm ioctl 3920:Parameters: struct kvm_ppc_resize_hpt (in) 3921:Returns: 0 on successful completion, 3922 -EFAULT if struct kvm_reinject_control cannot be read, 3923 -EINVAL if the supplied shift or flags are invalid, 3924 -ENXIO is there is no pending HPT, or the pending HPT doesn't 3925 have the requested size, 3926 -EBUSY if the pending HPT is not fully prepared, 3927 -ENOSPC if there was a hash collision when moving existing 3928 HPT entries to the new HPT, 3929 -EIO on other error conditions 3930 3931Used to implement the PAPR extension for runtime resizing of a guest's 3932Hashed Page Table (HPT). Specifically this requests that the guest be 3933transferred to working with the new HPT, essentially implementing the 3934H_RESIZE_HPT_COMMIT hypercall. 3935 3936This should only be called after KVM_PPC_RESIZE_HPT_PREPARE has 3937returned 0 with the same parameters. In other cases 3938KVM_PPC_RESIZE_HPT_COMMIT will return an error (usually -ENXIO or 3939-EBUSY, though others may be possible if the preparation was started, 3940but failed). 3941 3942This will have undefined effects on the guest if it has not already 3943placed itself in a quiescent state where no vcpu will make MMU enabled 3944memory accesses. 3945 3946On succsful completion, the pending HPT will become the guest's active 3947HPT and the previous HPT will be discarded. 3948 3949On failure, the guest will still be operating on its previous HPT. 3950 3951:: 3952 3953 struct kvm_ppc_resize_hpt { 3954 __u64 flags; 3955 __u32 shift; 3956 __u32 pad; 3957 }; 3958 39594.104 KVM_X86_GET_MCE_CAP_SUPPORTED 3960----------------------------------- 3961 3962:Capability: KVM_CAP_MCE 3963:Architectures: x86 3964:Type: system ioctl 3965:Parameters: u64 mce_cap (out) 3966:Returns: 0 on success, -1 on error 3967 3968Returns supported MCE capabilities. The u64 mce_cap parameter 3969has the same format as the MSR_IA32_MCG_CAP register. Supported 3970capabilities will have the corresponding bits set. 3971 39724.105 KVM_X86_SETUP_MCE 3973----------------------- 3974 3975:Capability: KVM_CAP_MCE 3976:Architectures: x86 3977:Type: vcpu ioctl 3978:Parameters: u64 mcg_cap (in) 3979:Returns: 0 on success, 3980 -EFAULT if u64 mcg_cap cannot be read, 3981 -EINVAL if the requested number of banks is invalid, 3982 -EINVAL if requested MCE capability is not supported. 3983 3984Initializes MCE support for use. The u64 mcg_cap parameter 3985has the same format as the MSR_IA32_MCG_CAP register and 3986specifies which capabilities should be enabled. The maximum 3987supported number of error-reporting banks can be retrieved when 3988checking for KVM_CAP_MCE. The supported capabilities can be 3989retrieved with KVM_X86_GET_MCE_CAP_SUPPORTED. 3990 39914.106 KVM_X86_SET_MCE 3992--------------------- 3993 3994:Capability: KVM_CAP_MCE 3995:Architectures: x86 3996:Type: vcpu ioctl 3997:Parameters: struct kvm_x86_mce (in) 3998:Returns: 0 on success, 3999 -EFAULT if struct kvm_x86_mce cannot be read, 4000 -EINVAL if the bank number is invalid, 4001 -EINVAL if VAL bit is not set in status field. 4002 4003Inject a machine check error (MCE) into the guest. The input 4004parameter is:: 4005 4006 struct kvm_x86_mce { 4007 __u64 status; 4008 __u64 addr; 4009 __u64 misc; 4010 __u64 mcg_status; 4011 __u8 bank; 4012 __u8 pad1[7]; 4013 __u64 pad2[3]; 4014 }; 4015 4016If the MCE being reported is an uncorrected error, KVM will 4017inject it as an MCE exception into the guest. If the guest 4018MCG_STATUS register reports that an MCE is in progress, KVM 4019causes an KVM_EXIT_SHUTDOWN vmexit. 4020 4021Otherwise, if the MCE is a corrected error, KVM will just 4022store it in the corresponding bank (provided this bank is 4023not holding a previously reported uncorrected error). 4024 40254.107 KVM_S390_GET_CMMA_BITS 4026---------------------------- 4027 4028:Capability: KVM_CAP_S390_CMMA_MIGRATION 4029:Architectures: s390 4030:Type: vm ioctl 4031:Parameters: struct kvm_s390_cmma_log (in, out) 4032:Returns: 0 on success, a negative value on error 4033 4034Errors: 4035 4036 ====== ============================================================= 4037 ENOMEM not enough memory can be allocated to complete the task 4038 ENXIO if CMMA is not enabled 4039 EINVAL if KVM_S390_CMMA_PEEK is not set but migration mode was not enabled 4040 EINVAL if KVM_S390_CMMA_PEEK is not set but dirty tracking has been 4041 disabled (and thus migration mode was automatically disabled) 4042 EFAULT if the userspace address is invalid or if no page table is 4043 present for the addresses (e.g. when using hugepages). 4044 ====== ============================================================= 4045 4046This ioctl is used to get the values of the CMMA bits on the s390 4047architecture. It is meant to be used in two scenarios: 4048 4049- During live migration to save the CMMA values. Live migration needs 4050 to be enabled via the KVM_REQ_START_MIGRATION VM property. 4051- To non-destructively peek at the CMMA values, with the flag 4052 KVM_S390_CMMA_PEEK set. 4053 4054The ioctl takes parameters via the kvm_s390_cmma_log struct. The desired 4055values are written to a buffer whose location is indicated via the "values" 4056member in the kvm_s390_cmma_log struct. The values in the input struct are 4057also updated as needed. 4058 4059Each CMMA value takes up one byte. 4060 4061:: 4062 4063 struct kvm_s390_cmma_log { 4064 __u64 start_gfn; 4065 __u32 count; 4066 __u32 flags; 4067 union { 4068 __u64 remaining; 4069 __u64 mask; 4070 }; 4071 __u64 values; 4072 }; 4073 4074start_gfn is the number of the first guest frame whose CMMA values are 4075to be retrieved, 4076 4077count is the length of the buffer in bytes, 4078 4079values points to the buffer where the result will be written to. 4080 4081If count is greater than KVM_S390_SKEYS_MAX, then it is considered to be 4082KVM_S390_SKEYS_MAX. KVM_S390_SKEYS_MAX is re-used for consistency with 4083other ioctls. 4084 4085The result is written in the buffer pointed to by the field values, and 4086the values of the input parameter are updated as follows. 4087 4088Depending on the flags, different actions are performed. The only 4089supported flag so far is KVM_S390_CMMA_PEEK. 4090 4091The default behaviour if KVM_S390_CMMA_PEEK is not set is: 4092start_gfn will indicate the first page frame whose CMMA bits were dirty. 4093It is not necessarily the same as the one passed as input, as clean pages 4094are skipped. 4095 4096count will indicate the number of bytes actually written in the buffer. 4097It can (and very often will) be smaller than the input value, since the 4098buffer is only filled until 16 bytes of clean values are found (which 4099are then not copied in the buffer). Since a CMMA migration block needs 4100the base address and the length, for a total of 16 bytes, we will send 4101back some clean data if there is some dirty data afterwards, as long as 4102the size of the clean data does not exceed the size of the header. This 4103allows to minimize the amount of data to be saved or transferred over 4104the network at the expense of more roundtrips to userspace. The next 4105invocation of the ioctl will skip over all the clean values, saving 4106potentially more than just the 16 bytes we found. 4107 4108If KVM_S390_CMMA_PEEK is set: 4109the existing storage attributes are read even when not in migration 4110mode, and no other action is performed; 4111 4112the output start_gfn will be equal to the input start_gfn, 4113 4114the output count will be equal to the input count, except if the end of 4115memory has been reached. 4116 4117In both cases: 4118the field "remaining" will indicate the total number of dirty CMMA values 4119still remaining, or 0 if KVM_S390_CMMA_PEEK is set and migration mode is 4120not enabled. 4121 4122mask is unused. 4123 4124values points to the userspace buffer where the result will be stored. 4125 41264.108 KVM_S390_SET_CMMA_BITS 4127---------------------------- 4128 4129:Capability: KVM_CAP_S390_CMMA_MIGRATION 4130:Architectures: s390 4131:Type: vm ioctl 4132:Parameters: struct kvm_s390_cmma_log (in) 4133:Returns: 0 on success, a negative value on error 4134 4135This ioctl is used to set the values of the CMMA bits on the s390 4136architecture. It is meant to be used during live migration to restore 4137the CMMA values, but there are no restrictions on its use. 4138The ioctl takes parameters via the kvm_s390_cmma_values struct. 4139Each CMMA value takes up one byte. 4140 4141:: 4142 4143 struct kvm_s390_cmma_log { 4144 __u64 start_gfn; 4145 __u32 count; 4146 __u32 flags; 4147 union { 4148 __u64 remaining; 4149 __u64 mask; 4150 }; 4151 __u64 values; 4152 }; 4153 4154start_gfn indicates the starting guest frame number, 4155 4156count indicates how many values are to be considered in the buffer, 4157 4158flags is not used and must be 0. 4159 4160mask indicates which PGSTE bits are to be considered. 4161 4162remaining is not used. 4163 4164values points to the buffer in userspace where to store the values. 4165 4166This ioctl can fail with -ENOMEM if not enough memory can be allocated to 4167complete the task, with -ENXIO if CMMA is not enabled, with -EINVAL if 4168the count field is too large (e.g. more than KVM_S390_CMMA_SIZE_MAX) or 4169if the flags field was not 0, with -EFAULT if the userspace address is 4170invalid, if invalid pages are written to (e.g. after the end of memory) 4171or if no page table is present for the addresses (e.g. when using 4172hugepages). 4173 41744.109 KVM_PPC_GET_CPU_CHAR 4175-------------------------- 4176 4177:Capability: KVM_CAP_PPC_GET_CPU_CHAR 4178:Architectures: powerpc 4179:Type: vm ioctl 4180:Parameters: struct kvm_ppc_cpu_char (out) 4181:Returns: 0 on successful completion, 4182 -EFAULT if struct kvm_ppc_cpu_char cannot be written 4183 4184This ioctl gives userspace information about certain characteristics 4185of the CPU relating to speculative execution of instructions and 4186possible information leakage resulting from speculative execution (see 4187CVE-2017-5715, CVE-2017-5753 and CVE-2017-5754). The information is 4188returned in struct kvm_ppc_cpu_char, which looks like this:: 4189 4190 struct kvm_ppc_cpu_char { 4191 __u64 character; /* characteristics of the CPU */ 4192 __u64 behaviour; /* recommended software behaviour */ 4193 __u64 character_mask; /* valid bits in character */ 4194 __u64 behaviour_mask; /* valid bits in behaviour */ 4195 }; 4196 4197For extensibility, the character_mask and behaviour_mask fields 4198indicate which bits of character and behaviour have been filled in by 4199the kernel. If the set of defined bits is extended in future then 4200userspace will be able to tell whether it is running on a kernel that 4201knows about the new bits. 4202 4203The character field describes attributes of the CPU which can help 4204with preventing inadvertent information disclosure - specifically, 4205whether there is an instruction to flash-invalidate the L1 data cache 4206(ori 30,30,0 or mtspr SPRN_TRIG2,rN), whether the L1 data cache is set 4207to a mode where entries can only be used by the thread that created 4208them, whether the bcctr[l] instruction prevents speculation, and 4209whether a speculation barrier instruction (ori 31,31,0) is provided. 4210 4211The behaviour field describes actions that software should take to 4212prevent inadvertent information disclosure, and thus describes which 4213vulnerabilities the hardware is subject to; specifically whether the 4214L1 data cache should be flushed when returning to user mode from the 4215kernel, and whether a speculation barrier should be placed between an 4216array bounds check and the array access. 4217 4218These fields use the same bit definitions as the new 4219H_GET_CPU_CHARACTERISTICS hypercall. 4220 42214.110 KVM_MEMORY_ENCRYPT_OP 4222--------------------------- 4223 4224:Capability: basic 4225:Architectures: x86 4226:Type: vm 4227:Parameters: an opaque platform specific structure (in/out) 4228:Returns: 0 on success; -1 on error 4229 4230If the platform supports creating encrypted VMs then this ioctl can be used 4231for issuing platform-specific memory encryption commands to manage those 4232encrypted VMs. 4233 4234Currently, this ioctl is used for issuing Secure Encrypted Virtualization 4235(SEV) commands on AMD Processors. The SEV commands are defined in 4236Documentation/virt/kvm/amd-memory-encryption.rst. 4237 42384.111 KVM_MEMORY_ENCRYPT_REG_REGION 4239----------------------------------- 4240 4241:Capability: basic 4242:Architectures: x86 4243:Type: system 4244:Parameters: struct kvm_enc_region (in) 4245:Returns: 0 on success; -1 on error 4246 4247This ioctl can be used to register a guest memory region which may 4248contain encrypted data (e.g. guest RAM, SMRAM etc). 4249 4250It is used in the SEV-enabled guest. When encryption is enabled, a guest 4251memory region may contain encrypted data. The SEV memory encryption 4252engine uses a tweak such that two identical plaintext pages, each at 4253different locations will have differing ciphertexts. So swapping or 4254moving ciphertext of those pages will not result in plaintext being 4255swapped. So relocating (or migrating) physical backing pages for the SEV 4256guest will require some additional steps. 4257 4258Note: The current SEV key management spec does not provide commands to 4259swap or migrate (move) ciphertext pages. Hence, for now we pin the guest 4260memory region registered with the ioctl. 4261 42624.112 KVM_MEMORY_ENCRYPT_UNREG_REGION 4263------------------------------------- 4264 4265:Capability: basic 4266:Architectures: x86 4267:Type: system 4268:Parameters: struct kvm_enc_region (in) 4269:Returns: 0 on success; -1 on error 4270 4271This ioctl can be used to unregister the guest memory region registered 4272with KVM_MEMORY_ENCRYPT_REG_REGION ioctl above. 4273 42744.113 KVM_HYPERV_EVENTFD 4275------------------------ 4276 4277:Capability: KVM_CAP_HYPERV_EVENTFD 4278:Architectures: x86 4279:Type: vm ioctl 4280:Parameters: struct kvm_hyperv_eventfd (in) 4281 4282This ioctl (un)registers an eventfd to receive notifications from the guest on 4283the specified Hyper-V connection id through the SIGNAL_EVENT hypercall, without 4284causing a user exit. SIGNAL_EVENT hypercall with non-zero event flag number 4285(bits 24-31) still triggers a KVM_EXIT_HYPERV_HCALL user exit. 4286 4287:: 4288 4289 struct kvm_hyperv_eventfd { 4290 __u32 conn_id; 4291 __s32 fd; 4292 __u32 flags; 4293 __u32 padding[3]; 4294 }; 4295 4296The conn_id field should fit within 24 bits:: 4297 4298 #define KVM_HYPERV_CONN_ID_MASK 0x00ffffff 4299 4300The acceptable values for the flags field are:: 4301 4302 #define KVM_HYPERV_EVENTFD_DEASSIGN (1 << 0) 4303 4304:Returns: 0 on success, 4305 -EINVAL if conn_id or flags is outside the allowed range, 4306 -ENOENT on deassign if the conn_id isn't registered, 4307 -EEXIST on assign if the conn_id is already registered 4308 43094.114 KVM_GET_NESTED_STATE 4310-------------------------- 4311 4312:Capability: KVM_CAP_NESTED_STATE 4313:Architectures: x86 4314:Type: vcpu ioctl 4315:Parameters: struct kvm_nested_state (in/out) 4316:Returns: 0 on success, -1 on error 4317 4318Errors: 4319 4320 ===== ============================================================= 4321 E2BIG the total state size exceeds the value of 'size' specified by 4322 the user; the size required will be written into size. 4323 ===== ============================================================= 4324 4325:: 4326 4327 struct kvm_nested_state { 4328 __u16 flags; 4329 __u16 format; 4330 __u32 size; 4331 4332 union { 4333 struct kvm_vmx_nested_state_hdr vmx; 4334 struct kvm_svm_nested_state_hdr svm; 4335 4336 /* Pad the header to 128 bytes. */ 4337 __u8 pad[120]; 4338 } hdr; 4339 4340 union { 4341 struct kvm_vmx_nested_state_data vmx[0]; 4342 struct kvm_svm_nested_state_data svm[0]; 4343 } data; 4344 }; 4345 4346 #define KVM_STATE_NESTED_GUEST_MODE 0x00000001 4347 #define KVM_STATE_NESTED_RUN_PENDING 0x00000002 4348 #define KVM_STATE_NESTED_EVMCS 0x00000004 4349 4350 #define KVM_STATE_NESTED_FORMAT_VMX 0 4351 #define KVM_STATE_NESTED_FORMAT_SVM 1 4352 4353 #define KVM_STATE_NESTED_VMX_VMCS_SIZE 0x1000 4354 4355 #define KVM_STATE_NESTED_VMX_SMM_GUEST_MODE 0x00000001 4356 #define KVM_STATE_NESTED_VMX_SMM_VMXON 0x00000002 4357 4358 #define KVM_STATE_VMX_PREEMPTION_TIMER_DEADLINE 0x00000001 4359 4360 struct kvm_vmx_nested_state_hdr { 4361 __u64 vmxon_pa; 4362 __u64 vmcs12_pa; 4363 4364 struct { 4365 __u16 flags; 4366 } smm; 4367 4368 __u32 flags; 4369 __u64 preemption_timer_deadline; 4370 }; 4371 4372 struct kvm_vmx_nested_state_data { 4373 __u8 vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; 4374 __u8 shadow_vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; 4375 }; 4376 4377This ioctl copies the vcpu's nested virtualization state from the kernel to 4378userspace. 4379 4380The maximum size of the state can be retrieved by passing KVM_CAP_NESTED_STATE 4381to the KVM_CHECK_EXTENSION ioctl(). 4382 43834.115 KVM_SET_NESTED_STATE 4384-------------------------- 4385 4386:Capability: KVM_CAP_NESTED_STATE 4387:Architectures: x86 4388:Type: vcpu ioctl 4389:Parameters: struct kvm_nested_state (in) 4390:Returns: 0 on success, -1 on error 4391 4392This copies the vcpu's kvm_nested_state struct from userspace to the kernel. 4393For the definition of struct kvm_nested_state, see KVM_GET_NESTED_STATE. 4394 43954.116 KVM_(UN)REGISTER_COALESCED_MMIO 4396------------------------------------- 4397 4398:Capability: KVM_CAP_COALESCED_MMIO (for coalesced mmio) 4399 KVM_CAP_COALESCED_PIO (for coalesced pio) 4400:Architectures: all 4401:Type: vm ioctl 4402:Parameters: struct kvm_coalesced_mmio_zone 4403:Returns: 0 on success, < 0 on error 4404 4405Coalesced I/O is a performance optimization that defers hardware 4406register write emulation so that userspace exits are avoided. It is 4407typically used to reduce the overhead of emulating frequently accessed 4408hardware registers. 4409 4410When a hardware register is configured for coalesced I/O, write accesses 4411do not exit to userspace and their value is recorded in a ring buffer 4412that is shared between kernel and userspace. 4413 4414Coalesced I/O is used if one or more write accesses to a hardware 4415register can be deferred until a read or a write to another hardware 4416register on the same device. This last access will cause a vmexit and 4417userspace will process accesses from the ring buffer before emulating 4418it. That will avoid exiting to userspace on repeated writes. 4419 4420Coalesced pio is based on coalesced mmio. There is little difference 4421between coalesced mmio and pio except that coalesced pio records accesses 4422to I/O ports. 4423 44244.117 KVM_CLEAR_DIRTY_LOG (vm ioctl) 4425------------------------------------ 4426 4427:Capability: KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 4428:Architectures: x86, arm, arm64, mips 4429:Type: vm ioctl 4430:Parameters: struct kvm_dirty_log (in) 4431:Returns: 0 on success, -1 on error 4432 4433:: 4434 4435 /* for KVM_CLEAR_DIRTY_LOG */ 4436 struct kvm_clear_dirty_log { 4437 __u32 slot; 4438 __u32 num_pages; 4439 __u64 first_page; 4440 union { 4441 void __user *dirty_bitmap; /* one bit per page */ 4442 __u64 padding; 4443 }; 4444 }; 4445 4446The ioctl clears the dirty status of pages in a memory slot, according to 4447the bitmap that is passed in struct kvm_clear_dirty_log's dirty_bitmap 4448field. Bit 0 of the bitmap corresponds to page "first_page" in the 4449memory slot, and num_pages is the size in bits of the input bitmap. 4450first_page must be a multiple of 64; num_pages must also be a multiple of 445164 unless first_page + num_pages is the size of the memory slot. For each 4452bit that is set in the input bitmap, the corresponding page is marked "clean" 4453in KVM's dirty bitmap, and dirty tracking is re-enabled for that page 4454(for example via write-protection, or by clearing the dirty bit in 4455a page table entry). 4456 4457If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 specifies 4458the address space for which you want to return the dirty bitmap. 4459They must be less than the value that KVM_CHECK_EXTENSION returns for 4460the KVM_CAP_MULTI_ADDRESS_SPACE capability. 4461 4462This ioctl is mostly useful when KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 4463is enabled; for more information, see the description of the capability. 4464However, it can always be used as long as KVM_CHECK_EXTENSION confirms 4465that KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 is present. 4466 44674.118 KVM_GET_SUPPORTED_HV_CPUID 4468-------------------------------- 4469 4470:Capability: KVM_CAP_HYPERV_CPUID 4471:Architectures: x86 4472:Type: vcpu ioctl 4473:Parameters: struct kvm_cpuid2 (in/out) 4474:Returns: 0 on success, -1 on error 4475 4476:: 4477 4478 struct kvm_cpuid2 { 4479 __u32 nent; 4480 __u32 padding; 4481 struct kvm_cpuid_entry2 entries[0]; 4482 }; 4483 4484 struct kvm_cpuid_entry2 { 4485 __u32 function; 4486 __u32 index; 4487 __u32 flags; 4488 __u32 eax; 4489 __u32 ebx; 4490 __u32 ecx; 4491 __u32 edx; 4492 __u32 padding[3]; 4493 }; 4494 4495This ioctl returns x86 cpuid features leaves related to Hyper-V emulation in 4496KVM. Userspace can use the information returned by this ioctl to construct 4497cpuid information presented to guests consuming Hyper-V enlightenments (e.g. 4498Windows or Hyper-V guests). 4499 4500CPUID feature leaves returned by this ioctl are defined by Hyper-V Top Level 4501Functional Specification (TLFS). These leaves can't be obtained with 4502KVM_GET_SUPPORTED_CPUID ioctl because some of them intersect with KVM feature 4503leaves (0x40000000, 0x40000001). 4504 4505Currently, the following list of CPUID leaves are returned: 4506 - HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS 4507 - HYPERV_CPUID_INTERFACE 4508 - HYPERV_CPUID_VERSION 4509 - HYPERV_CPUID_FEATURES 4510 - HYPERV_CPUID_ENLIGHTMENT_INFO 4511 - HYPERV_CPUID_IMPLEMENT_LIMITS 4512 - HYPERV_CPUID_NESTED_FEATURES 4513 - HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS 4514 - HYPERV_CPUID_SYNDBG_INTERFACE 4515 - HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES 4516 4517HYPERV_CPUID_NESTED_FEATURES leaf is only exposed when Enlightened VMCS was 4518enabled on the corresponding vCPU (KVM_CAP_HYPERV_ENLIGHTENED_VMCS). 4519 4520Userspace invokes KVM_GET_SUPPORTED_HV_CPUID by passing a kvm_cpuid2 structure 4521with the 'nent' field indicating the number of entries in the variable-size 4522array 'entries'. If the number of entries is too low to describe all Hyper-V 4523feature leaves, an error (E2BIG) is returned. If the number is more or equal 4524to the number of Hyper-V feature leaves, the 'nent' field is adjusted to the 4525number of valid entries in the 'entries' array, which is then filled. 4526 4527'index' and 'flags' fields in 'struct kvm_cpuid_entry2' are currently reserved, 4528userspace should not expect to get any particular value there. 4529 45304.119 KVM_ARM_VCPU_FINALIZE 4531--------------------------- 4532 4533:Architectures: arm, arm64 4534:Type: vcpu ioctl 4535:Parameters: int feature (in) 4536:Returns: 0 on success, -1 on error 4537 4538Errors: 4539 4540 ====== ============================================================== 4541 EPERM feature not enabled, needs configuration, or already finalized 4542 EINVAL feature unknown or not present 4543 ====== ============================================================== 4544 4545Recognised values for feature: 4546 4547 ===== =========================================== 4548 arm64 KVM_ARM_VCPU_SVE (requires KVM_CAP_ARM_SVE) 4549 ===== =========================================== 4550 4551Finalizes the configuration of the specified vcpu feature. 4552 4553The vcpu must already have been initialised, enabling the affected feature, by 4554means of a successful KVM_ARM_VCPU_INIT call with the appropriate flag set in 4555features[]. 4556 4557For affected vcpu features, this is a mandatory step that must be performed 4558before the vcpu is fully usable. 4559 4560Between KVM_ARM_VCPU_INIT and KVM_ARM_VCPU_FINALIZE, the feature may be 4561configured by use of ioctls such as KVM_SET_ONE_REG. The exact configuration 4562that should be performaned and how to do it are feature-dependent. 4563 4564Other calls that depend on a particular feature being finalized, such as 4565KVM_RUN, KVM_GET_REG_LIST, KVM_GET_ONE_REG and KVM_SET_ONE_REG, will fail with 4566-EPERM unless the feature has already been finalized by means of a 4567KVM_ARM_VCPU_FINALIZE call. 4568 4569See KVM_ARM_VCPU_INIT for details of vcpu features that require finalization 4570using this ioctl. 4571 45724.120 KVM_SET_PMU_EVENT_FILTER 4573------------------------------ 4574 4575:Capability: KVM_CAP_PMU_EVENT_FILTER 4576:Architectures: x86 4577:Type: vm ioctl 4578:Parameters: struct kvm_pmu_event_filter (in) 4579:Returns: 0 on success, -1 on error 4580 4581:: 4582 4583 struct kvm_pmu_event_filter { 4584 __u32 action; 4585 __u32 nevents; 4586 __u32 fixed_counter_bitmap; 4587 __u32 flags; 4588 __u32 pad[4]; 4589 __u64 events[0]; 4590 }; 4591 4592This ioctl restricts the set of PMU events that the guest can program. 4593The argument holds a list of events which will be allowed or denied. 4594The eventsel+umask of each event the guest attempts to program is compared 4595against the events field to determine whether the guest should have access. 4596The events field only controls general purpose counters; fixed purpose 4597counters are controlled by the fixed_counter_bitmap. 4598 4599No flags are defined yet, the field must be zero. 4600 4601Valid values for 'action':: 4602 4603 #define KVM_PMU_EVENT_ALLOW 0 4604 #define KVM_PMU_EVENT_DENY 1 4605 46064.121 KVM_PPC_SVM_OFF 4607--------------------- 4608 4609:Capability: basic 4610:Architectures: powerpc 4611:Type: vm ioctl 4612:Parameters: none 4613:Returns: 0 on successful completion, 4614 4615Errors: 4616 4617 ====== ================================================================ 4618 EINVAL if ultravisor failed to terminate the secure guest 4619 ENOMEM if hypervisor failed to allocate new radix page tables for guest 4620 ====== ================================================================ 4621 4622This ioctl is used to turn off the secure mode of the guest or transition 4623the guest from secure mode to normal mode. This is invoked when the guest 4624is reset. This has no effect if called for a normal guest. 4625 4626This ioctl issues an ultravisor call to terminate the secure guest, 4627unpins the VPA pages and releases all the device pages that are used to 4628track the secure pages by hypervisor. 4629 46304.122 KVM_S390_NORMAL_RESET 4631--------------------------- 4632 4633:Capability: KVM_CAP_S390_VCPU_RESETS 4634:Architectures: s390 4635:Type: vcpu ioctl 4636:Parameters: none 4637:Returns: 0 4638 4639This ioctl resets VCPU registers and control structures according to 4640the cpu reset definition in the POP (Principles Of Operation). 4641 46424.123 KVM_S390_INITIAL_RESET 4643---------------------------- 4644 4645:Capability: none 4646:Architectures: s390 4647:Type: vcpu ioctl 4648:Parameters: none 4649:Returns: 0 4650 4651This ioctl resets VCPU registers and control structures according to 4652the initial cpu reset definition in the POP. However, the cpu is not 4653put into ESA mode. This reset is a superset of the normal reset. 4654 46554.124 KVM_S390_CLEAR_RESET 4656-------------------------- 4657 4658:Capability: KVM_CAP_S390_VCPU_RESETS 4659:Architectures: s390 4660:Type: vcpu ioctl 4661:Parameters: none 4662:Returns: 0 4663 4664This ioctl resets VCPU registers and control structures according to 4665the clear cpu reset definition in the POP. However, the cpu is not put 4666into ESA mode. This reset is a superset of the initial reset. 4667 4668 46694.125 KVM_S390_PV_COMMAND 4670------------------------- 4671 4672:Capability: KVM_CAP_S390_PROTECTED 4673:Architectures: s390 4674:Type: vm ioctl 4675:Parameters: struct kvm_pv_cmd 4676:Returns: 0 on success, < 0 on error 4677 4678:: 4679 4680 struct kvm_pv_cmd { 4681 __u32 cmd; /* Command to be executed */ 4682 __u16 rc; /* Ultravisor return code */ 4683 __u16 rrc; /* Ultravisor return reason code */ 4684 __u64 data; /* Data or address */ 4685 __u32 flags; /* flags for future extensions. Must be 0 for now */ 4686 __u32 reserved[3]; 4687 }; 4688 4689cmd values: 4690 4691KVM_PV_ENABLE 4692 Allocate memory and register the VM with the Ultravisor, thereby 4693 donating memory to the Ultravisor that will become inaccessible to 4694 KVM. All existing CPUs are converted to protected ones. After this 4695 command has succeeded, any CPU added via hotplug will become 4696 protected during its creation as well. 4697 4698 Errors: 4699 4700 ===== ============================= 4701 EINTR an unmasked signal is pending 4702 ===== ============================= 4703 4704KVM_PV_DISABLE 4705 4706 Deregister the VM from the Ultravisor and reclaim the memory that 4707 had been donated to the Ultravisor, making it usable by the kernel 4708 again. All registered VCPUs are converted back to non-protected 4709 ones. 4710 4711KVM_PV_VM_SET_SEC_PARMS 4712 Pass the image header from VM memory to the Ultravisor in 4713 preparation of image unpacking and verification. 4714 4715KVM_PV_VM_UNPACK 4716 Unpack (protect and decrypt) a page of the encrypted boot image. 4717 4718KVM_PV_VM_VERIFY 4719 Verify the integrity of the unpacked image. Only if this succeeds, 4720 KVM is allowed to start protected VCPUs. 4721 47224.126 KVM_X86_SET_MSR_FILTER 4723---------------------------- 4724 4725:Capability: KVM_X86_SET_MSR_FILTER 4726:Architectures: x86 4727:Type: vm ioctl 4728:Parameters: struct kvm_msr_filter 4729:Returns: 0 on success, < 0 on error 4730 4731:: 4732 4733 struct kvm_msr_filter_range { 4734 #define KVM_MSR_FILTER_READ (1 << 0) 4735 #define KVM_MSR_FILTER_WRITE (1 << 1) 4736 __u32 flags; 4737 __u32 nmsrs; /* number of msrs in bitmap */ 4738 __u32 base; /* MSR index the bitmap starts at */ 4739 __u8 *bitmap; /* a 1 bit allows the operations in flags, 0 denies */ 4740 }; 4741 4742 #define KVM_MSR_FILTER_MAX_RANGES 16 4743 struct kvm_msr_filter { 4744 #define KVM_MSR_FILTER_DEFAULT_ALLOW (0 << 0) 4745 #define KVM_MSR_FILTER_DEFAULT_DENY (1 << 0) 4746 __u32 flags; 4747 struct kvm_msr_filter_range ranges[KVM_MSR_FILTER_MAX_RANGES]; 4748 }; 4749 4750flags values for ``struct kvm_msr_filter_range``: 4751 4752``KVM_MSR_FILTER_READ`` 4753 4754 Filter read accesses to MSRs using the given bitmap. A 0 in the bitmap 4755 indicates that a read should immediately fail, while a 1 indicates that 4756 a read for a particular MSR should be handled regardless of the default 4757 filter action. 4758 4759``KVM_MSR_FILTER_WRITE`` 4760 4761 Filter write accesses to MSRs using the given bitmap. A 0 in the bitmap 4762 indicates that a write should immediately fail, while a 1 indicates that 4763 a write for a particular MSR should be handled regardless of the default 4764 filter action. 4765 4766``KVM_MSR_FILTER_READ | KVM_MSR_FILTER_WRITE`` 4767 4768 Filter both read and write accesses to MSRs using the given bitmap. A 0 4769 in the bitmap indicates that both reads and writes should immediately fail, 4770 while a 1 indicates that reads and writes for a particular MSR are not 4771 filtered by this range. 4772 4773flags values for ``struct kvm_msr_filter``: 4774 4775``KVM_MSR_FILTER_DEFAULT_ALLOW`` 4776 4777 If no filter range matches an MSR index that is getting accessed, KVM will 4778 fall back to allowing access to the MSR. 4779 4780``KVM_MSR_FILTER_DEFAULT_DENY`` 4781 4782 If no filter range matches an MSR index that is getting accessed, KVM will 4783 fall back to rejecting access to the MSR. In this mode, all MSRs that should 4784 be processed by KVM need to explicitly be marked as allowed in the bitmaps. 4785 4786This ioctl allows user space to define up to 16 bitmaps of MSR ranges to 4787specify whether a certain MSR access should be explicitly filtered for or not. 4788 4789If this ioctl has never been invoked, MSR accesses are not guarded and the 4790default KVM in-kernel emulation behavior is fully preserved. 4791 4792Calling this ioctl with an empty set of ranges (all nmsrs == 0) disables MSR 4793filtering. In that mode, ``KVM_MSR_FILTER_DEFAULT_DENY`` is invalid and causes 4794an error. 4795 4796As soon as the filtering is in place, every MSR access is processed through 4797the filtering except for accesses to the x2APIC MSRs (from 0x800 to 0x8ff); 4798x2APIC MSRs are always allowed, independent of the ``default_allow`` setting, 4799and their behavior depends on the ``X2APIC_ENABLE`` bit of the APIC base 4800register. 4801 4802If a bit is within one of the defined ranges, read and write accesses are 4803guarded by the bitmap's value for the MSR index if the kind of access 4804is included in the ``struct kvm_msr_filter_range`` flags. If no range 4805cover this particular access, the behavior is determined by the flags 4806field in the kvm_msr_filter struct: ``KVM_MSR_FILTER_DEFAULT_ALLOW`` 4807and ``KVM_MSR_FILTER_DEFAULT_DENY``. 4808 4809Each bitmap range specifies a range of MSRs to potentially allow access on. 4810The range goes from MSR index [base .. base+nmsrs]. The flags field 4811indicates whether reads, writes or both reads and writes are filtered 4812by setting a 1 bit in the bitmap for the corresponding MSR index. 4813 4814If an MSR access is not permitted through the filtering, it generates a 4815#GP inside the guest. When combined with KVM_CAP_X86_USER_SPACE_MSR, that 4816allows user space to deflect and potentially handle various MSR accesses 4817into user space. 4818 4819Note, invoking this ioctl with a vCPU is running is inherently racy. However, 4820KVM does guarantee that vCPUs will see either the previous filter or the new 4821filter, e.g. MSRs with identical settings in both the old and new filter will 4822have deterministic behavior. 4823 4824 48255. The kvm_run structure 4826======================== 4827 4828Application code obtains a pointer to the kvm_run structure by 4829mmap()ing a vcpu fd. From that point, application code can control 4830execution by changing fields in kvm_run prior to calling the KVM_RUN 4831ioctl, and obtain information about the reason KVM_RUN returned by 4832looking up structure members. 4833 4834:: 4835 4836 struct kvm_run { 4837 /* in */ 4838 __u8 request_interrupt_window; 4839 4840Request that KVM_RUN return when it becomes possible to inject external 4841interrupts into the guest. Useful in conjunction with KVM_INTERRUPT. 4842 4843:: 4844 4845 __u8 immediate_exit; 4846 4847This field is polled once when KVM_RUN starts; if non-zero, KVM_RUN 4848exits immediately, returning -EINTR. In the common scenario where a 4849signal is used to "kick" a VCPU out of KVM_RUN, this field can be used 4850to avoid usage of KVM_SET_SIGNAL_MASK, which has worse scalability. 4851Rather than blocking the signal outside KVM_RUN, userspace can set up 4852a signal handler that sets run->immediate_exit to a non-zero value. 4853 4854This field is ignored if KVM_CAP_IMMEDIATE_EXIT is not available. 4855 4856:: 4857 4858 __u8 padding1[6]; 4859 4860 /* out */ 4861 __u32 exit_reason; 4862 4863When KVM_RUN has returned successfully (return value 0), this informs 4864application code why KVM_RUN has returned. Allowable values for this 4865field are detailed below. 4866 4867:: 4868 4869 __u8 ready_for_interrupt_injection; 4870 4871If request_interrupt_window has been specified, this field indicates 4872an interrupt can be injected now with KVM_INTERRUPT. 4873 4874:: 4875 4876 __u8 if_flag; 4877 4878The value of the current interrupt flag. Only valid if in-kernel 4879local APIC is not used. 4880 4881:: 4882 4883 __u16 flags; 4884 4885More architecture-specific flags detailing state of the VCPU that may 4886affect the device's behavior. The only currently defined flag is 4887KVM_RUN_X86_SMM, which is valid on x86 machines and is set if the 4888VCPU is in system management mode. 4889 4890:: 4891 4892 /* in (pre_kvm_run), out (post_kvm_run) */ 4893 __u64 cr8; 4894 4895The value of the cr8 register. Only valid if in-kernel local APIC is 4896not used. Both input and output. 4897 4898:: 4899 4900 __u64 apic_base; 4901 4902The value of the APIC BASE msr. Only valid if in-kernel local 4903APIC is not used. Both input and output. 4904 4905:: 4906 4907 union { 4908 /* KVM_EXIT_UNKNOWN */ 4909 struct { 4910 __u64 hardware_exit_reason; 4911 } hw; 4912 4913If exit_reason is KVM_EXIT_UNKNOWN, the vcpu has exited due to unknown 4914reasons. Further architecture-specific information is available in 4915hardware_exit_reason. 4916 4917:: 4918 4919 /* KVM_EXIT_FAIL_ENTRY */ 4920 struct { 4921 __u64 hardware_entry_failure_reason; 4922 __u32 cpu; /* if KVM_LAST_CPU */ 4923 } fail_entry; 4924 4925If exit_reason is KVM_EXIT_FAIL_ENTRY, the vcpu could not be run due 4926to unknown reasons. Further architecture-specific information is 4927available in hardware_entry_failure_reason. 4928 4929:: 4930 4931 /* KVM_EXIT_EXCEPTION */ 4932 struct { 4933 __u32 exception; 4934 __u32 error_code; 4935 } ex; 4936 4937Unused. 4938 4939:: 4940 4941 /* KVM_EXIT_IO */ 4942 struct { 4943 #define KVM_EXIT_IO_IN 0 4944 #define KVM_EXIT_IO_OUT 1 4945 __u8 direction; 4946 __u8 size; /* bytes */ 4947 __u16 port; 4948 __u32 count; 4949 __u64 data_offset; /* relative to kvm_run start */ 4950 } io; 4951 4952If exit_reason is KVM_EXIT_IO, then the vcpu has 4953executed a port I/O instruction which could not be satisfied by kvm. 4954data_offset describes where the data is located (KVM_EXIT_IO_OUT) or 4955where kvm expects application code to place the data for the next 4956KVM_RUN invocation (KVM_EXIT_IO_IN). Data format is a packed array. 4957 4958:: 4959 4960 /* KVM_EXIT_DEBUG */ 4961 struct { 4962 struct kvm_debug_exit_arch arch; 4963 } debug; 4964 4965If the exit_reason is KVM_EXIT_DEBUG, then a vcpu is processing a debug event 4966for which architecture specific information is returned. 4967 4968:: 4969 4970 /* KVM_EXIT_MMIO */ 4971 struct { 4972 __u64 phys_addr; 4973 __u8 data[8]; 4974 __u32 len; 4975 __u8 is_write; 4976 } mmio; 4977 4978If exit_reason is KVM_EXIT_MMIO, then the vcpu has 4979executed a memory-mapped I/O instruction which could not be satisfied 4980by kvm. The 'data' member contains the written data if 'is_write' is 4981true, and should be filled by application code otherwise. 4982 4983The 'data' member contains, in its first 'len' bytes, the value as it would 4984appear if the VCPU performed a load or store of the appropriate width directly 4985to the byte array. 4986 4987.. note:: 4988 4989 For KVM_EXIT_IO, KVM_EXIT_MMIO, KVM_EXIT_OSI, KVM_EXIT_PAPR, 4990 KVM_EXIT_EPR, KVM_EXIT_X86_RDMSR and KVM_EXIT_X86_WRMSR the corresponding 4991 operations are complete (and guest state is consistent) only after userspace 4992 has re-entered the kernel with KVM_RUN. The kernel side will first finish 4993 incomplete operations and then check for pending signals. Userspace 4994 can re-enter the guest with an unmasked signal pending to complete 4995 pending operations. 4996 4997:: 4998 4999 /* KVM_EXIT_HYPERCALL */ 5000 struct { 5001 __u64 nr; 5002 __u64 args[6]; 5003 __u64 ret; 5004 __u32 longmode; 5005 __u32 pad; 5006 } hypercall; 5007 5008Unused. This was once used for 'hypercall to userspace'. To implement 5009such functionality, use KVM_EXIT_IO (x86) or KVM_EXIT_MMIO (all except s390). 5010 5011.. note:: KVM_EXIT_IO is significantly faster than KVM_EXIT_MMIO. 5012 5013:: 5014 5015 /* KVM_EXIT_TPR_ACCESS */ 5016 struct { 5017 __u64 rip; 5018 __u32 is_write; 5019 __u32 pad; 5020 } tpr_access; 5021 5022To be documented (KVM_TPR_ACCESS_REPORTING). 5023 5024:: 5025 5026 /* KVM_EXIT_S390_SIEIC */ 5027 struct { 5028 __u8 icptcode; 5029 __u64 mask; /* psw upper half */ 5030 __u64 addr; /* psw lower half */ 5031 __u16 ipa; 5032 __u32 ipb; 5033 } s390_sieic; 5034 5035s390 specific. 5036 5037:: 5038 5039 /* KVM_EXIT_S390_RESET */ 5040 #define KVM_S390_RESET_POR 1 5041 #define KVM_S390_RESET_CLEAR 2 5042 #define KVM_S390_RESET_SUBSYSTEM 4 5043 #define KVM_S390_RESET_CPU_INIT 8 5044 #define KVM_S390_RESET_IPL 16 5045 __u64 s390_reset_flags; 5046 5047s390 specific. 5048 5049:: 5050 5051 /* KVM_EXIT_S390_UCONTROL */ 5052 struct { 5053 __u64 trans_exc_code; 5054 __u32 pgm_code; 5055 } s390_ucontrol; 5056 5057s390 specific. A page fault has occurred for a user controlled virtual 5058machine (KVM_VM_S390_UNCONTROL) on it's host page table that cannot be 5059resolved by the kernel. 5060The program code and the translation exception code that were placed 5061in the cpu's lowcore are presented here as defined by the z Architecture 5062Principles of Operation Book in the Chapter for Dynamic Address Translation 5063(DAT) 5064 5065:: 5066 5067 /* KVM_EXIT_DCR */ 5068 struct { 5069 __u32 dcrn; 5070 __u32 data; 5071 __u8 is_write; 5072 } dcr; 5073 5074Deprecated - was used for 440 KVM. 5075 5076:: 5077 5078 /* KVM_EXIT_OSI */ 5079 struct { 5080 __u64 gprs[32]; 5081 } osi; 5082 5083MOL uses a special hypercall interface it calls 'OSI'. To enable it, we catch 5084hypercalls and exit with this exit struct that contains all the guest gprs. 5085 5086If exit_reason is KVM_EXIT_OSI, then the vcpu has triggered such a hypercall. 5087Userspace can now handle the hypercall and when it's done modify the gprs as 5088necessary. Upon guest entry all guest GPRs will then be replaced by the values 5089in this struct. 5090 5091:: 5092 5093 /* KVM_EXIT_PAPR_HCALL */ 5094 struct { 5095 __u64 nr; 5096 __u64 ret; 5097 __u64 args[9]; 5098 } papr_hcall; 5099 5100This is used on 64-bit PowerPC when emulating a pSeries partition, 5101e.g. with the 'pseries' machine type in qemu. It occurs when the 5102guest does a hypercall using the 'sc 1' instruction. The 'nr' field 5103contains the hypercall number (from the guest R3), and 'args' contains 5104the arguments (from the guest R4 - R12). Userspace should put the 5105return code in 'ret' and any extra returned values in args[]. 5106The possible hypercalls are defined in the Power Architecture Platform 5107Requirements (PAPR) document available from www.power.org (free 5108developer registration required to access it). 5109 5110:: 5111 5112 /* KVM_EXIT_S390_TSCH */ 5113 struct { 5114 __u16 subchannel_id; 5115 __u16 subchannel_nr; 5116 __u32 io_int_parm; 5117 __u32 io_int_word; 5118 __u32 ipb; 5119 __u8 dequeued; 5120 } s390_tsch; 5121 5122s390 specific. This exit occurs when KVM_CAP_S390_CSS_SUPPORT has been enabled 5123and TEST SUBCHANNEL was intercepted. If dequeued is set, a pending I/O 5124interrupt for the target subchannel has been dequeued and subchannel_id, 5125subchannel_nr, io_int_parm and io_int_word contain the parameters for that 5126interrupt. ipb is needed for instruction parameter decoding. 5127 5128:: 5129 5130 /* KVM_EXIT_EPR */ 5131 struct { 5132 __u32 epr; 5133 } epr; 5134 5135On FSL BookE PowerPC chips, the interrupt controller has a fast patch 5136interrupt acknowledge path to the core. When the core successfully 5137delivers an interrupt, it automatically populates the EPR register with 5138the interrupt vector number and acknowledges the interrupt inside 5139the interrupt controller. 5140 5141In case the interrupt controller lives in user space, we need to do 5142the interrupt acknowledge cycle through it to fetch the next to be 5143delivered interrupt vector using this exit. 5144 5145It gets triggered whenever both KVM_CAP_PPC_EPR are enabled and an 5146external interrupt has just been delivered into the guest. User space 5147should put the acknowledged interrupt vector into the 'epr' field. 5148 5149:: 5150 5151 /* KVM_EXIT_SYSTEM_EVENT */ 5152 struct { 5153 #define KVM_SYSTEM_EVENT_SHUTDOWN 1 5154 #define KVM_SYSTEM_EVENT_RESET 2 5155 #define KVM_SYSTEM_EVENT_CRASH 3 5156 __u32 type; 5157 __u64 flags; 5158 } system_event; 5159 5160If exit_reason is KVM_EXIT_SYSTEM_EVENT then the vcpu has triggered 5161a system-level event using some architecture specific mechanism (hypercall 5162or some special instruction). In case of ARM/ARM64, this is triggered using 5163HVC instruction based PSCI call from the vcpu. The 'type' field describes 5164the system-level event type. The 'flags' field describes architecture 5165specific flags for the system-level event. 5166 5167Valid values for 'type' are: 5168 5169 - KVM_SYSTEM_EVENT_SHUTDOWN -- the guest has requested a shutdown of the 5170 VM. Userspace is not obliged to honour this, and if it does honour 5171 this does not need to destroy the VM synchronously (ie it may call 5172 KVM_RUN again before shutdown finally occurs). 5173 - KVM_SYSTEM_EVENT_RESET -- the guest has requested a reset of the VM. 5174 As with SHUTDOWN, userspace can choose to ignore the request, or 5175 to schedule the reset to occur in the future and may call KVM_RUN again. 5176 - KVM_SYSTEM_EVENT_CRASH -- the guest crash occurred and the guest 5177 has requested a crash condition maintenance. Userspace can choose 5178 to ignore the request, or to gather VM memory core dump and/or 5179 reset/shutdown of the VM. 5180 5181:: 5182 5183 /* KVM_EXIT_IOAPIC_EOI */ 5184 struct { 5185 __u8 vector; 5186 } eoi; 5187 5188Indicates that the VCPU's in-kernel local APIC received an EOI for a 5189level-triggered IOAPIC interrupt. This exit only triggers when the 5190IOAPIC is implemented in userspace (i.e. KVM_CAP_SPLIT_IRQCHIP is enabled); 5191the userspace IOAPIC should process the EOI and retrigger the interrupt if 5192it is still asserted. Vector is the LAPIC interrupt vector for which the 5193EOI was received. 5194 5195:: 5196 5197 struct kvm_hyperv_exit { 5198 #define KVM_EXIT_HYPERV_SYNIC 1 5199 #define KVM_EXIT_HYPERV_HCALL 2 5200 #define KVM_EXIT_HYPERV_SYNDBG 3 5201 __u32 type; 5202 __u32 pad1; 5203 union { 5204 struct { 5205 __u32 msr; 5206 __u32 pad2; 5207 __u64 control; 5208 __u64 evt_page; 5209 __u64 msg_page; 5210 } synic; 5211 struct { 5212 __u64 input; 5213 __u64 result; 5214 __u64 params[2]; 5215 } hcall; 5216 struct { 5217 __u32 msr; 5218 __u32 pad2; 5219 __u64 control; 5220 __u64 status; 5221 __u64 send_page; 5222 __u64 recv_page; 5223 __u64 pending_page; 5224 } syndbg; 5225 } u; 5226 }; 5227 /* KVM_EXIT_HYPERV */ 5228 struct kvm_hyperv_exit hyperv; 5229 5230Indicates that the VCPU exits into userspace to process some tasks 5231related to Hyper-V emulation. 5232 5233Valid values for 'type' are: 5234 5235 - KVM_EXIT_HYPERV_SYNIC -- synchronously notify user-space about 5236 5237Hyper-V SynIC state change. Notification is used to remap SynIC 5238event/message pages and to enable/disable SynIC messages/events processing 5239in userspace. 5240 5241 - KVM_EXIT_HYPERV_SYNDBG -- synchronously notify user-space about 5242 5243Hyper-V Synthetic debugger state change. Notification is used to either update 5244the pending_page location or to send a control command (send the buffer located 5245in send_page or recv a buffer to recv_page). 5246 5247:: 5248 5249 /* KVM_EXIT_ARM_NISV */ 5250 struct { 5251 __u64 esr_iss; 5252 __u64 fault_ipa; 5253 } arm_nisv; 5254 5255Used on arm and arm64 systems. If a guest accesses memory not in a memslot, 5256KVM will typically return to userspace and ask it to do MMIO emulation on its 5257behalf. However, for certain classes of instructions, no instruction decode 5258(direction, length of memory access) is provided, and fetching and decoding 5259the instruction from the VM is overly complicated to live in the kernel. 5260 5261Historically, when this situation occurred, KVM would print a warning and kill 5262the VM. KVM assumed that if the guest accessed non-memslot memory, it was 5263trying to do I/O, which just couldn't be emulated, and the warning message was 5264phrased accordingly. However, what happened more often was that a guest bug 5265caused access outside the guest memory areas which should lead to a more 5266meaningful warning message and an external abort in the guest, if the access 5267did not fall within an I/O window. 5268 5269Userspace implementations can query for KVM_CAP_ARM_NISV_TO_USER, and enable 5270this capability at VM creation. Once this is done, these types of errors will 5271instead return to userspace with KVM_EXIT_ARM_NISV, with the valid bits from 5272the HSR (arm) and ESR_EL2 (arm64) in the esr_iss field, and the faulting IPA 5273in the fault_ipa field. Userspace can either fix up the access if it's 5274actually an I/O access by decoding the instruction from guest memory (if it's 5275very brave) and continue executing the guest, or it can decide to suspend, 5276dump, or restart the guest. 5277 5278Note that KVM does not skip the faulting instruction as it does for 5279KVM_EXIT_MMIO, but userspace has to emulate any change to the processing state 5280if it decides to decode and emulate the instruction. 5281 5282:: 5283 5284 /* KVM_EXIT_X86_RDMSR / KVM_EXIT_X86_WRMSR */ 5285 struct { 5286 __u8 error; /* user -> kernel */ 5287 __u8 pad[7]; 5288 __u32 reason; /* kernel -> user */ 5289 __u32 index; /* kernel -> user */ 5290 __u64 data; /* kernel <-> user */ 5291 } msr; 5292 5293Used on x86 systems. When the VM capability KVM_CAP_X86_USER_SPACE_MSR is 5294enabled, MSR accesses to registers that would invoke a #GP by KVM kernel code 5295will instead trigger a KVM_EXIT_X86_RDMSR exit for reads and KVM_EXIT_X86_WRMSR 5296exit for writes. 5297 5298The "reason" field specifies why the MSR trap occurred. User space will only 5299receive MSR exit traps when a particular reason was requested during through 5300ENABLE_CAP. Currently valid exit reasons are: 5301 5302 KVM_MSR_EXIT_REASON_UNKNOWN - access to MSR that is unknown to KVM 5303 KVM_MSR_EXIT_REASON_INVAL - access to invalid MSRs or reserved bits 5304 KVM_MSR_EXIT_REASON_FILTER - access blocked by KVM_X86_SET_MSR_FILTER 5305 5306For KVM_EXIT_X86_RDMSR, the "index" field tells user space which MSR the guest 5307wants to read. To respond to this request with a successful read, user space 5308writes the respective data into the "data" field and must continue guest 5309execution to ensure the read data is transferred into guest register state. 5310 5311If the RDMSR request was unsuccessful, user space indicates that with a "1" in 5312the "error" field. This will inject a #GP into the guest when the VCPU is 5313executed again. 5314 5315For KVM_EXIT_X86_WRMSR, the "index" field tells user space which MSR the guest 5316wants to write. Once finished processing the event, user space must continue 5317vCPU execution. If the MSR write was unsuccessful, user space also sets the 5318"error" field to "1". 5319 5320:: 5321 5322 /* Fix the size of the union. */ 5323 char padding[256]; 5324 }; 5325 5326 /* 5327 * shared registers between kvm and userspace. 5328 * kvm_valid_regs specifies the register classes set by the host 5329 * kvm_dirty_regs specified the register classes dirtied by userspace 5330 * struct kvm_sync_regs is architecture specific, as well as the 5331 * bits for kvm_valid_regs and kvm_dirty_regs 5332 */ 5333 __u64 kvm_valid_regs; 5334 __u64 kvm_dirty_regs; 5335 union { 5336 struct kvm_sync_regs regs; 5337 char padding[SYNC_REGS_SIZE_BYTES]; 5338 } s; 5339 5340If KVM_CAP_SYNC_REGS is defined, these fields allow userspace to access 5341certain guest registers without having to call SET/GET_*REGS. Thus we can 5342avoid some system call overhead if userspace has to handle the exit. 5343Userspace can query the validity of the structure by checking 5344kvm_valid_regs for specific bits. These bits are architecture specific 5345and usually define the validity of a groups of registers. (e.g. one bit 5346for general purpose registers) 5347 5348Please note that the kernel is allowed to use the kvm_run structure as the 5349primary storage for certain register types. Therefore, the kernel may use the 5350values in kvm_run even if the corresponding bit in kvm_dirty_regs is not set. 5351 5352:: 5353 5354 }; 5355 5356 5357 53586. Capabilities that can be enabled on vCPUs 5359============================================ 5360 5361There are certain capabilities that change the behavior of the virtual CPU or 5362the virtual machine when enabled. To enable them, please see section 4.37. 5363Below you can find a list of capabilities and what their effect on the vCPU or 5364the virtual machine is when enabling them. 5365 5366The following information is provided along with the description: 5367 5368 Architectures: 5369 which instruction set architectures provide this ioctl. 5370 x86 includes both i386 and x86_64. 5371 5372 Target: 5373 whether this is a per-vcpu or per-vm capability. 5374 5375 Parameters: 5376 what parameters are accepted by the capability. 5377 5378 Returns: 5379 the return value. General error numbers (EBADF, ENOMEM, EINVAL) 5380 are not detailed, but errors with specific meanings are. 5381 5382 53836.1 KVM_CAP_PPC_OSI 5384------------------- 5385 5386:Architectures: ppc 5387:Target: vcpu 5388:Parameters: none 5389:Returns: 0 on success; -1 on error 5390 5391This capability enables interception of OSI hypercalls that otherwise would 5392be treated as normal system calls to be injected into the guest. OSI hypercalls 5393were invented by Mac-on-Linux to have a standardized communication mechanism 5394between the guest and the host. 5395 5396When this capability is enabled, KVM_EXIT_OSI can occur. 5397 5398 53996.2 KVM_CAP_PPC_PAPR 5400-------------------- 5401 5402:Architectures: ppc 5403:Target: vcpu 5404:Parameters: none 5405:Returns: 0 on success; -1 on error 5406 5407This capability enables interception of PAPR hypercalls. PAPR hypercalls are 5408done using the hypercall instruction "sc 1". 5409 5410It also sets the guest privilege level to "supervisor" mode. Usually the guest 5411runs in "hypervisor" privilege mode with a few missing features. 5412 5413In addition to the above, it changes the semantics of SDR1. In this mode, the 5414HTAB address part of SDR1 contains an HVA instead of a GPA, as PAPR keeps the 5415HTAB invisible to the guest. 5416 5417When this capability is enabled, KVM_EXIT_PAPR_HCALL can occur. 5418 5419 54206.3 KVM_CAP_SW_TLB 5421------------------ 5422 5423:Architectures: ppc 5424:Target: vcpu 5425:Parameters: args[0] is the address of a struct kvm_config_tlb 5426:Returns: 0 on success; -1 on error 5427 5428:: 5429 5430 struct kvm_config_tlb { 5431 __u64 params; 5432 __u64 array; 5433 __u32 mmu_type; 5434 __u32 array_len; 5435 }; 5436 5437Configures the virtual CPU's TLB array, establishing a shared memory area 5438between userspace and KVM. The "params" and "array" fields are userspace 5439addresses of mmu-type-specific data structures. The "array_len" field is an 5440safety mechanism, and should be set to the size in bytes of the memory that 5441userspace has reserved for the array. It must be at least the size dictated 5442by "mmu_type" and "params". 5443 5444While KVM_RUN is active, the shared region is under control of KVM. Its 5445contents are undefined, and any modification by userspace results in 5446boundedly undefined behavior. 5447 5448On return from KVM_RUN, the shared region will reflect the current state of 5449the guest's TLB. If userspace makes any changes, it must call KVM_DIRTY_TLB 5450to tell KVM which entries have been changed, prior to calling KVM_RUN again 5451on this vcpu. 5452 5453For mmu types KVM_MMU_FSL_BOOKE_NOHV and KVM_MMU_FSL_BOOKE_HV: 5454 5455 - The "params" field is of type "struct kvm_book3e_206_tlb_params". 5456 - The "array" field points to an array of type "struct 5457 kvm_book3e_206_tlb_entry". 5458 - The array consists of all entries in the first TLB, followed by all 5459 entries in the second TLB. 5460 - Within a TLB, entries are ordered first by increasing set number. Within a 5461 set, entries are ordered by way (increasing ESEL). 5462 - The hash for determining set number in TLB0 is: (MAS2 >> 12) & (num_sets - 1) 5463 where "num_sets" is the tlb_sizes[] value divided by the tlb_ways[] value. 5464 - The tsize field of mas1 shall be set to 4K on TLB0, even though the 5465 hardware ignores this value for TLB0. 5466 54676.4 KVM_CAP_S390_CSS_SUPPORT 5468---------------------------- 5469 5470:Architectures: s390 5471:Target: vcpu 5472:Parameters: none 5473:Returns: 0 on success; -1 on error 5474 5475This capability enables support for handling of channel I/O instructions. 5476 5477TEST PENDING INTERRUPTION and the interrupt portion of TEST SUBCHANNEL are 5478handled in-kernel, while the other I/O instructions are passed to userspace. 5479 5480When this capability is enabled, KVM_EXIT_S390_TSCH will occur on TEST 5481SUBCHANNEL intercepts. 5482 5483Note that even though this capability is enabled per-vcpu, the complete 5484virtual machine is affected. 5485 54866.5 KVM_CAP_PPC_EPR 5487------------------- 5488 5489:Architectures: ppc 5490:Target: vcpu 5491:Parameters: args[0] defines whether the proxy facility is active 5492:Returns: 0 on success; -1 on error 5493 5494This capability enables or disables the delivery of interrupts through the 5495external proxy facility. 5496 5497When enabled (args[0] != 0), every time the guest gets an external interrupt 5498delivered, it automatically exits into user space with a KVM_EXIT_EPR exit 5499to receive the topmost interrupt vector. 5500 5501When disabled (args[0] == 0), behavior is as if this facility is unsupported. 5502 5503When this capability is enabled, KVM_EXIT_EPR can occur. 5504 55056.6 KVM_CAP_IRQ_MPIC 5506-------------------- 5507 5508:Architectures: ppc 5509:Parameters: args[0] is the MPIC device fd; 5510 args[1] is the MPIC CPU number for this vcpu 5511 5512This capability connects the vcpu to an in-kernel MPIC device. 5513 55146.7 KVM_CAP_IRQ_XICS 5515-------------------- 5516 5517:Architectures: ppc 5518:Target: vcpu 5519:Parameters: args[0] is the XICS device fd; 5520 args[1] is the XICS CPU number (server ID) for this vcpu 5521 5522This capability connects the vcpu to an in-kernel XICS device. 5523 55246.8 KVM_CAP_S390_IRQCHIP 5525------------------------ 5526 5527:Architectures: s390 5528:Target: vm 5529:Parameters: none 5530 5531This capability enables the in-kernel irqchip for s390. Please refer to 5532"4.24 KVM_CREATE_IRQCHIP" for details. 5533 55346.9 KVM_CAP_MIPS_FPU 5535-------------------- 5536 5537:Architectures: mips 5538:Target: vcpu 5539:Parameters: args[0] is reserved for future use (should be 0). 5540 5541This capability allows the use of the host Floating Point Unit by the guest. It 5542allows the Config1.FP bit to be set to enable the FPU in the guest. Once this is 5543done the ``KVM_REG_MIPS_FPR_*`` and ``KVM_REG_MIPS_FCR_*`` registers can be 5544accessed (depending on the current guest FPU register mode), and the Status.FR, 5545Config5.FRE bits are accessible via the KVM API and also from the guest, 5546depending on them being supported by the FPU. 5547 55486.10 KVM_CAP_MIPS_MSA 5549--------------------- 5550 5551:Architectures: mips 5552:Target: vcpu 5553:Parameters: args[0] is reserved for future use (should be 0). 5554 5555This capability allows the use of the MIPS SIMD Architecture (MSA) by the guest. 5556It allows the Config3.MSAP bit to be set to enable the use of MSA by the guest. 5557Once this is done the ``KVM_REG_MIPS_VEC_*`` and ``KVM_REG_MIPS_MSA_*`` 5558registers can be accessed, and the Config5.MSAEn bit is accessible via the 5559KVM API and also from the guest. 5560 55616.74 KVM_CAP_SYNC_REGS 5562---------------------- 5563 5564:Architectures: s390, x86 5565:Target: s390: always enabled, x86: vcpu 5566:Parameters: none 5567:Returns: x86: KVM_CHECK_EXTENSION returns a bit-array indicating which register 5568 sets are supported 5569 (bitfields defined in arch/x86/include/uapi/asm/kvm.h). 5570 5571As described above in the kvm_sync_regs struct info in section 5 (kvm_run): 5572KVM_CAP_SYNC_REGS "allow[s] userspace to access certain guest registers 5573without having to call SET/GET_*REGS". This reduces overhead by eliminating 5574repeated ioctl calls for setting and/or getting register values. This is 5575particularly important when userspace is making synchronous guest state 5576modifications, e.g. when emulating and/or intercepting instructions in 5577userspace. 5578 5579For s390 specifics, please refer to the source code. 5580 5581For x86: 5582 5583- the register sets to be copied out to kvm_run are selectable 5584 by userspace (rather that all sets being copied out for every exit). 5585- vcpu_events are available in addition to regs and sregs. 5586 5587For x86, the 'kvm_valid_regs' field of struct kvm_run is overloaded to 5588function as an input bit-array field set by userspace to indicate the 5589specific register sets to be copied out on the next exit. 5590 5591To indicate when userspace has modified values that should be copied into 5592the vCPU, the all architecture bitarray field, 'kvm_dirty_regs' must be set. 5593This is done using the same bitflags as for the 'kvm_valid_regs' field. 5594If the dirty bit is not set, then the register set values will not be copied 5595into the vCPU even if they've been modified. 5596 5597Unused bitfields in the bitarrays must be set to zero. 5598 5599:: 5600 5601 struct kvm_sync_regs { 5602 struct kvm_regs regs; 5603 struct kvm_sregs sregs; 5604 struct kvm_vcpu_events events; 5605 }; 5606 56076.75 KVM_CAP_PPC_IRQ_XIVE 5608------------------------- 5609 5610:Architectures: ppc 5611:Target: vcpu 5612:Parameters: args[0] is the XIVE device fd; 5613 args[1] is the XIVE CPU number (server ID) for this vcpu 5614 5615This capability connects the vcpu to an in-kernel XIVE device. 5616 56177. Capabilities that can be enabled on VMs 5618========================================== 5619 5620There are certain capabilities that change the behavior of the virtual 5621machine when enabled. To enable them, please see section 4.37. Below 5622you can find a list of capabilities and what their effect on the VM 5623is when enabling them. 5624 5625The following information is provided along with the description: 5626 5627 Architectures: 5628 which instruction set architectures provide this ioctl. 5629 x86 includes both i386 and x86_64. 5630 5631 Parameters: 5632 what parameters are accepted by the capability. 5633 5634 Returns: 5635 the return value. General error numbers (EBADF, ENOMEM, EINVAL) 5636 are not detailed, but errors with specific meanings are. 5637 5638 56397.1 KVM_CAP_PPC_ENABLE_HCALL 5640---------------------------- 5641 5642:Architectures: ppc 5643:Parameters: args[0] is the sPAPR hcall number; 5644 args[1] is 0 to disable, 1 to enable in-kernel handling 5645 5646This capability controls whether individual sPAPR hypercalls (hcalls) 5647get handled by the kernel or not. Enabling or disabling in-kernel 5648handling of an hcall is effective across the VM. On creation, an 5649initial set of hcalls are enabled for in-kernel handling, which 5650consists of those hcalls for which in-kernel handlers were implemented 5651before this capability was implemented. If disabled, the kernel will 5652not to attempt to handle the hcall, but will always exit to userspace 5653to handle it. Note that it may not make sense to enable some and 5654disable others of a group of related hcalls, but KVM does not prevent 5655userspace from doing that. 5656 5657If the hcall number specified is not one that has an in-kernel 5658implementation, the KVM_ENABLE_CAP ioctl will fail with an EINVAL 5659error. 5660 56617.2 KVM_CAP_S390_USER_SIGP 5662-------------------------- 5663 5664:Architectures: s390 5665:Parameters: none 5666 5667This capability controls which SIGP orders will be handled completely in user 5668space. With this capability enabled, all fast orders will be handled completely 5669in the kernel: 5670 5671- SENSE 5672- SENSE RUNNING 5673- EXTERNAL CALL 5674- EMERGENCY SIGNAL 5675- CONDITIONAL EMERGENCY SIGNAL 5676 5677All other orders will be handled completely in user space. 5678 5679Only privileged operation exceptions will be checked for in the kernel (or even 5680in the hardware prior to interception). If this capability is not enabled, the 5681old way of handling SIGP orders is used (partially in kernel and user space). 5682 56837.3 KVM_CAP_S390_VECTOR_REGISTERS 5684--------------------------------- 5685 5686:Architectures: s390 5687:Parameters: none 5688:Returns: 0 on success, negative value on error 5689 5690Allows use of the vector registers introduced with z13 processor, and 5691provides for the synchronization between host and user space. Will 5692return -EINVAL if the machine does not support vectors. 5693 56947.4 KVM_CAP_S390_USER_STSI 5695-------------------------- 5696 5697:Architectures: s390 5698:Parameters: none 5699 5700This capability allows post-handlers for the STSI instruction. After 5701initial handling in the kernel, KVM exits to user space with 5702KVM_EXIT_S390_STSI to allow user space to insert further data. 5703 5704Before exiting to userspace, kvm handlers should fill in s390_stsi field of 5705vcpu->run:: 5706 5707 struct { 5708 __u64 addr; 5709 __u8 ar; 5710 __u8 reserved; 5711 __u8 fc; 5712 __u8 sel1; 5713 __u16 sel2; 5714 } s390_stsi; 5715 5716 @addr - guest address of STSI SYSIB 5717 @fc - function code 5718 @sel1 - selector 1 5719 @sel2 - selector 2 5720 @ar - access register number 5721 5722KVM handlers should exit to userspace with rc = -EREMOTE. 5723 57247.5 KVM_CAP_SPLIT_IRQCHIP 5725------------------------- 5726 5727:Architectures: x86 5728:Parameters: args[0] - number of routes reserved for userspace IOAPICs 5729:Returns: 0 on success, -1 on error 5730 5731Create a local apic for each processor in the kernel. This can be used 5732instead of KVM_CREATE_IRQCHIP if the userspace VMM wishes to emulate the 5733IOAPIC and PIC (and also the PIT, even though this has to be enabled 5734separately). 5735 5736This capability also enables in kernel routing of interrupt requests; 5737when KVM_CAP_SPLIT_IRQCHIP only routes of KVM_IRQ_ROUTING_MSI type are 5738used in the IRQ routing table. The first args[0] MSI routes are reserved 5739for the IOAPIC pins. Whenever the LAPIC receives an EOI for these routes, 5740a KVM_EXIT_IOAPIC_EOI vmexit will be reported to userspace. 5741 5742Fails if VCPU has already been created, or if the irqchip is already in the 5743kernel (i.e. KVM_CREATE_IRQCHIP has already been called). 5744 57457.6 KVM_CAP_S390_RI 5746------------------- 5747 5748:Architectures: s390 5749:Parameters: none 5750 5751Allows use of runtime-instrumentation introduced with zEC12 processor. 5752Will return -EINVAL if the machine does not support runtime-instrumentation. 5753Will return -EBUSY if a VCPU has already been created. 5754 57557.7 KVM_CAP_X2APIC_API 5756---------------------- 5757 5758:Architectures: x86 5759:Parameters: args[0] - features that should be enabled 5760:Returns: 0 on success, -EINVAL when args[0] contains invalid features 5761 5762Valid feature flags in args[0] are:: 5763 5764 #define KVM_X2APIC_API_USE_32BIT_IDS (1ULL << 0) 5765 #define KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK (1ULL << 1) 5766 5767Enabling KVM_X2APIC_API_USE_32BIT_IDS changes the behavior of 5768KVM_SET_GSI_ROUTING, KVM_SIGNAL_MSI, KVM_SET_LAPIC, and KVM_GET_LAPIC, 5769allowing the use of 32-bit APIC IDs. See KVM_CAP_X2APIC_API in their 5770respective sections. 5771 5772KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK must be enabled for x2APIC to work 5773in logical mode or with more than 255 VCPUs. Otherwise, KVM treats 0xff 5774as a broadcast even in x2APIC mode in order to support physical x2APIC 5775without interrupt remapping. This is undesirable in logical mode, 5776where 0xff represents CPUs 0-7 in cluster 0. 5777 57787.8 KVM_CAP_S390_USER_INSTR0 5779---------------------------- 5780 5781:Architectures: s390 5782:Parameters: none 5783 5784With this capability enabled, all illegal instructions 0x0000 (2 bytes) will 5785be intercepted and forwarded to user space. User space can use this 5786mechanism e.g. to realize 2-byte software breakpoints. The kernel will 5787not inject an operating exception for these instructions, user space has 5788to take care of that. 5789 5790This capability can be enabled dynamically even if VCPUs were already 5791created and are running. 5792 57937.9 KVM_CAP_S390_GS 5794------------------- 5795 5796:Architectures: s390 5797:Parameters: none 5798:Returns: 0 on success; -EINVAL if the machine does not support 5799 guarded storage; -EBUSY if a VCPU has already been created. 5800 5801Allows use of guarded storage for the KVM guest. 5802 58037.10 KVM_CAP_S390_AIS 5804--------------------- 5805 5806:Architectures: s390 5807:Parameters: none 5808 5809Allow use of adapter-interruption suppression. 5810:Returns: 0 on success; -EBUSY if a VCPU has already been created. 5811 58127.11 KVM_CAP_PPC_SMT 5813-------------------- 5814 5815:Architectures: ppc 5816:Parameters: vsmt_mode, flags 5817 5818Enabling this capability on a VM provides userspace with a way to set 5819the desired virtual SMT mode (i.e. the number of virtual CPUs per 5820virtual core). The virtual SMT mode, vsmt_mode, must be a power of 2 5821between 1 and 8. On POWER8, vsmt_mode must also be no greater than 5822the number of threads per subcore for the host. Currently flags must 5823be 0. A successful call to enable this capability will result in 5824vsmt_mode being returned when the KVM_CAP_PPC_SMT capability is 5825subsequently queried for the VM. This capability is only supported by 5826HV KVM, and can only be set before any VCPUs have been created. 5827The KVM_CAP_PPC_SMT_POSSIBLE capability indicates which virtual SMT 5828modes are available. 5829 58307.12 KVM_CAP_PPC_FWNMI 5831---------------------- 5832 5833:Architectures: ppc 5834:Parameters: none 5835 5836With this capability a machine check exception in the guest address 5837space will cause KVM to exit the guest with NMI exit reason. This 5838enables QEMU to build error log and branch to guest kernel registered 5839machine check handling routine. Without this capability KVM will 5840branch to guests' 0x200 interrupt vector. 5841 58427.13 KVM_CAP_X86_DISABLE_EXITS 5843------------------------------ 5844 5845:Architectures: x86 5846:Parameters: args[0] defines which exits are disabled 5847:Returns: 0 on success, -EINVAL when args[0] contains invalid exits 5848 5849Valid bits in args[0] are:: 5850 5851 #define KVM_X86_DISABLE_EXITS_MWAIT (1 << 0) 5852 #define KVM_X86_DISABLE_EXITS_HLT (1 << 1) 5853 #define KVM_X86_DISABLE_EXITS_PAUSE (1 << 2) 5854 #define KVM_X86_DISABLE_EXITS_CSTATE (1 << 3) 5855 5856Enabling this capability on a VM provides userspace with a way to no 5857longer intercept some instructions for improved latency in some 5858workloads, and is suggested when vCPUs are associated to dedicated 5859physical CPUs. More bits can be added in the future; userspace can 5860just pass the KVM_CHECK_EXTENSION result to KVM_ENABLE_CAP to disable 5861all such vmexits. 5862 5863Do not enable KVM_FEATURE_PV_UNHALT if you disable HLT exits. 5864 58657.14 KVM_CAP_S390_HPAGE_1M 5866-------------------------- 5867 5868:Architectures: s390 5869:Parameters: none 5870:Returns: 0 on success, -EINVAL if hpage module parameter was not set 5871 or cmma is enabled, or the VM has the KVM_VM_S390_UCONTROL 5872 flag set 5873 5874With this capability the KVM support for memory backing with 1m pages 5875through hugetlbfs can be enabled for a VM. After the capability is 5876enabled, cmma can't be enabled anymore and pfmfi and the storage key 5877interpretation are disabled. If cmma has already been enabled or the 5878hpage module parameter is not set to 1, -EINVAL is returned. 5879 5880While it is generally possible to create a huge page backed VM without 5881this capability, the VM will not be able to run. 5882 58837.15 KVM_CAP_MSR_PLATFORM_INFO 5884------------------------------ 5885 5886:Architectures: x86 5887:Parameters: args[0] whether feature should be enabled or not 5888 5889With this capability, a guest may read the MSR_PLATFORM_INFO MSR. Otherwise, 5890a #GP would be raised when the guest tries to access. Currently, this 5891capability does not enable write permissions of this MSR for the guest. 5892 58937.16 KVM_CAP_PPC_NESTED_HV 5894-------------------------- 5895 5896:Architectures: ppc 5897:Parameters: none 5898:Returns: 0 on success, -EINVAL when the implementation doesn't support 5899 nested-HV virtualization. 5900 5901HV-KVM on POWER9 and later systems allows for "nested-HV" 5902virtualization, which provides a way for a guest VM to run guests that 5903can run using the CPU's supervisor mode (privileged non-hypervisor 5904state). Enabling this capability on a VM depends on the CPU having 5905the necessary functionality and on the facility being enabled with a 5906kvm-hv module parameter. 5907 59087.17 KVM_CAP_EXCEPTION_PAYLOAD 5909------------------------------ 5910 5911:Architectures: x86 5912:Parameters: args[0] whether feature should be enabled or not 5913 5914With this capability enabled, CR2 will not be modified prior to the 5915emulated VM-exit when L1 intercepts a #PF exception that occurs in 5916L2. Similarly, for kvm-intel only, DR6 will not be modified prior to 5917the emulated VM-exit when L1 intercepts a #DB exception that occurs in 5918L2. As a result, when KVM_GET_VCPU_EVENTS reports a pending #PF (or 5919#DB) exception for L2, exception.has_payload will be set and the 5920faulting address (or the new DR6 bits*) will be reported in the 5921exception_payload field. Similarly, when userspace injects a #PF (or 5922#DB) into L2 using KVM_SET_VCPU_EVENTS, it is expected to set 5923exception.has_payload and to put the faulting address - or the new DR6 5924bits\ [#]_ - in the exception_payload field. 5925 5926This capability also enables exception.pending in struct 5927kvm_vcpu_events, which allows userspace to distinguish between pending 5928and injected exceptions. 5929 5930 5931.. [#] For the new DR6 bits, note that bit 16 is set iff the #DB exception 5932 will clear DR6.RTM. 5933 59347.18 KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 5935 5936:Architectures: x86, arm, arm64, mips 5937:Parameters: args[0] whether feature should be enabled or not 5938 5939Valid flags are:: 5940 5941 #define KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE (1 << 0) 5942 #define KVM_DIRTY_LOG_INITIALLY_SET (1 << 1) 5943 5944With KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE is set, KVM_GET_DIRTY_LOG will not 5945automatically clear and write-protect all pages that are returned as dirty. 5946Rather, userspace will have to do this operation separately using 5947KVM_CLEAR_DIRTY_LOG. 5948 5949At the cost of a slightly more complicated operation, this provides better 5950scalability and responsiveness for two reasons. First, 5951KVM_CLEAR_DIRTY_LOG ioctl can operate on a 64-page granularity rather 5952than requiring to sync a full memslot; this ensures that KVM does not 5953take spinlocks for an extended period of time. Second, in some cases a 5954large amount of time can pass between a call to KVM_GET_DIRTY_LOG and 5955userspace actually using the data in the page. Pages can be modified 5956during this time, which is inefficient for both the guest and userspace: 5957the guest will incur a higher penalty due to write protection faults, 5958while userspace can see false reports of dirty pages. Manual reprotection 5959helps reducing this time, improving guest performance and reducing the 5960number of dirty log false positives. 5961 5962With KVM_DIRTY_LOG_INITIALLY_SET set, all the bits of the dirty bitmap 5963will be initialized to 1 when created. This also improves performance because 5964dirty logging can be enabled gradually in small chunks on the first call 5965to KVM_CLEAR_DIRTY_LOG. KVM_DIRTY_LOG_INITIALLY_SET depends on 5966KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE (it is also only available on 5967x86 and arm64 for now). 5968 5969KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 was previously available under the name 5970KVM_CAP_MANUAL_DIRTY_LOG_PROTECT, but the implementation had bugs that make 5971it hard or impossible to use it correctly. The availability of 5972KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 signals that those bugs are fixed. 5973Userspace should not try to use KVM_CAP_MANUAL_DIRTY_LOG_PROTECT. 5974 59757.19 KVM_CAP_PPC_SECURE_GUEST 5976------------------------------ 5977 5978:Architectures: ppc 5979 5980This capability indicates that KVM is running on a host that has 5981ultravisor firmware and thus can support a secure guest. On such a 5982system, a guest can ask the ultravisor to make it a secure guest, 5983one whose memory is inaccessible to the host except for pages which 5984are explicitly requested to be shared with the host. The ultravisor 5985notifies KVM when a guest requests to become a secure guest, and KVM 5986has the opportunity to veto the transition. 5987 5988If present, this capability can be enabled for a VM, meaning that KVM 5989will allow the transition to secure guest mode. Otherwise KVM will 5990veto the transition. 5991 59927.20 KVM_CAP_HALT_POLL 5993---------------------- 5994 5995:Architectures: all 5996:Target: VM 5997:Parameters: args[0] is the maximum poll time in nanoseconds 5998:Returns: 0 on success; -1 on error 5999 6000This capability overrides the kvm module parameter halt_poll_ns for the 6001target VM. 6002 6003VCPU polling allows a VCPU to poll for wakeup events instead of immediately 6004scheduling during guest halts. The maximum time a VCPU can spend polling is 6005controlled by the kvm module parameter halt_poll_ns. This capability allows 6006the maximum halt time to specified on a per-VM basis, effectively overriding 6007the module parameter for the target VM. 6008 60097.21 KVM_CAP_X86_USER_SPACE_MSR 6010------------------------------- 6011 6012:Architectures: x86 6013:Target: VM 6014:Parameters: args[0] contains the mask of KVM_MSR_EXIT_REASON_* events to report 6015:Returns: 0 on success; -1 on error 6016 6017This capability enables trapping of #GP invoking RDMSR and WRMSR instructions 6018into user space. 6019 6020When a guest requests to read or write an MSR, KVM may not implement all MSRs 6021that are relevant to a respective system. It also does not differentiate by 6022CPU type. 6023 6024To allow more fine grained control over MSR handling, user space may enable 6025this capability. With it enabled, MSR accesses that match the mask specified in 6026args[0] and trigger a #GP event inside the guest by KVM will instead trigger 6027KVM_EXIT_X86_RDMSR and KVM_EXIT_X86_WRMSR exit notifications which user space 6028can then handle to implement model specific MSR handling and/or user notifications 6029to inform a user that an MSR was not handled. 6030 60318. Other capabilities. 6032====================== 6033 6034This section lists capabilities that give information about other 6035features of the KVM implementation. 6036 60378.1 KVM_CAP_PPC_HWRNG 6038--------------------- 6039 6040:Architectures: ppc 6041 6042This capability, if KVM_CHECK_EXTENSION indicates that it is 6043available, means that the kernel has an implementation of the 6044H_RANDOM hypercall backed by a hardware random-number generator. 6045If present, the kernel H_RANDOM handler can be enabled for guest use 6046with the KVM_CAP_PPC_ENABLE_HCALL capability. 6047 60488.2 KVM_CAP_HYPERV_SYNIC 6049------------------------ 6050 6051:Architectures: x86 6052 6053This capability, if KVM_CHECK_EXTENSION indicates that it is 6054available, means that the kernel has an implementation of the 6055Hyper-V Synthetic interrupt controller(SynIC). Hyper-V SynIC is 6056used to support Windows Hyper-V based guest paravirt drivers(VMBus). 6057 6058In order to use SynIC, it has to be activated by setting this 6059capability via KVM_ENABLE_CAP ioctl on the vcpu fd. Note that this 6060will disable the use of APIC hardware virtualization even if supported 6061by the CPU, as it's incompatible with SynIC auto-EOI behavior. 6062 60638.3 KVM_CAP_PPC_RADIX_MMU 6064------------------------- 6065 6066:Architectures: ppc 6067 6068This capability, if KVM_CHECK_EXTENSION indicates that it is 6069available, means that the kernel can support guests using the 6070radix MMU defined in Power ISA V3.00 (as implemented in the POWER9 6071processor). 6072 60738.4 KVM_CAP_PPC_HASH_MMU_V3 6074--------------------------- 6075 6076:Architectures: ppc 6077 6078This capability, if KVM_CHECK_EXTENSION indicates that it is 6079available, means that the kernel can support guests using the 6080hashed page table MMU defined in Power ISA V3.00 (as implemented in 6081the POWER9 processor), including in-memory segment tables. 6082 60838.5 KVM_CAP_MIPS_VZ 6084------------------- 6085 6086:Architectures: mips 6087 6088This capability, if KVM_CHECK_EXTENSION on the main kvm handle indicates that 6089it is available, means that full hardware assisted virtualization capabilities 6090of the hardware are available for use through KVM. An appropriate 6091KVM_VM_MIPS_* type must be passed to KVM_CREATE_VM to create a VM which 6092utilises it. 6093 6094If KVM_CHECK_EXTENSION on a kvm VM handle indicates that this capability is 6095available, it means that the VM is using full hardware assisted virtualization 6096capabilities of the hardware. This is useful to check after creating a VM with 6097KVM_VM_MIPS_DEFAULT. 6098 6099The value returned by KVM_CHECK_EXTENSION should be compared against known 6100values (see below). All other values are reserved. This is to allow for the 6101possibility of other hardware assisted virtualization implementations which 6102may be incompatible with the MIPS VZ ASE. 6103 6104== ========================================================================== 6105 0 The trap & emulate implementation is in use to run guest code in user 6106 mode. Guest virtual memory segments are rearranged to fit the guest in the 6107 user mode address space. 6108 6109 1 The MIPS VZ ASE is in use, providing full hardware assisted 6110 virtualization, including standard guest virtual memory segments. 6111== ========================================================================== 6112 61138.6 KVM_CAP_MIPS_TE 6114------------------- 6115 6116:Architectures: mips 6117 6118This capability, if KVM_CHECK_EXTENSION on the main kvm handle indicates that 6119it is available, means that the trap & emulate implementation is available to 6120run guest code in user mode, even if KVM_CAP_MIPS_VZ indicates that hardware 6121assisted virtualisation is also available. KVM_VM_MIPS_TE (0) must be passed 6122to KVM_CREATE_VM to create a VM which utilises it. 6123 6124If KVM_CHECK_EXTENSION on a kvm VM handle indicates that this capability is 6125available, it means that the VM is using trap & emulate. 6126 61278.7 KVM_CAP_MIPS_64BIT 6128---------------------- 6129 6130:Architectures: mips 6131 6132This capability indicates the supported architecture type of the guest, i.e. the 6133supported register and address width. 6134 6135The values returned when this capability is checked by KVM_CHECK_EXTENSION on a 6136kvm VM handle correspond roughly to the CP0_Config.AT register field, and should 6137be checked specifically against known values (see below). All other values are 6138reserved. 6139 6140== ======================================================================== 6141 0 MIPS32 or microMIPS32. 6142 Both registers and addresses are 32-bits wide. 6143 It will only be possible to run 32-bit guest code. 6144 6145 1 MIPS64 or microMIPS64 with access only to 32-bit compatibility segments. 6146 Registers are 64-bits wide, but addresses are 32-bits wide. 6147 64-bit guest code may run but cannot access MIPS64 memory segments. 6148 It will also be possible to run 32-bit guest code. 6149 6150 2 MIPS64 or microMIPS64 with access to all address segments. 6151 Both registers and addresses are 64-bits wide. 6152 It will be possible to run 64-bit or 32-bit guest code. 6153== ======================================================================== 6154 61558.9 KVM_CAP_ARM_USER_IRQ 6156------------------------ 6157 6158:Architectures: arm, arm64 6159 6160This capability, if KVM_CHECK_EXTENSION indicates that it is available, means 6161that if userspace creates a VM without an in-kernel interrupt controller, it 6162will be notified of changes to the output level of in-kernel emulated devices, 6163which can generate virtual interrupts, presented to the VM. 6164For such VMs, on every return to userspace, the kernel 6165updates the vcpu's run->s.regs.device_irq_level field to represent the actual 6166output level of the device. 6167 6168Whenever kvm detects a change in the device output level, kvm guarantees at 6169least one return to userspace before running the VM. This exit could either 6170be a KVM_EXIT_INTR or any other exit event, like KVM_EXIT_MMIO. This way, 6171userspace can always sample the device output level and re-compute the state of 6172the userspace interrupt controller. Userspace should always check the state 6173of run->s.regs.device_irq_level on every kvm exit. 6174The value in run->s.regs.device_irq_level can represent both level and edge 6175triggered interrupt signals, depending on the device. Edge triggered interrupt 6176signals will exit to userspace with the bit in run->s.regs.device_irq_level 6177set exactly once per edge signal. 6178 6179The field run->s.regs.device_irq_level is available independent of 6180run->kvm_valid_regs or run->kvm_dirty_regs bits. 6181 6182If KVM_CAP_ARM_USER_IRQ is supported, the KVM_CHECK_EXTENSION ioctl returns a 6183number larger than 0 indicating the version of this capability is implemented 6184and thereby which bits in run->s.regs.device_irq_level can signal values. 6185 6186Currently the following bits are defined for the device_irq_level bitmap:: 6187 6188 KVM_CAP_ARM_USER_IRQ >= 1: 6189 6190 KVM_ARM_DEV_EL1_VTIMER - EL1 virtual timer 6191 KVM_ARM_DEV_EL1_PTIMER - EL1 physical timer 6192 KVM_ARM_DEV_PMU - ARM PMU overflow interrupt signal 6193 6194Future versions of kvm may implement additional events. These will get 6195indicated by returning a higher number from KVM_CHECK_EXTENSION and will be 6196listed above. 6197 61988.10 KVM_CAP_PPC_SMT_POSSIBLE 6199----------------------------- 6200 6201:Architectures: ppc 6202 6203Querying this capability returns a bitmap indicating the possible 6204virtual SMT modes that can be set using KVM_CAP_PPC_SMT. If bit N 6205(counting from the right) is set, then a virtual SMT mode of 2^N is 6206available. 6207 62088.11 KVM_CAP_HYPERV_SYNIC2 6209-------------------------- 6210 6211:Architectures: x86 6212 6213This capability enables a newer version of Hyper-V Synthetic interrupt 6214controller (SynIC). The only difference with KVM_CAP_HYPERV_SYNIC is that KVM 6215doesn't clear SynIC message and event flags pages when they are enabled by 6216writing to the respective MSRs. 6217 62188.12 KVM_CAP_HYPERV_VP_INDEX 6219---------------------------- 6220 6221:Architectures: x86 6222 6223This capability indicates that userspace can load HV_X64_MSR_VP_INDEX msr. Its 6224value is used to denote the target vcpu for a SynIC interrupt. For 6225compatibilty, KVM initializes this msr to KVM's internal vcpu index. When this 6226capability is absent, userspace can still query this msr's value. 6227 62288.13 KVM_CAP_S390_AIS_MIGRATION 6229------------------------------- 6230 6231:Architectures: s390 6232:Parameters: none 6233 6234This capability indicates if the flic device will be able to get/set the 6235AIS states for migration via the KVM_DEV_FLIC_AISM_ALL attribute and allows 6236to discover this without having to create a flic device. 6237 62388.14 KVM_CAP_S390_PSW 6239--------------------- 6240 6241:Architectures: s390 6242 6243This capability indicates that the PSW is exposed via the kvm_run structure. 6244 62458.15 KVM_CAP_S390_GMAP 6246---------------------- 6247 6248:Architectures: s390 6249 6250This capability indicates that the user space memory used as guest mapping can 6251be anywhere in the user memory address space, as long as the memory slots are 6252aligned and sized to a segment (1MB) boundary. 6253 62548.16 KVM_CAP_S390_COW 6255--------------------- 6256 6257:Architectures: s390 6258 6259This capability indicates that the user space memory used as guest mapping can 6260use copy-on-write semantics as well as dirty pages tracking via read-only page 6261tables. 6262 62638.17 KVM_CAP_S390_BPB 6264--------------------- 6265 6266:Architectures: s390 6267 6268This capability indicates that kvm will implement the interfaces to handle 6269reset, migration and nested KVM for branch prediction blocking. The stfle 6270facility 82 should not be provided to the guest without this capability. 6271 62728.18 KVM_CAP_HYPERV_TLBFLUSH 6273---------------------------- 6274 6275:Architectures: x86 6276 6277This capability indicates that KVM supports paravirtualized Hyper-V TLB Flush 6278hypercalls: 6279HvFlushVirtualAddressSpace, HvFlushVirtualAddressSpaceEx, 6280HvFlushVirtualAddressList, HvFlushVirtualAddressListEx. 6281 62828.19 KVM_CAP_ARM_INJECT_SERROR_ESR 6283---------------------------------- 6284 6285:Architectures: arm, arm64 6286 6287This capability indicates that userspace can specify (via the 6288KVM_SET_VCPU_EVENTS ioctl) the syndrome value reported to the guest when it 6289takes a virtual SError interrupt exception. 6290If KVM advertises this capability, userspace can only specify the ISS field for 6291the ESR syndrome. Other parts of the ESR, such as the EC are generated by the 6292CPU when the exception is taken. If this virtual SError is taken to EL1 using 6293AArch64, this value will be reported in the ISS field of ESR_ELx. 6294 6295See KVM_CAP_VCPU_EVENTS for more details. 6296 62978.20 KVM_CAP_HYPERV_SEND_IPI 6298---------------------------- 6299 6300:Architectures: x86 6301 6302This capability indicates that KVM supports paravirtualized Hyper-V IPI send 6303hypercalls: 6304HvCallSendSyntheticClusterIpi, HvCallSendSyntheticClusterIpiEx. 6305 63068.21 KVM_CAP_HYPERV_DIRECT_TLBFLUSH 6307----------------------------------- 6308 6309:Architectures: x86 6310 6311This capability indicates that KVM running on top of Hyper-V hypervisor 6312enables Direct TLB flush for its guests meaning that TLB flush 6313hypercalls are handled by Level 0 hypervisor (Hyper-V) bypassing KVM. 6314Due to the different ABI for hypercall parameters between Hyper-V and 6315KVM, enabling this capability effectively disables all hypercall 6316handling by KVM (as some KVM hypercall may be mistakenly treated as TLB 6317flush hypercalls by Hyper-V) so userspace should disable KVM identification 6318in CPUID and only exposes Hyper-V identification. In this case, guest 6319thinks it's running on Hyper-V and only use Hyper-V hypercalls. 6320 63218.22 KVM_CAP_S390_VCPU_RESETS 6322----------------------------- 6323 6324:Architectures: s390 6325 6326This capability indicates that the KVM_S390_NORMAL_RESET and 6327KVM_S390_CLEAR_RESET ioctls are available. 6328 63298.23 KVM_CAP_S390_PROTECTED 6330--------------------------- 6331 6332:Architectures: s390 6333 6334This capability indicates that the Ultravisor has been initialized and 6335KVM can therefore start protected VMs. 6336This capability governs the KVM_S390_PV_COMMAND ioctl and the 6337KVM_MP_STATE_LOAD MP_STATE. KVM_SET_MP_STATE can fail for protected 6338guests when the state change is invalid. 6339 63408.24 KVM_CAP_STEAL_TIME 6341----------------------- 6342 6343:Architectures: arm64, x86 6344 6345This capability indicates that KVM supports steal time accounting. 6346When steal time accounting is supported it may be enabled with 6347architecture-specific interfaces. This capability and the architecture- 6348specific interfaces must be consistent, i.e. if one says the feature 6349is supported, than the other should as well and vice versa. For arm64 6350see Documentation/virt/kvm/devices/vcpu.rst "KVM_ARM_VCPU_PVTIME_CTRL". 6351For x86 see Documentation/virt/kvm/msr.rst "MSR_KVM_STEAL_TIME". 6352 63538.25 KVM_CAP_S390_DIAG318 6354------------------------- 6355 6356:Architectures: s390 6357 6358This capability enables a guest to set information about its control program 6359(i.e. guest kernel type and version). The information is helpful during 6360system/firmware service events, providing additional data about the guest 6361environments running on the machine. 6362 6363The information is associated with the DIAGNOSE 0x318 instruction, which sets 6364an 8-byte value consisting of a one-byte Control Program Name Code (CPNC) and 6365a 7-byte Control Program Version Code (CPVC). The CPNC determines what 6366environment the control program is running in (e.g. Linux, z/VM...), and the 6367CPVC is used for information specific to OS (e.g. Linux version, Linux 6368distribution...) 6369 6370If this capability is available, then the CPNC and CPVC can be synchronized 6371between KVM and userspace via the sync regs mechanism (KVM_SYNC_DIAG318). 6372 63738.26 KVM_CAP_X86_USER_SPACE_MSR 6374------------------------------- 6375 6376:Architectures: x86 6377 6378This capability indicates that KVM supports deflection of MSR reads and 6379writes to user space. It can be enabled on a VM level. If enabled, MSR 6380accesses that would usually trigger a #GP by KVM into the guest will 6381instead get bounced to user space through the KVM_EXIT_X86_RDMSR and 6382KVM_EXIT_X86_WRMSR exit notifications. 6383 63848.27 KVM_X86_SET_MSR_FILTER 6385--------------------------- 6386 6387:Architectures: x86 6388 6389This capability indicates that KVM supports that accesses to user defined MSRs 6390may be rejected. With this capability exposed, KVM exports new VM ioctl 6391KVM_X86_SET_MSR_FILTER which user space can call to specify bitmaps of MSR 6392ranges that KVM should reject access to. 6393 6394In combination with KVM_CAP_X86_USER_SPACE_MSR, this allows user space to 6395trap and emulate MSRs that are outside of the scope of KVM as well as 6396limit the attack surface on KVM's MSR emulation code. 6397 63988.28 KVM_CAP_ENFORCE_PV_CPUID 6399----------------------------- 6400 6401Architectures: x86 6402 6403When enabled, KVM will disable paravirtual features provided to the 6404guest according to the bits in the KVM_CPUID_FEATURES CPUID leaf 6405(0x40000001). Otherwise, a guest may use the paravirtual features 6406regardless of what has actually been exposed through the CPUID leaf. 6407 64089. Known KVM API problems 6409========================= 6410 6411In some cases, KVM's API has some inconsistencies or common pitfalls 6412that userspace need to be aware of. This section details some of 6413these issues. 6414 6415Most of them are architecture specific, so the section is split by 6416architecture. 6417 64189.1. x86 6419-------- 6420 6421``KVM_GET_SUPPORTED_CPUID`` issues 6422^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 6423 6424In general, ``KVM_GET_SUPPORTED_CPUID`` is designed so that it is possible 6425to take its result and pass it directly to ``KVM_SET_CPUID2``. This section 6426documents some cases in which that requires some care. 6427 6428Local APIC features 6429~~~~~~~~~~~~~~~~~~~ 6430 6431CPU[EAX=1]:ECX[21] (X2APIC) is reported by ``KVM_GET_SUPPORTED_CPUID``, 6432but it can only be enabled if ``KVM_CREATE_IRQCHIP`` or 6433``KVM_ENABLE_CAP(KVM_CAP_IRQCHIP_SPLIT)`` are used to enable in-kernel emulation of 6434the local APIC. 6435 6436The same is true for the ``KVM_FEATURE_PV_UNHALT`` paravirtualized feature. 6437 6438CPU[EAX=1]:ECX[24] (TSC_DEADLINE) is not reported by ``KVM_GET_SUPPORTED_CPUID``. 6439It can be enabled if ``KVM_CAP_TSC_DEADLINE_TIMER`` is present and the kernel 6440has enabled in-kernel emulation of the local APIC. 6441 6442CPU topology 6443~~~~~~~~~~~~ 6444 6445Several CPUID values include topology information for the host CPU: 64460x0b and 0x1f for Intel systems, 0x8000001e for AMD systems. Different 6447versions of KVM return different values for this information and userspace 6448should not rely on it. Currently they return all zeroes. 6449 6450If userspace wishes to set up a guest topology, it should be careful that 6451the values of these three leaves differ for each CPU. In particular, 6452the APIC ID is found in EDX for all subleaves of 0x0b and 0x1f, and in EAX 6453for 0x8000001e; the latter also encodes the core id and node id in bits 64547:0 of EBX and ECX respectively. 6455 6456Obsolete ioctls and capabilities 6457^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 6458 6459KVM_CAP_DISABLE_QUIRKS does not let userspace know which quirks are actually 6460available. Use ``KVM_CHECK_EXTENSION(KVM_CAP_DISABLE_QUIRKS2)`` instead if 6461available. 6462 6463Ordering of KVM_GET_*/KVM_SET_* ioctls 6464^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 6465 6466TBD 6467