1# SPDX-License-Identifier: GPL-2.0 2config MMU 3 def_bool y 4 5config CPU_BIG_ENDIAN 6 def_bool y 7 8config LOCKDEP_SUPPORT 9 def_bool y 10 11config STACKTRACE_SUPPORT 12 def_bool y 13 14config ARCH_HAS_ILOG2_U32 15 def_bool n 16 17config ARCH_HAS_ILOG2_U64 18 def_bool n 19 20config GENERIC_HWEIGHT 21 def_bool y 22 23config GENERIC_BUG 24 def_bool y if BUG 25 26config GENERIC_BUG_RELATIVE_POINTERS 27 def_bool y 28 29config GENERIC_LOCKBREAK 30 def_bool y if PREEMPTION 31 32config PGSTE 33 def_bool y if KVM 34 35config AUDIT_ARCH 36 def_bool y 37 38config NO_IOPORT_MAP 39 def_bool y 40 41config PCI_QUIRKS 42 def_bool n 43 44config ARCH_SUPPORTS_UPROBES 45 def_bool y 46 47config KASAN_SHADOW_OFFSET 48 hex 49 depends on KASAN 50 default 0x1C000000000000 51 52config S390 53 def_bool y 54 # 55 # Note: keep this list sorted alphabetically 56 # 57 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 58 select ARCH_32BIT_USTAT_F_TINODE 59 select ARCH_BINFMT_ELF_STATE 60 select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM 61 select ARCH_ENABLE_MEMORY_HOTREMOVE 62 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 63 select ARCH_HAS_DEBUG_VM_PGTABLE 64 select ARCH_HAS_DEBUG_WX 65 select ARCH_HAS_DEVMEM_IS_ALLOWED 66 select ARCH_HAS_ELF_RANDOMIZE 67 select ARCH_HAS_FORCE_DMA_UNENCRYPTED 68 select ARCH_HAS_FORTIFY_SOURCE 69 select ARCH_HAS_GCOV_PROFILE_ALL 70 select ARCH_HAS_GIGANTIC_PAGE 71 select ARCH_HAS_KCOV 72 select ARCH_HAS_MEM_ENCRYPT 73 select ARCH_HAS_PTE_SPECIAL 74 select ARCH_HAS_SCALED_CPUTIME 75 select ARCH_HAS_SET_MEMORY 76 select ARCH_HAS_STRICT_KERNEL_RWX 77 select ARCH_HAS_STRICT_MODULE_RWX 78 select ARCH_HAS_SYSCALL_WRAPPER 79 select ARCH_HAS_UBSAN_SANITIZE_ALL 80 select ARCH_HAS_VDSO_DATA 81 select ARCH_HAVE_NMI_SAFE_CMPXCHG 82 select ARCH_INLINE_READ_LOCK 83 select ARCH_INLINE_READ_LOCK_BH 84 select ARCH_INLINE_READ_LOCK_IRQ 85 select ARCH_INLINE_READ_LOCK_IRQSAVE 86 select ARCH_INLINE_READ_TRYLOCK 87 select ARCH_INLINE_READ_UNLOCK 88 select ARCH_INLINE_READ_UNLOCK_BH 89 select ARCH_INLINE_READ_UNLOCK_IRQ 90 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE 91 select ARCH_INLINE_SPIN_LOCK 92 select ARCH_INLINE_SPIN_LOCK_BH 93 select ARCH_INLINE_SPIN_LOCK_IRQ 94 select ARCH_INLINE_SPIN_LOCK_IRQSAVE 95 select ARCH_INLINE_SPIN_TRYLOCK 96 select ARCH_INLINE_SPIN_TRYLOCK_BH 97 select ARCH_INLINE_SPIN_UNLOCK 98 select ARCH_INLINE_SPIN_UNLOCK_BH 99 select ARCH_INLINE_SPIN_UNLOCK_IRQ 100 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE 101 select ARCH_INLINE_WRITE_LOCK 102 select ARCH_INLINE_WRITE_LOCK_BH 103 select ARCH_INLINE_WRITE_LOCK_IRQ 104 select ARCH_INLINE_WRITE_LOCK_IRQSAVE 105 select ARCH_INLINE_WRITE_TRYLOCK 106 select ARCH_INLINE_WRITE_UNLOCK 107 select ARCH_INLINE_WRITE_UNLOCK_BH 108 select ARCH_INLINE_WRITE_UNLOCK_IRQ 109 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE 110 select ARCH_STACKWALK 111 select ARCH_SUPPORTS_ATOMIC_RMW 112 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 113 select ARCH_SUPPORTS_HUGETLBFS 114 select ARCH_SUPPORTS_NUMA_BALANCING 115 select ARCH_USE_BUILTIN_BSWAP 116 select ARCH_USE_CMPXCHG_LOCKREF 117 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 118 select ARCH_WANTS_NO_INSTR 119 select ARCH_WANT_DEFAULT_BPF_JIT 120 select ARCH_WANT_IPC_PARSE_VERSION 121 select BUILDTIME_TABLE_SORT 122 select CLONE_BACKWARDS2 123 select CPU_NO_EFFICIENT_FFS if !HAVE_MARCH_Z9_109_FEATURES 124 select DMA_OPS if PCI 125 select DYNAMIC_FTRACE if FUNCTION_TRACER 126 select GENERIC_ALLOCATOR 127 select GENERIC_CPU_AUTOPROBE 128 select GENERIC_CPU_VULNERABILITIES 129 select GENERIC_ENTRY 130 select GENERIC_FIND_FIRST_BIT 131 select GENERIC_GETTIMEOFDAY 132 select GENERIC_PTDUMP 133 select GENERIC_SMP_IDLE_THREAD 134 select GENERIC_TIME_VSYSCALL 135 select GENERIC_VDSO_TIME_NS 136 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 137 select HAVE_ARCH_AUDITSYSCALL 138 select HAVE_ARCH_JUMP_LABEL 139 select HAVE_ARCH_JUMP_LABEL_RELATIVE 140 select HAVE_ARCH_KASAN 141 select HAVE_ARCH_KASAN_VMALLOC 142 select HAVE_ARCH_KCSAN 143 select HAVE_ARCH_KFENCE 144 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 145 select HAVE_ARCH_SECCOMP_FILTER 146 select HAVE_ARCH_SOFT_DIRTY 147 select HAVE_ARCH_TRACEHOOK 148 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 149 select HAVE_ARCH_VMAP_STACK 150 select HAVE_ASM_MODVERSIONS 151 select HAVE_CMPXCHG_DOUBLE 152 select HAVE_CMPXCHG_LOCAL 153 select HAVE_DEBUG_KMEMLEAK 154 select HAVE_DMA_CONTIGUOUS 155 select HAVE_DYNAMIC_FTRACE 156 select HAVE_DYNAMIC_FTRACE_WITH_REGS 157 select HAVE_EBPF_JIT if PACK_STACK && HAVE_MARCH_Z196_FEATURES 158 select HAVE_EFFICIENT_UNALIGNED_ACCESS 159 select HAVE_FAST_GUP 160 select HAVE_FENTRY 161 select HAVE_FTRACE_MCOUNT_RECORD 162 select HAVE_FUNCTION_ERROR_INJECTION 163 select HAVE_FUNCTION_GRAPH_TRACER 164 select HAVE_FUNCTION_TRACER 165 select HAVE_FUTEX_CMPXCHG if FUTEX 166 select HAVE_GCC_PLUGINS 167 select HAVE_GENERIC_VDSO 168 select HAVE_IOREMAP_PROT if PCI 169 select HAVE_KERNEL_BZIP2 170 select HAVE_KERNEL_GZIP 171 select HAVE_KERNEL_LZ4 172 select HAVE_KERNEL_LZMA 173 select HAVE_KERNEL_LZO 174 select HAVE_KERNEL_UNCOMPRESSED 175 select HAVE_KERNEL_XZ 176 select HAVE_KERNEL_ZSTD 177 select HAVE_KPROBES 178 select HAVE_KPROBES_ON_FTRACE 179 select HAVE_KRETPROBES 180 select HAVE_KVM 181 select HAVE_LIVEPATCH 182 select HAVE_MEMBLOCK_PHYS_MAP 183 select HAVE_MOD_ARCH_SPECIFIC 184 select HAVE_NMI 185 select HAVE_NOP_MCOUNT 186 select HAVE_PCI 187 select HAVE_PERF_EVENTS 188 select HAVE_PERF_REGS 189 select HAVE_PERF_USER_STACK_DUMP 190 select HAVE_REGS_AND_STACK_ACCESS_API 191 select HAVE_RELIABLE_STACKTRACE 192 select HAVE_RSEQ 193 select HAVE_SOFTIRQ_ON_OWN_STACK 194 select HAVE_SYSCALL_TRACEPOINTS 195 select HAVE_VIRT_CPU_ACCOUNTING 196 select HAVE_VIRT_CPU_ACCOUNTING_IDLE 197 select IOMMU_HELPER if PCI 198 select IOMMU_SUPPORT if PCI 199 select MMU_GATHER_NO_GATHER 200 select MMU_GATHER_RCU_TABLE_FREE 201 select MODULES_USE_ELF_RELA 202 select NEED_DMA_MAP_STATE if PCI 203 select NEED_SG_DMA_LENGTH if PCI 204 select OLD_SIGACTION 205 select OLD_SIGSUSPEND3 206 select PCI_DOMAINS if PCI 207 select PCI_MSI if PCI 208 select PCI_MSI_ARCH_FALLBACKS if PCI_MSI 209 select SPARSE_IRQ 210 select SWIOTLB 211 select SYSCTL_EXCEPTION_TRACE 212 select THREAD_INFO_IN_TASK 213 select TRACE_IRQFLAGS_SUPPORT 214 select TTY 215 select VIRT_CPU_ACCOUNTING 216 select ZONE_DMA 217 # Note: keep the above list sorted alphabetically 218 219config SCHED_OMIT_FRAME_POINTER 220 def_bool y 221 222config PGTABLE_LEVELS 223 int 224 default 5 225 226source "kernel/livepatch/Kconfig" 227 228menu "Processor type and features" 229 230config HAVE_MARCH_Z900_FEATURES 231 def_bool n 232 233config HAVE_MARCH_Z990_FEATURES 234 def_bool n 235 select HAVE_MARCH_Z900_FEATURES 236 237config HAVE_MARCH_Z9_109_FEATURES 238 def_bool n 239 select HAVE_MARCH_Z990_FEATURES 240 241config HAVE_MARCH_Z10_FEATURES 242 def_bool n 243 select HAVE_MARCH_Z9_109_FEATURES 244 245config HAVE_MARCH_Z196_FEATURES 246 def_bool n 247 select HAVE_MARCH_Z10_FEATURES 248 249config HAVE_MARCH_ZEC12_FEATURES 250 def_bool n 251 select HAVE_MARCH_Z196_FEATURES 252 253config HAVE_MARCH_Z13_FEATURES 254 def_bool n 255 select HAVE_MARCH_ZEC12_FEATURES 256 257config HAVE_MARCH_Z14_FEATURES 258 def_bool n 259 select HAVE_MARCH_Z13_FEATURES 260 261config HAVE_MARCH_Z15_FEATURES 262 def_bool n 263 select HAVE_MARCH_Z14_FEATURES 264 265choice 266 prompt "Processor type" 267 default MARCH_Z196 268 269config MARCH_Z900 270 bool "IBM zSeries model z800 and z900" 271 select HAVE_MARCH_Z900_FEATURES 272 depends on $(cc-option,-march=z900) 273 help 274 Select this to enable optimizations for model z800/z900 (2064 and 275 2066 series). This will enable some optimizations that are not 276 available on older ESA/390 (31 Bit) only CPUs. 277 278config MARCH_Z990 279 bool "IBM zSeries model z890 and z990" 280 select HAVE_MARCH_Z990_FEATURES 281 depends on $(cc-option,-march=z990) 282 help 283 Select this to enable optimizations for model z890/z990 (2084 and 284 2086 series). The kernel will be slightly faster but will not work 285 on older machines. 286 287config MARCH_Z9_109 288 bool "IBM System z9" 289 select HAVE_MARCH_Z9_109_FEATURES 290 depends on $(cc-option,-march=z9-109) 291 help 292 Select this to enable optimizations for IBM System z9 (2094 and 293 2096 series). The kernel will be slightly faster but will not work 294 on older machines. 295 296config MARCH_Z10 297 bool "IBM System z10" 298 select HAVE_MARCH_Z10_FEATURES 299 depends on $(cc-option,-march=z10) 300 help 301 Select this to enable optimizations for IBM System z10 (2097 and 302 2098 series). The kernel will be slightly faster but will not work 303 on older machines. 304 305config MARCH_Z196 306 bool "IBM zEnterprise 114 and 196" 307 select HAVE_MARCH_Z196_FEATURES 308 depends on $(cc-option,-march=z196) 309 help 310 Select this to enable optimizations for IBM zEnterprise 114 and 196 311 (2818 and 2817 series). The kernel will be slightly faster but will 312 not work on older machines. 313 314config MARCH_ZEC12 315 bool "IBM zBC12 and zEC12" 316 select HAVE_MARCH_ZEC12_FEATURES 317 depends on $(cc-option,-march=zEC12) 318 help 319 Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and 320 2827 series). The kernel will be slightly faster but will not work on 321 older machines. 322 323config MARCH_Z13 324 bool "IBM z13s and z13" 325 select HAVE_MARCH_Z13_FEATURES 326 depends on $(cc-option,-march=z13) 327 help 328 Select this to enable optimizations for IBM z13s and z13 (2965 and 329 2964 series). The kernel will be slightly faster but will not work on 330 older machines. 331 332config MARCH_Z14 333 bool "IBM z14 ZR1 and z14" 334 select HAVE_MARCH_Z14_FEATURES 335 depends on $(cc-option,-march=z14) 336 help 337 Select this to enable optimizations for IBM z14 ZR1 and z14 (3907 338 and 3906 series). The kernel will be slightly faster but will not 339 work on older machines. 340 341config MARCH_Z15 342 bool "IBM z15" 343 select HAVE_MARCH_Z15_FEATURES 344 depends on $(cc-option,-march=z15) 345 help 346 Select this to enable optimizations for IBM z15 (8562 347 and 8561 series). The kernel will be slightly faster but will not 348 work on older machines. 349 350endchoice 351 352config MARCH_Z900_TUNE 353 def_bool TUNE_Z900 || MARCH_Z900 && TUNE_DEFAULT 354 355config MARCH_Z990_TUNE 356 def_bool TUNE_Z990 || MARCH_Z990 && TUNE_DEFAULT 357 358config MARCH_Z9_109_TUNE 359 def_bool TUNE_Z9_109 || MARCH_Z9_109 && TUNE_DEFAULT 360 361config MARCH_Z10_TUNE 362 def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT 363 364config MARCH_Z196_TUNE 365 def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT 366 367config MARCH_ZEC12_TUNE 368 def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT 369 370config MARCH_Z13_TUNE 371 def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT 372 373config MARCH_Z14_TUNE 374 def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT 375 376config MARCH_Z15_TUNE 377 def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT 378 379choice 380 prompt "Tune code generation" 381 default TUNE_DEFAULT 382 help 383 Cause the compiler to tune (-mtune) the generated code for a machine. 384 This will make the code run faster on the selected machine but 385 somewhat slower on other machines. 386 This option only changes how the compiler emits instructions, not the 387 selection of instructions itself, so the resulting kernel will run on 388 all other machines. 389 390config TUNE_DEFAULT 391 bool "Default" 392 help 393 Tune the generated code for the target processor for which the kernel 394 will be compiled. 395 396config TUNE_Z900 397 bool "IBM zSeries model z800 and z900" 398 depends on $(cc-option,-mtune=z900) 399 400config TUNE_Z990 401 bool "IBM zSeries model z890 and z990" 402 depends on $(cc-option,-mtune=z990) 403 404config TUNE_Z9_109 405 bool "IBM System z9" 406 depends on $(cc-option,-mtune=z9-109) 407 408config TUNE_Z10 409 bool "IBM System z10" 410 depends on $(cc-option,-mtune=z10) 411 412config TUNE_Z196 413 bool "IBM zEnterprise 114 and 196" 414 depends on $(cc-option,-mtune=z196) 415 416config TUNE_ZEC12 417 bool "IBM zBC12 and zEC12" 418 depends on $(cc-option,-mtune=zEC12) 419 420config TUNE_Z13 421 bool "IBM z13s and z13" 422 depends on $(cc-option,-mtune=z13) 423 424config TUNE_Z14 425 bool "IBM z14 ZR1 and z14" 426 depends on $(cc-option,-mtune=z14) 427 428config TUNE_Z15 429 bool "IBM z15" 430 depends on $(cc-option,-mtune=z15) 431 432endchoice 433 434config 64BIT 435 def_bool y 436 437config COMPAT 438 def_bool y 439 prompt "Kernel support for 31 bit emulation" 440 select ARCH_WANT_OLD_COMPAT_IPC 441 select COMPAT_OLD_SIGACTION 442 select HAVE_UID16 443 depends on MULTIUSER 444 depends on !CC_IS_CLANG 445 help 446 Select this option if you want to enable your system kernel to 447 handle system-calls from ELF binaries for 31 bit ESA. This option 448 (and some other stuff like libraries and such) is needed for 449 executing 31 bit applications. It is safe to say "Y". 450 451config SYSVIPC_COMPAT 452 def_bool y if COMPAT && SYSVIPC 453 454config SMP 455 def_bool y 456 457config NR_CPUS 458 int "Maximum number of CPUs (2-512)" 459 range 2 512 460 default "64" 461 help 462 This allows you to specify the maximum number of CPUs which this 463 kernel will support. The maximum supported value is 512 and the 464 minimum value which makes sense is 2. 465 466 This is purely to save memory - each supported CPU adds 467 approximately sixteen kilobytes to the kernel image. 468 469config HOTPLUG_CPU 470 def_bool y 471 472config NUMA 473 bool "NUMA support" 474 depends on SCHED_TOPOLOGY 475 default n 476 help 477 Enable NUMA support 478 479 This option adds NUMA support to the kernel. 480 481config NODES_SHIFT 482 int 483 depends on NUMA 484 default "1" 485 486config SCHED_SMT 487 def_bool n 488 489config SCHED_MC 490 def_bool n 491 492config SCHED_BOOK 493 def_bool n 494 495config SCHED_DRAWER 496 def_bool n 497 498config SCHED_TOPOLOGY 499 def_bool y 500 prompt "Topology scheduler support" 501 select SCHED_SMT 502 select SCHED_MC 503 select SCHED_BOOK 504 select SCHED_DRAWER 505 help 506 Topology scheduler support improves the CPU scheduler's decision 507 making when dealing with machines that have multi-threading, 508 multiple cores or multiple books. 509 510source "kernel/Kconfig.hz" 511 512config KEXEC 513 def_bool y 514 select KEXEC_CORE 515 516config KEXEC_FILE 517 bool "kexec file based system call" 518 select KEXEC_CORE 519 depends on CRYPTO 520 depends on CRYPTO_SHA256 521 depends on CRYPTO_SHA256_S390 522 help 523 Enable the kexec file based system call. In contrast to the normal 524 kexec system call this system call takes file descriptors for the 525 kernel and initramfs as arguments. 526 527config ARCH_HAS_KEXEC_PURGATORY 528 def_bool y 529 depends on KEXEC_FILE 530 531config KEXEC_SIG 532 bool "Verify kernel signature during kexec_file_load() syscall" 533 depends on KEXEC_FILE && MODULE_SIG_FORMAT 534 help 535 This option makes kernel signature verification mandatory for 536 the kexec_file_load() syscall. 537 538 In addition to that option, you need to enable signature 539 verification for the corresponding kernel image type being 540 loaded in order for this to work. 541 542config ARCH_RANDOM 543 def_bool y 544 prompt "s390 architectural random number generation API" 545 help 546 Enable the s390 architectural random number generation API 547 to provide random data for all consumers within the Linux 548 kernel. 549 550 When enabled the arch_random_* functions declared in linux/random.h 551 are implemented. The implementation is based on the s390 CPACF 552 instruction subfunction TRNG which provides a real true random 553 number generator. 554 555 If unsure, say Y. 556 557config KERNEL_NOBP 558 def_bool n 559 prompt "Enable modified branch prediction for the kernel by default" 560 help 561 If this option is selected the kernel will switch to a modified 562 branch prediction mode if the firmware interface is available. 563 The modified branch prediction mode improves the behaviour in 564 regard to speculative execution. 565 566 With the option enabled the kernel parameter "nobp=0" or "nospec" 567 can be used to run the kernel in the normal branch prediction mode. 568 569 With the option disabled the modified branch prediction mode is 570 enabled with the "nobp=1" kernel parameter. 571 572 If unsure, say N. 573 574config EXPOLINE 575 def_bool n 576 prompt "Avoid speculative indirect branches in the kernel" 577 help 578 Compile the kernel with the expoline compiler options to guard 579 against kernel-to-user data leaks by avoiding speculative indirect 580 branches. 581 Requires a compiler with -mindirect-branch=thunk support for full 582 protection. The kernel may run slower. 583 584 If unsure, say N. 585 586choice 587 prompt "Expoline default" 588 depends on EXPOLINE 589 default EXPOLINE_FULL 590 591config EXPOLINE_OFF 592 bool "spectre_v2=off" 593 594config EXPOLINE_AUTO 595 bool "spectre_v2=auto" 596 597config EXPOLINE_FULL 598 bool "spectre_v2=on" 599 600endchoice 601 602config RELOCATABLE 603 bool "Build a relocatable kernel" 604 select MODULE_REL_CRCS if MODVERSIONS 605 default y 606 help 607 This builds a kernel image that retains relocation information 608 so it can be loaded at an arbitrary address. 609 The kernel is linked as a position-independent executable (PIE) 610 and contains dynamic relocations which are processed early in the 611 bootup process. 612 The relocations make the kernel image about 15% larger (compressed 613 10%), but are discarded at runtime. 614 615config RANDOMIZE_BASE 616 bool "Randomize the address of the kernel image (KASLR)" 617 depends on RELOCATABLE 618 default y 619 help 620 In support of Kernel Address Space Layout Randomization (KASLR), 621 this randomizes the address at which the kernel image is loaded, 622 as a security feature that deters exploit attempts relying on 623 knowledge of the location of kernel internals. 624 625endmenu 626 627menu "Memory setup" 628 629config ARCH_SPARSEMEM_ENABLE 630 def_bool y 631 select SPARSEMEM_VMEMMAP_ENABLE 632 select SPARSEMEM_VMEMMAP 633 634config ARCH_SPARSEMEM_DEFAULT 635 def_bool y 636 637config MAX_PHYSMEM_BITS 638 int "Maximum size of supported physical memory in bits (42-53)" 639 range 42 53 640 default "46" 641 help 642 This option specifies the maximum supported size of physical memory 643 in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB). 644 Increasing the number of bits also increases the kernel image size. 645 By default 46 bits (64TB) are supported. 646 647config PACK_STACK 648 def_bool y 649 prompt "Pack kernel stack" 650 help 651 This option enables the compiler option -mkernel-backchain if it 652 is available. If the option is available the compiler supports 653 the new stack layout which dramatically reduces the minimum stack 654 frame size. With an old compiler a non-leaf function needs a 655 minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With 656 -mkernel-backchain the minimum size drops to 16 byte on 31 bit 657 and 24 byte on 64 bit. 658 659 Say Y if you are unsure. 660 661config CHECK_STACK 662 def_bool y 663 depends on !VMAP_STACK 664 prompt "Detect kernel stack overflow" 665 help 666 This option enables the compiler option -mstack-guard and 667 -mstack-size if they are available. If the compiler supports them 668 it will emit additional code to each function prolog to trigger 669 an illegal operation if the kernel stack is about to overflow. 670 671 Say N if you are unsure. 672 673config STACK_GUARD 674 int "Size of the guard area (128-1024)" 675 range 128 1024 676 depends on CHECK_STACK 677 default "256" 678 help 679 This allows you to specify the size of the guard area at the lower 680 end of the kernel stack. If the kernel stack points into the guard 681 area on function entry an illegal operation is triggered. The size 682 needs to be a power of 2. Please keep in mind that the size of an 683 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit. 684 The minimum size for the stack guard should be 256 for 31 bit and 685 512 for 64 bit. 686 687endmenu 688 689menu "I/O subsystem" 690 691config QDIO 692 def_tristate y 693 prompt "QDIO support" 694 help 695 This driver provides the Queued Direct I/O base support for 696 IBM System z. 697 698 To compile this driver as a module, choose M here: the 699 module will be called qdio. 700 701 If unsure, say Y. 702 703if PCI 704 705config PCI_NR_FUNCTIONS 706 int "Maximum number of PCI functions (1-4096)" 707 range 1 4096 708 default "512" 709 help 710 This allows you to specify the maximum number of PCI functions which 711 this kernel will support. 712 713endif # PCI 714 715config HAS_IOMEM 716 def_bool PCI 717 718config CHSC_SCH 719 def_tristate m 720 prompt "Support for CHSC subchannels" 721 help 722 This driver allows usage of CHSC subchannels. A CHSC subchannel 723 is usually present on LPAR only. 724 The driver creates a device /dev/chsc, which may be used to 725 obtain I/O configuration information about the machine and 726 to issue asynchronous chsc commands (DANGEROUS). 727 You will usually only want to use this interface on a special 728 LPAR designated for system management. 729 730 To compile this driver as a module, choose M here: the 731 module will be called chsc_sch. 732 733 If unsure, say N. 734 735config SCM_BUS 736 def_bool y 737 prompt "SCM bus driver" 738 help 739 Bus driver for Storage Class Memory. 740 741config EADM_SCH 742 def_tristate m 743 prompt "Support for EADM subchannels" 744 depends on SCM_BUS 745 help 746 This driver allows usage of EADM subchannels. EADM subchannels act 747 as a communication vehicle for SCM increments. 748 749 To compile this driver as a module, choose M here: the 750 module will be called eadm_sch. 751 752config VFIO_CCW 753 def_tristate n 754 prompt "Support for VFIO-CCW subchannels" 755 depends on S390_CCW_IOMMU && VFIO_MDEV 756 help 757 This driver allows usage of I/O subchannels via VFIO-CCW. 758 759 To compile this driver as a module, choose M here: the 760 module will be called vfio_ccw. 761 762config VFIO_AP 763 def_tristate n 764 prompt "VFIO support for AP devices" 765 depends on S390_AP_IOMMU && VFIO_MDEV && KVM 766 depends on ZCRYPT 767 help 768 This driver grants access to Adjunct Processor (AP) devices 769 via the VFIO mediated device interface. 770 771 To compile this driver as a module, choose M here: the module 772 will be called vfio_ap. 773 774endmenu 775 776menu "Dump support" 777 778config CRASH_DUMP 779 bool "kernel crash dumps" 780 select KEXEC 781 help 782 Generate crash dump after being started by kexec. 783 Crash dump kernels are loaded in the main kernel with kexec-tools 784 into a specially reserved region and then later executed after 785 a crash by kdump/kexec. 786 Refer to <file:Documentation/s390/zfcpdump.rst> for more details on this. 787 This option also enables s390 zfcpdump. 788 See also <file:Documentation/s390/zfcpdump.rst> 789 790endmenu 791 792config CCW 793 def_bool y 794 795config HAVE_PNETID 796 tristate 797 default (SMC || CCWGROUP) 798 799menu "Virtualization" 800 801config PROTECTED_VIRTUALIZATION_GUEST 802 def_bool n 803 prompt "Protected virtualization guest support" 804 select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS 805 help 806 Select this option, if you want to be able to run this 807 kernel as a protected virtualization KVM guest. 808 Protected virtualization capable machines have a mini hypervisor 809 located at machine level (an ultravisor). With help of the 810 Ultravisor, KVM will be able to run "protected" VMs, special 811 VMs whose memory and management data are unavailable to KVM. 812 813config PFAULT 814 def_bool y 815 prompt "Pseudo page fault support" 816 help 817 Select this option, if you want to use PFAULT pseudo page fault 818 handling under VM. If running native or in LPAR, this option 819 has no effect. If your VM does not support PFAULT, PAGEEX 820 pseudo page fault handling will be used. 821 Note that VM 4.2 supports PFAULT but has a bug in its 822 implementation that causes some problems. 823 Everybody who wants to run Linux under VM != VM4.2 should select 824 this option. 825 826config CMM 827 def_tristate n 828 prompt "Cooperative memory management" 829 help 830 Select this option, if you want to enable the kernel interface 831 to reduce the memory size of the system. This is accomplished 832 by allocating pages of memory and put them "on hold". This only 833 makes sense for a system running under VM where the unused pages 834 will be reused by VM for other guest systems. The interface 835 allows an external monitor to balance memory of many systems. 836 Everybody who wants to run Linux under VM should select this 837 option. 838 839config CMM_IUCV 840 def_bool y 841 prompt "IUCV special message interface to cooperative memory management" 842 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV) 843 help 844 Select this option to enable the special message interface to 845 the cooperative memory management. 846 847config APPLDATA_BASE 848 def_bool n 849 prompt "Linux - VM Monitor Stream, base infrastructure" 850 depends on PROC_SYSCTL 851 help 852 This provides a kernel interface for creating and updating z/VM APPLDATA 853 monitor records. The monitor records are updated at certain time 854 intervals, once the timer is started. 855 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer, 856 i.e. enables or disables monitoring on the Linux side. 857 A custom interval value (in seconds) can be written to 858 /proc/appldata/interval. 859 860 Defaults are 60 seconds interval and timer off. 861 The /proc entries can also be read from, showing the current settings. 862 863config APPLDATA_MEM 864 def_tristate m 865 prompt "Monitor memory management statistics" 866 depends on APPLDATA_BASE && VM_EVENT_COUNTERS 867 help 868 This provides memory management related data to the Linux - VM Monitor 869 Stream, like paging/swapping rate, memory utilisation, etc. 870 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM 871 APPLDATA monitor record, i.e. enables or disables monitoring this record 872 on the z/VM side. 873 874 Default is disabled. 875 The /proc entry can also be read from, showing the current settings. 876 877 This can also be compiled as a module, which will be called 878 appldata_mem.o. 879 880config APPLDATA_OS 881 def_tristate m 882 prompt "Monitor OS statistics" 883 depends on APPLDATA_BASE 884 help 885 This provides OS related data to the Linux - VM Monitor Stream, like 886 CPU utilisation, etc. 887 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM 888 APPLDATA monitor record, i.e. enables or disables monitoring this record 889 on the z/VM side. 890 891 Default is disabled. 892 This can also be compiled as a module, which will be called 893 appldata_os.o. 894 895config APPLDATA_NET_SUM 896 def_tristate m 897 prompt "Monitor overall network statistics" 898 depends on APPLDATA_BASE && NET 899 help 900 This provides network related data to the Linux - VM Monitor Stream, 901 currently there is only a total sum of network I/O statistics, no 902 per-interface data. 903 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM 904 APPLDATA monitor record, i.e. enables or disables monitoring this record 905 on the z/VM side. 906 907 Default is disabled. 908 This can also be compiled as a module, which will be called 909 appldata_net_sum.o. 910 911config S390_HYPFS_FS 912 def_bool y 913 prompt "s390 hypervisor file system support" 914 select SYS_HYPERVISOR 915 help 916 This is a virtual file system intended to provide accounting 917 information in an s390 hypervisor environment. 918 919source "arch/s390/kvm/Kconfig" 920 921config S390_GUEST 922 def_bool y 923 prompt "s390 support for virtio devices" 924 select TTY 925 select VIRTUALIZATION 926 select VIRTIO 927 help 928 Enabling this option adds support for virtio based paravirtual device 929 drivers on s390. 930 931 Select this option if you want to run the kernel as a guest under 932 the KVM hypervisor. 933 934endmenu 935 936menu "Selftests" 937 938config S390_UNWIND_SELFTEST 939 def_tristate n 940 prompt "Test unwind functions" 941 help 942 This option enables s390 specific stack unwinder testing kernel 943 module. This option is not useful for distributions or general 944 kernels, but only for kernel developers working on architecture code. 945 946 Say N if you are unsure. 947 948endmenu 949