1# SPDX-License-Identifier: GPL-2.0 2# 3# KVM configuration 4# 5 6source "virt/kvm/Kconfig" 7 8menuconfig VIRTUALIZATION 9 bool "Virtualization" 10 default y 11 help 12 Say Y here to get to see options for using your Linux host to run other 13 operating systems inside virtual machines (guests). 14 This option alone does not add any kernel code. 15 16 If you say N, all options in this submenu will be skipped and disabled. 17 18if VIRTUALIZATION 19 20config KVM_X86 21 def_tristate KVM if (KVM_INTEL != n || KVM_AMD != n) 22 select KVM_COMMON 23 select KVM_GENERIC_MMU_NOTIFIER 24 select HAVE_KVM_IRQCHIP 25 select HAVE_KVM_PFNCACHE 26 select HAVE_KVM_DIRTY_RING_TSO 27 select HAVE_KVM_DIRTY_RING_ACQ_REL 28 select HAVE_KVM_IRQ_BYPASS 29 select HAVE_KVM_IRQ_ROUTING 30 select HAVE_KVM_READONLY_MEM 31 select VHOST_TASK 32 select KVM_ASYNC_PF 33 select USER_RETURN_NOTIFIER 34 select KVM_MMIO 35 select SCHED_INFO 36 select PERF_EVENTS 37 select GUEST_PERF_EVENTS 38 select HAVE_KVM_MSI 39 select HAVE_KVM_CPU_RELAX_INTERCEPT 40 select HAVE_KVM_NO_POLL 41 select KVM_XFER_TO_GUEST_WORK 42 select KVM_GENERIC_DIRTYLOG_READ_PROTECT 43 select KVM_VFIO 44 select HAVE_KVM_PM_NOTIFIER if PM 45 select KVM_GENERIC_HARDWARE_ENABLING 46 select KVM_GENERIC_PRE_FAULT_MEMORY 47 select KVM_GENERIC_PRIVATE_MEM if KVM_SW_PROTECTED_VM 48 select KVM_WERROR if WERROR 49 50config KVM 51 tristate "Kernel-based Virtual Machine (KVM) support" 52 depends on X86_LOCAL_APIC 53 help 54 Support hosting fully virtualized guest machines using hardware 55 virtualization extensions. You will need a fairly recent 56 processor equipped with virtualization extensions. You will also 57 need to select one or more of the processor modules below. 58 59 This module provides access to the hardware capabilities through 60 a character device node named /dev/kvm. 61 62 To compile this as a module, choose M here: the module 63 will be called kvm. 64 65 If unsure, say N. 66 67config KVM_WERROR 68 bool "Compile KVM with -Werror" 69 # Disallow KVM's -Werror if KASAN is enabled, e.g. to guard against 70 # randomized configs from selecting KVM_WERROR=y, which doesn't play 71 # nice with KASAN. KASAN builds generates warnings for the default 72 # FRAME_WARN, i.e. KVM_WERROR=y with KASAN=y requires special tuning. 73 # Building KVM with -Werror and KASAN is still doable via enabling 74 # the kernel-wide WERROR=y. 75 depends on KVM && ((EXPERT && !KASAN) || WERROR) 76 help 77 Add -Werror to the build flags for KVM. 78 79 If in doubt, say "N". 80 81config KVM_SW_PROTECTED_VM 82 bool "Enable support for KVM software-protected VMs" 83 depends on EXPERT 84 depends on KVM && X86_64 85 help 86 Enable support for KVM software-protected VMs. Currently, software- 87 protected VMs are purely a development and testing vehicle for 88 KVM_CREATE_GUEST_MEMFD. Attempting to run a "real" VM workload as a 89 software-protected VM will fail miserably. 90 91 If unsure, say "N". 92 93config KVM_INTEL 94 tristate "KVM for Intel (and compatible) processors support" 95 depends on KVM && IA32_FEAT_CTL 96 help 97 Provides support for KVM on processors equipped with Intel's VT 98 extensions, a.k.a. Virtual Machine Extensions (VMX). 99 100 To compile this as a module, choose M here: the module 101 will be called kvm-intel. 102 103config KVM_INTEL_PROVE_VE 104 bool "Check that guests do not receive #VE exceptions" 105 depends on KVM_INTEL && EXPERT 106 help 107 Checks that KVM's page table management code will not incorrectly 108 let guests receive a virtualization exception. Virtualization 109 exceptions will be trapped by the hypervisor rather than injected 110 in the guest. 111 112 Note: some CPUs appear to generate spurious EPT Violations #VEs 113 that trigger KVM's WARN, in particular with eptad=0 and/or nested 114 virtualization. 115 116 If unsure, say N. 117 118config X86_SGX_KVM 119 bool "Software Guard eXtensions (SGX) Virtualization" 120 depends on X86_SGX && KVM_INTEL 121 help 122 123 Enables KVM guests to create SGX enclaves. 124 125 This includes support to expose "raw" unreclaimable enclave memory to 126 guests via a device node, e.g. /dev/sgx_vepc. 127 128 If unsure, say N. 129 130config KVM_AMD 131 tristate "KVM for AMD processors support" 132 depends on KVM && (CPU_SUP_AMD || CPU_SUP_HYGON) 133 help 134 Provides support for KVM on AMD processors equipped with the AMD-V 135 (SVM) extensions. 136 137 To compile this as a module, choose M here: the module 138 will be called kvm-amd. 139 140config KVM_AMD_SEV 141 bool "AMD Secure Encrypted Virtualization (SEV) support" 142 default y 143 depends on KVM_AMD && X86_64 144 depends on CRYPTO_DEV_SP_PSP && !(KVM_AMD=y && CRYPTO_DEV_CCP_DD=m) 145 select ARCH_HAS_CC_PLATFORM 146 select KVM_GENERIC_PRIVATE_MEM 147 select HAVE_KVM_ARCH_GMEM_PREPARE 148 select HAVE_KVM_ARCH_GMEM_INVALIDATE 149 help 150 Provides support for launching encrypted VMs which use Secure 151 Encrypted Virtualization (SEV), Secure Encrypted Virtualization with 152 Encrypted State (SEV-ES), and Secure Encrypted Virtualization with 153 Secure Nested Paging (SEV-SNP) technologies on AMD processors. 154 155config KVM_SMM 156 bool "System Management Mode emulation" 157 default y 158 depends on KVM 159 help 160 Provides support for KVM to emulate System Management Mode (SMM) 161 in virtual machines. This can be used by the virtual machine 162 firmware to implement UEFI secure boot. 163 164 If unsure, say Y. 165 166config KVM_HYPERV 167 bool "Support for Microsoft Hyper-V emulation" 168 depends on KVM 169 default y 170 help 171 Provides KVM support for emulating Microsoft Hyper-V. This allows KVM 172 to expose a subset of the paravirtualized interfaces defined in the 173 Hyper-V Hypervisor Top-Level Functional Specification (TLFS): 174 https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/reference/tlfs 175 These interfaces are required for the correct and performant functioning 176 of Windows and Hyper-V guests on KVM. 177 178 If unsure, say "Y". 179 180config KVM_XEN 181 bool "Support for Xen hypercall interface" 182 depends on KVM 183 help 184 Provides KVM support for the hosting Xen HVM guests and 185 passing Xen hypercalls to userspace. 186 187 If in doubt, say "N". 188 189config KVM_PROVE_MMU 190 bool "Prove KVM MMU correctness" 191 depends on DEBUG_KERNEL 192 depends on KVM 193 depends on EXPERT 194 help 195 Enables runtime assertions in KVM's MMU that are too costly to enable 196 in anything remotely resembling a production environment, e.g. this 197 gates code that verifies a to-be-freed page table doesn't have any 198 present SPTEs. 199 200 If in doubt, say "N". 201 202config KVM_EXTERNAL_WRITE_TRACKING 203 bool 204 205config KVM_MAX_NR_VCPUS 206 int "Maximum number of vCPUs per KVM guest" 207 depends on KVM 208 range 1024 4096 209 default 4096 if MAXSMP 210 default 1024 211 help 212 Set the maximum number of vCPUs per KVM guest. Larger values will increase 213 the memory footprint of each KVM guest, regardless of how many vCPUs are 214 created for a given VM. 215 216endif # VIRTUALIZATION 217