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 KVM_ELIDE_TLB_FLUSH_IF_YOUNG 25 select KVM_MMU_LOCKLESS_AGING 26 select HAVE_KVM_IRQCHIP 27 select HAVE_KVM_PFNCACHE 28 select HAVE_KVM_DIRTY_RING_TSO 29 select HAVE_KVM_DIRTY_RING_ACQ_REL 30 select HAVE_KVM_IRQ_BYPASS 31 select HAVE_KVM_IRQ_ROUTING 32 select HAVE_KVM_READONLY_MEM 33 select VHOST_TASK 34 select KVM_ASYNC_PF 35 select USER_RETURN_NOTIFIER 36 select KVM_MMIO 37 select SCHED_INFO 38 select PERF_EVENTS 39 select GUEST_PERF_EVENTS 40 select HAVE_KVM_MSI 41 select HAVE_KVM_CPU_RELAX_INTERCEPT 42 select HAVE_KVM_NO_POLL 43 select KVM_XFER_TO_GUEST_WORK 44 select KVM_GENERIC_DIRTYLOG_READ_PROTECT 45 select KVM_VFIO 46 select HAVE_KVM_PM_NOTIFIER if PM 47 select KVM_GENERIC_HARDWARE_ENABLING 48 select KVM_GENERIC_PRE_FAULT_MEMORY 49 select KVM_GENERIC_PRIVATE_MEM if KVM_SW_PROTECTED_VM 50 select KVM_WERROR if WERROR 51 52config KVM 53 tristate "Kernel-based Virtual Machine (KVM) support" 54 depends on X86_LOCAL_APIC 55 help 56 Support hosting fully virtualized guest machines using hardware 57 virtualization extensions. You will need a fairly recent 58 processor equipped with virtualization extensions. You will also 59 need to select one or more of the processor modules below. 60 61 This module provides access to the hardware capabilities through 62 a character device node named /dev/kvm. 63 64 To compile this as a module, choose M here: the module 65 will be called kvm. 66 67 If unsure, say N. 68 69config KVM_WERROR 70 bool "Compile KVM with -Werror" 71 # Disallow KVM's -Werror if KASAN is enabled, e.g. to guard against 72 # randomized configs from selecting KVM_WERROR=y, which doesn't play 73 # nice with KASAN. KASAN builds generates warnings for the default 74 # FRAME_WARN, i.e. KVM_WERROR=y with KASAN=y requires special tuning. 75 # Building KVM with -Werror and KASAN is still doable via enabling 76 # the kernel-wide WERROR=y. 77 depends on KVM && ((EXPERT && !KASAN) || WERROR) 78 help 79 Add -Werror to the build flags for KVM. 80 81 If in doubt, say "N". 82 83config KVM_SW_PROTECTED_VM 84 bool "Enable support for KVM software-protected VMs" 85 depends on EXPERT 86 depends on KVM && X86_64 87 help 88 Enable support for KVM software-protected VMs. Currently, software- 89 protected VMs are purely a development and testing vehicle for 90 KVM_CREATE_GUEST_MEMFD. Attempting to run a "real" VM workload as a 91 software-protected VM will fail miserably. 92 93 If unsure, say "N". 94 95config KVM_INTEL 96 tristate "KVM for Intel (and compatible) processors support" 97 depends on KVM && IA32_FEAT_CTL 98 help 99 Provides support for KVM on processors equipped with Intel's VT 100 extensions, a.k.a. Virtual Machine Extensions (VMX). 101 102 To compile this as a module, choose M here: the module 103 will be called kvm-intel. 104 105config KVM_INTEL_PROVE_VE 106 bool "Check that guests do not receive #VE exceptions" 107 depends on KVM_INTEL && EXPERT 108 help 109 Checks that KVM's page table management code will not incorrectly 110 let guests receive a virtualization exception. Virtualization 111 exceptions will be trapped by the hypervisor rather than injected 112 in the guest. 113 114 Note: some CPUs appear to generate spurious EPT Violations #VEs 115 that trigger KVM's WARN, in particular with eptad=0 and/or nested 116 virtualization. 117 118 If unsure, say N. 119 120config X86_SGX_KVM 121 bool "Software Guard eXtensions (SGX) Virtualization" 122 depends on X86_SGX && KVM_INTEL 123 help 124 125 Enables KVM guests to create SGX enclaves. 126 127 This includes support to expose "raw" unreclaimable enclave memory to 128 guests via a device node, e.g. /dev/sgx_vepc. 129 130 If unsure, say N. 131 132config KVM_AMD 133 tristate "KVM for AMD processors support" 134 depends on KVM && (CPU_SUP_AMD || CPU_SUP_HYGON) 135 help 136 Provides support for KVM on AMD processors equipped with the AMD-V 137 (SVM) extensions. 138 139 To compile this as a module, choose M here: the module 140 will be called kvm-amd. 141 142config KVM_AMD_SEV 143 bool "AMD Secure Encrypted Virtualization (SEV) support" 144 default y 145 depends on KVM_AMD && X86_64 146 depends on CRYPTO_DEV_SP_PSP && !(KVM_AMD=y && CRYPTO_DEV_CCP_DD=m) 147 select ARCH_HAS_CC_PLATFORM 148 select KVM_GENERIC_PRIVATE_MEM 149 select HAVE_KVM_ARCH_GMEM_PREPARE 150 select HAVE_KVM_ARCH_GMEM_INVALIDATE 151 help 152 Provides support for launching encrypted VMs which use Secure 153 Encrypted Virtualization (SEV), Secure Encrypted Virtualization with 154 Encrypted State (SEV-ES), and Secure Encrypted Virtualization with 155 Secure Nested Paging (SEV-SNP) technologies on AMD processors. 156 157config KVM_SMM 158 bool "System Management Mode emulation" 159 default y 160 depends on KVM 161 help 162 Provides support for KVM to emulate System Management Mode (SMM) 163 in virtual machines. This can be used by the virtual machine 164 firmware to implement UEFI secure boot. 165 166 If unsure, say Y. 167 168config KVM_HYPERV 169 bool "Support for Microsoft Hyper-V emulation" 170 depends on KVM 171 default y 172 help 173 Provides KVM support for emulating Microsoft Hyper-V. This allows KVM 174 to expose a subset of the paravirtualized interfaces defined in the 175 Hyper-V Hypervisor Top-Level Functional Specification (TLFS): 176 https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/reference/tlfs 177 These interfaces are required for the correct and performant functioning 178 of Windows and Hyper-V guests on KVM. 179 180 If unsure, say "Y". 181 182config KVM_XEN 183 bool "Support for Xen hypercall interface" 184 depends on KVM 185 help 186 Provides KVM support for the hosting Xen HVM guests and 187 passing Xen hypercalls to userspace. 188 189 If in doubt, say "N". 190 191config KVM_PROVE_MMU 192 bool "Prove KVM MMU correctness" 193 depends on DEBUG_KERNEL 194 depends on KVM 195 depends on EXPERT 196 help 197 Enables runtime assertions in KVM's MMU that are too costly to enable 198 in anything remotely resembling a production environment, e.g. this 199 gates code that verifies a to-be-freed page table doesn't have any 200 present SPTEs. 201 202 If in doubt, say "N". 203 204config KVM_EXTERNAL_WRITE_TRACKING 205 bool 206 207config KVM_MAX_NR_VCPUS 208 int "Maximum number of vCPUs per KVM guest" 209 depends on KVM 210 range 1024 4096 211 default 4096 if MAXSMP 212 default 1024 213 help 214 Set the maximum number of vCPUs per KVM guest. Larger values will increase 215 the memory footprint of each KVM guest, regardless of how many vCPUs are 216 created for a given VM. 217 218endif # VIRTUALIZATION 219