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