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 select KVM_GENERIC_PRIVATE_MEM if INTEL_TDX_HOST 99 select KVM_GENERIC_MEMORY_ATTRIBUTES if INTEL_TDX_HOST 100 help 101 Provides support for KVM on processors equipped with Intel's VT 102 extensions, a.k.a. Virtual Machine Extensions (VMX). 103 104 To compile this as a module, choose M here: the module 105 will be called kvm-intel. 106 107config KVM_INTEL_PROVE_VE 108 bool "Check that guests do not receive #VE exceptions" 109 depends on KVM_INTEL && EXPERT 110 help 111 Checks that KVM's page table management code will not incorrectly 112 let guests receive a virtualization exception. Virtualization 113 exceptions will be trapped by the hypervisor rather than injected 114 in the guest. 115 116 Note: some CPUs appear to generate spurious EPT Violations #VEs 117 that trigger KVM's WARN, in particular with eptad=0 and/or nested 118 virtualization. 119 120 If unsure, say N. 121 122config X86_SGX_KVM 123 bool "Software Guard eXtensions (SGX) Virtualization" 124 depends on X86_SGX && KVM_INTEL 125 help 126 127 Enables KVM guests to create SGX enclaves. 128 129 This includes support to expose "raw" unreclaimable enclave memory to 130 guests via a device node, e.g. /dev/sgx_vepc. 131 132 If unsure, say N. 133 134config KVM_INTEL_TDX 135 bool "Intel Trust Domain Extensions (TDX) support" 136 default y 137 depends on INTEL_TDX_HOST 138 help 139 Provides support for launching Intel Trust Domain Extensions (TDX) 140 confidential VMs on Intel processors. 141 142 If unsure, say N. 143 144config KVM_AMD 145 tristate "KVM for AMD processors support" 146 depends on KVM && (CPU_SUP_AMD || CPU_SUP_HYGON) 147 help 148 Provides support for KVM on AMD processors equipped with the AMD-V 149 (SVM) extensions. 150 151 To compile this as a module, choose M here: the module 152 will be called kvm-amd. 153 154config KVM_AMD_SEV 155 bool "AMD Secure Encrypted Virtualization (SEV) support" 156 default y 157 depends on KVM_AMD && X86_64 158 depends on CRYPTO_DEV_SP_PSP && !(KVM_AMD=y && CRYPTO_DEV_CCP_DD=m) 159 select ARCH_HAS_CC_PLATFORM 160 select KVM_GENERIC_PRIVATE_MEM 161 select HAVE_KVM_ARCH_GMEM_PREPARE 162 select HAVE_KVM_ARCH_GMEM_INVALIDATE 163 help 164 Provides support for launching encrypted VMs which use Secure 165 Encrypted Virtualization (SEV), Secure Encrypted Virtualization with 166 Encrypted State (SEV-ES), and Secure Encrypted Virtualization with 167 Secure Nested Paging (SEV-SNP) technologies on AMD processors. 168 169config KVM_IOAPIC 170 bool "I/O APIC, PIC, and PIT emulation" 171 default y 172 depends on KVM 173 help 174 Provides support for KVM to emulate an I/O APIC, PIC, and PIT, i.e. 175 for full in-kernel APIC emulation. 176 177 If unsure, say Y. 178 179config KVM_SMM 180 bool "System Management Mode emulation" 181 default y 182 depends on KVM 183 help 184 Provides support for KVM to emulate System Management Mode (SMM) 185 in virtual machines. This can be used by the virtual machine 186 firmware to implement UEFI secure boot. 187 188 If unsure, say Y. 189 190config KVM_HYPERV 191 bool "Support for Microsoft Hyper-V emulation" 192 depends on KVM 193 default y 194 help 195 Provides KVM support for emulating Microsoft Hyper-V. This allows KVM 196 to expose a subset of the paravirtualized interfaces defined in the 197 Hyper-V Hypervisor Top-Level Functional Specification (TLFS): 198 https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/reference/tlfs 199 These interfaces are required for the correct and performant functioning 200 of Windows and Hyper-V guests on KVM. 201 202 If unsure, say "Y". 203 204config KVM_XEN 205 bool "Support for Xen hypercall interface" 206 depends on KVM 207 help 208 Provides KVM support for the hosting Xen HVM guests and 209 passing Xen hypercalls to userspace. 210 211 If in doubt, say "N". 212 213config KVM_PROVE_MMU 214 bool "Prove KVM MMU correctness" 215 depends on DEBUG_KERNEL 216 depends on KVM 217 depends on EXPERT 218 help 219 Enables runtime assertions in KVM's MMU that are too costly to enable 220 in anything remotely resembling a production environment, e.g. this 221 gates code that verifies a to-be-freed page table doesn't have any 222 present SPTEs. 223 224 If in doubt, say "N". 225 226config KVM_EXTERNAL_WRITE_TRACKING 227 bool 228 229config KVM_MAX_NR_VCPUS 230 int "Maximum number of vCPUs per KVM guest" 231 depends on KVM 232 range 1024 4096 233 default 4096 if MAXSMP 234 default 1024 235 help 236 Set the maximum number of vCPUs per KVM guest. Larger values will increase 237 the memory footprint of each KVM guest, regardless of how many vCPUs are 238 created for a given VM. 239 240endif # VIRTUALIZATION 241