# SPDX-License-Identifier: GPL-2.0 # # KVM configuration # source "virt/kvm/Kconfig" menuconfig VIRTUALIZATION bool "Virtualization" default y help Say Y here to get to see options for using your Linux host to run other operating systems inside virtual machines (guests). This option alone does not add any kernel code. If you say N, all options in this submenu will be skipped and disabled. if VIRTUALIZATION config KVM tristate "Kernel-based Virtual Machine (KVM) support" depends on HIGH_RES_TIMERS depends on X86_LOCAL_APIC select KVM_COMMON select KVM_GENERIC_MMU_NOTIFIER select HAVE_KVM_IRQCHIP select HAVE_KVM_PFNCACHE select HAVE_KVM_DIRTY_RING_TSO select HAVE_KVM_DIRTY_RING_ACQ_REL select HAVE_KVM_IRQ_BYPASS select HAVE_KVM_IRQ_ROUTING select HAVE_KVM_READONLY_MEM select KVM_ASYNC_PF select USER_RETURN_NOTIFIER select KVM_MMIO select SCHED_INFO select PERF_EVENTS select GUEST_PERF_EVENTS select HAVE_KVM_MSI select HAVE_KVM_CPU_RELAX_INTERCEPT select HAVE_KVM_NO_POLL select KVM_XFER_TO_GUEST_WORK select KVM_GENERIC_DIRTYLOG_READ_PROTECT select KVM_VFIO select HAVE_KVM_PM_NOTIFIER if PM select KVM_GENERIC_HARDWARE_ENABLING select KVM_GENERIC_PRE_FAULT_MEMORY select KVM_WERROR if WERROR help Support hosting fully virtualized guest machines using hardware virtualization extensions. You will need a fairly recent processor equipped with virtualization extensions. You will also need to select one or more of the processor modules below. This module provides access to the hardware capabilities through a character device node named /dev/kvm. To compile this as a module, choose M here: the module will be called kvm. If unsure, say N. config KVM_WERROR bool "Compile KVM with -Werror" # Disallow KVM's -Werror if KASAN is enabled, e.g. to guard against # randomized configs from selecting KVM_WERROR=y, which doesn't play # nice with KASAN. KASAN builds generates warnings for the default # FRAME_WARN, i.e. KVM_WERROR=y with KASAN=y requires special tuning. # Building KVM with -Werror and KASAN is still doable via enabling # the kernel-wide WERROR=y. depends on KVM && ((EXPERT && !KASAN) || WERROR) help Add -Werror to the build flags for KVM. If in doubt, say "N". config KVM_SW_PROTECTED_VM bool "Enable support for KVM software-protected VMs" depends on EXPERT depends on KVM && X86_64 select KVM_GENERIC_PRIVATE_MEM help Enable support for KVM software-protected VMs. Currently, software- protected VMs are purely a development and testing vehicle for KVM_CREATE_GUEST_MEMFD. Attempting to run a "real" VM workload as a software-protected VM will fail miserably. If unsure, say "N". config KVM_INTEL tristate "KVM for Intel (and compatible) processors support" depends on KVM && IA32_FEAT_CTL help Provides support for KVM on processors equipped with Intel's VT extensions, a.k.a. Virtual Machine Extensions (VMX). To compile this as a module, choose M here: the module will be called kvm-intel. config KVM_INTEL_PROVE_VE bool "Check that guests do not receive #VE exceptions" depends on KVM_INTEL && EXPERT help Checks that KVM's page table management code will not incorrectly let guests receive a virtualization exception. Virtualization exceptions will be trapped by the hypervisor rather than injected in the guest. Note: some CPUs appear to generate spurious EPT Violations #VEs that trigger KVM's WARN, in particular with eptad=0 and/or nested virtualization. If unsure, say N. config X86_SGX_KVM bool "Software Guard eXtensions (SGX) Virtualization" depends on X86_SGX && KVM_INTEL help Enables KVM guests to create SGX enclaves. This includes support to expose "raw" unreclaimable enclave memory to guests via a device node, e.g. /dev/sgx_vepc. If unsure, say N. config KVM_AMD tristate "KVM for AMD processors support" depends on KVM && (CPU_SUP_AMD || CPU_SUP_HYGON) help Provides support for KVM on AMD processors equipped with the AMD-V (SVM) extensions. To compile this as a module, choose M here: the module will be called kvm-amd. config KVM_AMD_SEV bool "AMD Secure Encrypted Virtualization (SEV) support" default y depends on KVM_AMD && X86_64 depends on CRYPTO_DEV_SP_PSP && !(KVM_AMD=y && CRYPTO_DEV_CCP_DD=m) select ARCH_HAS_CC_PLATFORM select KVM_GENERIC_PRIVATE_MEM select HAVE_KVM_GMEM_PREPARE select HAVE_KVM_GMEM_INVALIDATE help Provides support for launching Encrypted VMs (SEV) and Encrypted VMs with Encrypted State (SEV-ES) on AMD processors. config KVM_SMM bool "System Management Mode emulation" default y depends on KVM help Provides support for KVM to emulate System Management Mode (SMM) in virtual machines. This can be used by the virtual machine firmware to implement UEFI secure boot. If unsure, say Y. config KVM_HYPERV bool "Support for Microsoft Hyper-V emulation" depends on KVM default y help Provides KVM support for emulating Microsoft Hyper-V. This allows KVM to expose a subset of the paravirtualized interfaces defined in the Hyper-V Hypervisor Top-Level Functional Specification (TLFS): https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/reference/tlfs These interfaces are required for the correct and performant functioning of Windows and Hyper-V guests on KVM. If unsure, say "Y". config KVM_XEN bool "Support for Xen hypercall interface" depends on KVM help Provides KVM support for the hosting Xen HVM guests and passing Xen hypercalls to userspace. If in doubt, say "N". config KVM_PROVE_MMU bool "Prove KVM MMU correctness" depends on DEBUG_KERNEL depends on KVM depends on EXPERT help Enables runtime assertions in KVM's MMU that are too costly to enable in anything remotely resembling a production environment, e.g. this gates code that verifies a to-be-freed page table doesn't have any present SPTEs. If in doubt, say "N". config KVM_EXTERNAL_WRITE_TRACKING bool config KVM_MAX_NR_VCPUS int "Maximum number of vCPUs per KVM guest" depends on KVM range 1024 4096 default 4096 if MAXSMP default 1024 help Set the maximum number of vCPUs per KVM guest. Larger values will increase the memory footprint of each KVM guest, regardless of how many vCPUs are created for a given VM. endif # VIRTUALIZATION