tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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_SMM
170 bool "System Management Mode emulation"
171 default y
172 depends on KVM
173 help
174 Provides support for KVM to emulate System Management Mode (SMM)
175 in virtual machines. This can be used by the virtual machine
176 firmware to implement UEFI secure boot.
177
178 If unsure, say Y.
179
180config KVM_HYPERV
181 bool "Support for Microsoft Hyper-V emulation"
182 depends on KVM
183 default y
184 help
185 Provides KVM support for emulating Microsoft Hyper-V. This allows KVM
186 to expose a subset of the paravirtualized interfaces defined in the
187 Hyper-V Hypervisor Top-Level Functional Specification (TLFS):
188 https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/reference/tlfs
189 These interfaces are required for the correct and performant functioning
190 of Windows and Hyper-V guests on KVM.
191
192 If unsure, say "Y".
193
194config KVM_XEN
195 bool "Support for Xen hypercall interface"
196 depends on KVM
197 help
198 Provides KVM support for the hosting Xen HVM guests and
199 passing Xen hypercalls to userspace.
200
201 If in doubt, say "N".
202
203config KVM_PROVE_MMU
204 bool "Prove KVM MMU correctness"
205 depends on DEBUG_KERNEL
206 depends on KVM
207 depends on EXPERT
208 help
209 Enables runtime assertions in KVM's MMU that are too costly to enable
210 in anything remotely resembling a production environment, e.g. this
211 gates code that verifies a to-be-freed page table doesn't have any
212 present SPTEs.
213
214 If in doubt, say "N".
215
216config KVM_EXTERNAL_WRITE_TRACKING
217 bool
218
219config KVM_MAX_NR_VCPUS
220 int "Maximum number of vCPUs per KVM guest"
221 depends on KVM
222 range 1024 4096
223 default 4096 if MAXSMP
224 default 1024
225 help
226 Set the maximum number of vCPUs per KVM guest. Larger values will increase
227 the memory footprint of each KVM guest, regardless of how many vCPUs are
228 created for a given VM.
229
230endif # VIRTUALIZATION