xref: /linux/arch/x86/kvm/Kconfig (revision db624e82c55f227b84ac9ebfa3de2f6f5fad666b)
1# SPDX-License-Identifier: GPL-2.0
2#
3# KVM configuration
4#
5
6source "virt/kvm/Kconfig"
7
8menuconfig VIRTUALIZATION
9	bool "Virtualization"
10	depends on HAVE_KVM || X86
11	default y
12	help
13	  Say Y here to get to see options for using your Linux host to run other
14	  operating systems inside virtual machines (guests).
15	  This option alone does not add any kernel code.
16
17	  If you say N, all options in this submenu will be skipped and disabled.
18
19if VIRTUALIZATION
20
21config KVM
22	tristate "Kernel-based Virtual Machine (KVM) support"
23	depends on HAVE_KVM
24	depends on HIGH_RES_TIMERS
25	depends on X86_LOCAL_APIC
26	select KVM_COMMON
27	select KVM_GENERIC_MMU_NOTIFIER
28	select HAVE_KVM_IRQCHIP
29	select HAVE_KVM_PFNCACHE
30	select HAVE_KVM_DIRTY_RING_TSO
31	select HAVE_KVM_DIRTY_RING_ACQ_REL
32	select IRQ_BYPASS_MANAGER
33	select HAVE_KVM_IRQ_BYPASS
34	select HAVE_KVM_IRQ_ROUTING
35	select KVM_ASYNC_PF
36	select USER_RETURN_NOTIFIER
37	select KVM_MMIO
38	select SCHED_INFO
39	select PERF_EVENTS
40	select GUEST_PERF_EVENTS
41	select HAVE_KVM_MSI
42	select HAVE_KVM_CPU_RELAX_INTERCEPT
43	select HAVE_KVM_NO_POLL
44	select KVM_XFER_TO_GUEST_WORK
45	select KVM_GENERIC_DIRTYLOG_READ_PROTECT
46	select KVM_VFIO
47	select HAVE_KVM_PM_NOTIFIER if PM
48	select KVM_GENERIC_HARDWARE_ENABLING
49	help
50	  Support hosting fully virtualized guest machines using hardware
51	  virtualization extensions.  You will need a fairly recent
52	  processor equipped with virtualization extensions. You will also
53	  need to select one or more of the processor modules below.
54
55	  This module provides access to the hardware capabilities through
56	  a character device node named /dev/kvm.
57
58	  To compile this as a module, choose M here: the module
59	  will be called kvm.
60
61	  If unsure, say N.
62
63config KVM_WERROR
64	bool "Compile KVM with -Werror"
65	# Disallow KVM's -Werror if KASAN is enabled, e.g. to guard against
66	# randomized configs from selecting KVM_WERROR=y, which doesn't play
67	# nice with KASAN.  KASAN builds generates warnings for the default
68	# FRAME_WARN, i.e. KVM_WERROR=y with KASAN=y requires special tuning.
69	# Building KVM with -Werror and KASAN is still doable via enabling
70	# the kernel-wide WERROR=y.
71	depends on KVM && EXPERT && !KASAN
72	help
73	  Add -Werror to the build flags for KVM.
74
75	  If in doubt, say "N".
76
77config KVM_SW_PROTECTED_VM
78	bool "Enable support for KVM software-protected VMs"
79	depends on EXPERT
80	depends on KVM && X86_64
81	select KVM_GENERIC_PRIVATE_MEM
82	help
83	  Enable support for KVM software-protected VMs.  Currently, software-
84	  protected VMs are purely a development and testing vehicle for
85	  KVM_CREATE_GUEST_MEMFD.  Attempting to run a "real" VM workload as a
86	  software-protected VM will fail miserably.
87
88	  If unsure, say "N".
89
90config KVM_INTEL
91	tristate "KVM for Intel (and compatible) processors support"
92	depends on KVM && IA32_FEAT_CTL
93	help
94	  Provides support for KVM on processors equipped with Intel's VT
95	  extensions, a.k.a. Virtual Machine Extensions (VMX).
96
97	  To compile this as a module, choose M here: the module
98	  will be called kvm-intel.
99
100config X86_SGX_KVM
101	bool "Software Guard eXtensions (SGX) Virtualization"
102	depends on X86_SGX && KVM_INTEL
103	help
104
105	  Enables KVM guests to create SGX enclaves.
106
107	  This includes support to expose "raw" unreclaimable enclave memory to
108	  guests via a device node, e.g. /dev/sgx_vepc.
109
110	  If unsure, say N.
111
112config KVM_AMD
113	tristate "KVM for AMD processors support"
114	depends on KVM && (CPU_SUP_AMD || CPU_SUP_HYGON)
115	help
116	  Provides support for KVM on AMD processors equipped with the AMD-V
117	  (SVM) extensions.
118
119	  To compile this as a module, choose M here: the module
120	  will be called kvm-amd.
121
122config KVM_AMD_SEV
123	def_bool y
124	bool "AMD Secure Encrypted Virtualization (SEV) support"
125	depends on KVM_AMD && X86_64
126	depends on CRYPTO_DEV_SP_PSP && !(KVM_AMD=y && CRYPTO_DEV_CCP_DD=m)
127	help
128	  Provides support for launching Encrypted VMs (SEV) and Encrypted VMs
129	  with Encrypted State (SEV-ES) on AMD processors.
130
131config KVM_SMM
132	bool "System Management Mode emulation"
133	default y
134	depends on KVM
135	help
136	  Provides support for KVM to emulate System Management Mode (SMM)
137	  in virtual machines.  This can be used by the virtual machine
138	  firmware to implement UEFI secure boot.
139
140	  If unsure, say Y.
141
142config KVM_HYPERV
143	bool "Support for Microsoft Hyper-V emulation"
144	depends on KVM
145	default y
146	help
147	  Provides KVM support for emulating Microsoft Hyper-V.  This allows KVM
148	  to expose a subset of the paravirtualized interfaces defined in the
149	  Hyper-V Hypervisor Top-Level Functional Specification (TLFS):
150	  https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/reference/tlfs
151	  These interfaces are required for the correct and performant functioning
152	  of Windows and Hyper-V guests on KVM.
153
154	  If unsure, say "Y".
155
156config KVM_XEN
157	bool "Support for Xen hypercall interface"
158	depends on KVM
159	help
160	  Provides KVM support for the hosting Xen HVM guests and
161	  passing Xen hypercalls to userspace.
162
163	  If in doubt, say "N".
164
165config KVM_PROVE_MMU
166	bool "Prove KVM MMU correctness"
167	depends on DEBUG_KERNEL
168	depends on KVM
169	depends on EXPERT
170	help
171	  Enables runtime assertions in KVM's MMU that are too costly to enable
172	  in anything remotely resembling a production environment, e.g. this
173	  gates code that verifies a to-be-freed page table doesn't have any
174	  present SPTEs.
175
176	  If in doubt, say "N".
177
178config KVM_EXTERNAL_WRITE_TRACKING
179	bool
180
181config KVM_MAX_NR_VCPUS
182	int "Maximum number of vCPUs per KVM guest"
183	depends on KVM
184	range 1024 4096
185	default 4096 if MAXSMP
186	default 1024
187	help
188	  Set the maximum number of vCPUs per KVM guest. Larger values will increase
189	  the memory footprint of each KVM guest, regardless of how many vCPUs are
190	  created for a given VM.
191
192endif # VIRTUALIZATION
193