diff options
| author | Sean Christopherson <seanjc@google.com> | 2024-11-27 17:34:23 -0800 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2024-12-18 14:20:22 -0800 |
| commit | ac9d1b7591a22e63f66a8c596390eccf821885e8 (patch) | |
| tree | 4041b20e4b3799854a18e34d0d90bd5a9768daaa | |
| parent | 0fea7aa2dc6a7095fa6acc00bff2aaa108635e63 (diff) | |
KVM: x86: Explicitly track feature flags that are enabled at runtime
Add one last (hopefully) CPUID feature macro, RUNTIME_F(), and use it
to track features that KVM supports, but that are only set at runtime
(in response to other state), and aren't advertised to userspace via
KVM_GET_SUPPORTED_CPUID.
Currently, RUNTIME_F() is mostly just documentation, but tracking all
KVM-supported features will allow for asserting, at build time, take),
that all features that are set, cleared, *or* checked by KVM are known to
kvm_set_cpu_caps().
No functional change intended.
Link: https://lore.kernel.org/r/20241128013424.4096668-57-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
| -rw-r--r-- | arch/x86/kvm/cpuid.c | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 79a569bdb121..f35f99b27d02 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -790,6 +790,16 @@ do { \ }) /* + * Runtime Features - For features that KVM dynamically sets/clears at runtime, + * e.g. when CR4 changes, but which are never advertised to userspace. + */ +#define RUNTIME_F(name) \ +({ \ + KVM_VALIDATE_CPU_CAP_USAGE(name); \ + 0; \ +}) + +/* * Undefine the MSR bit macro to avoid token concatenation issues when * processing X86_FEATURE_SPEC_CTRL_SSBD. */ @@ -811,9 +821,11 @@ void kvm_set_cpu_caps(void) VENDOR_F(DTES64) | /* * NOTE: MONITOR (and MWAIT) are emulated as NOP, but *not* - * advertised to guests via CPUID! + * advertised to guests via CPUID! MWAIT is also technically a + * runtime flag thanks to IA32_MISC_ENABLES; mark it as such so + * that KVM is aware that it's a known, unadvertised flag. */ - 0 /* MONITOR */ | + RUNTIME_F(MWAIT) | VENDOR_F(VMX) | 0 /* DS-CPL, SMX, EST */ | 0 /* TM2 */ | @@ -834,7 +846,7 @@ void kvm_set_cpu_caps(void) EMULATED_F(TSC_DEADLINE_TIMER) | F(AES) | F(XSAVE) | - 0 /* OSXSAVE */ | + RUNTIME_F(OSXSAVE) | F(AVX) | F(F16C) | F(RDRAND) | @@ -908,7 +920,7 @@ void kvm_set_cpu_caps(void) F(AVX512VBMI) | PASSTHROUGH_F(LA57) | F(PKU) | - 0 /*OSPKE*/ | + RUNTIME_F(OSPKE) | F(RDPID) | F(AVX512_VPOPCNTDQ) | F(UMIP) | @@ -1210,6 +1222,7 @@ EXPORT_SYMBOL_GPL(kvm_set_cpu_caps); #undef PASSTHROUGH_F #undef ALIASED_1_EDX_F #undef VENDOR_F +#undef RUNTIME_F struct kvm_cpuid_array { struct kvm_cpuid_entry2 *entries; |