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.
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/cpuid.c | 21 +++++++++++++++++----
1 file changed, 17 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 5ac5fe2febf7..e03154b9833f 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -768,6 +768,16 @@ do { \
0; \
})
+/*
+ * 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.
@@ -790,9 +800,11 @@ 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 */ |
@@ -813,7 +825,7 @@ 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) |
@@ -887,7 +899,7 @@ 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) |
@@ -1189,6 +1201,7 @@ 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;
--
2.47.0.338.g60cca15819-goog
