[v8,6/8] x86/cpu, kvm: Add the SMM_CTL MSR not present feature

Commit Message

Kim Phillips Jan. 23, 2023, 10:56 p.m. UTC

The SMM_CTL MSR not present feature was being open-coded for KVM.
Add it to its newly added CPUID leaf 0x80000021 EAX proper.

Also drop the bit description comments now the code is more
self-describing.

Signed-off-by: Kim Phillips <[e-mail]>
---
 arch/x86/include/asm/cpufeatures.h | 1 +
 arch/x86/kvm/cpuid.c               | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

Patch

diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 403a534691cc..6dcc3c3d0c8d 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -432,6 +432,7 @@ 
 #define X86_FEATURE_NO_NESTED_DATA_BP	(20*32+ 0) /* "" No Nested Data Breakpoints */
 #define X86_FEATURE_LFENCE_RDTSC	(20*32+ 2) /* "" LFENCE always serializing / synchronizes RDTSC */
 #define X86_FEATURE_NULL_SEL_CLR_BASE	(20*32+ 6) /* "" Null Selector Clears Base */
+#define X86_FEATURE_NO_SMM_CTL_MSR	(20*32+ 9) /* "" SMM_CTL MSR is not present */
 
 /*
  * BUG word(s)
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index f1625a58b5ec..9ba75ad9d976 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -749,7 +749,7 @@  void kvm_set_cpu_caps(void)
 		kvm_cpu_cap_set(X86_FEATURE_LFENCE_RDTSC);
 	if (!static_cpu_has_bug(X86_BUG_NULL_SEG))
 		kvm_cpu_cap_set(X86_FEATURE_NULL_SEL_CLR_BASE);
-	kvm_cpu_caps[CPUID_8000_0021_EAX] |= BIT(9) /* NO_SMM_CTL_MSR */;
+	kvm_cpu_cap_set(X86_FEATURE_NO_SMM_CTL_MSR);
 
 	kvm_cpu_cap_mask(CPUID_C000_0001_EDX,
 		F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) |