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

Kim Phillips
2023-01-23T22:59:05Z

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 <kim.phillips@amd.com>
---
arch/x86/include/asm/cpufeatures.h | 1 +
arch/x86/kvm/cpuid.c | 2 +-
2 files changed, 2 insertions(+), 1 deletion(-)

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) |
--
2.34.1