The LFENCE_RDTSC / LFENCE always serializing feature was a scattered bit and open-coded for KVM in __do_cpuid_func(). Add it to its newly added CPUID leaf 0x80000021 EAX proper, and propagate it in kvm_set_cpu_caps() instead. Also drop the bit description comments now it's more self-describing. Whilst there, switch to using the more efficient cpu_feature_enabled() instead of static_cpu_has(). Signed-off-by: Kim Phillips <kim.phillips@xxxxxxx> --- arch/x86/include/asm/cpufeatures.h | 3 ++- arch/x86/kvm/cpuid.c | 9 ++++----- 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index 0cd7b4afd528..79da8e492c0f 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -97,7 +97,7 @@ #define X86_FEATURE_SYSENTER32 ( 3*32+15) /* "" sysenter in IA32 userspace */ #define X86_FEATURE_REP_GOOD ( 3*32+16) /* REP microcode works well */ #define X86_FEATURE_AMD_LBR_V2 ( 3*32+17) /* AMD Last Branch Record Extension Version 2 */ -#define X86_FEATURE_LFENCE_RDTSC ( 3*32+18) /* "" LFENCE synchronizes RDTSC */ +/* FREE, was #define X86_FEATURE_LFENCE_RDTSC ( 3*32+18) "" LFENCE synchronizes RDTSC */ #define X86_FEATURE_ACC_POWER ( 3*32+19) /* AMD Accumulated Power Mechanism */ #define X86_FEATURE_NOPL ( 3*32+20) /* The NOPL (0F 1F) instructions */ #define X86_FEATURE_ALWAYS ( 3*32+21) /* "" Always-present feature */ @@ -428,6 +428,7 @@ /* AMD-defined Extended Feature 2 EAX, CPUID level 0x80000021 (EAX), word 20 */ #define X86_FEATURE_NO_NESTED_DATA_BP (20*32+ 0) /* "" AMD No Nested Data Breakpoints */ +#define X86_FEATURE_LFENCE_RDTSC (20*32+ 2) /* "" LFENCE always serializing / synchronizes RDTSC */ /* * BUG word(s) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 69e433e4e9ff..88c970046c10 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -742,8 +742,10 @@ void kvm_set_cpu_caps(void) F(SME_COHERENT)); kvm_cpu_cap_mask(CPUID_8000_0021_EAX, - F(NO_NESTED_DATA_BP) + F(NO_NESTED_DATA_BP) | F(LFENCE_RDTSC) ); + if (cpu_feature_enabled(X86_FEATURE_LFENCE_RDTSC)) + kvm_cpu_cap_set(X86_FEATURE_LFENCE_RDTSC); kvm_cpu_cap_mask(CPUID_C000_0001_EDX, F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) | @@ -1229,7 +1231,6 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) cpuid_entry_override(entry, CPUID_8000_0021_EAX); /* * Pass down these bits: - * EAX 2 LAS, LFENCE always serializing * EAX 6 NSCB, Null selector clear base * * Other defined bits are for MSRs that KVM does not expose: @@ -1239,10 +1240,8 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) * KVM doesn't support SMM_CTL. * EAX 9 SMM_CTL MSR is not supported */ - entry->eax &= BIT(2) | BIT(6); + entry->eax &= BIT(6); entry->eax |= BIT(9); - if (static_cpu_has(X86_FEATURE_LFENCE_RDTSC)) - entry->eax |= BIT(2); if (!static_cpu_has_bug(X86_BUG_NULL_SEG)) entry->eax |= BIT(6); break; -- 2.34.1
