KVM: x86: Add a KVM-only leaf for CPUID_8000_0007_EDX

CPUID_8000_0007_EDX may come handy when X86_FEATURE_CONSTANT_TSC
needs to be checked.

No functional change intended.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221013095849.705943-3-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 0b5bf013fcb8e3f516d7bbda6351feb392f2bb61..ff342c9da17226aae13ce15b872fc6426d4d41aa 100644 (file)
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -701,6 +701,10 @@ void kvm_set_cpu_caps(void)
        if (!tdp_enabled && IS_ENABLED(CONFIG_X86_64))
                kvm_cpu_cap_set(X86_FEATURE_GBPAGES);
 
+       kvm_cpu_cap_init_kvm_defined(CPUID_8000_0007_EDX,
+               SF(CONSTANT_TSC)
+       );
+
        kvm_cpu_cap_mask(CPUID_8000_0008_EBX,
                F(CLZERO) | F(XSAVEERPTR) |
                F(WBNOINVD) | F(AMD_IBPB) | F(AMD_IBRS) | F(AMD_SSBD) | F(VIRT_SSBD) |
@@ -1153,8 +1157,8 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
                entry->edx &= ~GENMASK(17, 16);
                break;
        case 0x80000007: /* Advanced power management */
-               /* invariant TSC is CPUID.80000007H:EDX[8] */
-               entry->edx &= (1 << 8);
+               cpuid_entry_override(entry, CPUID_8000_0007_EDX);
+
                /* mask against host */
                entry->edx &= boot_cpu_data.x86_power;
                entry->eax = entry->ebx = entry->ecx = 0;

diff --git a/arch/x86/kvm/reverse_cpuid.h b/arch/x86/kvm/reverse_cpuid.h
index 203fdad07bae6cffe3c5385d787ff2aa87394781..25b9b51abb20de4cef932267b4619c76b821fc5b 100644 (file)
--- a/arch/x86/kvm/reverse_cpuid.h
+++ b/arch/x86/kvm/reverse_cpuid.h
@@ -14,6 +14,7 @@
 enum kvm_only_cpuid_leafs {
        CPUID_12_EAX     = NCAPINTS,
        CPUID_7_1_EDX,
+       CPUID_8000_0007_EDX,
        NR_KVM_CPU_CAPS,
 
        NKVMCAPINTS = NR_KVM_CPU_CAPS - NCAPINTS,
@@ -42,6 +43,9 @@ enum kvm_only_cpuid_leafs {
 #define X86_FEATURE_AVX_NE_CONVERT      KVM_X86_FEATURE(CPUID_7_1_EDX, 5)
 #define X86_FEATURE_PREFETCHITI         KVM_X86_FEATURE(CPUID_7_1_EDX, 14)
 
+/* CPUID level 0x80000007 (EDX). */
+#define KVM_X86_FEATURE_CONSTANT_TSC   KVM_X86_FEATURE(CPUID_8000_0007_EDX, 8)
+
 struct cpuid_reg {
        u32 function;
        u32 index;
@@ -67,6 +71,7 @@ static const struct cpuid_reg reverse_cpuid[] = {
        [CPUID_12_EAX]        = {0x00000012, 0, CPUID_EAX},
        [CPUID_8000_001F_EAX] = {0x8000001f, 0, CPUID_EAX},
        [CPUID_7_1_EDX]       = {         7, 1, CPUID_EDX},
+       [CPUID_8000_0007_EDX] = {0x80000007, 0, CPUID_EDX},
 };
 
 /*
@@ -97,6 +102,8 @@ static __always_inline u32 __feature_translate(int x86_feature)
                return KVM_X86_FEATURE_SGX1;
        else if (x86_feature == X86_FEATURE_SGX2)
                return KVM_X86_FEATURE_SGX2;
+       else if (x86_feature == X86_FEATURE_CONSTANT_TSC)
+               return KVM_X86_FEATURE_CONSTANT_TSC;
 
        return x86_feature;
 }