On Mon, Dec 12, 2022 at 6:37 PM Vipin Sharma <vipinsh@xxxxxxxxxx> wrote:
>
> From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
>
> 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@xxxxxxxxxx>
> Reviewed-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> ---
> arch/x86/kvm/cpuid.c | 8 ++++++--
> arch/x86/kvm/reverse_cpuid.h | 7 +++++++
> 2 files changed, 13 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
> index 723502181a3a..42913695fedd 100644
> --- 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 203fdad07bae..25b9b51abb20 100644
> --- 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;
> }
> --
> 2.39.0.rc1.256.g54fd8350bd-goog
>
I believe this version of the patch should have been taken instead of:
https://git.kernel.org/pub/scm/virt/kvm/kvm.git/commit/?h=queue&id=42b76c1ae40b89716c7a804cb575a4b52eb4e12f
I think it should be kvm_cpu_cap_init_kvm_defined() rather than
kvm_cpu_cap_init_scattered().
I'm getting this:
arch/x86/kvm/cpuid.c:705:2: error: call to undeclared function
'kvm_cpu_cap_init_scattered'; ISO C99 and later do not support
implicit function declarations [-Wimplicit-function-declaration]
kvm_cpu_cap_init_scattered(CPUID_8000_0007_EDX,
^
arch/x86/kvm/cpuid.c:705:2: note: did you mean 'kvm_cpu_cap_init_kvm_defined'?
arch/x86/kvm/cpuid.c:553:6: note: 'kvm_cpu_cap_init_kvm_defined' declared here
void kvm_cpu_cap_init_kvm_defined(enum kvm_only_cpuid_leafs leaf, u32 mask)
^
1 error generated.
