Re: [PATCH v3 1/4] KVM: x86: Update the reverse_cpuid list to include CPUID_7_EDX

From: Paolo Bonzini
Date: Tue Jan 30 2018 - 18:17:57 EST


On 29/01/2018 19:10, KarimAllah Ahmed wrote:
> [dwmw2: Stop using KF() for bits in it, too]
> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> Cc: Radim KrÄmÃÅ <rkrcmar@xxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: H. Peter Anvin <hpa@xxxxxxxxx>
> Cc: x86@xxxxxxxxxx
> Cc: kvm@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Signed-off-by: KarimAllah Ahmed <karahmed@xxxxxxxxx>
> Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx>

Reviewed-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>

> ---
> arch/x86/kvm/cpuid.c | 8 +++-----
> arch/x86/kvm/cpuid.h | 1 +
> 2 files changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
> index 0099e10..c0eb337 100644
> --- a/arch/x86/kvm/cpuid.c
> +++ b/arch/x86/kvm/cpuid.c
> @@ -67,9 +67,7 @@ u64 kvm_supported_xcr0(void)
>
> #define F(x) bit(X86_FEATURE_##x)
>
> -/* These are scattered features in cpufeatures.h. */
> -#define KVM_CPUID_BIT_AVX512_4VNNIW 2
> -#define KVM_CPUID_BIT_AVX512_4FMAPS 3
> +/* For scattered features from cpufeatures.h; we currently expose none */
> #define KF(x) bit(KVM_CPUID_BIT_##x)
>
> int kvm_update_cpuid(struct kvm_vcpu *vcpu)
> @@ -392,7 +390,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
>
> /* cpuid 7.0.edx*/
> const u32 kvm_cpuid_7_0_edx_x86_features =
> - KF(AVX512_4VNNIW) | KF(AVX512_4FMAPS);
> + F(AVX512_4VNNIW) | F(AVX512_4FMAPS);
>
> /* all calls to cpuid_count() should be made on the same cpu */
> get_cpu();
> @@ -477,7 +475,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
> if (!tdp_enabled || !boot_cpu_has(X86_FEATURE_OSPKE))
> entry->ecx &= ~F(PKU);
> entry->edx &= kvm_cpuid_7_0_edx_x86_features;
> - entry->edx &= get_scattered_cpuid_leaf(7, 0, CPUID_EDX);
> + cpuid_mask(&entry->edx, CPUID_7_EDX);
> } else {
> entry->ebx = 0;
> entry->ecx = 0;
> diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h
> index cdc70a3..dcfe227 100644
> --- a/arch/x86/kvm/cpuid.h
> +++ b/arch/x86/kvm/cpuid.h
> @@ -54,6 +54,7 @@ static const struct cpuid_reg reverse_cpuid[] = {
> [CPUID_8000_000A_EDX] = {0x8000000a, 0, CPUID_EDX},
> [CPUID_7_ECX] = { 7, 0, CPUID_ECX},
> [CPUID_8000_0007_EBX] = {0x80000007, 0, CPUID_EBX},
> + [CPUID_7_EDX] = { 7, 0, CPUID_EDX},
> };
>
> static __always_inline struct cpuid_reg x86_feature_cpuid(unsigned x86_feature)
>