Re: [PATCH] KVM: x86: Remove AMX-TF32 enumeration

From: Binbin Wu

Date: Mon Jul 20 2026 - 02:16:08 EST


On 7/9/2026 5:01 AM, Chang S. Bae wrote:
> AMX-TF32 enumeration was added based on the Intel documentation [1]. The
> recent update removed the feature, indicating that the feature is no
> longer planned for hardware implementation.
>
> [1] Intel Architecture Instruction Set Extensions and Future Features
>
> Cc: Zhao Liu <zhao1.liu@xxxxxxxxx>
> Cc: Binbin Wu <binbin.wu@xxxxxxxxxxxxxxx>
> Signed-off-by: Chang S. Bae <chang.seok.bae@xxxxxxxxx>

Reviewed-by: Binbin Wu <binbin.wu@xxxxxxxxxxxxxxx>

One nit below.

> ---
> Note: The feature first appeared in the September 2025 revision of the
> document and was removed in the June 2026 revision.

IMHO, the note is informative.
Is it better to move it to the body of the changelog?

> ---
> arch/x86/kvm/cpuid.c | 1 -
> arch/x86/kvm/reverse_cpuid.h | 1 -
> 2 files changed, 2 deletions(-)
>
> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
> index 591d2294acd7..759a1c557080 100644
> --- a/arch/x86/kvm/cpuid.c
> +++ b/arch/x86/kvm/cpuid.c
> @@ -1082,7 +1082,6 @@ void kvm_initialize_cpu_caps(void)
> F(AMX_COMPLEX_ALIAS),
> F(AMX_FP16_ALIAS),
> F(AMX_FP8),
> - F(AMX_TF32),
> F(AMX_AVX512),
> F(AMX_MOVRS),
> );
> diff --git a/arch/x86/kvm/reverse_cpuid.h b/arch/x86/kvm/reverse_cpuid.h
> index 2ad25781cefb..1bb13903c5b2 100644
> --- a/arch/x86/kvm/reverse_cpuid.h
> +++ b/arch/x86/kvm/reverse_cpuid.h
> @@ -56,7 +56,6 @@
> #define X86_FEATURE_AMX_COMPLEX_ALIAS KVM_X86_FEATURE(CPUID_1E_1_EAX, 2)
> #define X86_FEATURE_AMX_FP16_ALIAS KVM_X86_FEATURE(CPUID_1E_1_EAX, 3)
> #define X86_FEATURE_AMX_FP8 KVM_X86_FEATURE(CPUID_1E_1_EAX, 4)
> -#define X86_FEATURE_AMX_TF32 KVM_X86_FEATURE(CPUID_1E_1_EAX, 6)
> #define X86_FEATURE_AMX_AVX512 KVM_X86_FEATURE(CPUID_1E_1_EAX, 7)
> #define X86_FEATURE_AMX_MOVRS KVM_X86_FEATURE(CPUID_1E_1_EAX, 8)
>