Re: [PATCH] x86/cpufeatures: Make AVX512_BMM depend on AVX512F

From: Sean Christopherson

Date: Mon Jul 20 2026 - 15:50:32 EST


On Wed, Jul 15, 2026, Jim Mattson wrote:
> Add an explicit dependency between X86_FEATURE_AVX512_BMM and
> X86_FEATURE_AVX512F in the CPUID dependency table.
>
> AVX512 Bit Matrix Multiply (BMM) instructions operate on vector registers
> and require AVX512 Foundation support. Declaring this dependency ensures
> that if AVX512F is disabled (e.g. via clearcpuid or host capabilities),
> AVX512_BMM will be automatically cleared as well.
>
> Fixes: de0bfdc7137d ("KVM: x86: Advertise AVX512 Bit Matrix Multiply (BMM) to userspace")
> Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx>
> ---

Reviewed-by: Sean Christopherson <seanjc@xxxxxxxxxx>

I assume this will go through the tip tree.