Re: [PATCH] x86/cpuid: expose AVX512_4VNNIW and AVX512_4FMAPS features to kvm guest

From: Borislav Petkov
Date: Sat Oct 29 2016 - 08:25:56 EST


On Sat, Oct 29, 2016 at 08:21:17AM -0400, Paolo Bonzini wrote:
> Currently none of the bits in CPUID[7,0].edx is ever masked by the host, so
> this would be enough. If we ever need to do some masking, I guess I'll
> practice my puss-in-boots look and submit a patch to add CPUID[7,0] back
> as a separate cpufeature entr.

I don't understand - why can't it be filtered here if needed? I.e.,

return edx & KVM_CPUID_EDX_7_MASK;

or so?

Btw, we already have a cpuid_edx() helper in arch/x86/include/asm/processor.h

--
Regards/Gruss,
Boris.

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