linux-kernel - Re: [PATCH] x86/cpuid: expose AVX512_4VNNIW and AVX512

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Date:   Sat, 29 Oct 2016 14:53:10 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Piotr Luc <Piotr.Luc@...el.com>, kvm@...r.kernel.org,
        he chen <he.chen@...ux.intel.com>,
        linux-kernel@...r.kernel.org, tglx@...utronix.de, x86@...nel.org,
        hpa@...or.com, mingo@...hat.com, Luwei Kang <luwei.kang@...el.com>,
        rkrcmar@...hat.com
Subject: Re: [PATCH] x86/cpuid: expose AVX512_4VNNIW and AVX512_4FMAPS
 features to kvm guest

On Sat, Oct 29, 2016 at 08:36:11AM -0400, Paolo Bonzini wrote:
> Because then it wouldn't be in processor.h.

Easy:

	return cpuid_edx(…) & KVM_CPUID_EDX_7_MASK;

at the call site.

> Yes, but it doesn't take an ecx.

Looks like we need another set of macros :-)

> Anyhow this is not an issue for now.  It will depend on which other bits
> are added to CPUID[7,0].edx, but in general it's relatively rare to blacklist
> bits from cpufeature.

Right.

Thanks.

-- 
Regards/Gruss,
    Boris.

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