Re: [PATCH 4/6] x86: KVM: Enable AVX-VNNI-INT8 CPUID and expose it to guest

Borislav Petkov
2022-10-19T09:56:12Z

On Wed, Oct 19, 2022 at 04:47:32PM +0800, Jiaxi Chen wrote:
> AVX-VNNI-INT8 is a new set of instructions in the latest Intel platform
> Sierra Forest. It multiplies the individual bytes of two unsigned or
> unsigned source operands, then add and accumulate the results into the
> destination dword element size operand. This instruction allows for the
> platform to have superior AI capabilities.
>
> The bit definition:
> CPUID.(EAX=7,ECX=1):EDX[bit 4]
>
> This patch enables this CPUID in the kernel feature bits and expose it to
> guest OS. Since the CPUID involves a bit of EDX (EAX=7,ECX=1) which has not
> been enumerated yet, this patch adds CPUID_7_1_EDX to CPUID subleaves. At
> the same time, word 20 is newly-defined in CPU features for CPUID level

For all your commit messages:

Avoid having "This patch" or "This commit" in the commit message. It is
tautologically useless.

Also, do

$ git grep 'This patch' Documentation/process

for more details.

For this particular one, use scattered.c instead of adding a new leaf.

Thx.

--
Regards/Gruss,
Boris.