Re: [PATCH 1/2] Enumerate AVX Vector Neural Network instructions

[Yang Zhong <yang.zhong@intel.com>]

On Tue, Jan 05, 2021 at 01:14:56PM +0100, Borislav Petkov wrote:
> On Tue, Jan 05, 2021 at 12:47:23PM +0100, Paolo Bonzini wrote:
> > On 05/01/21 01:49, Yang Zhong wrote:
> > > From: Kyung Min Park <kyung.min.park@intel.com>
> > > 
> > > Add AVX version of the Vector Neural Network (VNNI) Instructions.
> > > 
> > > A processor supports AVX VNNI instructions if CPUID.0x07.0x1:EAX[4] is
> > > present. The following instructions are available when this feature is
> > > present.
> > >    1. VPDPBUS: Multiply and Add Unsigned and Signed Bytes
> > >    2. VPDPBUSDS: Multiply and Add Unsigned and Signed Bytes with Saturation
> > >    3. VPDPWSSD: Multiply and Add Signed Word Integers
> > >    4. VPDPWSSDS: Multiply and Add Signed Integers with Saturation
> > > 
> > > The only in-kernel usage of this is kvm passthrough. The CPU feature
> > > flag is shown as "avx_vnni" in /proc/cpuinfo.
> > > 
> > > This instruction is currently documented in the latest "extensions"
> > > manual (ISE). It will appear in the "main" manual (SDM) in the future.
> > > 
> > > Signed-off-by: Kyung Min Park <kyung.min.park@intel.com>
> > > Signed-off-by: Yang Zhong <yang.zhong@intel.com>
> > > Reviewed-by: Tony Luck <tony.luck@intel.com>
> > > ---
> > >   arch/x86/include/asm/cpufeatures.h | 1 +
> > >   1 file changed, 1 insertion(+)
> > > 
> > > diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
> > > index f5ef2d5b9231..d10d9962bd9b 100644
> > > --- a/arch/x86/include/asm/cpufeatures.h
> > > +++ b/arch/x86/include/asm/cpufeatures.h
> > > @@ -293,6 +293,7 @@
> > >   #define X86_FEATURE_PER_THREAD_MBA	(11*32+ 7) /* "" Per-thread Memory Bandwidth Allocation */
> > >   /* Intel-defined CPU features, CPUID level 0x00000007:1 (EAX), word 12 */
> > > +#define X86_FEATURE_AVX_VNNI		(12*32+ 4) /* AVX VNNI instructions */
> > >   #define X86_FEATURE_AVX512_BF16		(12*32+ 5) /* AVX512 BFLOAT16 instructions */
> > >   /* AMD-defined CPU features, CPUID level 0x80000008 (EBX), word 13 */
> > > 
> > 
> > Boris, is it possible to have a topic branch for this patch?
> 
> Just take it through your tree pls.
> 
> Acked-by: Borislav Petkov <bp@suse.de>
>
  
  Paolo, Boris has acked this kernel patch, and if i need send new patchset to add this 
  acked-by info ? or kvm tree will directly pull this patchset? thanks.

  Yang  

   
> Thx.
> 
> -- 
> Regards/Gruss,
>     Boris.
> 
> https://people.kernel.org/tglx/notes-about-netiquette