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

[Paolo Bonzini]

On 28/10/2016 13:08, Borislav Petkov wrote:
> On Fri, Oct 28, 2016 at 12:17:02PM +0200, Paolo Bonzini wrote:
>> Otherwise, if you add a cpuid_count_edx function to processor.h then one
>> can do:
>>
>> 	entry_>edx &= cpuid_count_edx(7, 0);
>>
>> which is decent too.
> 
> If you think of iterating over the cpuid_bits[] array and recreating the
> CPUID leaf for KVM, sure, why not...
> 

cpuid_count_edx would be just

static inline unsigned int cpuid_count_edx(unsigned op, unsigned count)
{
        unsigned int eax, ebx, ecx, edx;

        cpuid_count(op, count, &eax, &ebx, &ecx, &edx);

        return edx;
}

Paolo