Re: [PATCH RFC] kvm: x86: Expose AVX512_BF16 feature to guest

From: Paolo Bonzini
Date: Thu Jun 20 2019 - 08:21:41 EST


On 20/06/19 13:21, Jing Liu wrote:
> + for (i = 1; i <= times; i++) {
> + if (*nent >= maxnent)
> + goto out;
> + do_cpuid_1_ent(&entry[i], function, i);
> + entry[i].eax &= F(AVX512_BF16);
> + entry[i].ebx = 0;
> + entry[i].ecx = 0;
> + entry[i].edx = 0;
> + entry[i].flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
> + ++*nent;

This woud be wrong for i > 1, so instead make this

if (entry->eax >= 1)

and define F(AVX512_BF16) as a new constant kvm_cpuid_7_1_eax_features.

Paolo