Re: [PATCH 24/25] KVM: x86: Filter directly configurable TDX CPUID bits

[Paolo Bonzini]

On 8/13/24 00:48, Rick Edgecombe wrote:
> +
> +		cpuid_e = kvm_find_cpuid_entry2(supported_cpuid->entries, supported_cpuid->nent,
> +						dest->leaf, dest->sub_leaf);
> +		if (!cpuid_e) {
> +			dest->eax = dest->ebx = dest->ecx = dest->edx = 0;
> +		} else {
> +			dest->eax &= cpuid_e->eax;
> +			dest->ebx &= cpuid_e->ebx;
> +			dest->ecx &= cpuid_e->ecx;
> +			dest->edx &= cpuid_e->edx;
> +		}

This can only work with CPUID entries that consists of 4*32 features, so 
it has to be done specifically for each leaf, unfortunately.  I suggest 
defining a kvm_merge_cpuid_entries in cpuid.c that takes two struct 
cpuid_entry2* that refer to the same leaf and subleaf.

Paolo