Re: [PATCH 10/25] KVM: TDX: Initialize KVM supported capabilities when module setup

[Huang, Kai]

On Tue, 2024-08-13 at 11:25 +0800, Chao Gao wrote:
> > +	for (i = 0; i < td_conf->num_cpuid_config; i++) {
> > +		struct kvm_tdx_cpuid_config source = {
> > +			.leaf = (u32)td_conf->cpuid_config_leaves[i],
> > +			.sub_leaf = td_conf->cpuid_config_leaves[i] >> 32,
> > +			.eax = (u32)td_conf->cpuid_config_values[i].eax_ebx,
> > +			.ebx = td_conf->cpuid_config_values[i].eax_ebx >> 32,
> > +			.ecx = (u32)td_conf->cpuid_config_values[i].ecx_edx,
> > +			.edx = td_conf->cpuid_config_values[i].ecx_edx >> 32,
> > +		};
> > +		struct kvm_tdx_cpuid_config *dest =
> > +			&kvm_tdx_caps->cpuid_configs[i];
> > +
> > +		memcpy(dest, &source, sizeof(struct kvm_tdx_cpuid_config));
> 
> this memcpy() looks superfluous. does this work?
> 
> 		kvm_tdx_caps->cpuid_configs[i] = {
> 			.leaf = (u32)td_conf->cpuid_config_leaves[i],
> 			.sub_leaf = td_conf->cpuid_config_leaves[i] >> 32,
> 			.eax = (u32)td_conf->cpuid_config_values[i].eax_ebx,
> 			.ebx = td_conf->cpuid_config_values[i].eax_ebx >> 32,
> 			.ecx = (u32)td_conf->cpuid_config_values[i].ecx_edx,
> 			.edx = td_conf->cpuid_config_values[i].ecx_edx >> 32,
> 		};

This looks good to me.  I didn't try to optimize because it's done in the
module loading time.