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

Huang, Kai
2024-08-13T05:26:10Z

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.