Re: [PATCH 2/2] KVM: SVM: Add support for MPK feature on AMD

Paolo Bonzini
2020-05-07T08:07:55Z

On 07/05/20 00:26, Sean Christopherson wrote:
>> + /* Load the guest pkru state */
>> + if (static_cpu_has(X86_FEATURE_PKU) &&
>> + kvm_read_cr4_bits(vcpu, X86_CR4_PKE) &&
>> + vcpu->arch.pkru != svm->host_pkru)
>> + __write_pkru(vcpu->arch.pkru);
> This and the restoration should be moved to common x86 helpers, at a glance
> they look identical.
>
> In short, pretty much all of this belongs in common x86.
>

We could stick this in kvm_load_guest_xsave_state
kvm_load_host_xsave_state. It's not a perfect match, after all the code
itself proves that PKRU can be loaded without XSAVE; but it's close
enough and it's exactly in the right point of vmx_vcpu_run and svm_vcpu_run.

Paolo