Re: [PATCH 7/9] KVM: x86: simplify dr6 accessors in kvm_x86_ops

[Peter Xu]

On Wed, May 06, 2020 at 07:10:32AM -0400, Paolo Bonzini wrote:
> kvm_x86_ops.set_dr6 is only ever called with vcpu->arch.dr6 as the
> second argument, and for both SVM and VMX the VMCB value is kept
> synchronized with vcpu->arch.dr6 on #DB; we can therefore remove the
> read accessor.
> 
> For the write accessor we can avoid the retpoline penalty on Intel
> by accepting a NULL value and just skipping the call in that case.
> 
> Suggested-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>

(I think this patch and the previous one seem to be the same as the previous
 version.  Anyway...)

Reviewed-by: Peter Xu <peterx@xxxxxxxxxx>

-- 
Peter Xu