Re: [PATCH 21/43] KVM: nVMX: Don't reread VMCS-agnostic state when switching VMCS

From: Sean Christopherson
Date: Fri Jun 14 2019 - 12:30:29 EST


On Thu, Jun 13, 2019 at 07:03:07PM +0200, Paolo Bonzini wrote:
> From: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
>
> When switching between vmcs01 and vmcs02, there is no need to update
> state tracking for values that aren't tied to any particular VMCS as
> the per-vCPU values are already up-to-date (vmx_switch_vmcs() can only
> be called when the vCPU is loaded).
>
> Avoiding the update eliminates a RDMSR, and potentially a RDPKRU and
> posted-interrupt updated (cmpxchg64() and more).

Another typo, s/updated/update.

>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> ---