Re: [RFC PATCH v1 10/15] KVM: VMX: Use WRMSRNS or its immediate form when available

From: H. Peter Anvin
Date: Tue Apr 15 2025 - 02:58:06 EST


On April 14, 2025 10:48:47 AM PDT, Xin Li <xin@xxxxxxxxx> wrote:
>On 4/12/2025 4:10 PM, H. Peter Anvin wrote:
>> Also,*in this specific case* IA32_SPEC_CTRL is architecturally nonserializing, i.e. WRMSR executes as WRMSRNS anyway.
>
>While the immediate form WRMSRNS could be faster because the MSR index
>is available *much* earlier in the pipeline, right?

Yes, but then it would be redundant with the virtualization support.