Re: [PATCH v4] KVM: emulate: Don't inject #GP when emulating RDMPC if CR0.PE=0

From: Paolo Bonzini
Date: Wed Oct 20 2021 - 05:02:09 EST


On 20/10/21 10:52, Wanpeng Li wrote:
From: Wanpeng Li<wanpengli@xxxxxxxxxxx>

SDM mentioned that we should #GP for rdpmc if ECX is not valid or
(CR4.PCE is 0 and CPL is 1, 2, or 3 and CR0.PE is 1).

Let's add the CR0.PE is 1 checking to rdpmc emulate, though this isn't
strictly necessary since it's impossible for CPL to be >0 if CR0.PE=0.

Reviewed-by: Sean Christopherson<seanjc@xxxxxxxxxx>
Signed-off-by: Wanpeng Li<wanpengli@xxxxxxxxxxx>
---
v3 -> v4:
* add comments instead of pseudocode

No, the commit message was fine. What I meant is there's no need to change the code. Just add a comment about why CR0.PE isn't tested.

Paolo