Re: [PATCH 3/3] X86/nVMX: Update the MSR_BITMAP field with the L02 MSR BITMAP

From: KarimAllah Ahmed
Date: Fri Feb 09 2018 - 19:23:27 EST


On 02/10/2018 12:57 AM, Jim Mattson wrote:
On Fri, Feb 9, 2018 at 3:41 PM, KarimAllah Ahmed <karahmed@xxxxxxxxxx> wrote:

I assume you are referring to this:

https://patchwork.kernel.org/patch/10194819/

.. which is now:

commit 904e14fb7cb9 ("KVM: VMX: make MSR bitmaps per-VCPU")

right?

If this is the case, then I do not see where the MSR_BITMAP is being
updated here. In fact, would not this be the commit that actually broke
it?

I'm referring to
<1517938181-15317-6-git-send-email-dwmw@xxxxxxxxxxxx>, which has:

@@ -10043,6 +9954,9 @@ static void prepare_vmcs02(struct kvm_vcpu
*vcpu, struct vmcs12 *vmcs12)
if (kvm_has_tsc_control)
decache_tsc_multiplier(vmx);

+ if (cpu_has_vmx_msr_bitmap())
+ vmcs_write64(MSR_BITMAP, __pa(vmx->nested.vmcs02.msr_bitmap));
+
if (enable_vpid) {
/*
* There is no direct mapping between vpid02 and vpid12, the


Ooops, My bad! I must have ingested and old version of this commit that
did not have this hunk! Now actually looking at the upstream commit and
the backports from David, it is indeed there.

Sorry for the noise, please ignore this patch :)
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