Messages in this thread | | | Subject | Re: [PATCH v5 4/5] KVM: VMX: Allow direct access to MSR_IA32_SPEC_CTRL | From | Paolo Bonzini <> | Date | Wed, 31 Jan 2018 16:00:43 -0500 |
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On 31/01/2018 15:54, Jim Mattson wrote: > You seem to be making the assumption that there is one L2. What if > there are 100 L2s, and only one has write-access to IA32_SPEC_CTRL? Or > what if there once was such an L2, but it's been gone for months? The > current mechanism penalizes *all* L2s if any L2, ever, has > write-access to IA32_SPEC_CTRL.
Yes, but how would moving the field into struct loaded_vmcs do anything? Only vmon/vmoff would change anything in vmx->nested.vmcs02.
Even then, L1 vmexits will also be penalized because L1 has probably done an RDMSR/WRMSR on L2->L1 vmexit. So I don't think it's an issue?
Paolo
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