Messages in this thread | | | Date | Thu, 11 Apr 2024 14:54:09 -0700 | Subject | Re: [RFC PATCH 28/41] KVM: x86/pmu: Switch IA32_PERF_GLOBAL_CTRL at VM boundary | From | Sean Christopherson <> |
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On Fri, Jan 26, 2024, Xiong Zhang wrote: > +static void save_perf_global_ctrl_in_passthrough_pmu(struct vcpu_vmx *vmx) > +{ > + struct kvm_pmu *pmu = vcpu_to_pmu(&vmx->vcpu); > + int i; > + > + if (vm_exit_controls_get(vmx) & VM_EXIT_SAVE_IA32_PERF_GLOBAL_CTRL) { > + pmu->global_ctrl = vmcs_read64(GUEST_IA32_PERF_GLOBAL_CTRL); > + } else { > + i = vmx_find_loadstore_msr_slot(&vmx->msr_autostore.guest, > + MSR_CORE_PERF_GLOBAL_CTRL); > + if (i < 0) > + return; > + pmu->global_ctrl = vmx->msr_autostore.guest.val[i].value;
As before, NAK to using the MSR load/store lists unless there's a *really* good reason I'm missing.
And we should consider adding VCPU_EXREG_GLOBAL_CTRL so that we can defer the VMREAD until KVM actually tries to access the guest value.
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