Messages in this thread | | | Subject | Re: [PATCH][v2] kvm: x86: emulate APERF/MPERF registers | From | Xiaoyao Li <> | Date | Thu, 30 Apr 2020 14:49:24 +0800 |
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On 4/29/2020 1:46 PM, Li RongQing wrote: > Guest kernel reports a fixed cpu frequency in /proc/cpuinfo, > this is confused to user when turbo is enable, and aperf/mperf > can be used to show current cpu frequency after 7d5905dc14a > "(x86 / CPU: Always show current CPU frequency in /proc/cpuinfo)" > so we should emulate aperf mperf to achieve it > > the period of aperf/mperf in guest mode are accumulated as > emulated value, and add per-VM knod to enable emulate mperfaperf > > diff v1: > 1. support AMD > 2. support per-vm capability to enable > [...] > diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c > index 851e9cc79930..1d157a8dba46 100644 > --- a/arch/x86/kvm/svm.c > +++ b/arch/x86/kvm/svm.c > @@ -4310,6 +4310,12 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) > case MSR_F10H_DECFG: > msr_info->data = svm->msr_decfg; > break; > + case MSR_IA32_MPERF: > + msr_info->data = vcpu->arch.v_mperf; > + break; > + case MSR_IA32_APERF: > + msr_info->data = vcpu->arch.v_aperf; > + break; > default: > return kvm_get_msr_common(vcpu, msr_info); > } > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c > index 91749f1254e8..b05e276e262b 100644 > --- a/arch/x86/kvm/vmx/vmx.c > +++ b/arch/x86/kvm/vmx/vmx.c > @@ -1914,6 +1914,12 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) > !guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP)) > return 1; > goto find_shared_msr; > + case MSR_IA32_MPERF: > + msr_info->data = vcpu->arch.v_mperf; > + break; > + case MSR_IA32_APERF: > + msr_info->data = vcpu->arch.v_aperf; > + break;
They are same for both vmx and svm, you can put them in kvm_get_msr_common()
BTW, are those two MSR always readable regardless of guest's CPUID?
> default: > find_shared_msr: > msr = find_msr_entry(vmx, msr_info->index);
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