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);
