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Shenoy" , Mario Limonciello , "Rafael J. Wysocki" , Viresh Kumar , Srinivas Pandruvada , Len Brown Cc: "H. Peter Anvin" , Perry Yuan , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, Jim Mattson , Mingwei Zhang Implement MSR read/write handlers for IA32_APERF and IA32_MPERF to support both host and guest access: - Host userspace access via KVM_[GS]ET_MSRS only reads/writes the snapshot values in vcpu->arch.aperfmperf - Guest writes update both the hardware MSRs (via set_guest_[am]perf) and the snapshots - For host-initiated writes of IA32_MPERF, record the current TSC to establish a new baseline for background cycle accumulation - Guest reads don't reach these handlers as they access the MSRs directly Add both MSRs to msrs_to_save_base[] to ensure they are properly serialized during vCPU state save/restore operations. Signed-off-by: Mingwei Zhang Co-developed-by: Jim Mattson Signed-off-by: Jim Mattson --- arch/x86/kvm/x86.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index cd1f1ae86f83f..4394ecb291401 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -334,6 +334,7 @@ static const u32 msrs_to_save_base[] = { MSR_IA32_UMWAIT_CONTROL, MSR_IA32_XFD, MSR_IA32_XFD_ERR, + MSR_IA32_APERF, MSR_IA32_MPERF, }; static const u32 msrs_to_save_pmu[] = { @@ -4151,6 +4152,26 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) return 1; vcpu->arch.msr_misc_features_enables = data; break; + case MSR_IA32_APERF: + if ((data || !msr_info->host_initiated) && + !guest_can_use(vcpu, X86_FEATURE_APERFMPERF)) + return 1; + + vcpu->arch.aperfmperf.guest_aperf = data; + if (unlikely(!msr_info->host_initiated)) + set_guest_aperf(data); + break; + case MSR_IA32_MPERF: + if ((data || !msr_info->host_initiated) && + !guest_can_use(vcpu, X86_FEATURE_APERFMPERF)) + return 1; + + vcpu->arch.aperfmperf.guest_mperf = data; + if (likely(msr_info->host_initiated)) + vcpu->arch.aperfmperf.host_tsc = rdtsc(); + else + set_guest_mperf(data); + break; #ifdef CONFIG_X86_64 case MSR_IA32_XFD: if (!msr_info->host_initiated && @@ -4524,6 +4545,22 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) msr_info->data = vcpu->arch.guest_fpu.xfd_err; break; #endif + case MSR_IA32_APERF: + /* Guest read access should never reach here. */ + if (!msr_info->host_initiated) + return 1; + + msr_info->data = vcpu->arch.aperfmperf.guest_aperf; + break; + case MSR_IA32_MPERF: + /* Guest read access should never reach here. */ + if (!msr_info->host_initiated) + return 1; + + if (vcpu->arch.mp_state != KVM_MP_STATE_HALTED) + kvm_accumulate_background_guest_mperf(vcpu); + msr_info->data = vcpu->arch.aperfmperf.guest_mperf; + break; default: if (kvm_pmu_is_valid_msr(vcpu, msr_info->index)) return kvm_pmu_get_msr(vcpu, msr_info); @@ -7535,6 +7572,11 @@ static void kvm_probe_msr_to_save(u32 msr_index) if (!(kvm_get_arch_capabilities() & ARCH_CAP_TSX_CTRL_MSR)) return; break; + case MSR_IA32_APERF: + case MSR_IA32_MPERF: + if (!kvm_cpu_cap_has(KVM_X86_FEATURE_APERFMPERF)) + return; + break; default: break; }