[RFC PATCH 17/41] KVM: x86/pmu: Implement pmu function for Intel CPU to disable MSR interception

From: Xiong Zhang
Date: Fri Jan 26 2024 - 04:37:00 EST


From: Mingwei Zhang <mizhang@xxxxxxxxxx>

Disable PMU MSRs interception, these MSRs are defined in Architectural
Performance Monitoring from SDM, so that guest can access them without
VM-exit.

Signed-off-by: Mingwei Zhang <mizhang@xxxxxxxxxx>
---
arch/x86/kvm/vmx/pmu_intel.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)

diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index 15cc107ed573..7f6cabb2c378 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -794,6 +794,25 @@ void intel_pmu_cross_mapped_check(struct kvm_pmu *pmu)
}
}

+void intel_passthrough_pmu_msrs(struct kvm_vcpu *vcpu)
+{
+ int i;
+
+ for (i = 0; i < vcpu_to_pmu(vcpu)->nr_arch_gp_counters; i++) {
+ vmx_set_intercept_for_msr(vcpu, MSR_ARCH_PERFMON_EVENTSEL0 + i, MSR_TYPE_RW, false);
+ vmx_set_intercept_for_msr(vcpu, MSR_IA32_PERFCTR0 + i, MSR_TYPE_RW, false);
+ vmx_set_intercept_for_msr(vcpu, MSR_IA32_PMC0 + i, MSR_TYPE_RW, false);
+ }
+
+ vmx_set_intercept_for_msr(vcpu, MSR_CORE_PERF_FIXED_CTR_CTRL, MSR_TYPE_RW, false);
+ for (i = 0; i < vcpu_to_pmu(vcpu)->nr_arch_fixed_counters; i++)
+ vmx_set_intercept_for_msr(vcpu, MSR_CORE_PERF_FIXED_CTR0 + i, MSR_TYPE_RW, false);
+
+ vmx_set_intercept_for_msr(vcpu, MSR_CORE_PERF_GLOBAL_STATUS, MSR_TYPE_RW, false);
+ vmx_set_intercept_for_msr(vcpu, MSR_CORE_PERF_GLOBAL_CTRL, MSR_TYPE_RW, false);
+ vmx_set_intercept_for_msr(vcpu, MSR_CORE_PERF_GLOBAL_OVF_CTRL, MSR_TYPE_RW, false);
+}
+
struct kvm_pmu_ops intel_pmu_ops __initdata = {
.hw_event_available = intel_hw_event_available,
.pmc_idx_to_pmc = intel_pmc_idx_to_pmc,
@@ -808,6 +827,7 @@ struct kvm_pmu_ops intel_pmu_ops __initdata = {
.reset = intel_pmu_reset,
.deliver_pmi = intel_pmu_deliver_pmi,
.cleanup = intel_pmu_cleanup,
+ .passthrough_pmu_msrs = intel_passthrough_pmu_msrs,
.EVENTSEL_EVENT = ARCH_PERFMON_EVENTSEL_EVENT,
.MAX_NR_GP_COUNTERS = KVM_INTEL_PMC_MAX_GENERIC,
.MIN_NR_GP_COUNTERS = 1,
--
2.34.1