KVM: x86/pmu: Setup pmc->eventsel for fixed PMCs

The current pmc->eventsel for fixed counter is underutilised. The
pmc->eventsel can be setup for all known available fixed counters
since we have mapping between fixed pmc index and
the intel_arch_events array.

Either gp or fixed counter, it will simplify the later checks for
consistency between eventsel and perf_hw_id.

Signed-off-by: Like Xu <likexu@tencent.com>
Message-Id: <20211130074221.93635-2-likexu@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index d33e979..965fefb 100644 (file)
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -459,6 +459,21 @@ static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
        return 1;
 }
 
+static void setup_fixed_pmc_eventsel(struct kvm_pmu *pmu)
+{
+       size_t size = ARRAY_SIZE(fixed_pmc_events);
+       struct kvm_pmc *pmc;
+       u32 event;
+       int i;
+
+       for (i = 0; i < pmu->nr_arch_fixed_counters; i++) {
+               pmc = &pmu->fixed_counters[i];
+               event = fixed_pmc_events[array_index_nospec(i, size)];
+               pmc->eventsel = (intel_arch_events[event].unit_mask << 8) |
+                       intel_arch_events[event].eventsel;
+       }
+}
+
 static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
 {
        struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
@@ -507,6 +522,7 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
                        edx.split.bit_width_fixed, x86_pmu.bit_width_fixed);
                pmu->counter_bitmask[KVM_PMC_FIXED] =
                        ((u64)1 << edx.split.bit_width_fixed) - 1;
+               setup_fixed_pmc_eventsel(pmu);
        }
 
        pmu->global_ctrl = ((1ull << pmu->nr_arch_gp_counters) - 1) |