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-rw-r--r--virt/kvm/arm/pmu.c74
1 files changed, 74 insertions, 0 deletions
diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c
index f8dc17430813..591a11d1bd13 100644
--- a/virt/kvm/arm/pmu.c
+++ b/virt/kvm/arm/pmu.c
@@ -62,6 +62,27 @@ void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val)
vcpu_sys_reg(vcpu, reg) += (s64)val - kvm_pmu_get_counter_value(vcpu, select_idx);
}
+/**
+ * kvm_pmu_stop_counter - stop PMU counter
+ * @pmc: The PMU counter pointer
+ *
+ * If this counter has been configured to monitor some event, release it here.
+ */
+static void kvm_pmu_stop_counter(struct kvm_vcpu *vcpu, struct kvm_pmc *pmc)
+{
+ u64 counter, reg;
+
+ if (pmc->perf_event) {
+ counter = kvm_pmu_get_counter_value(vcpu, pmc->idx);
+ reg = (pmc->idx == ARMV8_PMU_CYCLE_IDX)
+ ? PMCCNTR_EL0 : PMEVCNTR0_EL0 + pmc->idx;
+ vcpu_sys_reg(vcpu, reg) = counter;
+ perf_event_disable(pmc->perf_event);
+ perf_event_release_kernel(pmc->perf_event);
+ pmc->perf_event = NULL;
+ }
+}
+
u64 kvm_pmu_valid_counter_mask(struct kvm_vcpu *vcpu)
{
u64 val = vcpu_sys_reg(vcpu, PMCR_EL0) >> ARMV8_PMU_PMCR_N_SHIFT;
@@ -127,3 +148,56 @@ void kvm_pmu_disable_counter(struct kvm_vcpu *vcpu, u64 val)
perf_event_disable(pmc->perf_event);
}
}
+
+static bool kvm_pmu_counter_is_enabled(struct kvm_vcpu *vcpu, u64 select_idx)
+{
+ return (vcpu_sys_reg(vcpu, PMCR_EL0) & ARMV8_PMU_PMCR_E) &&
+ (vcpu_sys_reg(vcpu, PMCNTENSET_EL0) & BIT(select_idx));
+}
+
+/**
+ * kvm_pmu_set_counter_event_type - set selected counter to monitor some event
+ * @vcpu: The vcpu pointer
+ * @data: The data guest writes to PMXEVTYPER_EL0
+ * @select_idx: The number of selected counter
+ *
+ * When OS accesses PMXEVTYPER_EL0, that means it wants to set a PMC to count an
+ * event with given hardware event number. Here we call perf_event API to
+ * emulate this action and create a kernel perf event for it.
+ */
+void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data,
+ u64 select_idx)
+{
+ struct kvm_pmu *pmu = &vcpu->arch.pmu;
+ struct kvm_pmc *pmc = &pmu->pmc[select_idx];
+ struct perf_event *event;
+ struct perf_event_attr attr;
+ u64 eventsel, counter;
+
+ kvm_pmu_stop_counter(vcpu, pmc);
+ eventsel = data & ARMV8_PMU_EVTYPE_EVENT;
+
+ memset(&attr, 0, sizeof(struct perf_event_attr));
+ attr.type = PERF_TYPE_RAW;
+ attr.size = sizeof(attr);
+ attr.pinned = 1;
+ attr.disabled = !kvm_pmu_counter_is_enabled(vcpu, select_idx);
+ attr.exclude_user = data & ARMV8_PMU_EXCLUDE_EL0 ? 1 : 0;
+ attr.exclude_kernel = data & ARMV8_PMU_EXCLUDE_EL1 ? 1 : 0;
+ attr.exclude_hv = 1; /* Don't count EL2 events */
+ attr.exclude_host = 1; /* Don't count host events */
+ attr.config = eventsel;
+
+ counter = kvm_pmu_get_counter_value(vcpu, select_idx);
+ /* The initial sample period (overflow count) of an event. */
+ attr.sample_period = (-counter) & pmc->bitmask;
+
+ event = perf_event_create_kernel_counter(&attr, -1, current, NULL, pmc);
+ if (IS_ERR(event)) {
+ pr_err_once("kvm: pmu event creation failed %ld\n",
+ PTR_ERR(event));
+ return;
+ }
+
+ pmc->perf_event = event;
+}