arm64: KVM: PMU: Add perf event map and introduce perf event creating function (7f766358) · Commits · 戴 / test

include/kvm/arm_pmu.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -43,6 +43,8 @@ void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val);
		u64 kvm_pmu_valid_counter_mask(struct kvm_vcpu *vcpu);
		void kvm_pmu_disable_counter(struct kvm_vcpu *vcpu, u64 val);
		void kvm_pmu_enable_counter(struct kvm_vcpu *vcpu, u64 val);
		void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data,
		u64 select_idx);
		#else
		struct kvm_pmu {
		};
		@@ -61,6 +63,8 @@ static inline u64 kvm_pmu_valid_counter_mask(struct kvm_vcpu *vcpu)
		}
		static inline void kvm_pmu_disable_counter(struct kvm_vcpu *vcpu, u64 val) {}
		static inline void kvm_pmu_enable_counter(struct kvm_vcpu *vcpu, u64 val) {}
		static inline void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu,
		u64 data, u64 select_idx) {}
		#endif

		#endif

virt/kvm/arm/pmu.c

+74 −0

Original line number	Diff line number	Diff line
		@@ -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;
		}

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