KVM: x86/pmu: Refactoring find_arch_event() to pmc_perf_hw_id()

The find_arch_event() returns a "unsigned int" value,
which is used by the pmc_reprogram_counter() to
program a PERF_TYPE_HARDWARE type perf_event.

The returned value is actually the kernel defined generic
perf_hw_id, let's rename it to pmc_perf_hw_id() with simpler
incoming parameters for better self-explanation.
Signed-off-by: Like Xu <likexu@tencent.com>
Message-Id: <20211130074221.93635-3-likexu@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/pmu.c

@@ -174,7 +174,6 @@ static bool pmc_resume_counter(struct kvm_pmc *pmc)
 void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel)
 {
 	unsigned config, type = PERF_TYPE_RAW;
-	u8 event_select, unit_mask;
 	struct kvm *kvm = pmc->vcpu->kvm;
 	struct kvm_pmu_event_filter *filter;
 	int i;
@@ -206,17 +205,12 @@ void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel)
 	if (!allow_event)
 		return;
 
-	event_select = eventsel & ARCH_PERFMON_EVENTSEL_EVENT;
-	unit_mask = (eventsel & ARCH_PERFMON_EVENTSEL_UMASK) >> 8;
-
 	if (!(eventsel & (ARCH_PERFMON_EVENTSEL_EDGE |
 			  ARCH_PERFMON_EVENTSEL_INV |
 			  ARCH_PERFMON_EVENTSEL_CMASK |
 			  HSW_IN_TX |
 			  HSW_IN_TX_CHECKPOINTED))) {
-		config = kvm_x86_ops.pmu_ops->find_arch_event(pmc_to_pmu(pmc),
-						      event_select,
-						      unit_mask);
+		config = kvm_x86_ops.pmu_ops->pmc_perf_hw_id(pmc);
 		if (config != PERF_COUNT_HW_MAX)
 			type = PERF_TYPE_HARDWARE;
 	}

arch/x86/kvm/pmu.h

@@ -24,8 +24,7 @@ struct kvm_event_hw_type_mapping {
 };
 
 struct kvm_pmu_ops {
-	unsigned (*find_arch_event)(struct kvm_pmu *pmu, u8 event_select,
-				    u8 unit_mask);
+	unsigned int (*pmc_perf_hw_id)(struct kvm_pmc *pmc);
 	unsigned (*find_fixed_event)(int idx);
 	bool (*pmc_is_enabled)(struct kvm_pmc *pmc);
 	struct kvm_pmc *(*pmc_idx_to_pmc)(struct kvm_pmu *pmu, int pmc_idx);

arch/x86/kvm/svm/pmu.c

@@ -138,10 +138,10 @@ static inline struct kvm_pmc *get_gp_pmc_amd(struct kvm_pmu *pmu, u32 msr,
 	return &pmu->gp_counters[msr_to_index(msr)];
 }
 
-static unsigned amd_find_arch_event(struct kvm_pmu *pmu,
-				    u8 event_select,
-				    u8 unit_mask)
+static unsigned int amd_pmc_perf_hw_id(struct kvm_pmc *pmc)
 {
+	u8 event_select = pmc->eventsel & ARCH_PERFMON_EVENTSEL_EVENT;
+	u8 unit_mask = (pmc->eventsel & ARCH_PERFMON_EVENTSEL_UMASK) >> 8;
 	int i;
 
 	for (i = 0; i < ARRAY_SIZE(amd_event_mapping); i++)
@@ -323,7 +323,7 @@ static void amd_pmu_reset(struct kvm_vcpu *vcpu)
 }
 
 struct kvm_pmu_ops amd_pmu_ops = {
-	.find_arch_event = amd_find_arch_event,
+	.pmc_perf_hw_id = amd_pmc_perf_hw_id,
 	.find_fixed_event = amd_find_fixed_event,
 	.pmc_is_enabled = amd_pmc_is_enabled,
 	.pmc_idx_to_pmc = amd_pmc_idx_to_pmc,

arch/x86/kvm/vmx/pmu_intel.c

@@ -68,10 +68,11 @@ static void global_ctrl_changed(struct kvm_pmu *pmu, u64 data)
 		reprogram_counter(pmu, bit);
 }
 
-static unsigned intel_find_arch_event(struct kvm_pmu *pmu,
-				      u8 event_select,
-				      u8 unit_mask)
+static unsigned int intel_pmc_perf_hw_id(struct kvm_pmc *pmc)
 {
+	struct kvm_pmu *pmu = pmc_to_pmu(pmc);
+	u8 event_select = pmc->eventsel & ARCH_PERFMON_EVENTSEL_EVENT;
+	u8 unit_mask = (pmc->eventsel & ARCH_PERFMON_EVENTSEL_UMASK) >> 8;
 	int i;
 
 	for (i = 0; i < ARRAY_SIZE(intel_arch_events); i++)
@@ -720,7 +721,7 @@ static void intel_pmu_cleanup(struct kvm_vcpu *vcpu)
 }
 
 struct kvm_pmu_ops intel_pmu_ops = {
-	.find_arch_event = intel_find_arch_event,
+	.pmc_perf_hw_id = intel_pmc_perf_hw_id,
 	.find_fixed_event = intel_find_fixed_event,
 	.pmc_is_enabled = intel_pmc_is_enabled,
 	.pmc_idx_to_pmc = intel_pmc_idx_to_pmc,