KVM: x86/pmu: Pass only "struct kvm_pmc *pmc" to reprogram_counter()

Passing the reference "struct kvm_pmc *pmc" when creating
pmc->perf_event is sufficient. This change helps to simplify the
calling convention by replacing reprogram_{gp, fixed}_counter()
with reprogram_counter() seamlessly.

No functional change intended.
Signed-off-by: Like Xu <likexu@tencent.com>
Message-Id: <20220518132512.37864-5-likexu@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/pmu.c

@@ -355,18 +355,13 @@ void reprogram_fixed_counter(struct kvm_pmc *pmc, u8 ctrl, int idx)
 }
 EXPORT_SYMBOL_GPL(reprogram_fixed_counter);
 
-void reprogram_counter(struct kvm_pmu *pmu, int pmc_idx)
+void reprogram_counter(struct kvm_pmc *pmc)
 {
-	struct kvm_pmc *pmc = static_call(kvm_x86_pmu_pmc_idx_to_pmc)(pmu, pmc_idx);
-
-	if (!pmc)
-		return;
-
 	if (pmc_is_gp(pmc))
 		reprogram_gp_counter(pmc, pmc->eventsel);
 	else {
-		int idx = pmc_idx - INTEL_PMC_IDX_FIXED;
-		u8 ctrl = fixed_ctrl_field(pmu->fixed_ctr_ctrl, idx);
+		int idx = pmc->idx - INTEL_PMC_IDX_FIXED;
+		u8 ctrl = fixed_ctrl_field(pmc_to_pmu(pmc)->fixed_ctr_ctrl, idx);
 
 		reprogram_fixed_counter(pmc, ctrl, idx);
 	}
@@ -385,8 +380,7 @@ void kvm_pmu_handle_event(struct kvm_vcpu *vcpu)
 			clear_bit(bit, pmu->reprogram_pmi);
 			continue;
 		}
-
-		reprogram_counter(pmu, bit);
+		reprogram_counter(pmc);
 	}
 
 	/*
@@ -559,13 +553,12 @@ void kvm_pmu_destroy(struct kvm_vcpu *vcpu)
 
 static void kvm_pmu_incr_counter(struct kvm_pmc *pmc)
 {
-	struct kvm_pmu *pmu = pmc_to_pmu(pmc);
 	u64 prev_count;
 
 	prev_count = pmc->counter;
 	pmc->counter = (pmc->counter + 1) & pmc_bitmask(pmc);
 
-	reprogram_counter(pmu, pmc->idx);
+	reprogram_counter(pmc);
 	if (pmc->counter < prev_count)
 		__kvm_perf_overflow(pmc, false);
 }

arch/x86/kvm/pmu.h

@@ -175,7 +175,7 @@ static inline void kvm_init_pmu_capability(void)
 
 void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel);
 void reprogram_fixed_counter(struct kvm_pmc *pmc, u8 ctrl, int fixed_idx);
-void reprogram_counter(struct kvm_pmu *pmu, int pmc_idx);
+void reprogram_counter(struct kvm_pmc *pmc);
 
 void kvm_pmu_deliver_pmi(struct kvm_vcpu *vcpu);
 void kvm_pmu_handle_event(struct kvm_vcpu *vcpu);

arch/x86/kvm/vmx/pmu_intel.c

@@ -56,16 +56,32 @@ static void reprogram_fixed_counters(struct kvm_pmu *pmu, u64 data)
 	pmu->fixed_ctr_ctrl = data;
 }
 
+static struct kvm_pmc *intel_pmc_idx_to_pmc(struct kvm_pmu *pmu, int pmc_idx)
+{
+	if (pmc_idx < INTEL_PMC_IDX_FIXED) {
+		return get_gp_pmc(pmu, MSR_P6_EVNTSEL0 + pmc_idx,
+				  MSR_P6_EVNTSEL0);
+	} else {
+		u32 idx = pmc_idx - INTEL_PMC_IDX_FIXED;
+
+		return get_fixed_pmc(pmu, idx + MSR_CORE_PERF_FIXED_CTR0);
+	}
+}
+
 /* function is called when global control register has been updated. */
 static void global_ctrl_changed(struct kvm_pmu *pmu, u64 data)
 {
 	int bit;
 	u64 diff = pmu->global_ctrl ^ data;
+	struct kvm_pmc *pmc;
 
 	pmu->global_ctrl = data;
 
-	for_each_set_bit(bit, (unsigned long *)&diff, X86_PMC_IDX_MAX)
-		reprogram_counter(pmu, bit);
+	for_each_set_bit(bit, (unsigned long *)&diff, X86_PMC_IDX_MAX) {
+		pmc = intel_pmc_idx_to_pmc(pmu, bit);
+		if (pmc)
+			reprogram_counter(pmc);
+	}
 }
 
 static unsigned int intel_pmc_perf_hw_id(struct kvm_pmc *pmc)
@@ -104,18 +120,6 @@ static bool intel_pmc_is_enabled(struct kvm_pmc *pmc)
 	return test_bit(pmc->idx, (unsigned long *)&pmu->global_ctrl);
 }
 
-static struct kvm_pmc *intel_pmc_idx_to_pmc(struct kvm_pmu *pmu, int pmc_idx)
-{
-	if (pmc_idx < INTEL_PMC_IDX_FIXED)
-		return get_gp_pmc(pmu, MSR_P6_EVNTSEL0 + pmc_idx,
-				  MSR_P6_EVNTSEL0);
-	else {
-		u32 idx = pmc_idx - INTEL_PMC_IDX_FIXED;
-
-		return get_fixed_pmc(pmu, idx + MSR_CORE_PERF_FIXED_CTR0);
-	}
-}
-
 static bool intel_is_valid_rdpmc_ecx(struct kvm_vcpu *vcpu, unsigned int idx)
 {
 	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);