KVM: x86/pmu: Drop "u8 ctrl, int idx" for reprogram_fixed_counter()

Since afrer reprogram_fixed_counter() is called, it's bound to assign
the requested fixed_ctr_ctrl to pmu->fixed_ctr_ctrl, this assignment step
can be moved forward (the stale value for diff is saved extra early),
thus simplifying the passing of parameters.

No functional change intended.
Signed-off-by: Like Xu <likexu@tencent.com>
Message-Id: <20220518132512.37864-7-likexu@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/pmu.c

@@ -327,8 +327,11 @@ void reprogram_gp_counter(struct kvm_pmc *pmc)
 }
 EXPORT_SYMBOL_GPL(reprogram_gp_counter);
 
-void reprogram_fixed_counter(struct kvm_pmc *pmc, u8 ctrl, int idx)
+void reprogram_fixed_counter(struct kvm_pmc *pmc)
 {
+	struct kvm_pmu *pmu = pmc_to_pmu(pmc);
+	int idx = pmc->idx - INTEL_PMC_IDX_FIXED;
+	u8 ctrl = fixed_ctrl_field(pmu->fixed_ctr_ctrl, idx);
 	unsigned en_field = ctrl & 0x3;
 	bool pmi = ctrl & 0x8;
 
@@ -358,12 +361,8 @@ void reprogram_counter(struct kvm_pmc *pmc)
 {
 	if (pmc_is_gp(pmc))
 		reprogram_gp_counter(pmc);
-	else {
-		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);
-	}
+	else
+		reprogram_fixed_counter(pmc);
 }
 EXPORT_SYMBOL_GPL(reprogram_counter);
 

arch/x86/kvm/pmu.h

@@ -174,7 +174,7 @@ static inline void kvm_init_pmu_capability(void)
 }
 
 void reprogram_gp_counter(struct kvm_pmc *pmc);
-void reprogram_fixed_counter(struct kvm_pmc *pmc, u8 ctrl, int fixed_idx);
+void reprogram_fixed_counter(struct kvm_pmc *pmc);
 void reprogram_counter(struct kvm_pmc *pmc);
 
 void kvm_pmu_deliver_pmi(struct kvm_vcpu *vcpu);

arch/x86/kvm/vmx/pmu_intel.c

@@ -37,23 +37,23 @@ static int fixed_pmc_events[] = {1, 0, 7};
 
 static void reprogram_fixed_counters(struct kvm_pmu *pmu, u64 data)
 {
+	struct kvm_pmc *pmc;
+	u8 old_fixed_ctr_ctrl = pmu->fixed_ctr_ctrl;
 	int i;
 
+	pmu->fixed_ctr_ctrl = data;
 	for (i = 0; i < pmu->nr_arch_fixed_counters; i++) {
 		u8 new_ctrl = fixed_ctrl_field(data, i);
-		u8 old_ctrl = fixed_ctrl_field(pmu->fixed_ctr_ctrl, i);
-		struct kvm_pmc *pmc;
-
-		pmc = get_fixed_pmc(pmu, MSR_CORE_PERF_FIXED_CTR0 + i);
+		u8 old_ctrl = fixed_ctrl_field(old_fixed_ctr_ctrl, i);
 
 		if (old_ctrl == new_ctrl)
 			continue;
 
+		pmc = get_fixed_pmc(pmu, MSR_CORE_PERF_FIXED_CTR0 + i);
+
 		__set_bit(INTEL_PMC_IDX_FIXED + i, pmu->pmc_in_use);
-		reprogram_fixed_counter(pmc, new_ctrl, i);
+		reprogram_fixed_counter(pmc);
 	}
-
-	pmu->fixed_ctr_ctrl = data;
 }
 
 static struct kvm_pmc *intel_pmc_idx_to_pmc(struct kvm_pmu *pmu, int pmc_idx)