linux-kernel - [PATCH v2 05/12] KVM: x86/pmu: Drop "u8 ctrl, int idx" for reprogram_fixed

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Message-Id: <20220302111334.12689-6-likexu@tencent.com>
Date:   Wed,  2 Mar 2022 19:13:27 +0800
From:   Like Xu <like.xu.linux@...il.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Jim Mattson <jmattson@...gle.com>, kvm@...r.kernel.org,
        Sean Christopherson <seanjc@...gle.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Joerg Roedel <joro@...tes.org>, linux-kernel@...r.kernel.org,
        Like Xu <likexu@...cent.com>
Subject: [PATCH v2 05/12] KVM: x86/pmu: Drop "u8 ctrl, int idx" for reprogram_fixed_counter()

From: Like Xu <likexu@...cent.com>

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@...cent.com>
---
 arch/x86/kvm/pmu.c           | 13 ++++++-------
 arch/x86/kvm/pmu.h           |  2 +-
 arch/x86/kvm/vmx/pmu_intel.c | 16 ++++++++--------
 3 files changed, 15 insertions(+), 16 deletions(-)

diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index 7b8a5f973a63..282e6e859c46 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -260,8 +260,11 @@ 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;
 
@@ -291,12 +294,8 @@ 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);
 
diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h
index 4db50c290c62..70a982c3cdad 100644
--- a/arch/x86/kvm/pmu.h
+++ b/arch/x86/kvm/pmu.h
@@ -141,7 +141,7 @@ static inline u64 get_sample_period(struct kvm_pmc *pmc, u64 counter_value)
 }
 
 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);
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index 2eefde7e4b1a..3ddbfdd16cd0 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/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;
 
-		__set_bit(INTEL_PMC_IDX_FIXED + i, pmu->pmc_in_use);
-		reprogram_fixed_counter(pmc, new_ctrl, i);
-	}
+		pmc = get_fixed_pmc(pmu, MSR_CORE_PERF_FIXED_CTR0 + i);
 
-	pmu->fixed_ctr_ctrl = data;
+		__set_bit(INTEL_PMC_IDX_FIXED + i, pmu->pmc_in_use);
+		reprogram_fixed_counter(pmc);
+	}
 }
 
 static struct kvm_pmc *intel_pmc_idx_to_pmc(struct kvm_pmu *pmu, int pmc_idx)
-- 
2.35.1