KVM: x86: Copy kvm_pmu_ops by value to eliminate layer of indirection

Replace the kvm_pmu_ops pointer in common x86 with an instance of the
struct to save one pointer dereference when invoking functions. Copy the
struct by value to set the ops during kvm_init().
Signed-off-by: Like Xu <likexu@tencent.com>
[sean: Move pmc_is_enabled(), make kvm_pmu_ops static]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220329235054.3534728-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/pmu.c

@@ -49,6 +49,18 @@
  *        * AMD:   [0 .. AMD64_NUM_COUNTERS-1] <=> gp counters
  */
 
+static struct kvm_pmu_ops kvm_pmu_ops __read_mostly;
+
+void kvm_pmu_ops_update(const struct kvm_pmu_ops *pmu_ops)
+{
+	memcpy(&kvm_pmu_ops, pmu_ops, sizeof(kvm_pmu_ops));
+}
+
+static inline bool pmc_is_enabled(struct kvm_pmc *pmc)
+{
+	return kvm_pmu_ops.pmc_is_enabled(pmc);
+}
+
 static void kvm_pmi_trigger_fn(struct irq_work *irq_work)
 {
 	struct kvm_pmu *pmu = container_of(irq_work, struct kvm_pmu, irq_work);
@@ -213,7 +225,7 @@ void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel)
 			  ARCH_PERFMON_EVENTSEL_CMASK |
 			  HSW_IN_TX |
 			  HSW_IN_TX_CHECKPOINTED))) {
-		config = kvm_x86_ops.pmu_ops->pmc_perf_hw_id(pmc);
+		config = kvm_pmu_ops.pmc_perf_hw_id(pmc);
 		if (config != PERF_COUNT_HW_MAX)
 			type = PERF_TYPE_HARDWARE;
 	}
@@ -263,7 +275,7 @@ void reprogram_fixed_counter(struct kvm_pmc *pmc, u8 ctrl, int idx)
 
 	pmc->current_config = (u64)ctrl;
 	pmc_reprogram_counter(pmc, PERF_TYPE_HARDWARE,
-			      kvm_x86_ops.pmu_ops->pmc_perf_hw_id(pmc),
+			      kvm_pmu_ops.pmc_perf_hw_id(pmc),
 			      !(en_field & 0x2), /* exclude user */
 			      !(en_field & 0x1), /* exclude kernel */
 			      pmi);
@@ -272,7 +284,7 @@ EXPORT_SYMBOL_GPL(reprogram_fixed_counter);
 
 void reprogram_counter(struct kvm_pmu *pmu, int pmc_idx)
 {
-	struct kvm_pmc *pmc = kvm_x86_ops.pmu_ops->pmc_idx_to_pmc(pmu, pmc_idx);
+	struct kvm_pmc *pmc = kvm_pmu_ops.pmc_idx_to_pmc(pmu, pmc_idx);
 
 	if (!pmc)
 		return;
@@ -294,7 +306,7 @@ void kvm_pmu_handle_event(struct kvm_vcpu *vcpu)
 	int bit;
 
 	for_each_set_bit(bit, pmu->reprogram_pmi, X86_PMC_IDX_MAX) {
-		struct kvm_pmc *pmc = kvm_x86_ops.pmu_ops->pmc_idx_to_pmc(pmu, bit);
+		struct kvm_pmc *pmc = kvm_pmu_ops.pmc_idx_to_pmc(pmu, bit);
 
 		if (unlikely(!pmc || !pmc->perf_event)) {
 			clear_bit(bit, pmu->reprogram_pmi);
@@ -316,7 +328,7 @@ void kvm_pmu_handle_event(struct kvm_vcpu *vcpu)
 /* check if idx is a valid index to access PMU */
 bool kvm_pmu_is_valid_rdpmc_ecx(struct kvm_vcpu *vcpu, unsigned int idx)
 {
-	return kvm_x86_ops.pmu_ops->is_valid_rdpmc_ecx(vcpu, idx);
+	return kvm_pmu_ops.is_valid_rdpmc_ecx(vcpu, idx);
 }
 
 bool is_vmware_backdoor_pmc(u32 pmc_idx)
@@ -366,7 +378,7 @@ int kvm_pmu_rdpmc(struct kvm_vcpu *vcpu, unsigned idx, u64 *data)
 	if (is_vmware_backdoor_pmc(idx))
 		return kvm_pmu_rdpmc_vmware(vcpu, idx, data);
 
-	pmc = kvm_x86_ops.pmu_ops->rdpmc_ecx_to_pmc(vcpu, idx, &mask);
+	pmc = kvm_pmu_ops.rdpmc_ecx_to_pmc(vcpu, idx, &mask);
 	if (!pmc)
 		return 1;
 
@@ -382,22 +394,22 @@ int kvm_pmu_rdpmc(struct kvm_vcpu *vcpu, unsigned idx, u64 *data)
 void kvm_pmu_deliver_pmi(struct kvm_vcpu *vcpu)
 {
 	if (lapic_in_kernel(vcpu)) {
-		if (kvm_x86_ops.pmu_ops->deliver_pmi)
-			kvm_x86_ops.pmu_ops->deliver_pmi(vcpu);
+		if (kvm_pmu_ops.deliver_pmi)
+			kvm_pmu_ops.deliver_pmi(vcpu);
 		kvm_apic_local_deliver(vcpu->arch.apic, APIC_LVTPC);
 	}
 }
 
 bool kvm_pmu_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
 {
-	return kvm_x86_ops.pmu_ops->msr_idx_to_pmc(vcpu, msr) ||
-		kvm_x86_ops.pmu_ops->is_valid_msr(vcpu, msr);
+	return kvm_pmu_ops.msr_idx_to_pmc(vcpu, msr) ||
+		kvm_pmu_ops.is_valid_msr(vcpu, msr);
 }
 
 static void kvm_pmu_mark_pmc_in_use(struct kvm_vcpu *vcpu, u32 msr)
 {
 	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
-	struct kvm_pmc *pmc = kvm_x86_ops.pmu_ops->msr_idx_to_pmc(vcpu, msr);
+	struct kvm_pmc *pmc = kvm_pmu_ops.msr_idx_to_pmc(vcpu, msr);
 
 	if (pmc)
 		__set_bit(pmc->idx, pmu->pmc_in_use);
@@ -405,13 +417,13 @@ static void kvm_pmu_mark_pmc_in_use(struct kvm_vcpu *vcpu, u32 msr)
 
 int kvm_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 {
-	return kvm_x86_ops.pmu_ops->get_msr(vcpu, msr_info);
+	return kvm_pmu_ops.get_msr(vcpu, msr_info);
 }
 
 int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 {
 	kvm_pmu_mark_pmc_in_use(vcpu, msr_info->index);
-	return kvm_x86_ops.pmu_ops->set_msr(vcpu, msr_info);
+	return kvm_pmu_ops.set_msr(vcpu, msr_info);
 }
 
 /* refresh PMU settings. This function generally is called when underlying
@@ -420,7 +432,7 @@ int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
  */
 void kvm_pmu_refresh(struct kvm_vcpu *vcpu)
 {
-	kvm_x86_ops.pmu_ops->refresh(vcpu);
+	kvm_pmu_ops.refresh(vcpu);
 }
 
 void kvm_pmu_reset(struct kvm_vcpu *vcpu)
@@ -428,7 +440,7 @@ void kvm_pmu_reset(struct kvm_vcpu *vcpu)
 	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 
 	irq_work_sync(&pmu->irq_work);
-	kvm_x86_ops.pmu_ops->reset(vcpu);
+	kvm_pmu_ops.reset(vcpu);
 }
 
 void kvm_pmu_init(struct kvm_vcpu *vcpu)
@@ -436,7 +448,7 @@ void kvm_pmu_init(struct kvm_vcpu *vcpu)
 	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 
 	memset(pmu, 0, sizeof(*pmu));
-	kvm_x86_ops.pmu_ops->init(vcpu);
+	kvm_pmu_ops.init(vcpu);
 	init_irq_work(&pmu->irq_work, kvm_pmi_trigger_fn);
 	pmu->event_count = 0;
 	pmu->need_cleanup = false;
@@ -468,14 +480,14 @@ void kvm_pmu_cleanup(struct kvm_vcpu *vcpu)
 		      pmu->pmc_in_use, X86_PMC_IDX_MAX);
 
 	for_each_set_bit(i, bitmask, X86_PMC_IDX_MAX) {
-		pmc = kvm_x86_ops.pmu_ops->pmc_idx_to_pmc(pmu, i);
+		pmc = kvm_pmu_ops.pmc_idx_to_pmc(pmu, i);
 
 		if (pmc && pmc->perf_event && !pmc_speculative_in_use(pmc))
 			pmc_stop_counter(pmc);
 	}
 
-	if (kvm_x86_ops.pmu_ops->cleanup)
-		kvm_x86_ops.pmu_ops->cleanup(vcpu);
+	if (kvm_pmu_ops.cleanup)
+		kvm_pmu_ops.cleanup(vcpu);
 
 	bitmap_zero(pmu->pmc_in_use, X86_PMC_IDX_MAX);
 }
@@ -505,7 +517,7 @@ static inline bool eventsel_match_perf_hw_id(struct kvm_pmc *pmc,
 	unsigned int config;
 
 	pmc->eventsel &= (ARCH_PERFMON_EVENTSEL_EVENT | ARCH_PERFMON_EVENTSEL_UMASK);
-	config = kvm_x86_ops.pmu_ops->pmc_perf_hw_id(pmc);
+	config = kvm_pmu_ops.pmc_perf_hw_id(pmc);
 	pmc->eventsel = old_eventsel;
 	return config == perf_hw_id;
 }
@@ -533,7 +545,7 @@ void kvm_pmu_trigger_event(struct kvm_vcpu *vcpu, u64 perf_hw_id)
 	int i;
 
 	for_each_set_bit(i, pmu->all_valid_pmc_idx, X86_PMC_IDX_MAX) {
-		pmc = kvm_x86_ops.pmu_ops->pmc_idx_to_pmc(pmu, i);
+		pmc = kvm_pmu_ops.pmc_idx_to_pmc(pmu, i);
 
 		if (!pmc || !pmc_is_enabled(pmc) || !pmc_speculative_in_use(pmc))
 			continue;

arch/x86/kvm/pmu.h

@@ -39,6 +39,8 @@ struct kvm_pmu_ops {
 	void (*cleanup)(struct kvm_vcpu *vcpu);
 };
 
+void kvm_pmu_ops_update(const struct kvm_pmu_ops *pmu_ops);
+
 static inline u64 pmc_bitmask(struct kvm_pmc *pmc)
 {
 	struct kvm_pmu *pmu = pmc_to_pmu(pmc);
@@ -86,11 +88,6 @@ static inline bool pmc_is_fixed(struct kvm_pmc *pmc)
 	return pmc->type == KVM_PMC_FIXED;
 }
 
-static inline bool pmc_is_enabled(struct kvm_pmc *pmc)
-{
-	return kvm_x86_ops.pmu_ops->pmc_is_enabled(pmc);
-}
-
 static inline bool kvm_valid_perf_global_ctrl(struct kvm_pmu *pmu,
 						 u64 data)
 {

arch/x86/kvm/x86.c

@@ -11632,6 +11632,8 @@ static inline void kvm_ops_update(struct kvm_x86_init_ops *ops)
 					   (void *)__static_call_return0);
 #include <asm/kvm-x86-ops.h>
 #undef __KVM_X86_OP
+
+	kvm_pmu_ops_update(ops->runtime_ops->pmu_ops);
 }
 
 int kvm_arch_hardware_setup(void *opaque)