kvm: svm: Introduce GA Log tracepoint for AVIC

GA Log tracepoint is useful when debugging AVIC performance
issue as it can be used with perf to count the number of times
IOMMU AVIC injects interrupts through the slow-path instead of
directly inject interrupts to the target vcpu.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/svm.c

@@ -1232,6 +1232,7 @@ static int avic_ga_log_notifier(u32 ga_tag)
 	u32 vcpu_id = AVIC_GATAG_TO_VCPUID(ga_tag);
 
 	pr_debug("SVM: %s: vm_id=%#x, vcpu_id=%#x\n", __func__, vm_id, vcpu_id);
+	trace_kvm_avic_ga_log(vm_id, vcpu_id);
 
 	spin_lock_irqsave(&svm_vm_data_hash_lock, flags);
 	hash_for_each_possible(svm_vm_data_hash, kvm_svm, hnode, vm_id) {

arch/x86/kvm/trace.h

@@ -1367,6 +1367,24 @@ TRACE_EVENT(kvm_avic_unaccelerated_access,
 		  __entry->vec)
 );
 
+TRACE_EVENT(kvm_avic_ga_log,
+	    TP_PROTO(u32 vmid, u32 vcpuid),
+	    TP_ARGS(vmid, vcpuid),
+
+	TP_STRUCT__entry(
+		__field(u32, vmid)
+		__field(u32, vcpuid)
+	),
+
+	TP_fast_assign(
+		__entry->vmid = vmid;
+		__entry->vcpuid = vcpuid;
+	),
+
+	TP_printk("vmid=%u, vcpuid=%u",
+		  __entry->vmid, __entry->vcpuid)
+);
+
 TRACE_EVENT(kvm_hv_timer_state,
 		TP_PROTO(unsigned int vcpu_id, unsigned int hv_timer_in_use),
 		TP_ARGS(vcpu_id, hv_timer_in_use),

arch/x86/kvm/x86.c

@@ -10562,4 +10562,5 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_pml_full);
 EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_pi_irte_update);
 EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_avic_unaccelerated_access);
 EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_avic_incomplete_ipi);
+EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_avic_ga_log);
 EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_apicv_update_request);