KVM: x86: Move posted interrupt tracepoint to common code

Move the pi_irte_update tracepoint to common x86, and call it whenever the
IRTE is modified.  Tracing only the modifications that result in an IRQ
being posted to a vCPU makes the tracepoint useless for debugging.

Drop the vendor specific address; plumbing that into common code isn't
worth the trouble, as the address is meaningless without a whole pile of
other information that isn't provided in any tracepoint.

Link: https://lore.kernel.org/r/20250611224604.313496-31-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

Author: sean-jc

arch/x86/kvm/irq.c

@@ -511,9 +511,11 @@ void kvm_arch_irq_routing_update(struct kvm *kvm)
 static int kvm_pi_update_irte(struct kvm_kernel_irqfd *irqfd,
 			      struct kvm_kernel_irq_routing_entry *entry)
 {
+	unsigned int host_irq = irqfd->producer->irq;
 	struct kvm *kvm = irqfd->kvm;
 	struct kvm_vcpu *vcpu = NULL;
 	struct kvm_lapic_irq irq;
+	int r;
 
 	if (!irqchip_in_kernel(kvm) ||
 	    !kvm_arch_has_irq_bypass() ||
@@ -540,8 +542,13 @@ static int kvm_pi_update_irte(struct kvm_kernel_irqfd *irqfd,
 			vcpu = NULL;
 	}
 
-	return kvm_x86_call(pi_update_irte)(irqfd, irqfd->kvm, irqfd->producer->irq,
-					    irqfd->gsi, vcpu, irq.vector);
+	r = kvm_x86_call(pi_update_irte)(irqfd, irqfd->kvm, host_irq, irqfd->gsi,
+					 vcpu, irq.vector);
+	if (r)
+		return r;
+
+	trace_kvm_pi_irte_update(host_irq, vcpu, irqfd->gsi, irq.vector, !!vcpu);
+	return 0;
 }
 
 int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons,
@@ -595,6 +602,7 @@ void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
 
 	spin_unlock_irq(&kvm->irqfds.lock);
 
+
 	kvm_arch_end_assignment(irqfd->kvm);
 }
 

arch/x86/kvm/svm/avic.c

@@ -816,9 +816,6 @@ int avic_pi_update_irte(struct kvm_kernel_irqfd *irqfd, struct kvm *kvm,
 	 */
 	svm_ir_list_del(irqfd);
 
-	pr_debug("SVM: %s: host_irq=%#x, guest_irq=%#x, set=%#x\n",
-		 __func__, host_irq, guest_irq, !!vcpu);
-
 	/**
 	 * Here, we setup with legacy mode in the following cases:
 	 * 1. When cannot target interrupt to a specific vcpu.
@@ -854,9 +851,6 @@ int avic_pi_update_irte(struct kvm_kernel_irqfd *irqfd, struct kvm *kvm,
 		 */
 		if (!ret)
 			ret = svm_ir_list_add(to_svm(vcpu), irqfd, &pi);
-
-		trace_kvm_pi_irte_update(host_irq, vcpu->vcpu_id, guest_irq,
-					 vector, vcpu_info.pi_desc_addr, true);
 	} else {
 		ret = irq_set_vcpu_affinity(host_irq, NULL);
 	}

arch/x86/kvm/trace.h

@@ -1176,37 +1176,32 @@ TRACE_EVENT(kvm_smm_transition,
  * Tracepoint for VT-d posted-interrupts and AMD-Vi Guest Virtual APIC.
  */
 TRACE_EVENT(kvm_pi_irte_update,
-	TP_PROTO(unsigned int host_irq, unsigned int vcpu_id,
-		 unsigned int gsi, unsigned int gvec,
-		 u64 pi_desc_addr, bool set),
-	TP_ARGS(host_irq, vcpu_id, gsi, gvec, pi_desc_addr, set),
+	TP_PROTO(unsigned int host_irq, struct kvm_vcpu *vcpu,
+		 unsigned int gsi, unsigned int gvec, bool set),
+	TP_ARGS(host_irq, vcpu, gsi, gvec, set),
 
 	TP_STRUCT__entry(
 		__field(	unsigned int,	host_irq	)
-		__field(	unsigned int,	vcpu_id		)
+		__field(	int,		vcpu_id		)
 		__field(	unsigned int,	gsi		)
 		__field(	unsigned int,	gvec		)
-		__field(	u64,		pi_desc_addr	)
 		__field(	bool,		set		)
 	),
 
 	TP_fast_assign(
 		__entry->host_irq	= host_irq;
-		__entry->vcpu_id	= vcpu_id;
+		__entry->vcpu_id	= vcpu ? vcpu->vcpu_id : -1;
 		__entry->gsi		= gsi;
 		__entry->gvec		= gvec;
-		__entry->pi_desc_addr	= pi_desc_addr;
 		__entry->set		= set;
 	),
 
-	TP_printk("PI is %s for irq %u, vcpu %u, gsi: 0x%x, "
-		  "gvec: 0x%x, pi_desc_addr: 0x%llx",
+	TP_printk("PI is %s for irq %u, vcpu %d, gsi: 0x%x, gvec: 0x%x",
 		  __entry->set ? "enabled and being updated" : "disabled",
 		  __entry->host_irq,
 		  __entry->vcpu_id,
 		  __entry->gsi,
-		  __entry->gvec,
-		  __entry->pi_desc_addr)
+		  __entry->gvec)
 );
 
 /*

arch/x86/kvm/vmx/posted_intr.c

@@ -308,9 +308,6 @@ int vmx_pi_update_irte(struct kvm_kernel_irqfd *irqfd, struct kvm *kvm,
 			.vector = vector,
 		};
 
-		trace_kvm_pi_irte_update(host_irq, vcpu->vcpu_id, guest_irq,
-					 vcpu_info.vector, vcpu_info.pi_desc_addr, true);
-
 		return irq_set_vcpu_affinity(host_irq, &vcpu_info);
 	} else {
 		return irq_set_vcpu_affinity(host_irq, NULL);

arch/x86/kvm/x86.c

@@ -13891,7 +13891,6 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_intercepts);
 EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_write_tsc_offset);
 EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_ple_window_update);
 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);