[patch 3/3] KVM: x86: add tracepoint to wait_lapic_expire

[Marcelo Tosatti <mtosatti@redhat.com>]

[-- Attachment #1: lapic-wait-tracepoint --]
[-- Type: text/plain, Size: 1918 bytes --]

Add tracepoint to wait_lapic_expire.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

Index: kvm/arch/x86/kvm/lapic.c
===================================================================
--- kvm.orig/arch/x86/kvm/lapic.c
+++ kvm/arch/x86/kvm/lapic.c
@@ -1120,7 +1120,7 @@ static bool lapic_timer_int_injected(str
 void wait_lapic_expire(struct kvm_vcpu *vcpu)
 {
 	struct kvm_lapic *apic = vcpu->arch.apic;
-	u64 guest_tsc, tsc_deadline;
+	u64 orig_guest_tsc, guest_tsc, tsc_deadline;
 
 	if (!kvm_vcpu_has_lapic(vcpu))
 		return;
@@ -1133,7 +1133,7 @@ void wait_lapic_expire(struct kvm_vcpu *
 
 	tsc_deadline = apic->lapic_timer.expired_tscdeadline;
 	apic->lapic_timer.expired_tscdeadline = 0;
-	guest_tsc = kvm_x86_ops->read_l1_tsc(vcpu, native_read_tsc());
+	orig_guest_tsc = guest_tsc = kvm_x86_ops->read_l1_tsc(vcpu, native_read_tsc());
 
 	while (guest_tsc < tsc_deadline) {
 		int delay = min(tsc_deadline - guest_tsc, 1000ULL);
@@ -1141,6 +1141,8 @@ void wait_lapic_expire(struct kvm_vcpu *
 		__delay(delay);
 		guest_tsc = kvm_x86_ops->read_l1_tsc(vcpu, native_read_tsc());
 	}
+
+	trace_kvm_wait_lapic_expire(vcpu->vcpu_id, orig_guest_tsc - tsc_deadline);
 }
 
 static void start_apic_timer(struct kvm_lapic *apic)
Index: kvm/arch/x86/kvm/trace.h
===================================================================
--- kvm.orig/arch/x86/kvm/trace.h
+++ kvm/arch/x86/kvm/trace.h
@@ -914,6 +914,25 @@ TRACE_EVENT(kvm_pvclock_update,
 		  __entry->flags)
 );
 
+TRACE_EVENT(kvm_wait_lapic_expire,
+	TP_PROTO(unsigned int vcpu_id, s64 delta),
+	TP_ARGS(vcpu_id, delta),
+
+	TP_STRUCT__entry(
+		__field(	unsigned int,	vcpu_id		)
+		__field(	s64,		delta		)
+	),
+
+	TP_fast_assign(
+		__entry->vcpu_id	   = vcpu_id;
+		__entry->delta             = delta;
+	),
+
+	TP_printk("vcpu %u: delta %lld",
+		  __entry->vcpu_id,
+		  __entry->delta)
+);
+
 #endif /* _TRACE_KVM_H */
 
 #undef TRACE_INCLUDE_PATH