KVM: x86: add tracepoint to wait_lapic_expire

Add tracepoint to wait_lapic_expire.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
[Remind reader if early or late. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

2 files changed, 21 insertions, 0 deletions

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index e1c0befaa9f6..3eb7f8d9992c 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1134,6 +1134,7 @@ void wait_lapic_expire(struct kvm_vcpu *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());
+        trace_kvm_wait_lapic_expire(vcpu->vcpu_id, guest_tsc - tsc_deadline);
 
         /* __delay is delay_tsc whenever the hardware has TSC, thus always.  */
         if (guest_tsc < tsc_deadline)
diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h
index c2a34bb5ad93..587149bd6f76 100644
--- a/arch/x86/kvm/trace.h
+++ b/arch/x86/kvm/trace.h
@@ -914,6 +914,26 @@ 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 (%s)",
+                  __entry->vcpu_id,
+                  __entry->delta,
+                  __entry->delta < 0 ? "early" : "late")
+);
+
 #endif /* _TRACE_KVM_H */
 
 #undef TRACE_INCLUDE_PATH