KVM: x86: trace "exit to userspace" event

Add tracepoint for userspace exit.

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

2 files changed, 31 insertions, 0 deletions

diff --git a/include/trace/events/kvm.h b/include/trace/events/kvm.h
index 9c2cc6a96e82..c86f4e8e0bc9 100644
--- a/include/trace/events/kvm.h
+++ b/include/trace/events/kvm.h
@@ -6,6 +6,36 @@
 #undef TRACE_SYSTEM
 #define TRACE_SYSTEM kvm
 
+#define ERSN(x) { KVM_EXIT_##x, "KVM_EXIT_" #x }
+
+#define kvm_trace_exit_reason                                           \
+        ERSN(UNKNOWN), ERSN(EXCEPTION), ERSN(IO), ERSN(HYPERCALL),      \
+        ERSN(DEBUG), ERSN(HLT), ERSN(MMIO), ERSN(IRQ_WINDOW_OPEN),      \
+        ERSN(SHUTDOWN), ERSN(FAIL_ENTRY), ERSN(INTR), ERSN(SET_TPR),    \
+        ERSN(TPR_ACCESS), ERSN(S390_SIEIC), ERSN(S390_RESET), ERSN(DCR),\
+        ERSN(NMI), ERSN(INTERNAL_ERROR), ERSN(OSI)
+
+TRACE_EVENT(kvm_userspace_exit,
+            TP_PROTO(__u32 reason, int errno),
+            TP_ARGS(reason, errno),
+
+        TP_STRUCT__entry(
+                __field(        __u32,          reason          )
+                __field(        int,            errno           )
+        ),
+
+        TP_fast_assign(
+                __entry->reason         = reason;
+                __entry->errno          = errno;
+        ),
+
+        TP_printk("reason %s (%d)",
+                  __entry->errno < 0 ?
+                  (__entry->errno == -EINTR ? "restart" : "error") :
+                  __print_symbolic(__entry->reason, kvm_trace_exit_reason),
+                  __entry->errno < 0 ? -__entry->errno : __entry->reason)
+);
+
 #if defined(__KVM_HAVE_IOAPIC)
 TRACE_EVENT(kvm_set_irq,
         TP_PROTO(unsigned int gsi, int level, int irq_source_id),
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 2803b4db2a38..880370caf9ed 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1562,6 +1562,7 @@ static long kvm_vcpu_ioctl(struct file *filp,
                 if (arg)
                         goto out;
                 r = kvm_arch_vcpu_ioctl_run(vcpu, vcpu->run);
+                trace_kvm_userspace_exit(vcpu->run->exit_reason, r);
                 break;
         case KVM_GET_REGS: {
                 struct kvm_regs *kvm_regs;