trace: Add event "guest_cpu_exit"

Signals the hot-unplugging of a virtual (guest) CPU.
Signed-off-by: NLluís Vilanova <vilanova@ac.upc.edu>
Message-id: 148278748597.1404.10546320797997984932.stgit@fimbulvetr.bsc.es
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

trace-events

@@ -141,6 +141,12 @@ memory_region_ram_device_write(int cpu_index, void *mr, uint64_t addr, uint64_t
 # Targets: all
 vcpu guest_cpu_enter(void)
 
+# Hot-unplug a virtual (guest) CPU
+#
+# Mode: user, softmmu
+# Targets: all
+vcpu guest_cpu_exit(void)
+
 # Reset the state of a virtual (guest) CPU
 #
 # Mode: user, softmmu

trace/control.c

@@ -26,6 +26,7 @@
 #include "qemu/error-report.h"
 #include "qemu/config-file.h"
 #include "monitor/monitor.h"
+#include "trace.h"
 
 int trace_events_enabled_count;
 
@@ -264,6 +265,8 @@ void trace_fini_vcpu(CPUState *vcpu)
     TraceEventIter iter;
     TraceEvent *ev;
 
+    trace_guest_cpu_exit(vcpu);
+
     trace_event_iter_init(&iter, NULL);
     while ((ev = trace_event_iter_next(&iter)) != NULL) {
         if (trace_event_is_vcpu(ev) &&