migration: create migration event

We have one argument that tells us what event has happened.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
diff --git a/migration/migration.c b/migration/migration.c
index ffaa5c8..d8415c4 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -27,6 +27,7 @@
 #include "qmp-commands.h"
 #include "trace.h"
 #include "qapi/util.h"
+#include "qapi-event.h"
 
 #define MAX_THROTTLE  (32 << 20)      /* Migration speed throttling */
 
@@ -510,6 +511,7 @@
 static void migrate_set_state(MigrationState *s, int old_state, int new_state)
 {
     if (atomic_cmpxchg(&s->state, old_state, new_state) == old_state) {
+        qapi_event_send_migration(new_state, &error_abort);
         trace_migrate_set_state(new_state);
     }
 }