Merge remote-tracking branch 'remotes/juanquintela/tags/migration/20151015' into staging

migration/next for 20151015

# gpg: Signature made Thu 15 Oct 2015 07:25:27 BST using RSA key ID 5872D723
# gpg: Good signature from "Juan Quintela <quintela@redhat.com>"
# gpg:                 aka "Juan Quintela <quintela@trasno.org>"

* remotes/juanquintela/tags/migration/20151015:
  migration: fix deadlock
  migration: announce VM's new home just before VM is runnable
  Migration: Generate the completed event only when we complete

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 13 insertions, 2 deletions

diff --git a/migration/migration.c b/migration/migration.c
index b7de9b7b3f..b092f386b4 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -294,17 +294,22 @@ static void process_incoming_migration_co(void *opaque)
         migrate_decompress_threads_join();
         exit(EXIT_FAILURE);
     }
-    migrate_generate_event(MIGRATION_STATUS_COMPLETED);
-    qemu_announce_self();
 
     /* Make sure all file formats flush their mutable metadata */
     bdrv_invalidate_cache_all(&local_err);
     if (local_err) {
+        migrate_generate_event(MIGRATION_STATUS_FAILED);
         error_report_err(local_err);
         migrate_decompress_threads_join();
         exit(EXIT_FAILURE);
     }
 
+    /*
+     * This must happen after all error conditions are dealt with and
+     * we're sure the VM is going to be running on this host.
+     */
+    qemu_announce_self();
+
     /* If global state section was not received or we are in running
        state, we need to obey autostart. Any other state is set with
        runstate_set. */
@@ -320,6 +325,12 @@ static void process_incoming_migration_co(void *opaque)
         runstate_set(global_state_get_runstate());
     }
     migrate_decompress_threads_join();
+    /*
+     * This must happen after any state changes since as soon as an external
+     * observer sees this event they might start to prod at the VM assuming
+     * it's ready to use.
+     */
+    migrate_generate_event(MIGRATION_STATUS_COMPLETED);
 }
 
 void process_incoming_migration(QEMUFile *f)