migration: isolate return path on src

There are some places that binded "return path" with postcopy. Let's be
prepared for its usage even without postcopy. This patch mainly did this
on source side.

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

diff --git a/migration/migration.c b/migration/migration.c
index fc95acbde6018b7851e3ec6779afb489e18170a0..9dfa19abe1d5749e13574c1e54f56a4859f329a4 100644 (file)
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1857,13 +1857,12 @@ static void migration_completion(MigrationState *s, int current_active_state,
      * cleaning everything else up (since if there are no failures
      * it will wait for the destination to send it's status in
      * a SHUT command).
-     * Postcopy opens rp if enabled (even if it's not avtivated)
      */
-    if (migrate_postcopy_ram()) {
+    if (s->rp_state.from_dst_file) {
         int rp_error;
-        trace_migration_completion_postcopy_end_before_rp();
+        trace_migration_return_path_end_before();
         rp_error = await_return_path_close_on_source(s);
-        trace_migration_completion_postcopy_end_after_rp(rp_error);
+        trace_migration_return_path_end_after(rp_error);
         if (rp_error) {
             goto fail_invalidate;
         }
@@ -1938,13 +1937,15 @@ static void *migration_thread(void *opaque)
 
     qemu_savevm_state_header(s->to_dst_file);
 
-    if (migrate_postcopy_ram()) {
+    if (s->to_dst_file) {
         /* Now tell the dest that it should open its end so it can reply */
         qemu_savevm_send_open_return_path(s->to_dst_file);
 
         /* And do a ping that will make stuff easier to debug */
         qemu_savevm_send_ping(s->to_dst_file, 1);
+    }
 
+    if (migrate_postcopy_ram()) {
         /*
          * Tell the destination that we *might* want to do postcopy later;
          * if the other end can't do postcopy it should fail now, nice and

diff --git a/migration/trace-events b/migration/trace-events
index 5b8ccf301c5fb57b3080622c4fdfd4d5f31516a0..38345be9c314ec6a28b7de470f363007e39492ba 100644 (file)
--- a/migration/trace-events
+++ b/migration/trace-events
@@ -88,8 +88,8 @@ migrate_send_rp_message(int msg_type, uint16_t len) "%d: len %d"
 migration_completion_file_err(void) ""
 migration_completion_postcopy_end(void) ""
 migration_completion_postcopy_end_after_complete(void) ""
-migration_completion_postcopy_end_before_rp(void) ""
-migration_completion_postcopy_end_after_rp(int rp_error) "%d"
+migration_return_path_end_before(void) ""
+migration_return_path_end_after(int rp_error) "%d"
 migration_thread_after_loop(void) ""
 migration_thread_file_err(void) ""
 migration_thread_setup_complete(void) ""