migration: fix incorrect enable return path

0425dc9 is actually v1 of that patch, but it was accidentally
merged (while there was a v2). That will cause problem when we try to
migrate to some old QEMUs when return path is not really there. Let's
fix it, then squashing this patch with 0425dc9 will be exactly patch
content of v2.

Fixes: 0425dc9 ("migration: isolate return path on src")
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

diff --git a/migration/migration.c b/migration/migration.c
index 8ef6d6c4120b5998b2999b2ab9c2c68b1eb4e5ed..f9053b07ddd3e9142d2be1c72639ebe142b5a955 100644 (file)
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1814,7 +1814,11 @@ static void *migration_thread(void *opaque)
 
     qemu_savevm_state_header(s->to_dst_file);
 
-    if (s->to_dst_file) {
+    /*
+     * If we opened the return path, we need to make sure dst has it
+     * opened as well.
+     */
+    if (s->rp_state.from_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);