migration/colo: make colo_incoming_co() return void

Currently, it always returns 0, no need to check the return value at all.
In addition, enter colo coroutine only if migration_incoming_colo_enabled()
is true.
Once the destination side enters the COLO* state, the COLO process will
take over the remaining processes until COLO exits.

Cc: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Zhang Chen <chen.zhang@intel.com>
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
[fixed mangled author email address]
Signed-off-by: Fabiano Rosas <farosas@suse.de>

1 files changed, 3 insertions, 3 deletions

diff --git a/migration/migration.c b/migration/migration.c
index 995f0ca923..c004637d29 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -776,9 +776,9 @@ process_incoming_migration_co(void *opaque)
         goto fail;
     }
 
-    if (colo_incoming_co() < 0) {
-        error_setg(&local_err, "colo incoming failed");
-        goto fail;
+    if (migration_incoming_colo_enabled()) {
+        /* yield until COLO exit */
+        colo_incoming_co();
     }
 
     migration_bh_schedule(process_incoming_migration_bh, mis);