Start up a postcopy/listener thread ready for incoming page data

The loading of a device state (during postcopy) may access guest
memory that's still on the source machine and thus might need
a page fill; split off a separate thread that handles the incoming
page data so that the original incoming migration code can finish
off the device data.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/migration/migration.c b/migration/migration.c
index 38d64ea58b..db3d2dd43e 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1441,6 +1441,12 @@ static int postcopy_start(MigrationState *ms, bool *old_vm_running)
         goto fail;
     }
 
+    /*
+     * Make sure the receiver can get incoming pages before we send the rest
+     * of the state
+     */
+    qemu_savevm_send_postcopy_listen(fb);
+
     qemu_savevm_state_complete_precopy(fb);
     qemu_savevm_send_ping(fb, 3);