Add migrate_incoming

Add migrate_incoming/migrate-incoming to start an incoming
migration.

Once a qemu has been started with
    -incoming defer

the migration can be started by issuing:
    migrate_incoming uri

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
diff --git a/hmp.c b/hmp.c
index 71c28bc..f6cde86 100644
--- a/hmp.c
+++ b/hmp.c
@@ -1116,6 +1116,20 @@
     qmp_migrate_cancel(NULL);
 }
 
+void hmp_migrate_incoming(Monitor *mon, const QDict *qdict)
+{
+    Error *err = NULL;
+    const char *uri = qdict_get_str(qdict, "uri");
+
+    qmp_migrate_incoming(uri, &err);
+
+    if (err) {
+        monitor_printf(mon, "%s\n", error_get_pretty(err));
+        error_free(err);
+        return;
+    }
+}
+
 void hmp_migrate_set_downtime(Monitor *mon, const QDict *qdict)
 {
     double value = qdict_get_double(qdict, "value");