Add a new qmp command to do checkpoint, query xen replication status

We can call this qmp command to do checkpoint outside of qemu.
Xen colo will need this function.

Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wencongyang@gmail.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>

migration/colo.c

@@ -173,6 +173,29 @@ void qmp_xen_set_replication(bool enable, bool primary,
     }
 }
 
+ReplicationStatus *qmp_query_xen_replication_status(Error **errp)
+{
+    Error *err = NULL;
+    ReplicationStatus *s = g_new0(ReplicationStatus, 1);
+
+    replication_get_error_all(&err);
+    if (err) {
+        s->error = true;
+        s->has_desc = true;
+        s->desc = g_strdup(error_get_pretty(err));
+    } else {
+        s->error = false;
+    }
+
+    error_free(err);
+    return s;
+}
+
+void qmp_xen_colo_do_checkpoint(Error **errp)
+{
+    replication_do_checkpoint_all(errp);
+}
+
 static void colo_send_message(QEMUFile *f, COLOMessage msg,
                               Error **errp)
 {

qapi-schema.json

@@ -6014,6 +6014,54 @@
 { 'command': 'xen-set-replication',
   'data': { 'enable': 'bool', 'primary': 'bool', '*failover' : 'bool' } }
 
+##
+# @ReplicationStatus:
+#
+# The result format for 'query-xen-replication-status'.
+#
+# @error: true if an error happened, false if replication is normal.
+#
+# @desc: #optional the human readable error description string, when
+#        @error is 'true'.
+#
+# Since: 2.9
+##
+{ 'struct': 'ReplicationStatus',
+  'data': { 'error': 'bool', '*desc': 'str' } }
+
+##
+# @query-xen-replication-status:
+#
+# Query replication status while the vm is running.
+#
+# Returns: A @ReplicationResult object showing the status.
+#
+# Example:
+#
+# -> { "execute": "query-xen-replication-status" }
+# <- { "return": { "error": false } }
+#
+# Since: 2.9
+##
+{ 'command': 'query-xen-replication-status',
+  'returns': 'ReplicationStatus' }
+
+##
+# @xen-colo-do-checkpoint:
+#
+# Xen uses this command to notify replication to trigger a checkpoint.
+#
+# Returns: nothing.
+#
+# Example:
+#
+# -> { "execute": "xen-colo-do-checkpoint" }
+# <- { "return": {} }
+#
+# Since: 2.9
+##
+{ 'command': 'xen-colo-do-checkpoint' }
+
 ##
 # @GICCapability:
 #