qmp: hmp: add migrate "resume" option

It will be used when we want to resume one paused migration.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20180502104740.12123-8-peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
s/2.12/2.13/

hmp-commands.hx

@@ -897,13 +897,14 @@ ETEXI
 
     {
         .name       = "migrate",
-        .args_type  = "detach:-d,blk:-b,inc:-i,uri:s",
-        .params     = "[-d] [-b] [-i] uri",
+        .args_type  = "detach:-d,blk:-b,inc:-i,resume:-r,uri:s",
+        .params     = "[-d] [-b] [-i] [-r] uri",
         .help       = "migrate to URI (using -d to not wait for completion)"
 		      "\n\t\t\t -b for migration without shared storage with"
 		      " full copy of disk\n\t\t\t -i for migration without "
 		      "shared storage with incremental copy of disk "
-		      "(base image shared between src and destination)",
+		      "(base image shared between src and destination)"
+                      "\n\t\t\t -r to resume a paused migration",
         .cmd        = hmp_migrate,
     },
 

hmp.c

@@ -1929,10 +1929,12 @@ void hmp_migrate(Monitor *mon, const QDict *qdict)
     bool detach = qdict_get_try_bool(qdict, "detach", false);
     bool blk = qdict_get_try_bool(qdict, "blk", false);
     bool inc = qdict_get_try_bool(qdict, "inc", false);
+    bool resume = qdict_get_try_bool(qdict, "resume", false);
     const char *uri = qdict_get_str(qdict, "uri");
     Error *err = NULL;
 
-    qmp_migrate(uri, !!blk, blk, !!inc, inc, false, false, &err);
+    qmp_migrate(uri, !!blk, blk, !!inc, inc,
+                false, false, true, resume, &err);
     if (err) {
         hmp_handle_error(mon, &err);
         return;

migration/migration.c

@@ -1413,7 +1413,7 @@ bool migration_is_blocked(Error **errp)
 
 void qmp_migrate(const char *uri, bool has_blk, bool blk,
                  bool has_inc, bool inc, bool has_detach, bool detach,
-                 Error **errp)
+                 bool has_resume, bool resume, Error **errp)
 {
     Error *local_err = NULL;
     MigrationState *s = migrate_get_current();

qapi/migration.json

@@ -1031,6 +1031,8 @@
 # @detach: this argument exists only for compatibility reasons and
 #          is ignored by QEMU
 #
+# @resume: resume one paused migration, default "off". (since 2.13)
+#
 # Returns: nothing on success
 #
 # Since: 0.14.0
@@ -1052,7 +1054,8 @@
 #
 ##
 { 'command': 'migrate',
-  'data': {'uri': 'str', '*blk': 'bool', '*inc': 'bool', '*detach': 'bool' } }
+  'data': {'uri': 'str', '*blk': 'bool', '*inc': 'bool',
+           '*detach': 'bool', '*resume': 'bool' } }
 
 ##
 # @migrate-incoming: