qapi: introduce preconfig runstate

New preconfig runstate will be used in follow up patches
related to introducing --preconfig CLI option and is
intended to replace prelaunch runstate from QEMU start
up to machine_init callback.
Signed-off-by: NIgor Mammedov <imammedo@redhat.com>
Message-Id: <1525423069-61903-4-git-send-email-imammedo@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
[ehabkost: Changed "since 2.13" to "since 3.0"]
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>

qapi/run-state.json

@@ -49,12 +49,15 @@
 # @colo: guest is paused to save/restore VM state under colo checkpoint,
 #        VM can not get into this state unless colo capability is enabled
 #        for migration. (since 2.8)
+# @preconfig: QEMU is paused before board specific init callback is executed.
+#             The state is reachable only if the --preconfig CLI option is used.
+#             (Since 3.0)
 ##
 { 'enum': 'RunState',
   'data': [ 'debug', 'inmigrate', 'internal-error', 'io-error', 'paused',
             'postmigrate', 'prelaunch', 'finish-migrate', 'restore-vm',
             'running', 'save-vm', 'shutdown', 'suspended', 'watchdog',
-            'guest-panicked', 'colo' ] }
+            'guest-panicked', 'colo', 'preconfig' ] }
 
 ##
 # @StatusInfo: