python/machine.py: use qmp.command

machine.py and qmp.py both do the same thing here; refactor machine.py
to use qmp.py's functionality more directly.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20201006235817.3280413-7-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>

python/qemu/machine.py

@@ -25,7 +25,13 @@
 import subprocess
 import tempfile
 from types import TracebackType
-from typing import List, Optional, Type
+from typing import (
+    Any,
+    Dict,
+    List,
+    Optional,
+    Type,
+)
 
 from . import console_socket, qmp
 from .qmp import QMPMessage, SocketAddrT
@@ -515,17 +521,23 @@ def set_qmp_monitor(self, enabled=True):
             self._qmp_set = False
             self._qmp = None
 
-    def qmp(self, cmd, conv_keys=True, **args):
-        """
-        Invoke a QMP command and return the response dict
-        """
+    @classmethod
+    def _qmp_args(cls, _conv_keys: bool = True, **args: Any) -> Dict[str, Any]:
         qmp_args = dict()
         for key, value in args.items():
-            if conv_keys:
+            if _conv_keys:
                 qmp_args[key.replace('_', '-')] = value
             else:
                 qmp_args[key] = value
+        return qmp_args
 
+    def qmp(self, cmd: str,
+            conv_keys: bool = True,
+            **args: Any) -> QMPMessage:
+        """
+        Invoke a QMP command and return the response dict
+        """
+        qmp_args = self._qmp_args(conv_keys, **args)
         return self._qmp.cmd(cmd, args=qmp_args)
 
     def command(self, cmd, conv_keys=True, **args):
@@ -534,12 +546,8 @@ def command(self, cmd, conv_keys=True, **args):
         On success return the response dict.
         On failure raise an exception.
         """
-        reply = self.qmp(cmd, conv_keys, **args)
-        if reply is None:
-            raise qmp.QMPError("Monitor is closed")
-        if "error" in reply:
-            raise qmp.QMPResponseError(reply)
-        return reply["return"]
+        qmp_args = self._qmp_args(conv_keys, **args)
+        return self._qmp.command(cmd, **qmp_args)
 
     def get_qmp_event(self, wait=False):
         """