[PATCH v4] python/qemu/qmp.py: QMP debug with VM label

[Oksana Vohchana <ovoshcha@redhat.com>]

QEMUMachine writes some messages to the default logger.
But it sometimes hard to read the output if we have requests to
more than one VM.
This patch adds a label to the logger in the debug mode.

Signed-off-by: Oksana Vohchana <ovoshcha@redhat.com>
---
v2:
 - Instead of shown the label in the message it provides the label
   only in the debug logger information.
v3:
 - Fixes coding style problems.
v4:
 - Use a suffix method to get a children's logger process from the parent.
---
 python/qemu/machine.py | 3 ++-
 python/qemu/qmp.py     | 5 ++++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/python/qemu/machine.py b/python/qemu/machine.py
index 183d8f3d38..f53abfa492 100644
--- a/python/qemu/machine.py
+++ b/python/qemu/machine.py
@@ -270,7 +270,8 @@ class QEMUMachine(object):
                 self._vm_monitor = os.path.join(self._sock_dir,
                                                 self._name + "-monitor.sock")
                 self._remove_files.append(self._vm_monitor)
-            self._qmp = qmp.QEMUMonitorProtocol(self._vm_monitor, server=True)
+            self._qmp = qmp.QEMUMonitorProtocol(self._vm_monitor, server=True,
+                                                nickname=self._name)
 
     def _post_launch(self):
         if self._qmp:
diff --git a/python/qemu/qmp.py b/python/qemu/qmp.py
index f40586eedd..d6c9b2f4b1 100644
--- a/python/qemu/qmp.py
+++ b/python/qemu/qmp.py
@@ -46,7 +46,7 @@ class QEMUMonitorProtocol:
     #: Logger object for debugging messages
     logger = logging.getLogger('QMP')
 
-    def __init__(self, address, server=False):
+    def __init__(self, address, server=False, nickname=None):
         """
         Create a QEMUMonitorProtocol class.
 
@@ -62,6 +62,9 @@ class QEMUMonitorProtocol:
         self.__address = address
         self.__sock = self.__get_sock()
         self.__sockfile = None
+        self._nickname = nickname
+        if self._nickname:
+            self.logger = logging.getLogger('QMP').getChild(self._nickname)
         if server:
             self.__sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
             self.__sock.bind(self.__address)
-- 
2.21.1