qvm_start_daemon: improve reset property handling

qubesadmin/tools/qvm_start_daemon.py

@@ -736,7 +736,7 @@ def on_domain_stopped(self, vm, _event, **_kwargs):
             self.cleanup_guid(stubdom_xid)
             self.cleanup_pacat_process(stubdom_xid)
 
-    def on_property_audiovm_set(self, vm, _event, **_kwargs):
+    def on_property_audiovm_set(self, vm, event, **kwargs):
         """Handler for catching event related to dynamic AudioVM set/unset"""
         if vm.name not in self.xid_cache:
             try:
@@ -745,7 +745,13 @@ def on_property_audiovm_set(self, vm, _event, **_kwargs):
                 log.error("vm.name: failed to determine XID: %s", str(e))
                 return
         xid, stubdom_xid = self.xid_cache[vm.name]
-        newvalue = _kwargs.get("newvalue", None)
+        # We ensure that on_property_audiovm_set is really called with
+        # newvalue as kwarg to not fallback all the times to vm.audiovm
+        # in order to have newvalue=None as requested.
+        if "newvalue" in kwargs:  # pylint: disable=consider-using-get
+            newvalue = kwargs["newvalue"]
+        else:
+            newvalue = str(getattr(vm, "audiovm", None))
         if newvalue != self.app.local_name:
             if xid != -1:
                 self.cleanup_pacat_process(xid)
@@ -756,8 +762,11 @@ def on_property_audiovm_set(self, vm, _event, **_kwargs):
                     del self.xid_cache[vm.name]
             except KeyError:
                 return
-        elif (newvalue == self.app.local_name and
-              vm.get_power_state() == "Running"):
+        if (
+                event in ["property-set:audiovm", "property-reset:audiovm"]
+                and newvalue == self.app.local_name
+                and vm.get_power_state() == "Running"
+        ):
             asyncio.ensure_future(self.start_audio(vm))
 
     def cleanup_guid(self, xid):
@@ -799,8 +808,12 @@ def register_events(self, events):
                            self.on_connection_established)
         events.add_handler('domain-stopped', self.on_domain_stopped)
 
-        for event in ["property-set:audiovm", "property-pre-set:audiovm",
-                      "property-pre-del:audiovm"]:
+        for event in [
+            "property-set:audiovm",
+            "property-pre-set:audiovm",
+            "property-pre-reset:audiovm",
+            "property-reset:audiovm"
+        ]:
             events.add_handler(event, self.on_property_audiovm_set)
 
     def is_watched(self, vm):