Watch for domain start/stop events and refresh VM connection info

QubesVm object caches some domain state (domain ID in libvirt object,
Qubes DB connection socket), which can become out of date in
case of start/stop events. Currently it needs manual trigger to refresh
itself.

qubesmanager/main.py

@@ -261,6 +261,7 @@ class VmManagerWindow(Ui_VmManagerWindow, QMainWindow):
         self.qvm_collection = qvm_collection
         self.blk_manager = blk_manager
         self.blk_manager.tray_message_func = trayIcon.showMessage
+        self.qubes_watch.setup_domain_watch(self.domain_state_changed_callback)
         self.qubes_watch.setup_block_watch(self.blk_manager.block_devs_event)
         self.blk_watch_thread = threading.Thread(target=self.qubes_watch.watch_loop)
         self.blk_watch_thread.daemon = True
@@ -510,6 +511,12 @@ class VmManagerWindow(Ui_VmManagerWindow, QMainWindow):
             self.manager_settings.setValue('position/y', self.y())
             # do not sync for performance reasons
 
+    def domain_state_changed_callback(self, name = None, uuid = None):
+        if name is not None:
+            vm = self.qvm_collection.get_vm_by_name(name)
+            if vm:
+                vm.refresh()
+
     def get_vms_list(self):
         self.qvm_collection.lock_db_for_reading()
         self.qvm_collection.load()