q-dev: make devclass required

Author: piotrbartman

qubesadmin/device_protocol.py

@@ -534,7 +534,7 @@ def serialize(self) -> bytes:
                 ('devclass', self.devclass)))
 
         properties += b' ' + DeviceSerializer.pack_property(
-            'backend_domain', self.backend_domain.name)
+            'backend_domain', self.backend_name)
 
         return properties
 
@@ -1252,12 +1252,12 @@ def _deserialize(
         return cls(**properties)
 
     def matches(self, device: VirtualDevice) -> bool:
+        if self.devclass != device.devclass:
+            return False
         if self.backend_domain != '*' and self.backend_domain != device.backend_domain:
             return False
         if self.port_id != '*' and self.port_id != device.port_id:
             return False
-        if self.devclass != '*' and self.devclass != device.devclass:
-            return False
         if self.device_id != '*' and self.device_id != device.device_id:
             return False
         return True

qubesadmin/tools/qvm_device.py

@@ -223,7 +223,7 @@ def assign_device(args):
     if args.only_port:
         device.device_id = None
     if args.only_device:
-        device.port = None
+        device.port = Port(None, None, device.devclass)
     options = dict(opt.split('=', 1) for opt in args.option or [])
     if args.ro:
         options['read-only'] = 'yes'