q-dev: backward compatible device_protocol

Author: piotrbartman

qubes/device_protocol.py

@@ -412,7 +412,10 @@ class DeviceInfo(Port):
 
     def __init__(
             self,
-            port: Port,
+            port: Optional[Port] = None,
+            backend_domain: Optional = None,
+            ident: Optional = None,
+            devclass: Optional = None,
             vendor: Optional[str] = None,
             product: Optional[str] = None,
             manufacturer: Optional[str] = None,
@@ -424,6 +427,8 @@ def __init__(
             self_identity: Optional[str] = None,
             **kwargs
     ):
+        if port is None:
+            port = Port(backend_domain, ident, devclass)
         super().__init__(port.backend_domain, port.ident, port.devclass)
 
         self._vendor = vendor
@@ -821,21 +826,24 @@ class DeviceAssignment(Port):
 
     def __init__(
             self,
-            port: Port,
+            port: Optional[Port] = None,
+            backend_domain: Optional = None,
+            ident: Optional = None,
+            devclass: Optional = None,
             device_identity=None,
             frontend_domain=None,
             options=None,
             mode: Union[str, AssignmentMode] = "manual",
     ):
+        if port is None:
+            port = Port(backend_domain, ident, devclass)
         super().__init__(port.backend_domain, port.ident, port.devclass)
         self.__options = options or {}
         if isinstance(mode, AssignmentMode):
             self.mode = mode
         else:
             self.mode = AssignmentMode(mode)
         self.frontend_domain = frontend_domain
-        if device_identity == 'any':
-            device_identity = None
         self.device_identity = device_identity
 
     def clone(self, **kwargs):
@@ -912,7 +920,7 @@ def attach_automatically(self) -> bool:
         return self.mode in (
             AssignmentMode.AUTO,
             AssignmentMode.ASK,
-            AssignmentMode.REQUIRED,
+            AssignmentMode.REQUIRED
         )
 
     @attach_automatically.setter