Return UnknownDevice for assignments where device is unknown

references QubesOS/qubes-issues#10409

Author: marmarta

qubesadmin/device_protocol.py

@@ -1356,8 +1356,9 @@ def devices(self) -> List[DeviceInfo]:
     @property
     def device(self) -> DeviceInfo:
         """
-        Get single DeviceInfo object or raise an error.
-
+        Get single DeviceInfo object or UnknownDevice, if the device has
+         not been found.
+        If there are more devices than one matching, raise ProtocolError.
         If port id is set we have exactly one device
         since we can attach ony one device to one port.
         If assignment is more general we can get 0 or many devices.
@@ -1367,7 +1368,8 @@ def device(self) -> DeviceInfo:
             return devices[0]
         if len(devices) > 1:
             raise ProtocolError("Too many devices matches to assignment")
-        raise ProtocolError("No devices matches to assignment")
+        return UnknownDevice(port=self.port,
+                             device_id=self.device_id)
 
     @property
     def port(self) -> Port:

qubesadmin/tests/mock_app.py

@@ -691,6 +691,7 @@ def __init__(
         vendor: str,
         attached: Optional[str] = None,
         assigned: Optional[List[Tuple[str, str, list[Any] | None]]] = None,
+        device_unknown: bool = False,
     ):
         """
         :param qapp: QubesTest object
@@ -712,6 +713,7 @@ def __init__(
         self.assigned = assigned
         self.product = product
         self.vendor = vendor
+        self.device_unknown = device_unknown
 
         self.interface = self.device_id.split(":")[-1]
 
@@ -761,16 +763,17 @@ def update_calls(self):
             )
         ]
 
-        self.qapp.expected_calls[
-            (
-                self.backend_vm,
-                f"admin.vm.device.{self.dev_class}.Available",
-                None,
-                None,
+        if not self.device_unknown:
+            self.qapp.expected_calls[
+                (
+                    self.backend_vm,
+                    f"admin.vm.device.{self.dev_class}.Available",
+                    None,
+                    None,
+                )
+            ] = (
+                current_response + self.device_string().encode()
             )
-        ] = (
-            current_response + self.device_string().encode()
-        )
 
         if self.attached:
             current_response = self.qapp.expected_calls[

qubesadmin/tools/qvm_device.py

@@ -236,6 +236,10 @@ def attach_device(args):
     try:
         try:
             dev = assignment.device
+            if isinstance(dev, UnknownDevice):
+                raise qubesadmin.exc.QubesException(
+                    "Unknown device, skipping attachment of device from the "
+                    f"port {assignment}")
         except ProtocolError as exc:
             raise qubesadmin.exc.QubesException(str(exc))