q-dev: assignment.device

qubes/device_protocol.py

@@ -1127,6 +1127,23 @@ def devices(self) -> List[DeviceInfo]:
                 result.append(dev)
         return result
 
+    @property
+    def device(self) -> DeviceInfo:
+        """
+        Get single DeviceInfo object or raise an error.
+
+        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.
+        """
+        devices = self.devices
+        if len(devices) == 1:
+            return devices[0]
+        if len(devices) > 1:
+            raise ProtocolError("Too many devices matches to assignment")
+        if len(devices) == 0:
+            raise ProtocolError("Any devices matches to assignment")
+
     @property
     def port(self) -> Port:
         """

qubes/devices.py

@@ -209,8 +209,8 @@ async def attach(self, assignment: DeviceAssignment):
             raise ValueError(
                 f'Cannot attach ambiguous {assignment.devclass} device.')
 
-        device = assignment.devices[0]
-        if device in [ass.devices[0] for ass in self.get_attached_devices()]:
+        device = assignment.device
+        if device in [ass.device for ass in self.get_attached_devices()]:
             raise DeviceAlreadyAttached(
                 'device {!s} of class {} already attached to {!s}'.format(
                     device, self._bus, self._vm))
@@ -307,7 +307,7 @@ async def detach(self, port: Port):
                 "You need to unassign device first.")
 
         # use the local object, only one device can match
-        port = assignment.devices[0].port
+        port = assignment.device.port
         await self._vm.fire_event_async(
             'device-pre-detach:' + self._bus, pre_event=True, port=port)
 

qubes/ext/utils.py

@@ -79,7 +79,7 @@ def device_list_change(
     for port_id, frontends in to_attach.items():
         if len(frontends) > 1:
             # unique
-            device = tuple(frontends.values())[0].devices[0]
+            device = tuple(frontends.values())[0].device
             target_name = confirm_device_attachment(device, frontends)
             for front in frontends:
                 if front.name == target_name:

templates/libvirt/xen.xml

@@ -157,21 +157,23 @@
             {# start external devices from xvdi #}
             {% set counter = {'i': 4} %}
             {% for assignment in vm.devices.block.get_assigned_devices(True) %}
-                {% set device = assignment.devices[0] %}
-                {% set options = assignment.options %}
-                {% include 'libvirt/devices/block.xml' %}
+                {% for device in assignment.devices %}
+                    {% set options = assignment.options %}
+                    {% include 'libvirt/devices/block.xml' %}
+                {% endfor %}
             {% endfor %}
 
             {% if vm.netvm %}
                 {% include 'libvirt/devices/net.xml' with context %}
             {% endif %}
 
             {% for assignment in vm.devices.pci.get_assigned_devices(True) %}
-                {% set device = assignment.devices[0] %}
-                {% set options = assignment.options %}
-                {% set power_mgmt =
-                    vm.app.domains[0].features.get('suspend-s0ix', False) %}
-                {% include 'libvirt/devices/pci.xml' %}
+                {% for device in assignment.devices %}
+                    {% set options = assignment.options %}
+                    {% set power_mgmt =
+                        vm.app.domains[0].features.get('suspend-s0ix', False) %}
+                    {% include 'libvirt/devices/pci.xml' %}
+                {% endfor %}
             {% endfor %}
 
             {% if vm.virt_mode == 'hvm' %}