qui-devices: Improve partition handling

At device_attached() function:
When a partition is attached, the parent device’s entry is immediately
removed from the QubesDB, the sub-device’s infomation is changed, and
an device-attach event is triggered. However, due to concurrency
issues, the API may not return information about the attached device.
In that case, let’s query the backend domain to get the proper device
information.

At device_removed() function:
If the parent device has sub-devices, updates their internal
information.

Fixes: QubesOS/qubes-issues#10828
Fixes: QubesOS/qubes-issues#10732

Author: noskb

qui/devices/device_widget.py

@@ -338,6 +338,36 @@ def device_removed(self, vm, _event, port):
             self.cameras_to_hide.remove(dev.parent)
         del self.devices[dev_id]
 
+        # If the removed device has sub-devices, update their states
+        if dev.has_children:
+            to_update = {}
+            to_delete = []
+            parent_dev = dev
+            for dev_id, device in self.devices.items():
+                if device.parent == parent_dev.port:
+                    vm.devices[parent_dev.device_class].clear_cache()
+                    for dev in (
+                         vm.devices[parent_dev.device_class]
+                        .get_exposed_devices()
+                        ):
+                        if str(dev.port) == device.port:
+                            to_update[dev] = [
+                                attachment
+                                for attachment in device.attachments
+                                if device.attachments
+                            ]
+                            if dev_id != backend.Device.id_from_device(dev):
+                                to_delete.append(device._full_id)
+
+            for dev, attachments in to_update.items():
+                dev_id = backend.Device.id_from_device(dev)
+                self.devices[dev_id] = backend.Device(dev, self)
+                if attachments:
+                    for attachment in attachments:
+                        self.devices[dev_id].attachments.add(attachment)
+            for dev_id in to_delete:
+                del self.devices[dev_id]
+
     def initialize_dev_data(self):
         # list all devices
         for domain in self.qapp.domains:
@@ -606,6 +636,17 @@ def device_attached(self, vm, _event, device, **_kwargs):
             # we don't have access to VM state
             return
 
+        if not isinstance(device, qubesadmin.device_protocol.DeviceInfo):
+            device.backend_domain.devices[device.devclass].clear_cache()
+            devices = (
+                     device.backend_domain
+                    .devices[device.devclass]
+                    .get_exposed_devices()
+            )
+            for dev in devices:
+                if dev.port_id == device.port_id:
+                    device = dev
+
         dev_id = backend.Device.id_from_device(device)
         if dev_id not in self.devices:
             self.devices[dev_id] = backend.Device(device, self)