Devices widget freezes and doesn't appear when USB qube is not named `sys-usb`

[konsultavicius]

Qubes OS release

4.3

Brief summary

The widget expects the USB vm to be named "sys-usb", but when installing on system with only USB internet and clicking option to merge sys-net and sys-usb, the USBVm is named "sys-net".

The issue can be worked around by replacing a "sys-usb" string literal in a python file in /usr/lib
with "sys-net".

The widget freezes, doesn't appear.

Steps to reproduce

Install Qubes OS with merged sys-net and sys-usb.
Try to use devices widget.
Observe it not working.

Expected behavior

Widget works no matter how the USB vm is named (or the installer should call the NETvm sys-usb)

Actual behavior

The widget freezes, doesn't appear.

[ben-grande]

I have three different USBVMs and none named sys-usb. I suggest finding devices of class 0c03 and the qubes they are attached to to assign multiple self.sysusb in qui/devices/device_widget.py.

[alimirjamali]

I have three different USBVMs and none named sys-usb.

I submitted a patch to avoid Qui Devices widget to crash in case no sys-usb USBVM exists. As for adding multiple List USB Devices (start $USBVM) menu items to the Qui Devices widget, I guess for highly customized scenarios where power users might have multiple USBVMs/controllers, they already know when and how to start them when they need them? And they could easily start them via Qube Manager or command line?

I suggest finding devices of class 0c03 and the qubes they are attached to to assign multiple self.sysusb in qui/devices/device_widget.py.

Of course this is doable. If it is still the case, I could unlink the PR from this issue (so a proper fix to show individual options to allow advanced user to start custom USBVMs to be developed for Qui Devices widget).

p.s.: Something like this:

>>> usbvms = []
>>> for qube in app.domains:
...     if qube.klass = "AdminVM":
...         continue
...     for dev in qube.devices["pci"].get_attached_devices():
...         for interface in dev.device.interfaces:
...             if interface.category == qubesadmin.device_protocol.DeviceCategory.PCI_USB:
...                 if not qube in usbvms:
...                     usbvms.append(qube)