[vfio-users] USB device passthrough regression?

[Patrick O'Callaghan]

I've been using a USB-attached slide scanner (Ion Slidesforever) under
a Windows 10 VM using QEMU/KVM USB passthrough, however it has now
stopped working.

The device still shows up under the Windows "device manager" console,
and the scanner app doesn't complain that it can't find it. The scanner
works correctly on a Windows laptop so the hardware is fine. I've also
removed and reinstalled the app (you never know with Windows) but with
no improvement.

Under the VM the app launches but doesn't appear to receive any input,
nor does it give an error message. Removing and reattaching the device
in the virt-manager console (and rebooting the VM) makes no difference.

Using xsane under Linux does capture an image, but unfortunately not at
full resolution, so I need the proprietary Windows app and driver to
work.

This may have nothing to do with VFIO, but I thought I'd ask in case
anyone has seen something similar. I have several thousand slides to
get through :-(

poc