I know that cards based on this controller chip have been discussed in other threads, but I believe my issue with my card is a little different. I purchased this card and upgraded the firmware as discussed in this thread. It works fine from within the Linux host and can even passthrough individual USB devices to guests.
However, as you might have guessed, I have issues when passing the entire card to a Windows 10 guest. I have segmented it to the following condition. If I have a device already plugged into the card (e.g. USB mouse) when the VM is started, it hangs on the TianoCore logo. If instead leave all ports empty, Windows 10 boots fine and after logging into Windows I can hot-plug and remove devices (even a USB stick) without any issues.
My suspicion at this point is that the guest’s UEFI (OVMF) is not initializing the card correctly (or the card does not respond properly) when there is already a device plugged in. I suppose I could switch to SeaBIOS, but I was not sure if there were any other implications to my existing Win10 guest install by switching the VM configuration in such a manner.
I am using a Xeon E-2288G in a WS C246 PRO motherboard under UnRAID 6.8.3, with ACS override, and guest is Q35-4.2. Not sure what other details might be relevant, so I’ll just leave it at that for now.