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.
From the description it seems more like the host OS is not ignoring the card.
Or does the problem happen only if you leave the USB device connected during boot? Because that’s the only time the UEFI does anything to devices.
The card I upgraded the firmware of in the thread is used in this specific setup
where I make sure the host keeps its hands off the card with the part about the script with “vfio-pci” > /sys/bus/pci/devices/$DEV/driver_override
and if I don’t do that the card will randomly fail to be connected or removed from VMs depedning on if something was connected to it.
I don’t know how to replicate that in Unraid
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.
If the Win10 guest was installed in a UEFI VM, switching to SeaBIOS means it will not boot. Windows has an automated procedure to migrate from BIOS to UEFI mode, but not to do the reverse.