[vfio-users] Guest freezes upon GPU passthrough

[arch user]

Minor update: I've been able to correlate the freeze with Windows attempting
to install the AMD graphics driver (I initially get VGA output, after which
Windows Update attempts to install the proper driver).

Once I reboot after the freeze it appears to get stuck in OVMF firmware. I've
enabled debug logging, which shows the last message from OVMF firmware is
"Found PCI VGA device". I suppose it's similar to [1] from there on, but in
my case I'm not seeing any asserts (assuming they're enabled?).

Could this be related to my graphics card BIOS? It ought to be UEFI
compatible - it even says so on the box... (I've been unable to dump
the oprom, for what it's worth, getting "Invalid ROM contents" in dmesg).

[1]: http://sourceforge.net/p/edk2/mailman/message/33482147/