https://bugs.freedesktop.org/show_bug.cgi?id=94530
--- Comment #2 from m.fehrenbach@protonmail.com --- I've got a VM which uses an R9 Nano via passthrough. Like Michael said, my system hangs both the VM and the host machine when installing AMD drier updates. Likewise my VM freezes and the fan revs up to maximum upon a normal resart of the VM, or I change anything in the QEMU startup command (e.g. adding another hard drive to the VM). And the only way to stop either of those issues is to power off the host machine.
The only way I have been able to change the driver for my card is during a fresh install of Windows when no drivers are previously installed (aside from the basic prepackaged ones are within Windows). Then I can get the lastest drivers I already downloaded from another hard drive and install them on my system, and it will work for the most part. However this doesn't address the core issue.
Whilst I'm unsure if this website is the appropriate place to file this bug report, the previous two posts are the only place I've seen this exact issue mentioned.