I've done this too! I was able to do it with my AMD FX-8350 and GA-990FX-UD3, as they both support IOMMU. Passing through my R9 390 to the Windows guest, and th

I've done this too! I was able to do it with my AMD FX-8350 and GA-990FX-UD3, as they both support IOMMU. Passing through my R9 390 to the Windows guest, and the only issue I've encountered the whole time was having to disable hardware acceleration for flash videos. The whole KVM/Qemu ecosystem is great.