I've managed to get pci-e passthough working on a gigabyte gaming 3 matx MB and Ryzen 1700, no ACS patch, using only 1 GPU - AMD r9 290. However I'm facing a problem with the whole KVM setup and not sure what it's related to. For the Windows10 guest with the GPU passed through it crashes (guest only, host is fine) whenever I try anything graphics intensive, for example running Witcher3. Normal desktop is fine.
Also my Linux guests are acting odd when I try to SSH to them, I notice that the SSH terminals just stop working randomly. And then there's the issue with very slow network throughout to both VMs. I have no idea what's going on. It used to work fine with my Intel setup. There's no logs in dmesg to show a problem either.
I'm going to try Seabios instead of OVMF to see if I can stop the crashing.
Any one having similar issues or anyone can advise?