Is there anyone with experience using QEMU, Passthrough and KVM that has got a decent performance from DOS 6.22, or more importantly Doom, inside a virtual machine?

My test rig is a fairly decent LGA 1150 cpu, and I am passing through an S3 Virge GX card and a Yahama YMF724. I have tried a few other FPS and scrolling 2D games and they all just crunch and tear through the screen. What can I be doing wrong here?