Yes this is a real drawback when you want to test this. Since I was curious to know if it works that's the reason why I bought a workstation on ebay to test it. I own my own hardware for Qemu/KVM.

The main reason is that it works with NVIDIA cards that it supposed to be Multi OS: Quadro 6000, Quadro 5000, 4800, 4000 and 2000.

Doing some researches on the Internet it seems to work with other cards too

Moreover ReactOS should work with pretty old cards.

Unfortunately Qemu/KVM is known to have some drawbacks with pretty olds cards.

In my case for my Quadro FX 4800, I had to

from the BIOS: switch off all USB devices

from the BIOS: switch off the IGD. No second screen

Quadro cards were set up for Professional Workstation.

so Qemu + Quadro can imply consumption issue if IGD is not switched off!!!