I read something interesting the other day. Running multiple VMs, on the same computer; the catch is that they are all running on the same desktop (not headless) sharing one display. The term is “kvm localized virtual desktops”.
The place I read this was the UnRaid blog, talking about KVM integration into the UnRaid 6 system (SOURCE).
Since OpenSuSE has tools and support for kvm, I shall try this.
It would be interesting to run linux and windows and not have to dual boot, and have access to the same GPU from both OSs.