Do macOS guests also work on macOS hosts in QEMU/KVM? (e.g. run 10.12 Sierra inside qemu on a 10.14 Mojave host) if True: any Link to a tutorial? What about performance? Is it enough performant to run GUI Apps?
(I have tried Virtual Box but found it too slow for real work)
I'm not sure you'll get the features of Virtualbox if needing GUI but there is Hypervisor.framework[1]
based upon xhyve[2]. It's what powers Docker Desktop on Mac.
You can build linux images with linux kit[3]
[1] https://developer.apple.com/documentation/hypervisor [2] https://github.com/machyve/xhyve [3] https://github.com/linuxkit/linuxkit