As far as I can tell the in-tree QEMU-traditional stubdomain is not tied to Linux.<p>Maybe you mean the effort to make Linux-based upstream QEMU stubdomain? That solution is not merged upstream. And there is alternative proposal called rump kernel based upstream QEMU stubdomain, which is not tied to any OS.<p>In fact open source Xen is becoming less and less Linux-centric. There is ongoing work to make FreeBSD Dom0. Arguably there are still much work to do, but at least they&#x27;re making progress.