I don't see why you couldn't parse the virtualisation instruction to a virtual machine. Modern hyper-visors don't emulate the CPU instructions any more, they're parsed through to the virtual machine.

While I'm certainly not sure, I do believe that at least some virtualisation solutions are able to parse the virtualisation instructions from the host CPU to the guest.

You only need to emulate the virtualization instructions. KVM does this and pretty much everyone else does too.

Hyper-V runs under Fusion, Qubes OS and Xen also work. Have not tested others, but this is one area where Fusion excels. Yes it will be slower, but for testing the concept that is usually fine.

I needed Xen for some experimentation. I had trouble running alpine-xen-3.4.4 in Fusion. XenServer 7 seems to work in Fusion, but I don't like it. I finally managed to get alpine-xen running inside KVM (Ubuntu 16.04) inside Fusion.