I don't think it's possible on any realistically consumer-available virtualization software, which is why I said it wasn't realistic for the OP. I think it requires an enterprise-level hypervisor, like vSphere. Only one I've seen actually used is Unraid.
As I understand, The way software detects it is running in a VM is usually by checking hardware for virtualized device names, or by checking BIOS copyrights and stuff. Most Virtual Machines virtualize that information. (eg. for VMWare devices like VMWare SVGA II, VMWare network bridge, and a bunch of stuff software could check for like VMWare Tools) Unraid- at least from what I can find- has the ability to pass-through the "real" information to Virtual Machines instead. Which is intended largely to deal with these sorts of software checks. I think games do that to prevent hacking or cheating since that could be done via a VM.
I wish I could find somebody else that did it, because they annoy me, but LinusTechTips did a
"7-gamers, one CPU" system doing more or less what they did with the 2-workstation setup. (I think that video largely covers the hardware, and a follow up has all 7 being used in Crysis 3. Allegedly that game has VM detection which (presumably) didn't get tripped because of how they were setting stuff up.
of course, it could all be smoke and mirrors, but as much as I can't stand the channel I don't think they've outright lied like that before. And I'm pretty sure this sort of thing is done for enterprise stuff, for things like VPS setups, so it doesn't seem like a big leap that the same approach could be taken to spin out separate gaming setups.
EDIT: SnapRAID might be a free/Open Source alternative? It seems to have hardware passthrough though all I can find relates to it passing through Disk controller cards.