Not claiming to be knowledgeable about OS X internals, but... it ships with a hypervisor now?
Is it at all similar to BSD jails?
Is it at all similar to BSD jails?
FreeBSD's hypervisor is called bhyve (and it uses vmm.ko), and xhyve is a port of bhyve to macOS (uses Apple's Hypervisor.framework). There are other things that use Hypervisor.framework too.
Docker's macOS installer uses it rather than VirtualBox now if memory serves.
Still nice to know about Hypervisor.framework. If I ever get back to OS X I'll have to check it out!