Allow allocation of virtual disks created by other software just like physical disks

I am running ZFS on macOS, and have been for years. It is, without a doubt, what APFS should have been but never will be.

It is capable of creating very efficient virtual disks (zvols) that macOS is very happy with. I use them for many things, most recently targets for Time Machine backups over SMB. Very very reliable.

I'd like to be able to add them to a VM just like I can add physical disks. Would be very useful for testing, but also in some production situations.

From looking at the PVS files with physical disks attached, I see no reason the virtual disks wouldn't work fine. The are just disks, as far as Parallels would be concerned. I intend to try to modify a PVS file to prove this, if you guys have any advice on what fields are critical in the XML v those that are not.

Thanks.