Actually v3 has one user. Our Sandia Labs compute miniclusters use the digital logic boards and run v3. I just remembered this the other day. I forgot it because v3 has been so usable on those boards we no longer think about it.
If you think about it, SMI, VSA, ACPI, EFI, and even the old BIOS -- all are there to virtualize resources that in some cases don't even exist, but in other cases are non-standard.I am wondering about stepping back from the problem and going at it with this approach -- that a runtime BIOS is really there to virtualize resourcs. Viewed this way, the answer is somewhat easier. The runtime BIOS can be a hypervisor. The models supported by these many varying systems are viewed as subset functions of a hypervisor.
If this seems crazy, it is actually the approach used in the PS/3. is that good or bad?
Where do we get a hypervisor? From the Xen guys, for one choice.
Just a thought. Rather than merely redo old ideas like SMI and old-style BIOS, we could step out ahead and do something very powerful.
ron