This article on AMD's upcoming CPU support for hardware virtualization has the best description of virtualization I've read to date:
Yes, I am familiar with that-- it’s called paravirtualization:
http://en.wikipedia.org/wiki/Paravirtualization
It is interesting, but ultimately I think the hardware solutions have more promise because they’re more general and require very little effort on anyone’s part to get the best performance.
Plus, the odds of MS letting someone modify the Windows source is… slim… 
The big question is, when will the virtualization vendors be able to virtualize the video card, rather than emulate a mid-1990s, very basic card. Once Vista/Aero Glass hit, working in virtual machines is going to be a lot less enticing until they figure out the video issue.
But can you run a virtual machine inside a virtual machine under this new scheme? IIRC, IBM’s supported this for decades.
Congratulations.
The PC will finally be able to do what the IBM System/390 (zSeries mainframe) has been doing for zillions of years.
VM/ESA, VM/CMS / MVS, etc.
Oh yeah, Tandem systems do this, too.
I’ve had good luck with Linux VServer – multiple completely separate systems running on the same hardware, sharing the same kernel. Very low overhead. It’s best for webhost-type situations, where you have lots of somewhat-similar things running, but each system should be separately “jailed” away from the others.
Good thing you didn’t call your post Ring -1, because the first result on Google when you search for “Ring -1” with quotes is an adult toy (a href="http://www.amazon.com/gp/product/B000AS7EW4/102-6565027-6012124?v=glancen=3760901)…"http://www.amazon.com/gp/product/B000AS7EW4/102-6565027-6012124?v=glancen=3760901)…/a
It’s kind of infuriating when you’re searching for good heuristics for the A* algorithm, because searching for “a-star” gets you all sorts of results with “…and a star was…”
Searching for “A*” gets you everything that starts with A.
sigh
Take a look at Xen. It’s interesting because it offers better performance than traditional virtualisation systems by modifying both host OS and guest OS. It’s really interesting to learn about its optimisation techniques.
The PC will finally be able to do what the IBM System/390 (zSeries mainframe) has been doing for zillions of years.
I’ve told you a zillion times to stop exaggerating. But seriously, isn’t this the entire history of the PC in a nutshell?
Use the period operator in Google to search for ring-1, thusly:
ring…1 intel OR virtualization
Imprecise but it basically works.