I'm no VM hacker, but I recall the following thread on comp.arch being an interesting read. http://groups.google.com/groups?hl=en&threadm=rozr931tn2f.fsf%40thulcandra.houst.sgi.com&rnum=1&prev=/groups%3Fq%3Dgroup:comp.arch%2Binsubject:pages%26hl%3Den%26rnum%3D1%26selm%3Drozr931tn2f.fsf%2540thulcandra.houst.sgi.com -george