Increasing KVM on amd64

[Alan Cox]

You can download a patch from 
http://www.cs.rice.edu/~alc/amd64_kvm_6GB.patch that increases amd64's 
kernel virtual address space to 6GB.  This patch also increases the 
default for the kmem map to almost 2GB.  I believe that kernel loadable 
modules still work.  However, I suspect that mini-dumps are broken.

I don't plan on committing this patch in its current form.  Some of the 
changes are done in a hackish way.  I am, however, curious to hear 
whether or not it works for you.

Alan