On Sun, 2012-09-09 at 09:56 -0700, H. Peter Anvin wrote:

quoted

So it should either be start=0xfffffffffffff000 end=0xffffffffffffffff
or it should be start=0xfffffffffffff000 len=0x1000.

I would strongly object to the former; that kind of inclusive ranges 
breed a whole class of bugs by themselves.

Another alternative that avoids overflow issues is to use a PFN rather
than a byte address.

-- 
dwmw2