[Libvir] unsigned long

[John Levon]

I just saw an email about unsigned long and max memory fly by along with
a comment like "32-bit will never have more than 'X' Gb" ...

This raises an obvious question: is libvirt explictly not 32/64 clean?
On Solaris we build everything 32-bit by default unless there is a
reason for it to be 64-bit. If a 32-bit libvirt can't handle a 64-bit
kernel, then we have a problem.

IMO an API should *always* use explicitly-sized integers when they
contain range or size values (or use size_t etc.). Not doing so is both
dangerous and confusing...

(Xen does indeed have this problem, so we run all their tools with
native word size. Currently we always use a 32-bit libvirt for
'virt-install', and it does seem to work fine. It would be a pity for
this to change).

cheers
john