FreeBSD Xen Dom0 Support

[Sean Bruno]

On Wed, 2012-05-30 at 07:56 -0700, Carsten Heesch wrote:
> However, if you intend to run 64bit, you are restricted to HVM (use
> the XENHVM kernel to get better performance from the optimised device
> drivers for HVM). 
> If you are planning on running 32bit, you can use PV.
> I think that is still valid for 9.0. And mind you, PV is (or was?)
> also limited to about 850M memory in the DomU. 
> 
> 

A couple of nits here, alc@ fixed the PV memory restrictions so the 850M
limit isn't a thing anymore:

FreeBSD ref9-xen32.freebsd.org 9.0-STABLE FreeBSD 9.0-STABLE #2 r231914:
Mon Feb 20 05:30:49 PST 2012
sbruno at ref9-xen32.freebsd.org:/var/tmp/dumpster/scratch/sbruno-scratch/9/sys/XEN  i386
[sbruno at ref9-xen32 ~]$ sysctl hw.physmem
hw.physmem: 2136674304


And, I think, there is a 64bit PV config now in development at:
http://svnweb.freebsd.org/base/projects/amd64_xen_pv/

This is prerequisite work for a dom0 on freebsd which is under
development.  Stay tuned, things are happening!

Sean