I did some googling around, and found mostly information in the  
archives of this mailing list.  I hope this isn't a question that's  
been answered "too many times".

   The information I found seemed to mostly deal with running a  
NetBSD dom0, of course, and with older versions of NetBSD.  I have  
NetBSD 4ish (the current top of the netbsd-4 branch) built, and want  
to run it on a big machine I have at work running Xen 3.0.3 with an  
Ubuntu 6.06 userland.  This is an amd64 machine, running on a machine  
with HVM support, so it can do full virtualization, but I don't want  
it to.

   What would I have to do to create a domU that I could install  
NetBSD onto?  Does the ISO generated with the new 'iso-image'  
build.sh target know how to boot a para-virtualization aware kernel  
on a machine?  I don't want to end up running fully virtualized,  
which I suspect is what would happen with a GENERIC kernel.  Is it  
even possible/practical to run para-virtualized with i386 on an amd64  
machine?  If I build amd64 netbsd-4 code, can that run under a linux  
dom0 (2.6.16.29-xen) ?

   Thanks.  Any pointers to FAQs I missed on the web, or the like,  
very appreciated.  Sorry if this is a question I should've been able  
to find the answer to myself.

   (Also note that I'm no Xen expert.  I've been using it some at  
work, but only understand the basics at this point.)

                                                  - Chris