Hi,
I've just updated the xenkernel and xentools to 3.0.3. To run this you'll
need a very recent current. I have patches for the netbsd-3 branch 
(to run NetBSD 3.x guests on Xen 3.0.3) but they won't make it for 3.1 I fear.
There's probably some cool things in here but I don't have a comprehensive
list yet. One interesting thing it that it seems that Xen can now dynamically
move a guest from a CPU to another on SMP systems, but I've not done specific
tests for this (note that I've done all my tests on a systems
that exposes 8 CPUs to the OS though).

I've also added a xentools30-hvm package, which contains the bit needed
to run non-xen-aware guests on systems with the VT or VMX extentions
(and an example configuration :)
I choose to add a second package because of the dependancy on X.
I've tested this on a VT system (Intel), and I could boot:
a scientific linux install CD (and perform the install),
a NetBSD/i386 boot CD with some quirks:
 - you need to boot -c and disable fdc or the boot hang
 - the emulated rtk8139 ethernet is matched by re(4), but it only work 
   with rtk (I think the emulated revision is wrong in qemu) so disable
   re(4) with boot -c
But of course, as the system uses emulation for the devices disk and network
access are much slower than with a Xen guest kernel, and cause significant
CPU load to dom0. But, you have a virtual VGA screen in an X-window :)

freedos and win98's dos cause a crash quite fast (I do get the win98 splash
screen though), this may be better on a AMD VMX system.
I will try a 32bit windows when I get my hands on a bootable CD (actually
booting dos was to start the installer from the non-bootable XP CD I have :)

Enjoy !

-- 
Manuel Bouyer <bouyer@antioche.eu.org>
     NetBSD: 26 ans d'experience feront toujours la difference
--