Re: [Xen-users] about migration betweendifferents architecture

[Mark Williamson <mark.williamson@xxxxxxxxxxxx>]

> > > I always thought that on a x86-64-system only 64 bit-domU's will work
> > > and on i386 only 32 bit. Is this not true anymore?
> >
> > Right now it's still true.
>
> i think the mantra is something like "the memory model of a paravirtualized
> kernel must match that of the hypervisor"

Yes, for now.

There are plans to relax this a bit at some stage, but it'll require 
additional support in the system for translating between different memory 
layouts / hypercall tables.

> > So, folks, no migrating between 64 and 32 bit architectures.  It's
> > naughty,
> >
> > yall hear?  ;-)
>
> in this particular case, it might be a solution to just use the x86-64 in
> totally 32 bit mode, with 32bit xen hypervisor.  would that work?

It'll work if the processors are reasonably compatible...

E.g. between a 32-bit Athlon and an Opteron in 32-bit mode...

If one of the CPUs has instructions the other doesn't it'll be a problem.  
E.g. if 3dnow instructions are being used by the domain and you migrate it to 
an Intel system, you'll get breakages.

Cheers,
Mark

-- 
Dave: Just a question. What use is a unicyle with no seat?  And no pedals!
Mark: To answer a question with a question: What use is a skateboard?
Dave: Skateboards have wheels.
Mark: My wheel has a wheel!

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users