Re: Vertualization of Unmodified Operating Systems

[Anthony Liguori <aliguori@us.ibm.com>]

On Sat, 15 Apr 2006 17:39:10 -0500, Dave Feustel wrote:

> AMD Pacifica and Intel's VT make possible the virtualization of unmodified
> operating systems. Is it still necessary to add code to the hypervisor to
> support specific operating systems, or can Xen, as written, support any
> arbitrary OS that successfully boots on a PC? (I'm thinking of the BSDs
> here).

This sort of thing has been addressed here before.  While theoritically,
VT and SVM ought to allow any OS to run under Xen, in practice, if an OS
hasn't been tested as a guest under Xen, it is likely to turn up some bugs
or incompleteness.  Over time, this will certainly be a less of an issue.

The problem has to do with the fact that different OS's will use different
instructions when accessing things like page tables.  Right now, Xen only
emulates the instructions that we know are used by the systems we test
with (things like Linux and certain versions of Windows).

Regards,

Anthony Liguori

> Thanks,
> Dave Feustel