Re: [XenAccess-devel] Getting the IDT of an HVM guest

[Bryan D. P. <br...@th...>]

This information should be in the VMCS.  You can access this via the
__vmread() function in the hypervisor, but to get this from dom0 may
be trickier.  It could be that this is what the comment on the mailing
list is referring to (basically finding the VMCS information in the
state to extract the IDTR information).  You could also add a
hypercall that exposes the VMCS information, but that is probably a
second choice if there's already another way using the existing API.

-bryan


On Feb 1, 2008 12:25 PM, Matthew Donovan <ma...@at...> wrote:
> Hey,
>
> I'm trying to retrieve the IDT of an HVM guest (XP/Vista) but the
> xc_vcpu_getcontext() function doesn't return anything useful.  I asked on
> the Xen devel mailing list and was told:
>
> "Unfortunately the IDTR is not exposed via vcpu_context for HVM guests. The
> only way to get it right now is to do a hvm save hypercall and then parse
> the pickled state to find the IDTR. It actually should be quite easy."
>
> I was digging around in the Xen source and found a hvm_save() function but
> it isn't in the Xen headers I have.
>
> Have you looked at this at all?
>
> Thanks
> -matthew


-- 
Bryan D. Payne
Graduate Student, Computer Science
Georgia Tech Information Security Center
http://www.bryanpayne.org