Jens Nerche wrote:
> >Unfortunately, if you set the DPL to != 3, this means that the
> >guest code runs in a ring != 3 (in the case of a code segment),
> >which we obviously can't allow for security reasons (and also
> >because access protection via supervisor bits etc. won't work) ...
> No, it only causes the guest trapping, so we can emulate loading
> a segment selector and updating the GDT. Of course we have to
> set the DPL to 3 then...
Look, if we set the guest code segment descriptor to DPL 0 (say)
then the 'iret' from monitor to guest code will jump to a ring-0
descriptor, and the guest code will run in ring-0.
And as we were talking about just this guest code segment descriptor
the whole time, I don't understand what you mean ...
Bye,
Ulrich
--
Ulrich Weigand,
IMMD 1, Universitaet Erlangen-Nuernberg,
Martensstr. 3, D-91058 Erlangen, Phone: +49 9131 85-27688
