Re: [PATCH] export notifier #1

Robin Holt
2008-01-23T14:18:14Z

On Wed, Jan 23, 2008 at 03:12:36PM +0100, Gerd Hoffmann wrote:
> Hi,
>
> >> That would render the notifies useless for Xen too. Xen needs to
> >> intercept the actual pte clear and instead of just zapping it use the
> >> hypercall to do the unmap and release the grant.
> >
> > We are tackling that by having our own page table hanging off the
> > structure representing our seg (thing created when we do the equiv of
> > your grant call).
>
> --verbose please. I don't understand that "own page table" trick. Is
> that page table actually used by the processor or is it just used to
> maintain some sort of page list?

We have a seg structure which is similar to some structure you probably
have which describes the grant. One of the things hanging off that
seg structure is essentially a page table containing PFNs with their
respective flags (XPMEM specific and not the same as the pfn flags in
the processor page tables).

Thanks,
Robin