Re: [Xen-devel] [PATCH v4 08/11] xen/arm: Handle remove foreign mapping

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

On Mon, 2013-12-16 at 17:06 +0000, Julien Grall wrote:
> >> +                    /* TODO: Handle other p2m type */
> >> +                    if ( pte.p2m.valid && p2m_is_foreign(pte.p2m.type) )
> >> +                    {
> >> +                        ASSERT(mfn_valid(mfn));
> >
> > Something somewhere is making sure we don't put foreign MMIO regions
> > into the p2m, right?
> 
> I misread this part. And the answer is still yes because in this case 
> MMIO won't belong to a domain (there is no reference on it), so get_page 
> will return NULL when the foreign mapping is created in 
> xenmem_add_to_physmap_one.

It would be pretty easy for xenmem_add_to_physmap_one() to request the
type (it calls get_page_from_gfn anyway) and filter to just the ram
types.

As I said in another reply we probably want to avoid mappings of foreign
mappings and grant tables too.

Ian.


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel