On 14/03/2019 17:02, David Hildenbrand wrote: > The XEN balloon driver - in contrast to other balloon drivers - allows > to map some inflated pages to user space. Such pages are allocated via > alloc_xenballooned_pages() and freed via free_xenballooned_pages(). > The pfn space of these allocated pages is used to map other things > by the hypervisor using hypercalls. > > Pages marked with PG_offline must never be mapped to user space (as > this page type uses the mapcount field of struct pages). > > So what we can do is, clear/set PG_offline when allocating/freeing an > inflated pages. This way, most inflated pages can be excluded by > dumping tools and the "reused for other purpose" balloon pages are > correctly not marked as PG_offline. > > Fixes: 77c4adf6a6df (xen/balloon: mark inflated pages PG_offline) > Reported-by: Julien Grall <julien.grall@xxxxxxx> > Tested-by: Julien Grall <julien.grall@xxxxxxx> > Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> Pushed to xen/tip.git for-linus-5.1b Juergen
