On 11/14/2017 05:28 PM, David Hildenbrand wrote: > On 13.11.2017 16:19, Janosch Frank wrote: >> This is KVM, not qemu, subject s/x// >> >> >> On 10.11.2017 16:18, David Hildenbrand wrote: >>> gmap_mprotect_notify() refuses shadow gmaps. Turns out that >>> a) gmap_protect_range() >>> b) gmap_read_table() >>> c) gmap_pte_op_walk() >>> >>> Are never called for gmap shadows. And never should be. This dates back >>> to gmap shadow prototypes where we allowed to call mprotect_notify() on >>> the gmap shadow (to get notified about the prefix pages getting removed). >>> This is avoided by always getting notified about any change on the gmap >>> shadow. >>> >>> The only real function for walking page tables on shadow gmaps is >>> gmap_table_walk(). >>> >>> So, essentially, these functions should never get called and >>> gmap_pte_op_walk() can be cleaned up. Add some checks to callers of >>> gmap_pte_op_walk(). >> >> This already made sense when discussing, but I traced the callers anyhow >> to make sure we didn't accidentally forget one. >> >> Reviewed-by: Janosch Frank <frankja@xxxxxxxxxxxxxxxxxx> with one nit below >> > > Thanks! > >>> @@ -889,7 +879,6 @@ static void gmap_pte_op_end(spinlock_t *ptl) >>> * >>> * Called with sg->mm->mmap_sem in read. >>> * >>> - * Note: Can also be called for shadow gmaps. >> >> How about also getting rid of the line above this one? >> > > Sure, can the person picking this up fix that one up? done. applied. Not sure yet if this goes via my tree or Martins tree, but the big mm things (e.g. hugetlbfs) will probably go via Martins tree.
