[Intel-gfx] [PATCH 4/4] drm/i915: Add cpu fault handler for mmap_offset

[Chris Wilson]

Quoting Chris Wilson (2019-11-28 11:08:35)
> Quoting Abdiel Janulgue (2019-11-19 11:37:10)
> > Fault handler to handle missing pages for shmem-backed objects.
> > 
> > v2: bail out of inserting PTEs when failing to insert the
> >     fault address
> > v3: has struct page check
> > v4: Add self-test for validating CPU fault handler to ensure PTEs
> >     are revoked when an object is unbound.
> > v5: Add comment where PTEs are revoked (Chris)
> > 
> > Signed-off-by: Abdiel Janulgue <abdiel.janulgue at linux.intel.com>
> > Signed-off-by: Matthew Auld <matthew.auld at intel.com>
> > Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> > Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
> 
> Uh oh, the mmap() does remain valid past a gem_close() -- the
> vm_area_struct is lacking a reference to the object?

Hmm, test is misleading -- may just be a coherency bug.
-Chris