[Intel-gfx] [PATCH] drm/i915: Restrict the aliasing-ppgtt to the size of the ggtt

[Chris Wilson]

The aliasing-ppgtt is not allowed to be smaller than the ggtt, nor
should we advertise it as being any bigger, or else we may get sued for
false advertisement.

Testcase: igt/gem_exec_big
Fixes: 0b718ba1e884 ("drm/i915/gtt: Downgrade Cherryview back to aliasing-ppgtt")
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld at intel.com>
---
 drivers/gpu/drm/i915/i915_gem_gtt.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index ee51fd1a6207..906dc6fff383 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -2597,6 +2597,8 @@ static int init_aliasing_ppgtt(struct i915_ggtt *ggtt)
 	GEM_BUG_ON(ggtt->vm.vma_ops.unbind_vma != ggtt_unbind_vma);
 	ggtt->vm.vma_ops.unbind_vma = aliasing_gtt_unbind_vma;
 
+	ppgtt->vm.total = ggtt->vm.total;
+
 	return 0;
 
 err_ppgtt:
-- 
2.23.0