[PATCH] drm/i915: Fix the kernel panic when using aliasing ppgtt

[Chris Wilson]

Quoting Chuanxiao Dong (2017-07-07 07:00:09)
> The ppgtt should be get directly from i915_address_space *vm instead of
> vma->vm as in alias ppgtt case the vma->vm is not same with vm.

And for consistency, also

@@ -2242,7 +2242,7 @@ static void bxt_vtd_ggtt_insert_entries__BKL(struct i915_address_space *vm,
                                             enum i915_cache_level level,
                                             u32 unused)
 {
-       struct insert_entries arg = { vma->vm, vma, level };
+       struct insert_entries arg = { vm, vma, level };
 
        stop_machine(bxt_vtd_ggtt_insert_entries__cb, &arg, NULL);
 }