[Intel-gfx] [PATCH v7 12/63] drm/i915: No longer allow exporting userptr through dma-buf

[Jason Ekstrand]

I double-checked and Vulkan doesn't do/allow this.

Acked-by: Jason Ekstrand <jason at jlekstrand.net>

On Thu, Jan 28, 2021 at 10:26 AM Maarten Lankhorst
<maarten.lankhorst at linux.intel.com> wrote:
>
> It doesn't make sense to export a memory address, we will prevent
> allowing access this way to different address spaces when we
> rework userptr handling, so best to explicitly disable it.
>
> Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> Reviewed-by: Thomas Hellström <thomas.hellstrom at linux.intel.com>
> Cc: Jason Ekstrand <jason at jlekstrand.net>
>
> -- Still needs an ack from relevant userspace that it won't break, but should be good.
> ---
>  drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
> index 5a19699c2d7e..0c30ca52dee3 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
> @@ -694,10 +694,9 @@ i915_gem_userptr_release(struct drm_i915_gem_object *obj)
>  static int
>  i915_gem_userptr_dmabuf_export(struct drm_i915_gem_object *obj)
>  {
> -       if (obj->userptr.mmu_object)
> -               return 0;
> +       drm_dbg(obj->base.dev, "Exporting userptr no longer allowed\n");
>
> -       return i915_gem_userptr_init__mmu_notifier(obj, 0);
> +       return -EINVAL;
>  }
>
>  static int
> --
> 2.30.0
>