[Intel-gfx] [PATCH] drm/i915: Introduce a new create ioctl for user specified placement

[Chris Wilson]

On Tue, Jul 09, 2013 at 11:10:13AM +0200, Daniel Vetter wrote:
> One ugly part is that conceptually I think we want to support dma_buf
> exporting of stolen memory objects. After all exporting scanout buffers
> for rendering by the dgpu is the prime use-case of dma_buf.

No. prime only exports an intermediate buffer, I don't see how you would
maintain coherency between the display engine and a foriegn GPU, given
the limited API. However fd passing remains a real issue. Do we not in
that case simply resolve the fd into a new handle onto the old bo and
discard the dma-buf? Phew we do, so that still works. The only case we
have to worry about is exporting stolen over dma-buf to a discrete GPU,
which will actually be rare and we could just forbid exporting the stolen
bo? Better to fix it up from the start though.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre