Re: [Linaro-mm-sig] [PATCH v3 1/4] dma-buf: add support for virtio exported objects

On Thu, May 14, 2020 at 09:59:52AM +0200, Gerd Hoffmann wrote:

Hi,

...

• for the runtime upcasting the usual approach is to check the ->ops

pointer. Which means that would need to be the same for all virtio dma_bufs, which might get a bit awkward. But I'd really prefer we not add allocator specific stuff like this to dma-buf.

This is exactly the problem, it gets messy quickly, also when it comes to using the drm_prime.c helpers ...

drm_prime.c helpers (not the core bits) exist becaues nvidia needed something that wasnt EXPORT_SYMBOL_GPL.

I wouldn't shed a big tear if they don't fit anymore, they're kinda not great to begin with. Much midlayer, not much of valued added, but at least the _GPL is gone. -Daniel