Hi Am 16.06.23 um 05:59 schrieb Zack Rusin:
On Thu, 2023-06-15 at 11:31 +0200, Thomas Zimmermann wrote:Set drm_gem_prime_handle_to_fd() and drm_gem_prime_fd_to_handle() for all DRM drivers. Even drivers that do not support PRIME import or export of dma-bufs can now import their own buffer objects. This is required by some userspace, such as wlroots-based compositors, to share buffers among processes. The only driver that does not use the drm_gem_prime_*() helpers is vmwgfx. Once it has been converted, the callbacks in struct drm_driver can be removed.Hmm, I'm not sure that's ever going to be possible on vmwgfx. Or at least not until Xorg is used by anything. Some things in vmwgfx stack create "surfaces" which are not GEM's (they can be backed by a GEM object, but don't have to) and the prime implementation on vmwgfx has to be able to export and import those.
I see that's not easily fixable, if at all. I'd remove the TODO item and change the callback comments to say that they are reserved for vmwgfx.
In an ideal world I'd just delete the ioctl's that allow creating those "surfaces", but of course that's a no-no, so possibility of introducing vmwgfx2 with a saner/modern ioctl model has been floating around internally. Which at least would open a path to removing vmwgfx at some point in the future, but there's not much that can be done about vmwgfx having to be able to prime import/export GEM's and wonky non-GEM objects.
We have removed ioctls before, but over years so that userspace had time to update. Removing the ioctls would require a change to the driver version, I think.
You could explore the option of implementing GEM-based objects with the GEM helpers and the non-GEM objects with the current code. If done correctly, the old non-GEM support could be hidden behind a Kconfig option.
Anyway, I'll change the patchset to reflect the current state. Best regards Thomas
z
-- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Frankenstrasse 146, 90461 Nuernberg, Germany GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman HRB 36809 (AG Nuernberg)
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