Re: [PATCH v5 00/16] drm/vkms: Add configfs support

[Louis Chauvet <louis.chauvet@bootlin.com>]

+CC: Mark (Google), Sebastian (Mutter), Xaver (KWin), Victoria (Cosmic)

Hi everyone,

Last week, I presented this work at the Display Next Hackfest, and the 
feedback from compositors was very positive. At least KWin, Mutter, and 
Cosmic are interested in integrating it into their tests, so it would be 
great if someone could review it.

Sebastian quickly tested this work (using [2] for full features) with 
their existing VKMS tests [1], and it worked. From what I understand, 
the tests are quite basic —just sanity checks— but we were able to 
reproduce the default vkms device using ConfigFS.

If another compositor wants to test the ConfigFS interface (I will try 
to keep [2] updated), that would be amazing. Feel free to send feedback!

A small note: This series has a minor conflict since the conversion to 
the faux device, but it can be applied using `b4 am -3 ... && git am -3 
...`.
@josé, if you send a new iteration, can you add markyacoub@google.com in 
copy, and maybe Sebastian, Xaver, Victoria if they want to follow the 
upstreaming?

Thank you,
Louis Chauvet

[1]:https://gitlab.gnome.org/swick/mutter/-/commit/88a7354942d9728dae06fb83cc4f2d2c7b08b694
[2]:https://github.com/Fomys/linux/tree/configfs-everything



Le 07/05/2025 à 15:54, José Expósito a écrit :
> Hi everyone,
> 
> This series allow to configure one or more VKMS instances without having
> to reload the driver using configfs.
> 
> The series is structured in 3 blocks:
> 
>    - Patches 1..11: Basic device configuration. For simplicity, I kept the
>      available options as minimal as possible.
> 
>    - Patches 12 and 13: New option to skip the default device creation and to-do
>      cleanup.
> 
>    - Patches 14, 15 and 16: Allow to hot-plug and unplug connectors. This is not
>      part of the minimal set of options, but I included in this series so it can
>      be used as a template/example of how new configurations can be added.
> 
> The process of configuring a VKMS device is documented in "vkms.rst".
> 
> Finally, the code is thoroughly tested by a collection of IGT tests [1].
> 
> Best wishes,
> José Expósito
> 
> [1] https://lists.freedesktop.org/archives/igt-dev/2025-February/086071.html
> 
> Changes in v5:
> 
>    - Added Reviewed-by tags, thanks Louis!
>    - Rebased on top of drm-misc-next
>    - Link to v4: https://lore.kernel.org/dri-devel/20250407081425.6420-1-jose.exposito89@gmail.com/
> 
> Changes in v4:
> 
>    - Since Louis and I worked on this together, set him as the author of some of
>      the patches and me as co-developed-by to reflect this joint effort.
>    - Rebased on top of drm-misc-next
>    - Link to v3: https://lore.kernel.org/all/20250307163353.5896-1-jose.exposito89@gmail.com/
> 
> Changes in v3:
> 
>    - Applied review comments by Louis Chauvet: (thanks!!)
>      - Use scoped_guard() instead of guard(mutex)(...)
>      - Fix a use-after-free error in the connector hot-plug code
>    - Rebased on top of drm-misc-next
>    - Link to v2: https://lore.kernel.org/all/20250225175936.7223-1-jose.exposito89@gmail.com/
> 
> Changes in v2:
> 
>    - Applied review comments by Louis Chauvet:
>      - Use guard(mutex)(...) instead of lock/unlock
>      - Return -EBUSY when trying to modify a enabled device
>      - Move the connector hot-plug related patches to the end
>    - Rebased on top of drm-misc-next
>    - Link to v1: https://lore.kernel.org/dri-devel/20250218170808.9507-1-jose.exposito89@gmail.com/T/
> 
> José Expósito (6):
>    drm/vkms: Expose device creation and destruction
>    drm/vkms: Allow to configure the default device creation
>    drm/vkms: Remove completed task from the TODO list
>    drm/vkms: Allow to configure connector status
>    drm/vkms: Allow to update the connector status
>    drm/vkms: Allow to configure connector status via configfs
> 
> Louis Chauvet (10):
>    drm/vkms: Add and remove VKMS instances via configfs
>    drm/vkms: Allow to configure multiple planes via configfs
>    drm/vkms: Allow to configure the plane type via configfs
>    drm/vkms: Allow to configure multiple CRTCs via configfs
>    drm/vkms: Allow to configure CRTC writeback support via configfs
>    drm/vkms: Allow to attach planes and CRTCs via configfs
>    drm/vkms: Allow to configure multiple encoders via configfs
>    drm/vkms: Allow to attach encoders and CRTCs via configfs
>    drm/vkms: Allow to configure multiple connectors via configfs
>    drm/vkms: Allow to attach connectors and encoders via configfs
> 
>   Documentation/gpu/vkms.rst                    | 100 ++-
>   drivers/gpu/drm/vkms/Kconfig                  |   1 +
>   drivers/gpu/drm/vkms/Makefile                 |   3 +-
>   drivers/gpu/drm/vkms/tests/vkms_config_test.c |  24 +
>   drivers/gpu/drm/vkms/vkms_config.c            |   8 +-
>   drivers/gpu/drm/vkms/vkms_config.h            |  26 +
>   drivers/gpu/drm/vkms/vkms_configfs.c          | 833 ++++++++++++++++++
>   drivers/gpu/drm/vkms/vkms_configfs.h          |   8 +
>   drivers/gpu/drm/vkms/vkms_connector.c         |  35 +
>   drivers/gpu/drm/vkms/vkms_connector.h         |   9 +
>   drivers/gpu/drm/vkms/vkms_drv.c               |  18 +-
>   drivers/gpu/drm/vkms/vkms_drv.h               |  20 +
>   12 files changed, 1072 insertions(+), 13 deletions(-)
>   create mode 100644 drivers/gpu/drm/vkms/vkms_configfs.c
>   create mode 100644 drivers/gpu/drm/vkms/vkms_configfs.h
> 
> 
> base-commit: a6c0a91ccb257eaec2aee080df06863ce7601315

-- 
Louis Chauvet, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com