Re: [PATCH] drm: Remove DRIVER_GEM_GPUVA feature flag

[Liviu Dudau <liviu.dudau@arm.com>]

On Tue, Apr 21, 2026 at 10:47:01AM +0200, Laura Nao wrote:
> The DRIVER_GEM_GPUVA feature flag is currently only used to control two
> behaviors within the DRM core:
> - calling  drm_gem_gpuva_init() during
>   GEM object initialization
> - creating the "gpuvas" debugfs entry
> 
> drm_gem_gpuva_init() is a plain INIT_LIST_HEAD() and therefore is cheap
> to run for every GEM object. The DRM_DEBUGFS_GPUVA_INFO macro is only
> referenced by GPU-VA capable drivers, so clearing the feature bit does
> not cause any unrelated drivers to get the "gpuvas" debugfs node. The
> flag doesn't have any relevant purpose (e.g. gating ioctl handlers or MM
> logic) and doesn't provide any practical benefit.
> 
> Remove the flag definition and drop it from all drivers that use it,
> call drm_gem_gpuva_init() unconditionally and clear the driver features
> bit in DRM_DEBUGFS_GPUVA_INFO.
> 
> Signed-off-by: Laura Nao <laura.nao@collabora.com>
> ---
>  drivers/gpu/drm/drm_gem.c             | 3 +--
>  drivers/gpu/drm/imagination/pvr_drv.c | 2 +-
>  drivers/gpu/drm/msm/msm_drv.c         | 2 --
>  drivers/gpu/drm/nouveau/nouveau_drm.c | 1 -
>  drivers/gpu/drm/panthor/panthor_drv.c | 2 +-

For panthor changes:

Acked-by: Liviu Dudau <liviu.dudau@arm.com>

Best regards,
Liviu

>  drivers/gpu/drm/xe/xe_device.c        | 2 +-
>  include/drm/drm_debugfs.h             | 2 +-
>  include/drm/drm_drv.h                 | 6 ------
>  include/drm/drm_gem.h                 | 3 ---
>  9 files changed, 5 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
> index 0377a5fd402d..cb703d0072aa 100644
> --- a/drivers/gpu/drm/drm_gem.c
> +++ b/drivers/gpu/drm/drm_gem.c
> @@ -232,8 +232,7 @@ void drm_gem_private_object_init(struct drm_device *dev,
>  	if (!obj->resv)
>  		obj->resv = &obj->_resv;
>  
> -	if (drm_core_check_feature(dev, DRIVER_GEM_GPUVA))
> -		drm_gem_gpuva_init(obj);
> +	drm_gem_gpuva_init(obj);
>  
>  	drm_vma_node_reset(&obj->vma_node);
>  	INIT_LIST_HEAD(&obj->lru_node);
> diff --git a/drivers/gpu/drm/imagination/pvr_drv.c b/drivers/gpu/drm/imagination/pvr_drv.c
> index 268900464ab6..80033d4cb66a 100644
> --- a/drivers/gpu/drm/imagination/pvr_drv.c
> +++ b/drivers/gpu/drm/imagination/pvr_drv.c
> @@ -1375,7 +1375,7 @@ pvr_drm_driver_postclose(__always_unused struct drm_device *drm_dev,
>  DEFINE_DRM_GEM_FOPS(pvr_drm_driver_fops);
>  
>  static struct drm_driver pvr_drm_driver = {
> -	.driver_features = DRIVER_GEM | DRIVER_GEM_GPUVA | DRIVER_RENDER |
> +	.driver_features = DRIVER_GEM | DRIVER_RENDER |
>  			   DRIVER_SYNCOBJ | DRIVER_SYNCOBJ_TIMELINE,
>  	.open = pvr_drm_driver_open,
>  	.postclose = pvr_drm_driver_postclose,
> diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> index 195f40e331e5..ee38c18715f0 100644
> --- a/drivers/gpu/drm/msm/msm_drv.c
> +++ b/drivers/gpu/drm/msm/msm_drv.c
> @@ -825,7 +825,6 @@ static const struct file_operations fops = {
>  
>  #define DRIVER_FEATURES_GPU ( \
>  		DRIVER_GEM | \
> -		DRIVER_GEM_GPUVA | \
>  		DRIVER_RENDER | \
>  		DRIVER_SYNCOBJ | \
>  		DRIVER_SYNCOBJ_TIMELINE | \
> @@ -833,7 +832,6 @@ static const struct file_operations fops = {
>  
>  #define DRIVER_FEATURES_KMS ( \
>  		DRIVER_GEM | \
> -		DRIVER_GEM_GPUVA | \
>  		DRIVER_ATOMIC | \
>  		DRIVER_MODESET | \
>  		0 )
> diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c b/drivers/gpu/drm/nouveau/nouveau_drm.c
> index 5d8475e4895e..0f5f662e5429 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_drm.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_drm.c
> @@ -1364,7 +1364,6 @@ static struct drm_driver
>  driver_stub = {
>  	.driver_features = DRIVER_GEM |
>  			   DRIVER_SYNCOBJ | DRIVER_SYNCOBJ_TIMELINE |
> -			   DRIVER_GEM_GPUVA |
>  			   DRIVER_MODESET |
>  			   DRIVER_RENDER,
>  	.open = nouveau_drm_open,
> diff --git a/drivers/gpu/drm/panthor/panthor_drv.c b/drivers/gpu/drm/panthor/panthor_drv.c
> index 87d27c3c1456..1a1d40a744db 100644
> --- a/drivers/gpu/drm/panthor/panthor_drv.c
> +++ b/drivers/gpu/drm/panthor/panthor_drv.c
> @@ -1805,7 +1805,7 @@ static void panthor_debugfs_init(struct drm_minor *minor)
>   */
>  static const struct drm_driver panthor_drm_driver = {
>  	.driver_features = DRIVER_RENDER | DRIVER_GEM | DRIVER_SYNCOBJ |
> -			   DRIVER_SYNCOBJ_TIMELINE | DRIVER_GEM_GPUVA,
> +			   DRIVER_SYNCOBJ_TIMELINE,
>  	.open = panthor_open,
>  	.postclose = panthor_postclose,
>  	.show_fdinfo = panthor_show_fdinfo,
> diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
> index ffea4a453c01..b3acc202df76 100644
> --- a/drivers/gpu/drm/xe/xe_device.c
> +++ b/drivers/gpu/drm/xe/xe_device.c
> @@ -393,7 +393,7 @@ static struct drm_driver driver = {
>  	.driver_features =
>  	    DRIVER_GEM |
>  	    DRIVER_RENDER | DRIVER_SYNCOBJ |
> -	    DRIVER_SYNCOBJ_TIMELINE | DRIVER_GEM_GPUVA,
> +	    DRIVER_SYNCOBJ_TIMELINE,
>  	.open = xe_file_open,
>  	.postclose = xe_file_close,
>  
> diff --git a/include/drm/drm_debugfs.h b/include/drm/drm_debugfs.h
> index ea8cba94208a..eb93512b0f23 100644
> --- a/include/drm/drm_debugfs.h
> +++ b/include/drm/drm_debugfs.h
> @@ -48,7 +48,7 @@
>   * For each DRM GPU VA space drivers should call drm_debugfs_gpuva_info() from
>   * their @show callback.
>   */
> -#define DRM_DEBUGFS_GPUVA_INFO(show, data) {"gpuvas", show, DRIVER_GEM_GPUVA, data}
> +#define DRM_DEBUGFS_GPUVA_INFO(show, data) {"gpuvas", show, 0, data}
>  
>  /**
>   * struct drm_info_list - debugfs info list entry
> diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
> index 42fc085f986d..e09559495c5b 100644
> --- a/include/drm/drm_drv.h
> +++ b/include/drm/drm_drv.h
> @@ -107,12 +107,6 @@ enum drm_driver_feature {
>  	 * acceleration should be handled by two drivers that are connected using auxiliary bus.
>  	 */
>  	DRIVER_COMPUTE_ACCEL            = BIT(7),
> -	/**
> -	 * @DRIVER_GEM_GPUVA:
> -	 *
> -	 * Driver supports user defined GPU VA bindings for GEM objects.
> -	 */
> -	DRIVER_GEM_GPUVA		= BIT(8),
>  	/**
>  	 * @DRIVER_CURSOR_HOTSPOT:
>  	 *
> diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
> index 86f5846154f7..996aa418dce9 100644
> --- a/include/drm/drm_gem.h
> +++ b/include/drm/drm_gem.h
> @@ -663,9 +663,6 @@ static inline bool drm_gem_is_imported(const struct drm_gem_object *obj)
>   *
>   * This initializes the &drm_gem_object's &drm_gpuvm_bo list.
>   *
> - * Calling this function is only necessary for drivers intending to support the
> - * &drm_driver_feature DRIVER_GEM_GPUVA.
> - *
>   * See also drm_gem_gpuva_set_lock().
>   */
>  static inline void drm_gem_gpuva_init(struct drm_gem_object *obj)
> -- 
> 2.39.5
> 

-- 
====================
| I would like to |
| fix the world,  |
| but they're not |
| giving me the   |
 \ source code!  /
  ---------------
    ¯\_(ツ)_/¯