Re: [PATCH v3 1/2] drm, drm/xe: Fix xe userptr in the absence of CONFIG_DEVICE_PRIVATE

[Matthew Auld <matthew.auld@intel.com>]

On 21/01/2026 09:10, Thomas Hellström wrote:
> CONFIG_DEVICE_PRIVATE is not selected by default by some distros,
> for example Fedora, and that leads to a regression in the xe driver
> since userptr support gets compiled out.
> 
> It turns out that DRM_GPUSVM, which is needed for xe userptr support
> compiles also without CONFIG_DEVICE_PRIVATE, but doesn't compile
> without CONFIG_ZONE_DEVICE.
> Exclude the drm_pagemap files from compilation with !CONFIG_ZONE_DEVICE,
> and remove the CONFIG_DEVICE_PRIVATE dependency from CONFIG_DRM_GPUSVM and
> the xe driver's selection of it, re-enabling xe userptr for those configs.
> 
> v2:
> - Don't compile the drm_pagemap files unless CONFIG_ZONE_DEVICE is set.
> - Adjust the drm_pagemap.h header accordingly.
> 
> Fixes: 9e9787414882 ("drm/xe/userptr: replace xe_hmm with gpusvm")
> Cc: Matthew Auld <matthew.auld@intel.com>
> Cc: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
> Cc: Matthew Brost <matthew.brost@intel.com>
> Cc: "Thomas Hellström" <thomas.hellstrom@linux.intel.com>
> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Cc: dri-devel@lists.freedesktop.org
> Cc: <stable@vger.kernel.org> # v6.18+
> Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>

Let me double check that while it does at least build it is also 
functional without DRM_XE_GPUSVM. I think it takes a different init path 
and maybe some other differences. Unless you already did?

Reviewed-by: Matthew Auld <matthew.auld@intel.com>

> ---
>   drivers/gpu/drm/Kconfig    |  2 +-
>   drivers/gpu/drm/Makefile   |  4 +++-
>   drivers/gpu/drm/xe/Kconfig |  2 +-
>   include/drm/drm_pagemap.h  | 18 ++++++++++++++----
>   4 files changed, 19 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> index a33b90251530..d3d52310c9cc 100644
> --- a/drivers/gpu/drm/Kconfig
> +++ b/drivers/gpu/drm/Kconfig
> @@ -210,7 +210,7 @@ config DRM_GPUVM
>   
>   config DRM_GPUSVM
>   	tristate
> -	depends on DRM && DEVICE_PRIVATE
> +	depends on DRM
>   	select HMM_MIRROR
>   	select MMU_NOTIFIER
>   	help
> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> index 0deee72ef935..0c21029c446f 100644
> --- a/drivers/gpu/drm/Makefile
> +++ b/drivers/gpu/drm/Makefile
> @@ -108,9 +108,11 @@ obj-$(CONFIG_DRM_EXEC) += drm_exec.o
>   obj-$(CONFIG_DRM_GPUVM) += drm_gpuvm.o
>   
>   drm_gpusvm_helper-y := \
> -	drm_gpusvm.o\
> +	drm_gpusvm.o
> +drm_gpusvm_helper-$(CONFIG_ZONE_DEVICE) += \
>   	drm_pagemap.o\
>   	drm_pagemap_util.o
> +
>   obj-$(CONFIG_DRM_GPUSVM) += drm_gpusvm_helper.o
>   
>   obj-$(CONFIG_DRM_BUDDY) += drm_buddy.o
> diff --git a/drivers/gpu/drm/xe/Kconfig b/drivers/gpu/drm/xe/Kconfig
> index 4b288eb3f5b0..c34be1be155b 100644
> --- a/drivers/gpu/drm/xe/Kconfig
> +++ b/drivers/gpu/drm/xe/Kconfig
> @@ -39,7 +39,7 @@ config DRM_XE
>   	select DRM_TTM
>   	select DRM_TTM_HELPER
>   	select DRM_EXEC
> -	select DRM_GPUSVM if !UML && DEVICE_PRIVATE
> +	select DRM_GPUSVM if !UML
>   	select DRM_GPUVM
>   	select DRM_SCHED
>   	select MMU_NOTIFIER
> diff --git a/include/drm/drm_pagemap.h b/include/drm/drm_pagemap.h
> index 46e9c58f09e0..2baf0861f78f 100644
> --- a/include/drm/drm_pagemap.h
> +++ b/include/drm/drm_pagemap.h
> @@ -243,6 +243,8 @@ struct drm_pagemap_devmem_ops {
>   			   struct dma_fence *pre_migrate_fence);
>   };
>   
> +#if IS_ENABLED(CONFIG_ZONE_DEVICE)
> +
>   int drm_pagemap_init(struct drm_pagemap *dpagemap,
>   		     struct dev_pagemap *pagemap,
>   		     struct drm_device *drm,
> @@ -252,17 +254,22 @@ struct drm_pagemap *drm_pagemap_create(struct drm_device *drm,
>   				       struct dev_pagemap *pagemap,
>   				       const struct drm_pagemap_ops *ops);
>   
> -#if IS_ENABLED(CONFIG_DRM_GPUSVM)
> +struct drm_pagemap *drm_pagemap_page_to_dpagemap(struct page *page);
>   
>   void drm_pagemap_put(struct drm_pagemap *dpagemap);
>   
>   #else
>   
> +static inline struct drm_pagemap *drm_pagemap_page_to_dpagemap(struct page *page)
> +{
> +	return NULL;
> +}
> +
>   static inline void drm_pagemap_put(struct drm_pagemap *dpagemap)
>   {
>   }
>   
> -#endif /* IS_ENABLED(CONFIG_DRM_GPUSVM) */
> +#endif /* IS_ENABLED(CONFIG_ZONE_DEVICE) */
>   
>   /**
>    * drm_pagemap_get() - Obtain a reference on a struct drm_pagemap
> @@ -334,6 +341,8 @@ struct drm_pagemap_migrate_details {
>   	u32 source_peer_migrates : 1;
>   };
>   
> +#if IS_ENABLED(CONFIG_ZONE_DEVICE)
> +
>   int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation,
>   				  struct mm_struct *mm,
>   				  unsigned long start, unsigned long end,
> @@ -343,8 +352,6 @@ int drm_pagemap_evict_to_ram(struct drm_pagemap_devmem *devmem_allocation);
>   
>   const struct dev_pagemap_ops *drm_pagemap_pagemap_ops_get(void);
>   
> -struct drm_pagemap *drm_pagemap_page_to_dpagemap(struct page *page);
> -
>   void drm_pagemap_devmem_init(struct drm_pagemap_devmem *devmem_allocation,
>   			     struct device *dev, struct mm_struct *mm,
>   			     const struct drm_pagemap_devmem_ops *ops,
> @@ -359,4 +366,7 @@ int drm_pagemap_populate_mm(struct drm_pagemap *dpagemap,
>   void drm_pagemap_destroy(struct drm_pagemap *dpagemap, bool is_atomic_or_reclaim);
>   
>   int drm_pagemap_reinit(struct drm_pagemap *dpagemap);
> +
> +#endif /* IS_ENABLED(CONFIG_ZONE_DEVICE) */
> +
>   #endif