5bd24e7882
The construct allocating only parts of the vma structure when the userptr part is not needed is very fragile. A developer could add additional fields below the userptr part, and the code could easily attempt to access the userptr part even if its not persent. So introduce xe_userptr_vma which subclasses struct xe_vma the proper way, and accordingly modify a couple of interfaces. This should also help if adding userptr helpers to drm_gpuvm. v2: - Fix documentation of to_userptr_vma() (Matthew Brost) - Fix allocation and freeing of vmas to clearer distinguish between the types. Closes: https://lore.kernel.org/intel-xe/0c4cc1a7-f409-4597-b110-81f9e45d1ffe@embeddedor.com/T/#u Fixes: a4cc60a55fd9 ("drm/xe: Only alloc userptr part of xe_vma for userptrs") Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Lucas De Marchi <lucas.demarchi@intel.com> Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> Reviewed-by: Matthew Brost <matthew.brost@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20240131091628.12318-1-thomas.hellstrom@linux.intel.com