drm/xe/vm: Validate userptr during gpu vma prefetching

If a userptr vma subject to prefetching was already invalidated
or invalidated during the prefetch operation, the operation would
repeatedly return -EAGAIN which would typically cause an infinite
loop.

Validate the userptr to ensure this doesn't happen.

v2:
- Don't fallthrough from UNMAP to PREFETCH (Matthew Brost)

Fixes: 5bd24e78829a ("drm/xe/vm: Subclass userptr vmas")
Fixes: 617eebb9c480 ("drm/xe: Fix array of binds")
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: <stable@vger.kernel.org> # v6.9+
Suggested-by: Matthew Brost <matthew.brost@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/20250228073058.59510-2-thomas.hellstrom@linux.intel.com
(cherry picked from commit 03c346d4d0d85d210d549d43c8cfb3dfb7f20e0a)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
index 30259eba450b5805ba39c24b76d5a63fb0575820..d2cd227e4d69448fb78f59420abf87d3f5711dcd 100644 (file)
--- a/drivers/gpu/drm/xe/xe_vm.c
+++ b/drivers/gpu/drm/xe/xe_vm.c
@@ -2286,8 +2286,17 @@ static int vm_bind_ioctl_ops_parse(struct xe_vm *vm, struct drm_gpuva_ops *ops,
                        break;
                }
                case DRM_GPUVA_OP_UNMAP:
+                       xe_vma_ops_incr_pt_update_ops(vops, op->tile_mask);
+                       break;
                case DRM_GPUVA_OP_PREFETCH:
-                       /* FIXME: Need to skip some prefetch ops */
+                       vma = gpuva_to_vma(op->base.prefetch.va);
+
+                       if (xe_vma_is_userptr(vma)) {
+                               err = xe_vma_userptr_pin_pages(to_userptr_vma(vma));
+                               if (err)
+                                       return err;
+                       }
+
                        xe_vma_ops_incr_pt_update_ops(vops, op->tile_mask);
                        break;
                default: