diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 4a89b6acb6af..8d25cc65707d 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -187,6 +187,7 @@ void drm_gem_private_object_init(struct drm_device *dev,
 	kref_init(&obj->refcount);
 	obj->handle_count = 0;
 	obj->size = size;
+	mutex_init(&obj->gpuva.lock);
 	dma_resv_init(&obj->_resv);
 	if (!obj->resv)
 		obj->resv = &obj->_resv;
@@ -210,6 +211,7 @@ void drm_gem_private_object_fini(struct drm_gem_object *obj)
 	WARN_ON(obj->dma_buf);
 
 	dma_resv_fini(&obj->_resv);
+	mutex_destroy(&obj->gpuva.lock);
 }
 EXPORT_SYMBOL(drm_gem_private_object_fini);
 
diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
index d3a7b43e2c63..a995c0c1b63c 100644
--- a/include/drm/drm_gem.h
+++ b/include/drm/drm_gem.h
@@ -398,16 +398,28 @@ struct drm_gem_object {
 	struct dma_resv _resv;
 
 	/**
-	 * @gpuva:
-	 *
-	 * Provides the list of GPU VAs attached to this GEM object.
-	 *
-	 * Drivers should lock list accesses with the GEMs &dma_resv lock
-	 * (&drm_gem_object.resv) or a custom lock if one is provided.
+	 * @gpuva: Fields used by GPUVM to manage mappings pointing to this GEM object.
 	 */
 	struct {
+		/**
+		 * @gpuva.list: list of GPUVM mappings attached to this GEM object.
+		 *
+		 * Drivers should lock list accesses with either the GEMs
+		 * &dma_resv lock (&drm_gem_object.resv) or the
+		 * &drm_gem_object.gpuva.lock mutex.
+		 */
 		struct list_head list;
 
+		/**
+		 * @gpuva.lock: lock protecting access to &drm_gem_object.gpuva.list
+		 * when the resv lock can't be used.
+		 *
+		 * Should only be used when the VM is being modified in a fence
+		 * signalling path, otherwise you should use &drm_gem_object.resv to
+		 * protect accesses to &drm_gem_object.gpuva.list.
+		 */
+		struct mutex lock;
+
 #ifdef CONFIG_LOCKDEP
 		struct lockdep_map *lock_dep_map;
 #endif