[Intel-gfx] [PATCH v8 16/24] iommufd/device: Add iommufd_access_detach() API

[Jon Pan-Doh]

On 2023/3/27 02:40, Yi Liu wrote:
> diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h
> index 2e6e8e217cce..ec2ce3ef187d 100644
> --- a/drivers/iommu/iommufd/iommufd_private.h
> +++ b/drivers/iommu/iommufd/iommufd_private.h
> @@ -263,6 +263,8 @@ struct iommufd_access {
>  	struct iommufd_object obj;
>  	struct iommufd_ctx *ictx;
>  	struct iommufd_ioas *ioas;
> +	struct iommufd_ioas *ioas_unpin;
> +	struct mutex ioas_lock;
>  	const struct iommufd_access_ops *ops;
>  	void *data;
>  	unsigned long iova_alignment;

I think you may need to initialize ioas_lock. I got lockdep warnings running
iommufd selftests against this patch. Those went away when I added mutex_init().

---
 drivers/iommu/iommufd/device.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c
index f0522d80919d..0eaae60f3537 100644
--- a/drivers/iommu/iommufd/device.c
+++ b/drivers/iommu/iommufd/device.c
@@ -474,6 +474,7 @@ iommufd_access_create(struct iommufd_ctx *ictx,
 	iommufd_ctx_get(ictx);
 	iommufd_object_finalize(ictx, &access->obj);
 	*id = access->obj.id;
+	mutex_init(&access->ioas_lock);
 	return access;
 }
 EXPORT_SYMBOL_NS_GPL(iommufd_access_create, IOMMUFD);
-- 
2.40.0.348.gf938b09366-goog