Re: [PATCH v6 20/24] vfio: Add cdev for vfio_device

["Tian, Kevin" <kevin.tian@xxxxxxxxx>]

> From: Liu, Yi L <yi.l.liu@xxxxxxxxx>
> Sent: Wednesday, March 8, 2023 9:29 PM
> 
> +	/*
> +	 * Placing it before vfio_device_put_registration() to prevent
> +	 * new registration refcount increment by
> VFIO_GROUP_GET_DEVICE_FD
> +	 * during the unregister time.
> +	 */
> +	vfio_device_group_unregister(device);
> +
> +	/*
> +	 * Balances vfio_device_add() in the register path. Placing it before
> +	 * vfio_device_put_registration() to prevent new registration refcount
> +	 * increment by the device cdev open during the unregister time.
> +	 */
> +	vfio_device_del(device);
> +

What about below?

	/*
	 * Cleanup to pair with the register path. Must be done
	 * before vfio_device_put_registration () to avoid racing with
	 * a new registration.
	 */
	vfio_device_group_unregister(device);
	vfio_device_del(device);