Re: [PATCH 3/3] s390/vfio-ap: Wire in the vfio_device_ops request callback

["Cédric Le Goater" <clegoate@redhat.com>]

On 5/31/23 00:35, Tony Krowiak wrote:
> The mdev device is being removed, so pass the request to userspace to
> ask for a graceful cleanup. This should free up the thread that
> would otherwise loop waiting for the device to be fully released.
> 
> Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>

Reviewed-by: Cédric Le Goater <clg@redhat.com>

Thanks,

C.


> ---
>   drivers/s390/crypto/vfio_ap_ops.c | 21 +++++++++++++++++++++
>   1 file changed, 21 insertions(+)
> 
> diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
> index 44f159136891..a8f58e133e6e 100644
> --- a/drivers/s390/crypto/vfio_ap_ops.c
> +++ b/drivers/s390/crypto/vfio_ap_ops.c
> @@ -1736,6 +1736,26 @@ static void vfio_ap_mdev_close_device(struct vfio_device *vdev)
>   	vfio_ap_mdev_unset_kvm(matrix_mdev);
>   }
>   
> +static void vfio_ap_mdev_request(struct vfio_device *vdev, unsigned int count)
> +{
> +	struct device *dev = vdev->dev;
> +	struct ap_matrix_mdev *matrix_mdev;
> +
> +	matrix_mdev = container_of(vdev, struct ap_matrix_mdev, vdev);
> +
> +	if (matrix_mdev->req_trigger) {
> +		if (!(count % 10))
> +			dev_notice_ratelimited(dev,
> +					       "Relaying device request to user (#%u)\n",
> +					       count);
> +
> +		eventfd_signal(matrix_mdev->req_trigger, 1);
> +	} else if (count == 0) {
> +		dev_notice(dev,
> +			   "No device request registered, blocked until released by user\n");
> +	}
> +}
> +
>   static int vfio_ap_mdev_get_device_info(unsigned long arg)
>   {
>   	unsigned long minsz;
> @@ -1955,6 +1975,7 @@ static const struct vfio_device_ops vfio_ap_matrix_dev_ops = {
>   	.bind_iommufd = vfio_iommufd_emulated_bind,
>   	.unbind_iommufd = vfio_iommufd_emulated_unbind,
>   	.attach_ioas = vfio_iommufd_emulated_attach_ioas,
> +	.request = vfio_ap_mdev_request
>   };
>   
>   static struct mdev_driver vfio_ap_matrix_driver = {