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

Cédric Le Goater
2023-05-31T13:09:18Z

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 = {