s390/vfio-ap: wire in the vfio_device_ops request callback

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>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Link: https://lore.kernel.org/r/20230530223538.279198-4-akrowiak@linux.ibm.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 44f159136891a381e9add27d76bad36941447b64..a8f58e133e6e6c59031dad6b7c22485570284657 100644 (file)
--- 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 = {