virtio/s390: handle error values in irb

The common I/O layer may pass an error value as the irb in the device's
interrupt handler (for classic channel I/O). This won't happen in
current virtio-ccw implementations, but it's better to be safe than
sorry.

Let's just return the error conveyed by the irb and clear any possible
pending I/O indications.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Guenther Hutzl <hutzl@linux.vnet.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c
index b2a1a81e6fc8f048c202b7eca54b2b0b6c22b368..1b831598df7c6544057f23ef69da5ea54bbafcdd 100644 (file)
--- a/drivers/s390/virtio/virtio_ccw.c
+++ b/drivers/s390/virtio/virtio_ccw.c
@@ -984,6 +984,36 @@ static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,
        return vq;
 }
 
+static void virtio_ccw_check_activity(struct virtio_ccw_device *vcdev,
+                                     __u32 activity)
+{
+       if (vcdev->curr_io & activity) {
+               switch (activity) {
+               case VIRTIO_CCW_DOING_READ_FEAT:
+               case VIRTIO_CCW_DOING_WRITE_FEAT:
+               case VIRTIO_CCW_DOING_READ_CONFIG:
+               case VIRTIO_CCW_DOING_WRITE_CONFIG:
+               case VIRTIO_CCW_DOING_WRITE_STATUS:
+               case VIRTIO_CCW_DOING_SET_VQ:
+               case VIRTIO_CCW_DOING_SET_IND:
+               case VIRTIO_CCW_DOING_SET_CONF_IND:
+               case VIRTIO_CCW_DOING_RESET:
+               case VIRTIO_CCW_DOING_READ_VQ_CONF:
+               case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
+               case VIRTIO_CCW_DOING_SET_VIRTIO_REV:
+                       vcdev->curr_io &= ~activity;
+                       wake_up(&vcdev->wait_q);
+                       break;
+               default:
+                       /* don't know what to do... */
+                       dev_warn(&vcdev->cdev->dev,
+                                "Suspicious activity '%08x'\n", activity);
+                       WARN_ON(1);
+                       break;
+               }
+       }
+}
+
 static void virtio_ccw_int_handler(struct ccw_device *cdev,
                                   unsigned long intparm,
                                   struct irb *irb)
@@ -995,6 +1025,12 @@ static void virtio_ccw_int_handler(struct ccw_device *cdev,
 
        if (!vcdev)
                return;
+       if (IS_ERR(irb)) {
+               vcdev->err = PTR_ERR(irb);
+               virtio_ccw_check_activity(vcdev, activity);
+               /* Don't poke around indicators, something's wrong. */
+               return;
+       }
        /* Check if it's a notification from the host. */
        if ((intparm == 0) &&
            (scsw_stctl(&irb->scsw) ==
@@ -1010,31 +1046,7 @@ static void virtio_ccw_int_handler(struct ccw_device *cdev,
                        /* Map everything else to -EIO. */
                        vcdev->err = -EIO;
        }
-       if (vcdev->curr_io & activity) {
-               switch (activity) {
-               case VIRTIO_CCW_DOING_READ_FEAT:
-               case VIRTIO_CCW_DOING_WRITE_FEAT:
-               case VIRTIO_CCW_DOING_READ_CONFIG:
-               case VIRTIO_CCW_DOING_WRITE_CONFIG:
-               case VIRTIO_CCW_DOING_WRITE_STATUS:
-               case VIRTIO_CCW_DOING_SET_VQ:
-               case VIRTIO_CCW_DOING_SET_IND:
-               case VIRTIO_CCW_DOING_SET_CONF_IND:
-               case VIRTIO_CCW_DOING_RESET:
-               case VIRTIO_CCW_DOING_READ_VQ_CONF:
-               case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
-               case VIRTIO_CCW_DOING_SET_VIRTIO_REV:
-                       vcdev->curr_io &= ~activity;
-                       wake_up(&vcdev->wait_q);
-                       break;
-               default:
-                       /* don't know what to do... */
-                       dev_warn(&cdev->dev, "Suspicious activity '%08x'\n",
-                                activity);
-                       WARN_ON(1);
-                       break;
-               }
-       }
+       virtio_ccw_check_activity(vcdev, activity);
        for_each_set_bit(i, &vcdev->indicators,
                         sizeof(vcdev->indicators) * BITS_PER_BYTE) {
                /* The bit clear must happen before the vring kick. */