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>

1 files changed, 37 insertions, 25 deletions

diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c
index b2a1a81e6fc8..1b831598df7c 100644
--- 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. */