virtio_ccw: finalize_features error handling

We previously tried to use device even if finalize_features failed, but
that's wrong since driver and device are now out of sync.

Fail probe if we detect failures during finalize_features.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 10 insertions, 6 deletions

diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c
index f92b9e66c200..71d7802aa8b4 100644
--- a/drivers/s390/kvm/virtio_ccw.c
+++ b/drivers/s390/kvm/virtio_ccw.c
@@ -757,6 +757,7 @@ static int virtio_ccw_finalize_features(struct virtio_device *vdev)
         struct virtio_ccw_device *vcdev = to_vc_device(vdev);
         struct virtio_feature_desc *features;
         struct ccw1 *ccw;
+        int ret;
 
         if (vcdev->revision >= 1 &&
             !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
@@ -767,12 +768,13 @@ static int virtio_ccw_finalize_features(struct virtio_device *vdev)
 
         ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
         if (!ccw)
-                return 0;
+                return -ENOMEM;
 
         features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
-        if (!features)
+        if (!features) {
+                ret = -ENOMEM;
                 goto out_free;
-
+        }
         /* Give virtio_ring a chance to accept features. */
         vring_transport_features(vdev);
 
@@ -783,7 +785,9 @@ static int virtio_ccw_finalize_features(struct virtio_device *vdev)
         ccw->flags = 0;
         ccw->count = sizeof(*features);
         ccw->cda = (__u32)(unsigned long)features;
-        ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
+        ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
+        if (ret)
+                goto out_free;
 
         if (vcdev->revision == 0)
                 goto out_free;
@@ -795,13 +799,13 @@ static int virtio_ccw_finalize_features(struct virtio_device *vdev)
         ccw->flags = 0;
         ccw->count = sizeof(*features);
         ccw->cda = (__u32)(unsigned long)features;
-        ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
+        ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
 
 out_free:
         kfree(features);
         kfree(ccw);
 
-        return 0;
+        return ret;
 }
 
 static void virtio_ccw_get_config(struct virtio_device *vdev,