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authorMichael S. Tsirkin <mst@redhat.com>2014-12-04 18:59:50 +0200
committerMichael S. Tsirkin <mst@redhat.com>2014-12-09 16:32:32 +0200
commitce15408f350c4b97635618692a45aedabfdd2696 (patch)
tree26cb818d379d72c914763a505fd486b2de9bc986 /drivers/s390
parentb6098c30423cb1f0f5a4d0a5495e2670e274e544 (diff)
virtio_ccw: legacy: don't negotiate rev 1/features
Legacy balloon device doesn't pretend to support revision 1 or 64 bit features. But just in case someone implements a broken one that does, let's not even try to drive legacy only devices using revision 1, and let's not give them a chance to say they support VIRTIO_F_VERSION_1 by not reading or writing high feature bits. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Diffstat (limited to 'drivers/s390')
-rw-r--r--drivers/s390/kvm/virtio_ccw.c16
1 files changed, 13 insertions, 3 deletions
diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c
index 4a3e6e510294..c792b5fe0bc9 100644
--- a/drivers/s390/kvm/virtio_ccw.c
+++ b/drivers/s390/kvm/virtio_ccw.c
@@ -733,6 +733,9 @@ static u64 virtio_ccw_get_features(struct virtio_device *vdev)
rc = le32_to_cpu(features->features);
+ if (vcdev->revision == 0)
+ goto out_free;
+
/* Read second half of the feature bits from the host. */
features->index = 1;
ccw->cmd_code = CCW_CMD_READ_FEAT;
@@ -775,6 +778,9 @@ static void virtio_ccw_finalize_features(struct virtio_device *vdev)
ccw->cda = (__u32)(unsigned long)features;
ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
+ if (vcdev->revision == 0)
+ goto out_free;
+
features->index = 1;
features->features = cpu_to_le32(vdev->features >> 32);
/* Write the second half of the feature bits to the host. */
@@ -1182,9 +1188,13 @@ static int virtio_ccw_online(struct ccw_device *cdev)
vcdev->vdev.id.vendor = cdev->id.cu_type;
vcdev->vdev.id.device = cdev->id.cu_model;
- ret = virtio_ccw_set_transport_rev(vcdev);
- if (ret)
- goto out_free;
+ if (virtio_device_is_legacy_only(vcdev->vdev.id)) {
+ vcdev->revision = 0;
+ } else {
+ ret = virtio_ccw_set_transport_rev(vcdev);
+ if (ret)
+ goto out_free;
+ }
ret = register_virtio_device(&vcdev->vdev);
if (ret) {