diff options
| author | Michael S. Tsirkin <mst@redhat.com> | 2014-12-04 17:59:50 +0100 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2014-12-09 15:32:32 +0100 |
| commit | ce15408f350c4b97635618692a45aedabfdd2696 (patch) | |
| tree | 26cb818d379d72c914763a505fd486b2de9bc986 /drivers/s390 | |
| parent | virtio: add API to detect legacy devices (diff) | |
| download | linux-ce15408f350c4b97635618692a45aedabfdd2696.tar.xz linux-ce15408f350c4b97635618692a45aedabfdd2696.zip | |
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.c | 16 |
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) { |