What does it mean if rev 1 device does not set VIRTIO_F_VERSION_1? E.g. is it native endian?
Let's not even try to drive such devices: skip attempts to finalize features or set status. virtio core will detect this and bail out. Signed-off-by: Michael S. Tsirkin <[email protected]> --- drivers/s390/kvm/virtio_ccw.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c index 088bdf1..0ceeb25 100644 --- a/drivers/s390/kvm/virtio_ccw.c +++ b/drivers/s390/kvm/virtio_ccw.c @@ -65,6 +65,7 @@ struct virtio_ccw_device { bool is_thinint; bool going_away; bool device_lost; + bool features_invalid; void *airq_info; }; @@ -746,6 +747,12 @@ static u64 virtio_ccw_get_features(struct virtio_device *vdev) if (ret == 0) rc |= (u64)le32_to_cpu(features->features) << 32; + /* Devices MUST set VIRTIO_F_VERSION_1 */ + if (!(rc & BIT_ULL(VIRTIO_F_VERSION_1))) { + vcdev->features_invalid = true; + rc |= BIT_ULL(VIRTIO_F_VERSION_1); + } + out_free: kfree(features); kfree(ccw); @@ -758,6 +765,10 @@ static void virtio_ccw_finalize_features(struct virtio_device *vdev) struct virtio_feature_desc *features; struct ccw1 *ccw; + /* Invalid features? Let's not try to drive this device. */ + if (vcdev->features_invalid) + return; + ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL); if (!ccw) return; @@ -869,6 +880,10 @@ static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status) struct ccw1 *ccw; int ret; + /* Invalid features? Let's not try to drive this device. */ + if (vcdev->features_invalid) + return; + ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL); if (!ccw) return; -- MST -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
