We currently trigger BUG when VIRTIO_NET_F_CTRL_VQ is not set but one of features depending on it is. That's not a friendly way to report errors to hypervisors. Let's check, and fail probe instead.
Cc: Rusty Russell <ru...@rustcorp.com.au> Cc: Cornelia Huck <cornelia.h...@de.ibm.com> Cc: Wanlong Gao <gaowanl...@cn.fujitsu.com> Signed-off-by: Michael S. Tsirkin <m...@redhat.com> Signed-off-by: Jason Wang <jasow...@redhat.com> --- Changes from V2: - only check the features for ctrl vq (this fix the real bug) - better error message and simplify API --- drivers/net/virtio_net.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index ec2a8b4..a6bcfce 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -1673,6 +1673,40 @@ static const struct attribute_group virtio_net_mrg_rx_group = { }; #endif +static bool virtnet_fail_on_feature(struct virtio_device *vdev, + unsigned int fbit, + const char *fname, const char *dname) +{ + if (!virtio_has_feature(vdev, fbit)) + return false; + + dev_err(&vdev->dev, "Hypervisor bug: advertise feature %s but not %s", + fname, dname); + + return true; +} + +#define VIRTNET_FAIL_ON(vdev, fbit, dbit) \ + virtnet_fail_on_feature(vdev, fbit, #fbit, #dbit) + +static bool virtnet_validate_features(struct virtio_device *vdev) +{ + if (!virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) && + (VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_RX, + VIRTIO_NET_F_CTRL_VQ) || + VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_VLAN, + VIRTIO_NET_F_CTRL_VQ) || + VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE, + VIRTIO_NET_F_TRL_VQ) || + VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_MQ, VIRTIO_NET_F_CTRL_VQ) || + VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR, + VIRTIO_NET_F_CTRL_VQ))) { + return false; + } + + return true; +} + static int virtnet_probe(struct virtio_device *vdev) { int i, err; @@ -1680,6 +1714,9 @@ static int virtnet_probe(struct virtio_device *vdev) struct virtnet_info *vi; u16 max_queue_pairs; + if (!virtnet_validate_features(vdev)) + return -EINVAL; + /* Find if host supports multiqueue virtio_net device */ err = virtio_cread_feature(vdev, VIRTIO_NET_F_MQ, struct virtio_net_config, -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/