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 <rusty@xxxxxxxxxxxxxxx>
Cc: Cornelia Huck <cornelia.huck@xxxxxxxxxx>
Cc: Wanlong Gao <gaowanlong@xxxxxxxxxxxxxx>
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
---
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
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