RE: [PATCH net-next] virtio_net: set link state down when virtqueue is broken

-----Original Message-----

quoted

From: Yunjian Wang <redacted>

The NIC can't receive/send packets if a rx/tx virtqueue is broken.
However, the link state of the NIC is still normal. As a result, the
user cannot detect the NIC exception.

Doesn't we have:

        /* This should not happen! */
         if (unlikely(err)) {
                 dev->stats.tx_fifo_errors++;
                 if (net_ratelimit())
                         dev_warn(&dev->dev,
                                  "Unexpected TXQ (%d) queue
failure: %d\n",
                                  qnum, err);
                 dev->stats.tx_dropped++;
                 dev_kfree_skb_any(skb);
                 return NETDEV_TX_OK;
         }

Which should be sufficient?

There may be other reasons for this error, e.g -ENOSPC(no free desc).
And if rx virtqueue is broken, there is no error statistics.

quoted

The driver can set the link state down when the virtqueue is broken.
If the state is down, the user can switch over to another NIC.

Note that, we probably need the watchdog for virtio-net in order to be a
complete solution.

Yes, I can think of is that the virtqueue's broken exception is detected on watchdog.
Is there anything else that needs to be done?

Thanks

Thanks

quoted