Re: virtio_net hang

[Emmanuel Lacour <elacour@easter-eggs.com>]

On Fri, Nov 14, 2008 at 06:26:44PM +0000, Mark McLoughlin wrote:
> 
> Right, the tap device tx queue is full because kvm-userspace isn't
> reading packets from it.
> 
> This could be because kvm-userspace has just stopped noticing that
> there's data available from the tapfd or because virtio_net in the guest
> has stopped noticing that packets are available in the ring.
> 
> One thing you could easily check is whether:
> 
>   ip link set eth0 down
>   ip link set eth0 up
> 
> in the host is sufficient to fix it? If it is, then it points to a guest
> driver issue.
> 

I made the test, putting link down then up fix it.

So what can I do next time to help fixing this ?