Re: [dpdk-dev] [dpdk-virtio] DPDK stopped working on virtio

[Yuanhan Liu <yuanhan.liu@linux.intel.com>]

On Mon, Feb 22, 2016 at 11:15:57AM -0800, Clarylin L wrote:
> I am running DPDK application (testpmd) within a VM based on virtio. With
> the same hypervisor and same DPDK code, it used to work well. But it
> stopped working since last week. The VM's port could not receive anything.
> I ran tcpdump on host's physical port, bridge interface as well as vnet
> interface, and did see packets coming in. However on VM's port there was
> nothing.
> 
> I ran gdb trying to debug, it hit function virtio_recv_mergeable_pkts(),
> but nb_used=VIRTQUEUE_NUSED(rxvq) always gave 0. I guess it's because the
> queue was empty.
> 
> I enabled the PMD debug logging and the only thing that might be an issue
> was the following part. Other than this I could not see any thing that
> could indicate potential issues.
> 
> Thu Feb 18 19:20:10 2016^@PMD: get_uio_dev(): Could not find uio resource
> Thu Feb 18 19:20:10 2016^@PMD: virtio_resource_init_by_ioports(): PCI Port
> IO found start=0xc040 with size=0x40

That could be normal, when you don't bind the driver to igb_uio.

> If someone can give any pointers that I should further look into, that'd be
> very helpful. Appreciate your help!

What's the last commit you are testing? And what are the steps
to reproduce it? I have a quick try with vhost-switch example,
with pkts injected by IXIA; it works fine here.

Or better, mind do a git bisect? There aren't too many commits
there. It should be a pretty fast bisect.

	--yliu