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

[Yuanhan Liu]

On Mon, Feb 22, 2016 at 11:00:28PM -0800, Clarylin L wrote:
> I am working with DPDK 2.0. 
> 
> I guess it's not DPDK code issue , but more like an environment issue (as same
> code has been working fine before. It's even working on another setup now).
> Someone might have accidentally changed my setup, and I want to find out what
> made dpdk-virtio stop working. 
> 
> Is DPDK-virtio dependent on any specific modules on the hypervisor? or are
> there any configurations on the hypervisor that would impact the functionality
> of  virtio?

Nope, none that I can think of.

> or anything else I need to look into and check? My VM is running on
> Ubuntu KVM.

The vhost and virtio log?

	--yliu
> 
> On Mon, Feb 22, 2016 at 7:50 PM, Yuanhan Liu <yuanhan.liu at linux.intel.com>
> wrote:
> 
>     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
> 
>