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 [off-list ref]
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