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

[Clarylin L <clearasu@gmail.com>]

Played with it a little bit more. It can receive packets only if
promiscuous mode is enabled in DPDK.

On Mon, Feb 22, 2016 at 11:00 PM, Clarylin L <clearasu@gmail.com> 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? or anything else I need to look into and check?
> My VM is running on Ubuntu KVM.
>
> On Mon, Feb 22, 2016 at 7:50 PM, Yuanhan Liu <yuanhan.liu@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
>>
>
>