[ovs-dev] vhost-user: port is dropping packets in transmission

[Mauricio Vásquez]

Dear all,

I am testing a setup where two VMs have to communicate using vhost-user
ports, it works using OvS 2.4 but it does not work with the master version
nor with 2.5.

The setup is quite simple, a pair of VMs connected to OvS using vhost-user
ports, two flows configured to forward the packets between the VMs, ping is
used to test connectivity between the VMs (ips and routing tables are
configured).

The problem that I can see is that a vhost-user port is dropping packets on
transmission:

OFPST_PORT reply (xid=0x2): 3 ports
port 1:
  rx pkts=330, bytes=14172, drop=?, errs=0, frame=?, over=?, crc=?
  tx pkts=0, bytes=0, drop=8, errs=?, coll=?

port LOCAL:
  rx pkts=0, bytes=0, drop=0, errs=0, frame=0, over=0, crc=0
  tx pkts=0, bytes=0, drop=0, errs=0, coll=0

port 2:
  rx pkts=8, bytes=648, drop=?, errs=0, frame=?, over=?, crc=?
  tx pkts=0, bytes=0, drop=330, errs=?, coll=?

I found that somebody has a similar problem:
http://openvswitch.org/pipermail/dev/2016-March/067152.html, I tried to
change pmd-cpu-mask but the problem is always there. I did some debug and
the problems is that qid is always -1 in the function
__netdev_dpdk_vhost_send.

Here it is some extra debug info:

ovs-vswithd.log:
http://pastebin.com/2CUyjGED

ovs-vsctl show
Bridge "br0"
  Port "br0" Interface "br0" type: internal
  Port "vhost-user-2" Interface "vhost-user-2" type: dpdkvhostuser
  Port "vhost-user-1" Interface "vhost-user-1" type: dpdkvhostuser

ovs-appctl dpctl/show
netdev at ovs-netdev:
lookups: hit:411 missed:1 lost:0
  flows: 1
 port 0: ovs-netdev (internal)
 port 1: vhost-user-1 (dpdkvhostuser: configured_rx_queues=1,
configured_tx_queues=1, requested_rx_queues=1, requested_tx_queues=9)
 port 2: br0 (tap)
 port 3: vhost-user-2 (dpdkvhostuser: configured_rx_queues=1,
configured_tx_queues=1, requested_rx_queues=1, requested_tx_queues=9)

ovs-appctl dpif-netdev/pmd-rxq-show
pmd thread numa_id 0 core_id 0:
 port: vhost-user-1 queue-id: 0
 port: vhost-user-2 queue-id: 0

Thank you very much,

Mauricio V,