Description of problem:
vhost-user stop receiving packets after migration.

Version-Release number of selected component (if applicable):
openvswitch-2.9.0-124.el7fdp.x86_64
openvswitch-selinux-extra-policy-1.0-15.el7fdp.noarch
3.10.0-1122.el7.x86_64
qemu-kvm-rhev-2.12.0-42.el7.x86_64
libvirt-4.5.0-31.el7.x86_64
dpdk-18.11.2-1.el7_6.x86_64

How reproducible:
100%

Steps to Reproduce:

1. Boot ovs with dpdkvhostuserclient ports on both src and des hosts, refer to[1]

# ovs-vsctl show
83dd9e54-2fb4-4eed-be58-cab15e4d4c3e
    Bridge "ovsbr1"
        Port "ovsbr1"
            Interface "ovsbr1"
                type: internal
        Port "vhost-user1"
            Interface "vhost-user1"
                type: dpdkvhostuserclient
                options: {vhost-server-path="/tmp/vhostuser1.sock"}
        Port "dpdk1"
            Interface "dpdk1"
                type: dpdk
                options: {dpdk-devargs="0000:5e:00.1", n_rxq="1"}
    Bridge "ovsbr0"
        Port "ovsbr0"
            Interface "ovsbr0"
                type: internal
        Port "dpdk0"
            Interface "dpdk0"
                type: dpdk
                options: {dpdk-devargs="0000:5e:00.0", n_rxq="1"}
        Port "vhost-user0"
            Interface "vhost-user0"
                type: dpdkvhostuserclient
                options: {vhost-server-path="/tmp/vhostuser0.sock"}

2. Boot VM on src host

3. Start testpmd in guest

# /usr/bin/testpmd \
-l 1,2,3,4,5 \
-n 4 \
-d /usr/lib64/librte_pmd_virtio.so \
-w 0000:06:00.0 -w 0000:07:00.0 \
--iova-mode pa \
-- \
--nb-cores=4 \
-i \
--disable-rss \
--rxd=512 --txd=512 \
--rxq=1 --txq=1


4. Start MoonGen in another host

# ./build/MoonGen /home/nfv-virt-rt-kvm/tests/utils/rfc1242.lua 0 1 64 3000000 4.1

5. Check testpmd in guest, it can receive packets well.

testpmd> show port stats all

  ######################## NIC statistics for port 0  ########################
  RX-packets: 10094535   RX-missed: 0          RX-bytes:  605672100
  RX-errors: 0
  RX-nombuf:  0         
  TX-packets: 10093278   TX-errors: 0          TX-bytes:  605596680

  Throughput (since last show)
  Rx-pps:       995333
  Tx-pps:       995336
  ############################################################################

  ######################## NIC statistics for port 1  ########################
  RX-packets: 10094564   RX-missed: 0          RX-bytes:  605673840
  RX-errors: 0
  RX-nombuf:  0         
  TX-packets: 10093305   TX-errors: 0          TX-bytes:  605598300

  Throughput (since last show)
  Rx-pps:       995324
  Tx-pps:       995321
  ############################################################################


6. Migrate guest from src host to des host

# /bin/virsh migrate --verbose --persistent --live rhel7.8 qemu+ssh://10.73.72.196/system

7. Check in guest, testpmd stop receiving packets, Rx-pps and TX-pps become 0.

testpmd> show port stats all

  ######################## NIC statistics for port 0  ########################
  RX-packets: 124726123  RX-missed: 0          RX-bytes:  7483569564
  RX-errors: 0
  RX-nombuf:  0         
  TX-packets: 124724797  TX-errors: 0          TX-bytes:  7483490008

  Throughput (since last show)
  Rx-pps:            0
  Tx-pps:            0
  ############################################################################

  ######################## NIC statistics for port 1  ########################
  RX-packets: 124726111  RX-missed: 0          RX-bytes:  7483568844
  RX-errors: 0
  RX-nombuf:  0         
  TX-packets: 124724482  TX-errors: 0          TX-bytes:  7483471108

  Throughput (since last show)
  Rx-pps:            0
  Tx-pps:            0
  ############################################################################



Actual results:
vhost-user stop receiving packets after migration.

Expected results:
vhost-user should keep receiving packets after migration.

Additional info:
1. This is a regression bug.

openvswitch-2.9.0-122.el7fdp.x86_64  works well


Reference:
[1]
# cat boot_ovs_client.sh 
#!/bin/bash

set -e

echo "killing old ovs process"
pkill -f ovs-vswitchd || true
sleep 5
pkill -f ovsdb-server || true

echo "probing ovs kernel module"
modprobe -r openvswitch || true
modprobe openvswitch

echo "clean env"
DB_FILE=/etc/openvswitch/conf.db
rm -rf /var/run/openvswitch
mkdir /var/run/openvswitch
rm -f $DB_FILE

echo "init ovs db and boot db server"
export DB_SOCK=/var/run/openvswitch/db.sock
ovsdb-tool create /etc/openvswitch/conf.db /usr/share/openvswitch/vswitch.ovsschema
ovsdb-server --remote=punix:$DB_SOCK --remote=db:Open_vSwitch,Open_vSwitch,manager_options --pidfile --detach --log-file
ovs-vsctl --no-wait init

echo "start ovs vswitch daemon"
ovs-vsctl --no-wait set Open_vSwitch . other_config:dpdk-init=true
ovs-vsctl --no-wait set Open_vSwitch . other_config:dpdk-socket-mem="1024,1024"
ovs-vsctl --no-wait set Open_vSwitch . other_config:dpdk-lcore-mask="0x1"
ovs-vsctl --no-wait set Open_vSwitch . other_config:vhost-iommu-support=true
ovs-vswitchd unix:$DB_SOCK --pidfile --detach --log-file=/var/log/openvswitch/ovs-vswitchd.log

echo "creating bridge and ports"

ovs-vsctl --if-exists del-br ovsbr0
ovs-vsctl add-br ovsbr0 -- set bridge ovsbr0 datapath_type=netdev
ovs-vsctl add-port ovsbr0 dpdk0 -- set Interface dpdk0 type=dpdk options:dpdk-devargs=0000:5e:00.0 
ovs-vsctl add-port ovsbr0 vhost-user0 -- set Interface vhost-user0 type=dpdkvhostuserclient options:vhost-server-path=/tmp/vhostuser0.sock
ovs-ofctl del-flows ovsbr0
ovs-ofctl add-flow ovsbr0 "in_port=1,idle_timeout=0 actions=output:2"
ovs-ofctl add-flow ovsbr0 "in_port=2,idle_timeout=0 actions=output:1"

ovs-vsctl --if-exists del-br ovsbr1
ovs-vsctl add-br ovsbr1 -- set bridge ovsbr1 datapath_type=netdev
ovs-vsctl add-port ovsbr1 dpdk1 -- set Interface dpdk1 type=dpdk options:dpdk-devargs=0000:5e:00.1
ovs-vsctl add-port ovsbr1 vhost-user1 -- set Interface vhost-user1 type=dpdkvhostuserclient options:vhost-server-path=/tmp/vhostuser1.sock
ovs-ofctl del-flows ovsbr1
ovs-ofctl add-flow ovsbr1 "in_port=1,idle_timeout=0 actions=output:2"
ovs-ofctl add-flow ovsbr1 "in_port=2,idle_timeout=0 actions=output:1"

ovs-vsctl set Open_vSwitch . other_config={}
ovs-vsctl set Open_vSwitch . other_config:dpdk-lcore-mask=0x1
ovs-vsctl set Open_vSwitch . other_config:pmd-cpu-mask=0x1554
ovs-vsctl set Interface dpdk0 options:n_rxq=1
ovs-vsctl set Interface dpdk1 options:n_rxq=1

echo "all done"