Not able create ports in OVS - openvswitch

Question

I have an Ubuntu Host with two VM's and I am trying to create a bridge between the two VM's. I have a bridge say br0 and I am trying to create a port say tap0 and tap1 for the two VM's. So far I was able to create the bridge but when I do try to create the port, I get the below error.
root#dpdk:~# ovs-vsctl add-br br0 -- set bridge br0 datapath_type=netdev
root#dpdk:~# ovs-vsctl add-port br0 tap1
ovs-vsctl: Error detected while setting up 'tap1'. See ovs-vswitchd log for details.
root#dpdk:~# sudo ovs-vsctl show
4c3a769e-f900-4c8d-81a7-ba685d4e364a
Bridge "br0"
Port "tap1"
Interface "tap1"
error: "could not open network device tap1 (No such device)"
Port "br0"
Interface "br0"
type: internal
ovs_version: "2.5.2"
I am doing this to run a DPDK pktgen application.

Answer 1

You need to create a tap device first.
You can either create it yourself:
$ tunctl -t tap0
$ ip link set tap0 up
$ ovs-vsctl add-port br0 tap0
or let QEMU/KVM create it for you:
$ cat << 'EOF' > /etc/ovs-ifup
#!/bin/sh
switch='br0'
ip link set $1 up
ovs-vsctl add-port ${switch} $1
EOF
$ cat << 'EOF' > /etc/ovs-ifdown
#!/bin/sh
switch='br0'
ip addr flush dev $1
ip link set $1 down
ovs-vsctl del-port ${switch} $1
EOF
$ kvm -m 512 -net nic,macaddr=00:11:22:EE:EE:EE -net \
tap,script=/etc/ovs-ifup,downscript=/etc/ovs-ifdown -drive \
file=/path/to/disk-image,boot=on
(The first two commands create two utility scripts as callbacks for kvm. See Open vSwitch's documentation.)