I modify the etc file like this:

1、{odl_dir}/etc/opendaylight/datastore/initial/config/genius-itm-config.xml ：

<def-tz-enabled>false</def-tz-enabled>

 <gpe-extension-enabled>true</gpe-extension-enabled>

2、{odl_dir}/etc/opendaylight/datastore/initial/config/netvirt-elanmanager-config.xml ：

<auto-config-transport-zones>true</auto-config-transport-zones>

 <use-of-tunnels>true</use-of-tunnels>

After the vm is created ,the vxlan tunnels are also built.

But there were two same vxlan tunnels. For example:

[root@wlz-controller odl]# ovs-vsctl show
e3894f29-cb8b-484e-a711-98411854e978
Manager "tcp:172.23.27.12:6640"
is_connected: true
Bridge br-int
Controller "tcp:172.23.27.12:6653"
fail_mode: secure
Port "tunad8b9653c61"
Interface "tunad8b9653c61"
type: vxlan
options: {exts=gpe, key=flow, local_ip="10.0.1.91", remote_ip=flow}
Port br-int
Interface br-int
type: internal
Port "tun9285edd6d47"
Interface "tun9285edd6d47"
type: vxlan
options: {exts=gpe, key=flow, local_ip="10.0.1.91", remote_ip=flow}
Port "tapc5d79335-8b"

[root@wlz-controller odl]# ovs-ofctl show -O Openflow13 br-int
OFPT_FEATURES_REPLY (OF1.3) (xid=0x2): dpid:0000fce6e8bafdd6
n_tables:254, n_buffers:256
capabilities: FLOW_STATS TABLE_STATS PORT_STATS GROUP_STATS QUEUE_STATS
OFPST_PORT_DESC reply (OF1.3) (xid=0x3):
1(tapc5d79335-8b): addr:b6:f7:6d:4a:92:84
config: PORT_DOWN
state: LINK_DOWN
speed: 0 Mbps now, 0 Mbps max
2(tunad8b9653c61): addr:c6:78:1c:b0:c4:4f
config: 0
state: 0
speed: 0 Mbps now, 0 Mbps max
7(tap5000f882-28): addr:00:00:00:00:0c:51
config: PORT_DOWN
state: LINK_DOWN
speed: 0 Mbps now, 0 Mbps max
LOCAL(br-int): addr:fc:e6:e8:ba:fd:d6
config: PORT_DOWN
state: LINK_DOWN
speed: 0 Mbps now, 0 Mbps max
OFPT_GET_CONFIG_REPLY (OF1.3) (xid=0x5): frags=normal miss_send_len

It shows that two same vxlan tunnels were bulit and one of them did not have port number.