KVM with OVS GRE has been supported on 4.3 release ?

[lifuhui]

Hello, everyone, 
Has anyone used OVS GRE with KVM on 4.3 release for isolation guest network ?
Why there is no code support such as in 

private String getGreEndpointIP(Host host, Network nw) 
...
switch (hvType) {
        case XenServer:
            String label = physNetTT.getXenNetworkLabel();
            if ((label != null) && (!label.equals(""))) {
                physNetLabel = label;
            }
            break;
        default:
            throw new CloudRuntimeException("Hypervisor " +
                    hvType.toString() +
                    " unsupported by OVS Tunnel Manager");
...

PS: Using 4.3 release code

If not support, why a release doc has mentioned as below:

3.4 The OVS Plugin
3.4.1 Introduction to the OVS Plugin
The OVS plugin is the native SDN implementations in CloudStack, using GRE 
isolation method. The plugin can be
used by CloudStack to implement isolated guest networks and to provide 
additional services like NAT, port forwarding
and load balancing.
Features of the OVS Plugin
The following table lists the CloudStack network services provided by the OVS 
Plugin.
Network Service
Virtual Networking
Static NAT
Port Forwarding
Load Balancing
CloudStack version
>= 4.0
>= 4.3
>= 4.3
>= 4.3
Table: Supported Services
Note: The Virtual Networking service was originally called ‘Connectivity’ in 
CloudStack 4.0
The following hypervisors are supported by the OVS Plugin.
Hypervisor
XenServer
KVM
CloudStack version
>= 4.0
>= 4.3
Table: Supported Hypervisors

Thanks