How to enable Active-Active on VMAX Cinder Driver?

Hello, Experts.

It's said that cinder active-active is supported since Ocata is released. It's also said that there's some work to do to enable Active-Active on the driver side, like set "SUPPORTS_ACTIVE_ACTIVE" and setup DLM, etc.

Stated in OpenStack Docs: High Availability:

  "Real testing of Active-Active deployments requires multiple Cinder Volume nodes on different hosts, as well as a properly configured Tooz DLM."

Is there any detailed procedure on how to enable Active-Active on VMAX cinder Driver?

Thanks in advance.

Ryan Bao