Versioning PostGIS is an extension built on top of the PostGIS datastore that adds version, history and rollback support.
For more information about the concepts, the implementation and the protocol see the versioning research pages.

Configuration

Being Versioning PostGIS just an extended PostGIS datastore, the configuration parameters are largely the same.
The only difference is an extra parameter:

Beware: version enabling a feature type means altering the very structure of your database table. New columns will be added, and the primary key will be altered.
The versioning PostGIS datastore has code to undo that and get back to the unversioned table with the original structure, but GeoServer does not have any UI to expose that.
So be careful and don't version enable valuable data for which you don't have a full backup.

Limitations

At the moment versioning works only on tables whose primary key is a serial type, that is, an integer whose default value is the next value of a sequence.

The versioning WFS protocol will also need you to configure the changesets table so that it's a visible feature type in order to support the GetLog GML2 and GML3 output formats. Failing to do so will result in an exception stating the feature type "prefix:changesets" has not been found.