The licensing requirements for Microsoft SQL vary between Versions and Editions. When calculating the requirements for a specific datacenter it mostly it comes down to gathering data about CPU or RAM for either the hardware backing the servers or for the servers running the SQL instances.
Regardless of how to perform the license calculation, the information is easy to retrieve in vScope.
In the case of SQL 2012 and 2014 you may run as many Virtual Machines with SQL instances as you like as long as you license the hardware hosts running the VMs. In vScope this is displayed in a pre-defined Table Preset Called MS SQL Licensing (Hardware RAM & CPU).
Older versions of MS SQL may be licensed per virtual or physical server hosing the database. This can be viewed in the Table Preset MS SQL Licensing (Machine).
Resources for further reading
We have gathered a few resources for more information about Microsoft SQL Licensing here: