Server 2012 licensing problem

Hi,

I have a few questions related to Server 2012 R2 Licensing. 

1. As I know if we are running Hyper-V on Windows Servers 2012 R2 we can run 2 VM's with the same server license. With my understanding

  One Server 2012 R2 License

•   1 Physical License
•   2 VM's on Hyper -V

Is this correct or wrong?

2. If we are planning to implement UAT Servers and Test Server in the production environment how is the licensing process. Do we have to purchase the license for Test servers and UAT? All Servers planning to run on Hyper-V

Looking for experts comments