The MAS software is meant for a physical server. Mitel doesn't support taking it and installing it in vMWare. They offer a specific product call a vMAS that is prepackaged and preconfigured for vMWare. What others are saying is that you can take a MAS installation and convert it to a vMAS through some appropriate licensing.
Only supported on ESXi so you are on your own if you try Server or Player versions of vMWare.
I have never run a full MAS in a VM, other than supported vMAS installation...
That being said, I have run MBG, ME, and UCA stand alone servers virtually on several VM platforms (Hyper-V, CoWare, several "unsupported" VMware servers) with no issues, just build it in you VM manager as a generic Linux OS and give it sufficient resources then install manually from CD. Sometimes, especially with MBG in Gateway mode, it takes a little tweaking on the host side to get everything working.
This is not a supported configuration, but I can verify it works in several installations over several years. None of these actually was a virtual licensed application from Mitel.
YMMV... Take it with a grain of salt.