Version 2.13 properly recognized running as a VM in hyper-v 2012 R2. Synthetic drivers and VM utilities such as shutdown worked fine. Upon either upgrade or new install of 2.15 these no longer worked. Only the Legacy network adapters worked and VM utilities stopped functioning.
I did edit /etc/sysconfig/modules as documentation suggested with no affect.
Incidentally, I did not have to edit the modules file when installing 2.13. It appropriately recognized the synthetic drivers.