Realize this post is old, but just want to clear up some possible confusion you may have about Hyper-V. Adding the Hyper-V role on a Windows 10 system will not make the host OS a child role. The Win10 system will now act as the parent role which is a VM that has direct access to hardware in contrast to child roles that accesses virtualised hardware - the two are not the same or interchangeable. Therefore, no gaming performance hit should even be noticable on that level. The shared performance on CPU/RAM/Disk is an issue you'd have to evaluate and prioritize though.

Point is, the parent OS has direct hardware access, not virtualized. It's not a child VM like the ones you create afterwards. Microsoft documents this well.