Family Safety will not log or see what is happening in a VM unless you limit the PC account to a non admin user on his PC and disable all VM software.
I would recommend looking at OpenDNS. If you configure that on your router but don't enable any of the blocking functions you can monitor sites visited from all PCs including regular VMs if you really want to do that. If you enable some of the blocking he can configure a PC to bypass it.
A smart son can likely bypass most things the average parent can setup and having him use PCs in a shared family location is likely the best way to regulate and limit use. That and having some hard talks about consequences.