I have 8x2.8 ghz Xeon cores 32 GB of RAM and a 970 GTX in my gaming vm. Works perfectly for DOOM, Witcher 3, all at 1920x1080 on high settings (maybe not full but damn pretty). Consensus on the forum seems to be you lose low single digit performance.

It's a KVM hypervisor and I haven't played online, why would they ban you for using a VM?