With Intel GVT-g (KVMGT) benn upstreamed from kernel 4.10, Intel has updated the GVT-g architecture to upstream friendly.
This document highlights the key difference of new architecture, for example, resource mangement, interrupt, GGPTT, scheduling, display. For more details, please check out the latest upstream GVT-g code.
P.S. XenGT upstream is working in progress.