I hope in the near future Apple will release an API for GPU virtualization. In fact Intel Iris Pro devices already support GVT-d. The problem is that Iris Pro is only used in the expensive Macbook models, the cheaper one come with regular Iris that don't have hardware support for it
Although if GVT-d gives the GPU fully over to the VM, which GPU will OS X itself be using? In the high-end 15" MBP, I suppose OS X could switch to the discrete GPU and let the VM use Iris Pro, but it's not a great solution and would only work on (the fairly small number of) dual-GPU Macs.
Actually gpu virtualization works quite similar to cpu. You don't pass a cpu core exclusively to a VM rather the cpu itself maintains independent contexts: for the host and each VM. When a CPU runs a VM it just switches the context. So is the GPU. You don't need two GPUs to make it work.
That's very good news – so far, at every Docker-related meeting or training session I've attended half of the people spending the first hour or two trying to get everything installed or configured, troubleshoot VirtualBox, etc.
Anything you can do to make that easier would be quite welcome, particularly for educators, tutorial writers, etc.
