Ask HN: Is it likely we will see efficient GPU sharing in VMs for gaming setups?

If I would like to use Linux or MacOS as a host machine but run Windows in a VM to play games on, currently it's not possible to share the GPU with the host through VMWare or VirtualBox.

You can dedicate you graphics card to the guest, but you need two GPUs for that (one for the host and one for the guest).

CPU passthrough seems to have no performance penalty and allows me to pass all of my cores through to the guest.

Will we see something like that for GPUs? What is the blocker for this sort of technology?