Well thats the perk, you get games compatibility. Windows runs in a window with direct access to the GPU. I primary Windows because of games and music software, and I'm looking forward to trying it out.
As another comment points out, its called VFIO. From that subreddit: "VFIO stands for Virtual Function I/O. VFIO is a device driver that is used to assign devices to virtual machines. One of the most common uses of vfio is setting up a virtual machine with full access to a dedicated GPU. This enables near-bare-metal gaming performance in a Windows VM, offering a great alternative to dual-booting"
AFAIK, for the setup they're talking about, you do need a dedicated GPU. You blacklist it on the host, and pass it through to the windows VM.
I haven't worked in windows space in awhile though, and state changes rapidly, so there may be other options now that utilize a single GPU across host and vm without losing performance.
As another comment points out, its called VFIO. From that subreddit: "VFIO stands for Virtual Function I/O. VFIO is a device driver that is used to assign devices to virtual machines. One of the most common uses of vfio is setting up a virtual machine with full access to a dedicated GPU. This enables near-bare-metal gaming performance in a Windows VM, offering a great alternative to dual-booting"