hyper-v GPU partitioning

[totaam]

Explore alternatives to #4418 which is a pure-software way of dealing with GPU codec resources on the host side.
This ticket is about enabling more complete GPU access, not just the encoder.

RemoteFX has been abandoned due to unfixable security issues in its architecture and it's not clear to me how much better and safer the VFIO / SR-IOV alternatives are.
After all, running code directly on the GPU is going to be (many) orders of magnitude easier to exploit than running it mediated by a pure-software layer like vglrun.

Links:

• Microsoft Hyper-v GPU partitioning
• Intel: SR-IOV
• API level: add-vmgpupartitionadapter
• Microsoft Hyper-v: Partition and assign GPUs to a virtual machine
• Easy-GPU-PV
• linaro: A closer look at VirtIO and GPU virtualisation

Alternative options, GPU pass-through, API virtualization:

• vgpu_unlock
• containers are easier: does nvidia-container-toolkit work on MS Windows servers via WSL2?
• pass through one device per VM: DDA: Direct Device Assignment
• Ubuntu: GPU virtualization with QEMU/KVM
• virgl
• qemu: virtio-gpu

FWIW, there used to be a number of other solutions, but most of them seem to have been abandoned.
ie: GVTd

[totaam]

Since the main resource contention with GPU sharing is the RAM, this may help: Device Memory "DMEM" Cgroup Support

[totaam]

Fresh news: AMDGPU VirtIO Native Context Merged: Native AMD Driver Support Within Guest VMs: AMDGPU native context support for VirtIO to allow for using native OpenGL and Vulkan graphics drivers within guest virtual machines for better performance