Virtio-nvgpu: Near-native Nvidia GPU access inside a KVM guest

Near-native NVIDIA GPU access inside a KVM guest. A guest renders within 2% of the machine it is running on, and costs the same CPU.

virtio-nvgpu forwards NVIDIA kernel driver ioctls between a Linux guest and the host at the driver ABI level , bypassing API-level translation entirely. The guest runs NVIDIA's own user-mode drivers, unmodified — the same libraries, the same Vulkan and NVENC, talking to the same card.

The target is headless streaming : a compositor inside the VM renders, composites and encodes frames on the GPU, then sends compressed video out. The VM has no monitor, and the host keeps the card.

It works, and it has been measured. A Wayland client presents inside a guest, the capture layer encodes on the game's own device, and the H.264 comes out the other side — 618 frames that ffmpeg decodes without an error.