gpu

go-virtio/gpu

Pure-Go virtio-gpu (2D framebuffer) driver targeting the go-virtio/common transport interfaces. Implements the modern-transport (Virtio 1.0+) init sequence and the control-queue command path for the standard PCI-bound virtio-gpu device (VID 0x1AF4, DID 0x1050).

Scope

2D framebuffer only. 3D / virgl is explicitly out of scope: it requires a Mesa-class GL/Vulkan stack to generate the OpenGL command streams the host consumes, which does not exist in Go. The driver negotiates exactly VIRTIO_F_VERSION_1 and deliberately does not negotiate VIRTIO_GPU_F_VIRGL (bit 0), keeping the device in plain 2D mode (Virtio 1.1 §5.7).

Like the sibling drivers this package owns device bring-up, both virtqueues — the control queue (controlq, carrying every 2D command) and the cursor queue (cursorq, set up for spec-completeness but unused) — and the on-the-wire virtio-gpu control protocol. Every command is a 2-descriptor chain (a read-only request followed by a device-writable response), built with common.AddChain.

It exposes a scanout-enumeration + framebuffer API:

• DisplayInfo lists the device's scanouts (GET_DISPLAY_INFO).
• SetupFramebuffer creates a host 2D resource, attaches guest backing, and binds it to a scanout (RESOURCE_CREATE_2D + RESOURCE_ATTACH_BACKING + SET_SCANOUT). The returned Framebuffer.Pix is a BGRA byte buffer the caller draws into.
• Framebuffer.Flush pushes the drawn pixels to the host and refreshes the scanout (TRANSFER_TO_HOST_2D + RESOURCE_FLUSH).

Quick start

import (
    virtiogpu "github.com/go-virtio/gpu"
)

// transport is any value that implements go-virtio/common.Transport.
g, err := virtiogpu.OpenVirtioGPU(transport)
if err != nil {
    return err
}

displays, err := g.DisplayInfo()
if err != nil {
    return err
}
d := displays[0] // first scanout

fb, err := g.SetupFramebuffer(d.ScanoutID, d.Width, d.Height)
if err != nil {
    return err
}

// Draw BGRA pixels into fb.Pix, then push to the display.
for i := 0; i+3 < len(fb.Pix); i += 4 {
    fb.Pix[i+0] = 0x20 // B
    fb.Pix[i+1] = 0x80 // G
    fb.Pix[i+2] = 0xFF // R
    fb.Pix[i+3] = 0xFF // A
}
err = fb.Flush()

Sibling packages

• github.com/go-virtio/common — transport-agnostic infrastructure (PCI cap walker, modern config layout, split-virtqueue + descriptor-chain impl, transport interfaces).
• github.com/go-virtio/net — pure-Go virtio-net driver.
• github.com/go-virtio/rng — pure-Go virtio-rng driver.
• github.com/go-virtio/vsock — pure-Go virtio-vsock driver.
• github.com/go-virtio/blk — pure-Go virtio-blk driver (the descriptor-chain reference this package mirrors).

License

BSD-3-Clause. See LICENSE.