gokvm

gokvm is a hypervisor that uses KVM as an acceleration. It is implemented completely in the Go language and has no dependencies other than the standard library. With only 1.5k lines of code, it can boot Linux 5.10, the latest version at the time, without any modifications (see v0.0.1). It includes naive and simple device emulation for serial console, virtio-net, and virtio-blk. The execution environment is limited to the x86-64 Linux environment. This should be useful for those who are interested in how to use KVM from userland. The latest version supports the following features:

• kvm acceleration
• multi processors
• serial console
• virtio-net
• virtio-blk

This is an experimental project, so please do not use it in production.

CLI

Extract the latest release from the Github Release tab and run it. Before running, make sure /dev/kvm exists. You can use existing bzImage and initrd, or you can create them using the Makefile of this project.

tar zxvf gokvm*.tar.gz
./gokvm -k ./bzImage -i ./initrd  # To exit, press Ctrl-a x.

Go package

This project includes a thin wrapper for the KVM API using ioctl. Please refer to the following link to use it.

https://pkg.go.dev/github.com/bobuhiro11/gokvm

Reference

Thanks to the many useful resources on KVM, this project was able to boot Linux on a virtual machine.

• Using the KVM API, lwn.net
• kvmtest.c, lwn.net
• KVM tool
• kvm-hello-world
• aghosn/kvm.go
• KVM HOST IN A FEW LINES OF CODE
• zserge/kvm-host.c
• CS 695: Virtualization and Cloud Computing, cse.iitb.ac.in
• The Linux/x86 Boot Protocol, kernel.org
• Build and run minimal Linux / Busybox systems in Qemu
• kvm_cost.go, google/gvisor
• Serial UART information, www.lammertbies.nl
• Virtual I/O Device (VIRTIO) Version 1.1
• rust-vmm/vm-virtio
• ハイパーバイザの作り方～ちゃんと理解する仮想化技術～ 第１１回 virtioによる準仮想化デバイス その１「virtioの概要とVirtio PCI」
• ハイパーバイザの作り方～ちゃんと理解する仮想化技術～ 第１２回 virtioによる準仮想化デバイス その２「Virtqueueとvirtio-netの実現」