Creating Virtual Machines Using QEMU/KVM on Linux

What is QEMU? QEMU is a free and open-source machine emulator that can perform hardware virtualization. It is a lot faster than VMWare or Virtualbox because it is a KVM-based virtualization platform.

What is KVM? KVM is a virtualization module in the Linux kernel.

In this guide, we will manage our virtual machines through the terminal, but you could use virt-manager as a GUI for controlling virtual machines.

Table of Contents

• Dependencies

  • QEMU
  • KVM

• Kali Linux

  • Downloading .iso
  • Booting in Live Mode
  • Creating data storage
  • Installing Kali Linux

• MacOS

Dependencies

QEMU

Download QEMU

KVM

Try your distro's packaging system, this is the easiest and recommended way of installing KVM. It's usually called qemu-kvm or kvm.

Kali Linux

Downloading .iso

First of all, you need to download the .iso file for Kali Linux (or any other operational system) on the official website.

Booting in Live Mode

Go to the directory where you downloaded the official .iso and run this command in your terminal to boot a live version of Kali Linux. No changes to the operational system will be saved.

qemu-system-x86_64 \
  --enable-kvm \
  -m 4G \
  -smp 4 \
  -name 'Kali Linux Live' \
  -boot d \
  -cdrom kali-linux-2020.3-live-amd64.iso

Shortcut to get in and out of fullscreen mode: Ctrl + Alt + F

Shortcut to release the mouse from the virtual machine window: Ctrl + Alt + G

Creating data storage

You will need to create a .qcow2 file that will act as a virtual data storage. Use qemu-image like this:

qemu-img create -f qcow2 kalidisk.qcow2 30G

I have decided to create a data storage named kalidisk that contains 30 GB of memory.

Installing Kali Linux

Now you can modify the previous command to install Kali Linux in the virtual disk that you created earlier.

1. Add -hda kalidisk.qcow2 to our previous script and run the live version once again. This time it will recognize the new disk and you will have the option to install the system there.

2. After installing Kali Linux, you can boot from disk if you remove both -boot d and -cdrom kali-linux-2020.3-live-amd64.iso flags from our command.

3. You can create a Bash script (don't forget to make it executable running chmod +x script.sh in your terminal) and use it every time you want to start the virtual machine. You can tweak this script to customize your virtual machine, for example adding more RAM or CPU cores.

#!/bin/bash

qemu-system-x86_64 \
  --enable-kvm \
  -m 4G \
  -smp 4 \
  -name 'Kali Linux' \
  -hda kalidisk.qcow2

MacOS

There is a nice README that explains how to set up a macOS virtual machine using QEMU accelerated by KVM. Here is the final result of a virtual machine running macOS Catalina in dark mode: