QEMU/KVM Virtualization Setup Guide

Description:: This guide walks through the process of setting up QEMU and KVM on Linux.
Reviewed:: This document was last reviewed on 8/16/2025.
Copyright:: This document has been placed in the public domain.

QEMU (short for Quick Emulator) is a free and open source virtualization and emulation software. KVM is a virtualization layer built into Linux, which comes with many benefits like near instant performance and better networking support.

Prerequisites

A Debian-based Linux distribution
Root access
Check your CPU, it SHOULD support virtualization technology. To do this, run this command:
```
grep -E --color=auto 'vmx|svm' /proc/cpuinfo
```
If there is no output to the command, your CPU does NOT support it, which means performance will be worse, OR that you forgot to enable it in the BIOS.
An ISO image for an operating system you wish to virtualize, you can grab this at any time, make sure it's on your main partition.

Step 1: Update and Install Dependencies

sudo apt update
sudo apt install qemu-kvm libvirt-daemon-system libvirt-clients bridge-utils virt-manager

Step 2: Add Your User to the LibVirt Group

sudo usermod -aG libvirt $(whoami)
sudo usermod -aG kvm $(whoami)

Step 3: Start the Daemon

sudo systemctl enable --now libvirtd

Step 4: Start the Networking Stack

sudo virsh net-start default
sudo virsh net-autostart default

Step 5: Edit the libvirtd.conf File

sudo nano /etc/libvirt/libvirtd.conf

Then uncomment these lines:

unix_sock_group = "libvirt"
unix_sock_rw_perms = "0770"

Step 6: Install dmidecode

sudo apt install dmidecode

Step 7: Restart

sudo reboot now

Great! Now it should be working.

Now look in the apps list for a generic / dated looking app named "Virtual Machine Manager" and open it.

Creating a Virtual Machine

Starting the VM Creation Process

To do this, click the button in the top left that looks like a monitor. You'll see something like this. Click Forward.

Selecting Your ISO

Now, you will be presented with an option to select a drive, click Browse then Desktop. Select your ISO, and click Choose Volume.

Operating System Configuration

Now, make sure to uncheck automatic OS detection and select "Generic Linux 2024" which should autofill from the dropdown. Now click Forward.

Memory and CPU Configuration

Give it memory and CPU cores. It'll tell you in small text below each how much is available on your hardware, I recommend no more than 70% of your total system resources.

Storage Configuration

Now you might want a storage disk. If you do, select its size, and make sure the checkbox above is checked. Then click Forward.

Finalizing VM Setup

Now give it a name and hit Configure before running.

To start your VM, click the play icon in the top left and then a window should pop up with its display.

Configuring Graphics and Display

Go to Video Virtio and check the box for 3D acceleration.
Go to Display Spice and set Listen Type to None, then check the box for OpenGL.
Now hit Apply and then Begin Installation in the top left.

The VM should start (if not, hit the play button), and you can enjoy your brand new VM!

Improve Your Experience

Display Settings

Once you have your VM running, you should see a top bar with buttons.

Hover over View > Scale Display and set it to Always. This will fix the resolution mismatch.
Hover over View and uncheck Toolbar because it's entirely redundant. All of its settings can be accessed by hovering over Virtual Machine and selecting one of the options.

Enjoy!

Finished!

Your QEMU/KVM virtualization environment is now ready for use. You can create additional virtual machines following the same process, and experiment with different operating systems in a safe, isolated environment.