How to install KVM/QEMU on Linux Mint 20.1

From time to time I want to run a virtual machine on my computer, a sandbox containing another operating system with some programs running in total isolation. Under Linux my answer for this need is a set of three components:

1. KVM – a virtualization module in the Linux kernel that allows the kernel to function as a hypervisor. (Wikipedia)
2. QEMU – a machine emulator and virtualizer that can perform hardware virtualization. It can cooperate with KVM to run virtual machines at near-native speed (Wikipedia)
3. Virtual Machine Manager – a nice GUI to use above things as simply as possible.

Problem

How prepare all above components on a fresh installation of Linux Mint 20.1?

Solution

This solution is based on the article “Install KVM Virtualization on Linux Mint 20” with my additions.

First execute following commands:

sudo apt-get install qemu-kvm libvirt-daemon-system libvirt-clients bridge-utils virt-manager
sudo adduser $USER libvirt
sudo adduser $USER kvm
sudo adduser $USER libvirt-qemu

Here the above-mentioned article claimed everything is ready and working. But it wasn’t in my case. So just restart Linux now. Then proceed with verification steps:

virsh -c qemu:///system list

The output should be:

 Id   Name   State
--------------------

Then execute:

systemctl status libvirtd.service

The output should start with following lines:

● libvirtd.service - Virtualization daemon
     Loaded: loaded (/lib/systemd/system/libvirtd.service; enabled; vendor preset: enabled)
     Active: active (running) since Wed 2021-02-03 22:54:41 CET; 31s ago

Then start Virtual Machine Manager. It should show that it is connected to KVM/QEMU. It should look like this:

Now it’s ready.