What is about?

This blog is about installing and setting up KVM on Linux Mint(a Ubuntu distro), then install a Rocky Linux(a RHEL distro) VM via command line. I am referring to this blog for steps.

What is KVM?

According to the wiki, KVM - Kernel-base Virtual Machine is a free open source virtualization module in the Linux Kernel that allows the kernel to function as a hypervisor. It was merged into the mainline Linux Kernel in 2007. KVM requires a CPU with hardware virtualization extensions such as Intel VT and AMD-V.

Installing KVM

I assume you that have some understanding about Linux, shell commands, installing an Linux OS to continue on reading.

Step 1. Check CPU virtualization support

Open terminal, run the lscpu command to list CPU information. Flag “vmx” is from Intel CPUs and flag “svm” is from AMD CPUs.

lscpu | grep -E 'vmx|svm'

Step 2. Enable virtualization in BIOS/UEFI

In new computer, UEFI replaces BIOS for computer hardware bootstrap. Here my laptop is on UEFI and I can press F2 to enter into UEFI to enable CPU hardware virtualization.

You can do this by rebooting your machine and pressing keys like F2, F10 or Delete to enter into BIOS/UEFI. Different keys depend on different manufacturers.

Step 3. Install KVM packages

The main ones are libvirt a lib for KVM virtualization and virt-manager which is its GUI. In Linux Mint and other Ubuntu distros, we use the built-in apt to install packages.

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

Step 4.1. Verify KVM installation

After apt exits successfully, your system should have command virsh, run the command to verify KVM installation.

sudo virsh list --all

Expect to return without errors.

Step 4.2 Verify libvirtd daemon starting

The service libvirtd is the daemon should be starting by systemd. Verify whether it is starting

sudo systemctl status libvirtd

If not starting, run this

sudo systemctl enable libvirtd
sudo systemctl start libvirtd

Step 4.3 Verify Linux kernel module

Run this

lsmod | grep kvm

Expect to see something like “kvm_intel” if your machine is with Intel CPU.

Step 5 Add your current user to KVM and libvirt group

Your current user has to be in groups kvm and libvirt so that you are granted to manage virtual machines.

Run this

sudo usermod -aG kvm,libvirt $USER
newgrp libvirt

Command newgrp logs current user in a new group.

Step 6 Configure networking for VM

KVM connects to the network or the internet from your host OS. NAT (aka Network Address Translation) is the default one and suits for most basic setups.

Network address translation (NAT) is a method of mapping an IP address space into another by modifying network address information in the IP header of packets while they are in transit across a traffic routing device.[1] The technique was initially used to bypass the need to assign a new address to every host when a network was moved, or when the upstream Internet service provider was replaced but could not route the network’s address space. It has become a popular and essential tool in conserving global address space in the face of IPv4 address exhaustion. One Internet-routable IP address of a NAT gateway can be used for an entire private network.

To talk about NAT is another deep topic, I may separate into another blog to explain it.

NAT 
sudo virsh net-list --all

Expect to see default is active state. Default is NAT.

If not seeing active, run

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

Step 7 Launching Virtual Machine Manager

The installation includes the GUI for Virtual Machine Manager. Start it from command line

sudo virt-manager
Virt Manager

Horray! Installation accomplished!

Summary

I pause and postpone to create VM for Rocky Linux at this point as I’ve found that the blog is already too wordy. I wrap up this as the Part 1. I will write Part n for the other content.

In summary, this blog walks you through steps to install KVM on Linux Mint. Related software and packages are associated with links to extensive content in the internet. You can opt to read them if you are interested to learn more.

On rule of thumb, for linux commands, if you are using Linux, you can run man <command> that shows you comprehensive document for the command. You can learn the command from man, that is a good and convenient way.