Install KVM, QEMU and Virt Manager on Arch Linux / Manjaro

Here is the Complete guide on how to install KVM, QEMU and Virt Manager on Arch Linux and Manjaro. KVM is one of the most used Virtualization software in Linux World. In fact, most cloud providers use KVM as their Hypervisor of choice. Big projects including Openstack use KVM as default Virtualization tool.

In this tutorial, we’ll install KVM on Arch Linux and set Kernel modules required to automatically load at boot. We’ll also install a guest machine running CentOS 7.

Our previous tutorials on KVM include:

• Create and Configure Bridge Networking For KVM in Linux
• How To Clone and Use KVM Virtual Machine in Linux
• How to extend/increase KVM Virtual Machine (VM) disk size

Step 1: Install KVM packages

First step is installing all packages needed to run KVM:

sudo pacman -Syy
sudo reboot 
sudo pacman -S archlinux-keyring
sudo pacman -S qemu virt-manager virt-viewer dnsmasq vde2 bridge-utils openbsd-netcat

Also install ebtables  and iptables packages:

sudo pacman -S ebtables iptables

Step 2: Install libguestfs on Arch Linux / Manjaro

libguestfs is a set of tools used to access and modify virtual machine (VM) disk images. You can use this for:

• viewing and editing files inside guests
• scripting changes to VMs
• monitoring disk used/free statistics
• creating guests
• P2V
• V2V
• performing backup e.t.c

sudo pacman -S libguestfs

Step 3: Start KVM libvirt service

Once the installation is done, start and enable libvirtd service to start at boot:

sudo systemctl enable libvirtd.service
sudo systemctl start libvirtd.service

Status show it’s running:

$ systemctl status libvirtd.service
 ● libvirtd.service - Virtualization daemon
    Loaded: loaded (/usr/lib/systemd/system/libvirtd.service; enabled; vendor preset: disabled)
    Active: active (running) since Thu 2019-04-18 20:55:34 EAT; 11h ago
      Docs: man:libvirtd(8)
            https://libvirt.org
  Main PID: 646 (libvirtd)
     Tasks: 26 (limit: 32768)
    Memory: 74.0M
    CGroup: /system.slice/libvirtd.service
            ├─  646 /usr/bin/libvirtd
            ├─  754 /usr/bin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-ro --dhcp-script=/usr/lib/libvirt/libvirt_leases>
            ├─  755 /usr/bin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-ro --dhcp-script=/usr/lib/libvirt/libvirt_leases>
            ├─  777 /usr/bin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/docker-machines.conf --leasefile-ro --dhcp-script=/usr/lib/libvirt/libvir>
            ├─  778 /usr/bin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/docker-machines.conf --leasefile-ro --dhcp-script=/usr/lib/libvirt/libvir>
            ├─25924 /usr/bin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/vagrant-libvirt.conf --leasefile-ro --dhcp-script=/usr/lib/libvirt/libvir>
            ├─25925 /usr/bin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/vagrant-libvirt.conf --leasefile-ro --dhcp-script=/usr/lib/libvirt/libvir>
            ├─25959 /usr/bin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/fed290.conf --leasefile-ro --dhcp-script=/usr/lib/libvirt/libvirt_leasesh>
            └─25960 /usr/bin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/fed290.conf --leasefile-ro --dhcp-script=/usr/lib/libvirt/libvirt_leasesh>

Step 4: Enable normal user account to use KVM

Since we want to use our standard Linux user account to manage KVM, let’s configure KVM to allow this.

Open the file /etc/libvirt/libvirtd.conf for editing.

sudo pacman -S vim
sudo vim /etc/libvirt/libvirtd.conf

Set the UNIX domain socket group ownership to libvirt, (around line 85)

unix_sock_group = "libvirt"

Set the UNIX socket permissions for the R/W socket (around line 102)

unix_sock_rw_perms = "0770"

Add your user account to libvirt group.

sudo usermod -a -G libvirt $(whoami)
newgrp libvirt

Restart libvirt daemon.

sudo systemctl restart libvirtd.service

Step 5: Enable Nested Virtualization (Optional)

Nested Virtualization feature enables you to run Virtual Machines inside a VM. Enable Nested virtualization for kvm_intel / kvm_amd by enabling kernel module as shown.

### Intel Processor ###
sudo modprobe -r kvm_intel
sudo modprobe kvm_intel nested=1

### AMD Processor ###
sudo modprobe -r kvm_amd
sudo modprobe kvm_amd nested=1

To make this configuration persistent,run:

echo "options kvm-intel nested=1" | sudo tee /etc/modprobe.d/kvm-intel.conf

Confirm that Nested Virtualization is set to Yes:

### Intel Processor ###
$ systool -m kvm_intel -v | grep nested
    nested              = "Y"
    nested_early_check  = "N"
$ cat /sys/module/kvm_intel/parameters/nested 
Y

### AMD Processor ###
$ systool -m kvm_amd -v | grep nested
    nested              = "Y"
    nested_early_check  = "N"
$ cat /sys/module/kvm_amd/parameters/nested 
Y

Step 6: Using KVM on Arch Linux / Manjaro

You have successfully installed KVM, QEMU and Virt Manager on Arch Linux and Manjaro. You are now good to go. You can install a Linux or Windows OS Virtual Machine and build your study labs.