Use virt-manager as a non-root user on Linux

The priority of KVM is security and by default it limits the management access to root users. If you want to run virt-manager without being asked for sudo password, then this article is for you. We will be using a group with correct permissions to manage KVM, this enables you to grant multiple users in the system permissions to administer KVM hypervisor.

Original content from computingforgeeks.com - post 1024

In our previous guide we covered in detail the procedure of installing and configuring KVM hypervisor. With KVM installed and working, follow the steps below if you want to run Virt Manager without sudo permissions.

1) Create unix group for KVM

First check if group already exist, if not create it with commands below.

sudo getent group | grep libvirt

Some distributions may be using libvirtd.

sudo getent group | grep libvirtd

If the group does’t exist add using groupadd command.

sudo groupadd --system libvirt

2) Add users to the libvirt group

Add user to the group using the syntax.

sudo usermod -a -G libvirt <username>
newgrp libvirt

Example of adding the current user account you are logged in as.

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

Confirm that the user has been added to the group.

$ id cloudspinx
uid=1001(cloudspinx) gid=1001(cloudspinx) groups=1001(cloudspinx),986(libvirt)

3) Edit libvirtd configuration file

Open Libvirtd configuration file /etc/libvirt/libvirtd.conf for editing.

# Using vim
sudo vim /etc/libvirt/libvirtd.conf

# Using nano
sudo nano /etc/libvirt/libvirtd.conf

Find the unix_sock_group line and uncomment to define domain socket group ownership for libvirtd, (around line 85)

unix_sock_group = "libvirt"

Also assign UNIX socket permissions for the socket – we are setting R/W (around line 102)

unix_sock_rw_perms = "0770"

When done with the changes restart libvirtd service.

sudo systemctl restart libvirtd.service

Confirm service status:

$ systemctl status libvirtd.service
● libvirtd.service - Virtualization daemon
   Loaded: loaded (/usr/lib/systemd/system/libvirtd.service; enabled; vendor preset: enabled)
   Active: active (running) since Mon 2024-07-08 13:02:26 EAT; 19min ago
     Docs: man:libvirtd(8)
           https://libvirt.org
 Main PID: 104329 (libvirtd)
    Tasks: 27 (limit: 32768)
   Memory: 94.5M
   CGroup: /system.slice/libvirtd.service
           ├─  1737 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/crc.conf --leasefile-ro --dhcp-script=/usr/libexec/libvirt_leaseshelper
           ├─  1739 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/crc.conf --leasefile-ro --dhcp-script=/usr/libexec/libvirt_leaseshelper
           ├─  1815 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-ro --dhcp-script=/usr/libexec/libvirt_leaseshelper
           ├─  1816 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-ro --dhcp-script=/usr/libexec/libvirt_leaseshelper
           └─104329 /usr/sbin/libvirtd --timeout 120

Jul 08 13:02:26 kvm01.home.cloudlabske.io systemd[1]: Starting Virtualization daemon...
Jul 08 13:02:26 kvm01.home.cloudlabske.io systemd[1]: Started Virtualization daemon.
Jul 08 13:02:26 kvm01.home.cloudlabske.io dnsmasq[1815]: read /etc/hosts - 2 addresses
Jul 08 13:02:26 kvm01.home.cloudlabske.io dnsmasq[1737]: read /etc/hosts - 2 addresses
Jul 08 13:02:26 kvm01.home.cloudlabske.io dnsmasq[1737]: read /var/lib/libvirt/dnsmasq/crc.addnhosts - 0 addresses
Jul 08 13:02:26 kvm01.home.cloudlabske.io dnsmasq[1815]: read /var/lib/libvirt/dnsmasq/default.addnhosts - 0 addresses
Jul 08 13:02:26 kvm01.home.cloudlabske.io dnsmasq-dhcp[1815]: read /var/lib/libvirt/dnsmasq/default.hostsfile
Jul 08 13:02:26 kvm01.home.cloudlabske.io dnsmasq-dhcp[1737]: read /var/lib/libvirt/dnsmasq/crc.hostsfile

Launch virt-manager and test

Open your terminal and launch Virt Manager. You can also use GUI launcher.

virt-manager

You should be able to connect without any permissions being asked.

That’s all on how to allow non-root users to manage VMs on KVM using virshor virt-manager without sudo permissions.

Check more articles available on KVM.

• Using Vagrant with Libvirt on Linux.
• How to Provision VMs on KVM with Terraform
• How to Create CentOS / Fedora / RHEL VM Templates on KVM
• RHEL and CentOS Kickstart on KVM Automated Installation With virt-install

Further reading:

• Mastering KVM Virtualization
• Virtualization Essentials, 2nd Edition