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‎_posts/2025/2025-05-27-install-qemu-kvm.md‎

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---
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title: Installing Virtual Machines with QEMU KVM on Ubuntu 24
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image: /assets/img/default-banner.jpg
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author: jack
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date: 2025-05-27 20:55:00 +0800
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categories: [blog, linux]
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tags: [linux]
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math: false
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pin: false
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---
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QEMU/KVM, short for Quick Emulator, is an open-source virtualization solution that combines the emulation capabilities of QEMU with the hardware acceleration of KVM (Kernel-based Virtual Machine). QEMU is a Type 2 hypervisor that emulates virtual machines via software, but when paired with KVM—a Type 1 hypervisor—it can achieve near-native performance. Deploying QEMU/KVM on Ubuntu 24 allows you to efficiently create and manage virtual machines, making it a powerful and stable platform for development, testing, and learning.
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## Installing QEMU/KVM
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Enable the libvirtd virtualization service:
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```
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$ sudo systemctl enable libvirtd.service
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$ sudo systemctl start libvirtd.service
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```
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Install QEMU/KVM and related packages, then reboot:
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```
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$ sudo apt update
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$ sudo apt install qemu-kvm virt-manager bridge-utils
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$ sudo reboot now
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```
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To allow your user account to operate virtual machines without root privileges, you need to add your user to the following permission groups:
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- `libvirt`: Allows interaction with the libvirt daemon to create, start, pause, and manage VMs.
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- `libvirt-qemu` or `libvirt-kvm`: Grants access to QEMU/KVM backend, including VM images and virtual networks.
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```
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$ groups
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lin adm cdrom sudo dip plugdev users lpadmin libvirt
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$ sudo useradd -g $USER libvirt
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$ sudo useradd -g $USER libvirt-kvm
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```
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## Creating a Virtual Machine
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Download the ISO image for the Linux distribution you want to install. In this example, we use Ubuntu 24 Server.
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Launch the Virtual Machine Manager by running `virt-manager` in the terminal or finding it in your system’s application menu.
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![](https://raw.githubusercontent.com/blueskyson/image-host/refs/heads/master/2025/qemu-kvm-1.png)
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Click **File -> New Virtual Machine** in the top-left corner.
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In the new window, choose **Local install media (ISO image or CDROM)**, then click **Forward**.
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Select the ISO image you downloaded earlier and click **Forward**.
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Set the virtual machine name, memory size, number of CPU cores, and other settings.
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After completing the configuration, the virtual machine will automatically boot and enter the Linux installation process.
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## Configuring NAT DHCP to Assign IP Addresses to Virtual Machines
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By default, QEMU/KVM uses NAT mode for networking, and will automatically assign a random IP address (e.g., 192.168.XXX.XXX) to each virtual machine. If you want to assign a **static IP address** to a VM, you can do so by editing the `/etc/libvirt/qemu/networks/default.xml` file.
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First, check the MAC addresses of each virtual machine. For example, assume there are four virtual machines:
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![](https://raw.githubusercontent.com/blueskyson/image-host/refs/heads/master/2025/qemu-kvm-2.png)
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```
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$ virsh dumpxml vm1 | grep 'mac address'
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<mac address='52:54:00:e4:de:fb'/>
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$ virsh dumpxml vm2 | grep 'mac address'
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<mac address='52:54:00:14:67:fa'/>
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$ virsh dumpxml vm3 | grep 'mac address'
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<mac address='52:54:00:39:aa:1d'/>
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$ virsh dumpxml vm4 | grep 'mac address'
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<mac address='52:54:00:95:aa:41'/>
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```
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Check the current NAT network (usually named `default`):
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```
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$ virsh net-list
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Name State Autostart Persistent
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--------------------------------------------
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default active yes yes
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```
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Edit the `default.xml` configuration file:
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```
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$ virsh net-edit default
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```
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Or in the GUI: go to **Edit -> Preferences -> Enable XML editing**, then use **Edit -> Connection Details -> Virtual Networks -> XML** to modify the configuration.
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![](https://raw.githubusercontent.com/blueskyson/image-host/refs/heads/master/2025/qemu-kvm-3.png)
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The original `<dhcp>` block should look like this:
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```xml
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<dhcp>
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<range start="192.168.122.100" end="192.168.122.254"/>
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</dhcp>
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```
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Add <host> entries below the <range> section to define static IPs for specific MAC addresses:
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```xml
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<dhcp>
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<range start="192.168.122.2" end="192.168.122.254"/>
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<host mac="52:54:00:e4:de:fb" name="vm1" ip="192.168.122.11"/>
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<host mac="52:54:00:14:67:fa" name="vm2" ip="192.168.122.12"/>
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<host mac="52:54:00:39:aa:1d" name="vm3" ip="192.168.122.13"/>
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<host mac="52:54:00:95:aa:41" name="vm4" ip="192.168.122.14"/>
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</dhcp>
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```
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After saving and closing the file, restart the NAT network:
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```
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$ virsh net-destroy default
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$ virsh net-start default
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```
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Then reboot your virtual machines. If the OpenSSH server is installed, you can connect from your host machine via SSH like so:
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```
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$ ssh user@192.168.122.11
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```
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## References
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- [How To install QEMU KVM & VirtManager on Ubuntu Run Virtual Machines On Ubuntu](https://www.youtube.com/watch?v=4m6eHhPypWI)
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- [KVM/libvirt: How to configure static guest IP addresses on the virtualisation host](https://serverfault.com/questions/627238/kvm-libvirt-how-to-configure-static-guest-ip-addresses-on-the-virtualisation-ho)

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