What are some good Xen alternatives? 5 options

Depending on use case and performance requirements, it might make sense to consider looking for a Xen alternative. We’ve compiled a list of five alternatives to Xen and included the advantages and disadvantages of each hypervisor.

The best Xen alternatives in direct comparison

KVM

KVM (Kernel-based Virtual Machine) is virtualisation software based on Linux and has been incorporated into the Linux kernel from version 2.6.20 onward. Developed by Red Hat, it can function as a type 1 hypervisor through a setup that is similar to Xen. Typically, it operates as a type 2 hypervisor though, which is why it’s commonly regarded as a hybrid hypervisor solution.

With KVM, you can host various guest systems, such as BSD (Berkeley Software Distribution), Solaris, Windows, ReactOS and macOS, making it a versatile alternative to Xen.

Integration into the Linux kernel ensures that KVM consistently receives updates for security and performance. The hypervisor offers robust security features, including combining SELinux and sVirt (secure virtualisation) to protect and isolate your virtual machines.

By deploying KVM on a supported Linux distribution such as RHEL, you can enhance its functionality. For example, you can boost system performance or facilitate resource sharing among guest systems.

VirtualBox

Originally developed by InnoTek Systemberatung GmbH in Baden-Württemberg, Germany, the Xen alternative VirtualBox has been maintained by the U.S. company Oracle since 2008. Unlike Xen, VirtualBox is a type 2 hypervisor that runs on Windows, Linux, macOS and Solaris platforms. In terms of guest systems, the application has hardly any restrictions. In addition to Windows and Linux systems, various Solaris and BSD editions can also be used as hosts. VirtualBox offers lots of flexibility when it comes to operating systems and gives you the option of desktop virtualisation, which is not possible with Xen.

VirtualBox does not, however, allow you to transfer VMs between physical hosts during live operations without experiencing downtime, resulting in less flexibility for virtual machine migration. Since users need to carry out migrations manually, the virtualisation application is less suitable for projects that require very high availability.

A clear advantage of the Oracle software is its ease of use for beginners. The graphical user interface makes managing virtual machines easy, even for beginners who may have little experience with command-line inputs like those required in Xen.

Xvisor

Like Xen, Xvisor (short for Xtensible Versatile hypervISOR) is also an open-source type 1 hypervisor that is known for its high flexibility and portability. Xvisor demonstrates its impressive versatility with the large number of architectures it supports. In addition to x86 and x86_64, supported CPU architectures include ARM and RISC-V.

The Xvisor source code can be ported to any 32- and 64-bit platforms as long as a Paged Memory Management Unit (PMMU) and a port of the GNU C compiler (GCC) are available. Although the Xen alternative primarily relies on full virtualisation, allowing numerous unmodified guest OSs, it binds the host system to a Linux distribution.

Xvisor virtualisation is efficient and saves space, partly because the software does not incorporate any security enhancements. Similar to Xen, you can enable paravirtualisation if the architecture you are using supports it.

QEMU

QEMU, short for Quick EMUlator, is a Xen alternative that can be used as an emulator or a type 2 hypervisor. As a hypervisor, QEMU achieves close to native performance by executing guest code directly on the host CPU. However, for this purpose, the virtualisation software has to use either the Xen hypervisor or the Linux KVM kernel module.

Compared to Xen, QEMU offers a much larger ecosystem and supports significantly more architectures and operating systems. For this reason, the program is suitable for a wide range of applications including development, testing and operation of legacy software.

As a type 2 hypervisor, QEMU does not have direct access to hardware resources, resulting in slightly lower performance compared to Xen. In return, however, the tool is more user-friendly thanks to its graphical user interface. In addition to a large and active community that provides regular updates, the virtualisation solution has also been integrated into many other virtualisation solutions and cloud platforms.

UTM

UTM is a virtualisation solution that can be used to emulate various operating systems on your Mac device, iPhone or iPad (iOS 11 or higher). Among other things, the software uses Apple’s hypervisor virtualisation framework to run ARM64 operating systems on devices with Apple Silicon processors, achieving almost native performance.

On older Macs with Intel processors, you can virtualise guest systems with x86 and x86_64 architecture if necessary. The hypervisor also supports various other architectures such as ARM32, MIPS, PPC and RISC-V.

This Xen alternative is an excellent choice if you want to run Windows systems on your Mac or iOS mobile device.

UTM is built on the solution we looked at in the last section, QEMU. While QEMU is very flexible and powerful, like Xen, it may pose some challenges for beginners. Due to the abundance of command-line options and flags in these two options, they are difficult to set up and configure when compared with UTM.

UTM was developed with the aim of offering users the flexibility of QEMU and at the same time, being as user-friendly as possible.