Virtualization Sneak Peek
Core Technology
Ever wondered what's happening inside a virtual machine? Join us for an exciting tour into virtualization deep waters.
Today most of us enjoy the benefits of virtualization. With hardware support that finally came to x86 a decade ago and powerful open source hypervisors (also called virtual machine managers), such as VirtualBox or KVM, it's pretty straightforward to run Windows alongside Linux or share a single physical server between a dozen of tenants. In early 2000, to give a new Linux distro a try, you'd install it on a separate hard disk or perhaps run it directly from the CD. Now, you can just boot a virtual machine (VM) from the downloaded ISO image and have fun while reading your friends' tweets.
Yet virtualization internals is still a hairy topic that you may not have a complete picture of. In Linux, Qemu/KVM is the de facto standard tool – or tools (Figure 1). These two have quite a different history but are now seen together more often than not. What's the reason? How does Qemu interact with KVM (and vice versa) to keep your VMs running? In this Core Tech, we'll build a big picture of how an x86 hypervisor operates internally. Qemu, however, is a large and complex project, so we'll dissect a lighter alternative instead: kvmtool. It is simpler yet still real-world and functional, so you may find it useful in your virtualization scenarios.
A Need for Qemu (or Something)
KVM stands for Kernel-based Virtual Machine, so why is there a userspace part in the first place? To answer this question, we need to learn a little bit about how virtualization works in x86.
[...]
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
US / Canada
UK / Australia
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.
News
-
System76 Releases COSMIC Alpha 7
With scores of bug fixes and a really cool workspaces feature, COSMIC is looking to soon migrate from alpha to beta.
-
OpenMandriva Lx 6.0 Available for Installation
The latest release of OpenMandriva has arrived with a new kernel, an updated Plasma desktop, and a server edition.
-
TrueNAS 25.04 Arrives with Thousands of Changes
One of the most popular Linux-based NAS solutions has rolled out the latest edition, based on Ubuntu 25.04.
-
Fedora 42 Available with Two New Spins
The latest release from the Fedora Project includes the usual updates, a new kernel, an official KDE Plasma spin, and a new System76 spin.
-
So Long, ArcoLinux
The ArcoLinux distribution is the latest Linux distribution to shut down.
-
What Open Source Pros Look for in a Job Role
Learn what professionals in technical and non-technical roles say is most important when seeking a new position.
-
Asahi Linux Runs into Issues with M4 Support
Due to Apple Silicon changes, the Asahi Linux project is at odds with adding support for the M4 chips.
-
Plasma 6.3.4 Now Available
Although not a major release, Plasma 6.3.4 does fix some bugs and offer a subtle change for the Plasma sidebar.
-
Linux Kernel 6.15 First Release Candidate Now Available
Linux Torvalds has announced that the release candidate for the final release of the Linux 6.15 series is now available.
-
Akamai Will Host kernel.org
The organization dedicated to cloud-based solutions has agreed to host kernel.org to deliver long-term stability for the development team.