Use case · Virtualisation
KVM virtualisation
KVM is the virtualisation technology built into the Linux kernel, turning Linux into a hypervisor that runs virtual machines with near-native performance through hardware-assisted virtualisation. It is the open-source foundation many platforms build on. Running it on dedicated bare metal gives full performance and control; self-hosting on EU infrastructure keeps virtualised workloads sovereign.
Key points
- KVM is the virtualisation technology built into the Linux kernel.
- Hardware-assisted virtualisation gives KVM virtual machines near-native performance.
- KVM is usually used with QEMU and managed through libvirt.
- It's the open-source foundation many virtualisation platforms and clouds build on.
- Running KVM on dedicated bare metal in the EU keeps virtualised workloads sovereign.
What is KVM, and why host it?
KVM, the Kernel-based Virtual Machine, is the virtualisation technology built into the Linux kernel, which turns a Linux system into a hypervisor able to run virtual machines. Rather than being a separate product, KVM is part of Linux itself, so a Linux server with KVM can run virtual machines directly, each an isolated system running its own operating system. KVM is the open-source virtualisation foundation that a great deal of virtualisation is built on — many virtualisation platforms and cloud providers use KVM underneath — making it one of the most important virtualisation technologies in use.
Hosting KVM means running it on a capable server, where Linux with KVM virtualises the hardware to run virtual machines on it. The server needs the compute, memory, and storage for the virtual machines it will run, and KVM runs on the hardware to host them. Organisations use KVM directly when they want virtualisation at the level of the technology itself, or to build their own virtualisation on the open-source foundation, rather than through a higher-level platform. This page focuses on KVM as the virtualisation technology; Proxmox, a platform built on KVM, is covered on its own page, while what follows attends to KVM itself.
How KVM works: hardware-assisted virtualisation
KVM achieves near-native performance by using the hardware virtualisation features built into modern processors, rather than emulating hardware in software. Processors from Intel and AMD include virtualisation extensions that let virtual machines run their instructions largely directly on the processor, with the hypervisor involved mainly where needed, so KVM virtual machines run at close to the speed of the physical hardware. This hardware-assisted approach is why KVM performs well — the overhead of virtualisation is modest, because the processor's own features do much of the work of running the virtual machines efficiently.
This near-native performance makes KVM suitable for demanding virtualised workloads, where the overhead of virtualisation must be low. Because KVM leans on the processor's virtualisation features, its virtual machines get performance close to running on the hardware directly, so workloads that need strong performance can run virtualised under KVM without losing much to the virtualisation. Realising this performance depends on the processor's virtualisation features, which modern server processors provide. We provide servers with processors whose virtualisation features KVM uses, so that KVM virtual machines run with the near-native performance hardware-assisted virtualisation gives, suiting KVM to demanding virtualised workloads.
KVM, QEMU, and libvirt: the stack
KVM is usually used together with QEMU and managed through libvirt, which together form the common stack for running virtual machines with KVM. KVM provides the core virtualisation in the kernel; QEMU provides the emulation of the devices a virtual machine needs and works with KVM to run the machines; and libvirt provides a management layer — an interface and tools for defining, starting, and managing the virtual machines. This combination is the standard way KVM virtualisation is run, with each part playing its role in running and managing the virtual machines.
Understanding this stack clarifies what running KVM involves: the kernel's KVM, QEMU running the machines, and libvirt managing them, with tools that let virtual machines be created and controlled. Managing KVM directly through this stack gives fine control over the virtualisation, at a lower level than a higher-level platform provides. For those who want that control, or to build on the KVM stack, running it directly suits. We host the infrastructure to run the KVM stack — servers where KVM, QEMU, and libvirt run virtual machines — so that organisations wanting to run KVM directly have capable hardware for it, with the control that managing virtualisation at this level gives.
KVM directly, or a platform built on it?
It is worth being clear about the choice between running KVM directly and using a platform such as Proxmox that is built on KVM, since they suit different needs. KVM is the underlying virtualisation technology; platforms like Proxmox add a management layer on top — a web interface, clustering, high availability, and more — making virtualisation easier to run without working at the level of the KVM stack directly. Running KVM directly, through libvirt and its tools, gives fine, low-level control and suits those who want it or are building their own virtualisation; using a platform gives convenience and higher-level features.
Neither is simply better; the right choice depends on what you want. Those who want a managed, full-featured virtualisation experience with a web interface and clustering often prefer a platform like Proxmox, which is built on KVM and adds these; those who want low-level control, are integrating KVM into their own systems, or prefer to run the KVM stack directly may run KVM itself. We host the dedicated infrastructure for both — running KVM directly, or running a platform like Proxmox built on it — and will not push one over the other. We provide capable bare-metal servers for KVM virtualisation however you choose to run it, whether directly or through a platform, matching the infrastructure to how you want to virtualise.
Bare metal, performance, and isolation
KVM runs on bare metal — a Linux server with KVM is the hypervisor on the hardware — which gives its virtual machines the hardware's full performance without an additional virtualisation layer beneath. Because KVM turns the physical Linux server into the hypervisor, running directly on the hardware, there is no other virtualisation layer between KVM and the metal, so the virtual machines get the hardware's performance mediated only by KVM's efficient, hardware-assisted virtualisation. This is how KVM achieves its near-native performance in practice: running on dedicated hardware as the hypervisor, not on top of another virtualisation layer.
KVM virtual machines are also well isolated, each running as a separate virtual machine with its own operating system, which gives strong separation between workloads. Each KVM virtual machine is an isolated system, so workloads on different virtual machines are well separated, which matters for security and for running independent workloads on shared hardware. This isolation, combined with near-native performance, makes KVM suitable for running multiple workloads on a server with both good performance and strong separation. We host KVM on dedicated bare-metal servers, so that its virtual machines run with the full performance and strong isolation KVM provides, on hardware dedicated to the organisation running them.
Self-hosted virtualisation and sovereignty
Running KVM on dedicated infrastructure gives self-hosted virtualisation under an organisation's control, and on EU infrastructure, sovereignty over the virtualised workloads and their data. The virtual machines KVM runs hold the organisation's workloads and data, so where the KVM host runs governs them. Being open-source and part of Linux, KVM involves no licensing cost for the virtualisation technology, so self-hosting it is economical, and it gives full control over the virtualisation. Self-hosting on infrastructure the organisation controls keeps the virtual machines and their data in its hands.
Self-hosting KVM on EU infrastructure adds European sovereignty. VV Internet Hosting is incorporated in the Netherlands, within the EU, so KVM virtualisation hosted with us runs under European jurisdiction and outside the direct reach of the US CLOUD Act, keeping the virtual machines and their data under European law. For organisations running virtualised workloads whose data should stay sovereign, self-hosting KVM in the EU keeps it under European law and on controlled infrastructure. The combination — open-source virtualisation with no licensing cost, self-hosted with full control and European sovereignty — suits organisations wanting to run virtualisation on their own terms and under European jurisdiction.
Where VV Internet Hosting fits — and where it does not
We host dedicated bare-metal servers for KVM virtualisation: capable hardware with processors whose virtualisation features KVM uses, sized for the virtual machines an organisation will run, in EU datacenters under European jurisdiction. This suits organisations running self-hosted KVM virtualisation — whether directly through the KVM stack or via a platform built on it — that want the near-native performance and strong isolation KVM provides, open-source virtualisation without licensing cost, full control, and European sovereignty. For that, we are a strong fit, and we will size the server to the virtualised workloads.
We are clear about our limits. We provide the dedicated bare-metal hardware KVM runs on; we do not operate the virtualisation for you as a managed service, nor manage your virtual machines — you run KVM, directly or through a platform, on the hardware we provide. If you want a fully managed virtualisation service, that is a different offering. We are the dedicated, sovereign bare-metal infrastructure on which you run KVM virtualisation — suited to those who want the performance, control, and European sovereignty of running their own virtualisation on hardware they command. If self-hosting KVM fits your needs, we can host the hardware for it well.
Related use cases
Questions
KVM, answered plainly
Common questions about hosting for KVM.
What is KVM?
The Kernel-based Virtual Machine — the virtualisation technology built into the Linux kernel, which turns a Linux system into a hypervisor able to run virtual machines. It's part of Linux itself, open-source, and the foundation a great deal of virtualisation is built on, since many virtualisation platforms and cloud providers use KVM underneath.
Why does KVM perform well?
Because it uses the hardware virtualisation features built into modern Intel and AMD processors, rather than emulating hardware in software. These let virtual machines run their instructions largely directly on the processor, with the hypervisor involved mainly where needed — so KVM virtual machines run at close to the speed of the physical hardware, with modest virtualisation overhead.
Should I run KVM directly or use a platform like Proxmox?
It depends on what you want. KVM is the underlying technology; platforms like Proxmox add a management layer — web interface, clustering, high availability — on top of KVM. Running KVM directly gives fine, low-level control and suits those building their own virtualisation; a platform gives convenience and higher-level features. Neither is simply better. We host infrastructure for both.
Planning KVM infrastructure?
We host dedicated, EU-sovereign infrastructure sized to your workload — and we will tell you plainly when something else fits better. Tell us what you're building.