TinyKVM is a simple, slim and specialized userspace emulator library with native performance.
TinyKVM is designed to execute regular Linux programs and also excels at request-based workloads in high-performance HTTP caches and web servers.
KVM is the most robust, battle-hardened virtualization API that exists right now. It is only 40k LOC in the kernel, and it is the foundation of the modern public cloud. TinyKVM uses only a fraction of the KVM API.
Userspace emulation means running userspace programs. You can take a regular Linux program that you just built in your terminal and run it in TinyKVM. It will have the same exact run-time, the same exact CPU features and so on.
The rule-of-thumb is thus: If you can run it locally on your machine, you can run it in TinyKVM, at the same speed.
But there are some differences:
- TinyKVM has an execution timeout feature, allowing automatic stopping of stuck programs
- TinyKVM has memory limits
- TinyKVM can fork an initialized program into hundreds of pre-initialized VMs
- TinyKVM can load programs while preferring hugepages, leading to performance gains
A very understated feature of running directly on the CPU using hardware virtualization is that you don't need fancy toolchains to build programs. This is a most surprising and welcome feature as building and working with other architectures is often a struggle.
Secondly, as CPUs evolve, so does TinyKVM. It never has to be updated, yet it will continue to run at native speeds on your CPU.
TinyKVM and VMOD-TinyKVM are released under a dual licensing model:
- Open Source License: GPL‑3.0 (see LICENSE).
- Commercial License: Available under terms controlled by Varnish Software.
For commercial licensing inquiries, please contact: compliance@varnish-software.com.
We welcome contributions! By submitting a pull request or other contribution, you agree to our Contributor License Agreement and our Code of Conduct.
For details on how to contribute, please refer to this document.
