Run Cloud Virtual Machines Securely and Efficiently

Cloud Hypervisor is an open source Virtual Machine Monitor (VMM) implemented in Rust that focuses on running modern, cloud workloads, with minimal hardware emulation.

Get Started

Get the source on GitHub

Secure 🔒

Minimal emulated devices and implemented in Rust to avoid many common security issues

Fast ⚡️

Boot to userspace in less than 100ms with direct kernel boot

🪟 & 🐧

Supports running modern Linux and Windows guests

Kata Containers

Supported by Kata Containers for running secure containerised workloads

Powerful REST API

Programmatically control the lifecyle of the VM using an HTTP API


Minimal memory overhead for dense deployments

Cross platform

Runs on both x86-64 and aarch64

Broad device support

Support for wide range of paravirtualised devices and physical device passthrough

Live migration

Migrate VMs from one host to another without interruption

Get Involved:

Cloud Hypervisor is governed openly as part of the Linux Foundation and supported by multiple organisations:

  • Alibaba
  • AMD
  • Ampere
  • ARM
  • ByteDance
  • Intel
  • Microsoft
  • Tencent Cloud

Join our Slack community: Invite

Participate in our community activities: Slack channel

Check out and participate in our roadmap on GitHub

For full details of our governance model please see our community repository on GitHub and our founding charter.

For bug reports please use GitHub isssues; for broader community discussions please use our mailing list

Latest news from Cloud Hypervisor project:

Cloud Hypervisor v36.0 Released!

Posted November 2, 2023 by Cloud Hypervisor Team ‐ 2 min read

This release has been tracked in our roadmap project as iteration v36.0. The following user visible changes have been made:

Command Line Changes

We switched back to use the clap crate to create our command line, since the argh crate is barely maintained. There were several syntax changes:

  • All --option value commands now are --option=value.
  • The --disk DISK1 --disk DISK2 command now is --disk DISK1 DISK2.
  • The -v -v -vcommand now is -vvv.

Note: the released binary size increased around 0.3M due to this change.

Enabled Features Reported via API Endpoint and CLI

Now the enabled (Cargo) features of the running Cloud Hypervisor instance can be queried via API endpoint (/ and CLI (--version -v).

NUMA Support for PCI segments

The --numa command is augmented with a new option pci_segment=, so that users can define the relationship between PCI segments and NUMA nodes. Examples can be found from the memory documentation

CPU Topology Support on AMD Platforms

Now the CPU topology on x86_64 platforms supports multiple vendors.

Unix Socket Backend for Serial Port

The --serial command is augmented with a new option socket=, allowing users to access the serial port using a Unix socket.

AIO Backend for Block Devices

An AIO backend is added for virtio-block devices to improve block device performance when the io_uring feature is not supported by the host Operating System.

Documentation Improvements

Notable Bug Fixes

  • Fix a deadlock when TDX is enabled (#5845)
  • Only advertise AMX feature bits to guest when the AMX cpu feature is enabled (#5834)
  • Correct default value for vCPU topology on AArch64 (#5893)


Many thanks to everyone who has contributed to our release:


See the GitHub Release for the release assets.