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

Slim

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 v47.0 Released!

Posted July 22, 2025 by Cloud Hypervisor Team ‐ 1 min read

This release has been tracked in v47.0 group of our roadmap project.

Block Device Error Reporting to the Guest

Instead of exiting on I/O errors, the virtio-block device now reports errors to the guest using VIRTIO_BLK_S_IOERR. It improves the user experience particularly when the guest rootfs is not backed by the affected block device. (#7107)

Nice Error Messages on Exit

We now have the chain of errors being reported and printed nicely, when Cloud Hypervisor or ch-remote exits on errors. (#7066)

Alphabetically Sorted CLI Options for ch-remote

To improve readability, ch-remote now prints help information in alphabetical order. (#7130)

Notable Bug Fixes

  • Error out early when block device serial is too long (#7124)
  • Fix partial commands being discarded for virtio-vsock (#7195)
  • Disable the broken interrupt support for the rtc_pl031 device to prevent spurious guest interrupts (#7199)

Deprecations

  • A default IP (192.168.249.1) and mask (255.255.255.0) are currently assigned to the virtio-net device if no value is specified by users. Such behavior is now deprecated. Users of this behavior will receive a warning message and should make adjustments. The behavior will be removed in two release cycles (v49.0).

Download

See the GitHub Release for the release assets.