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 v35.0 Released!

Posted September 21, 2023 by Cloud Hypervisor Team ‐ 2 min read

This release has been tracked in our roadmap project as iteration v35.0. The following user visible changes have been made:

virtio-vsock Support for Linux Guest Kernel v6.3+

Since kernel v6.3, a vsock packet can be included in a single descriptor, instead of being split over two descriptors. Our virtio-vsock implementation now support both situations.

User Specified Serial Number for virtio-block

A new option serial is added to the --block command that allows users to specify a serial number for block devices which will be guest visible.

vCPU TSC Frequency Included in Migration State

This ensures migration works correctly between hosts that have different TSC frequencies if the guest is running with TSC as the source of timekeeping.

Notable Bug Fixes

  • Disallow concurrent CPU resizing (#5668)
  • Handle APIC EOI message for MSHV (#5681)
  • Use wrapping add for memory offset from instruction emulator (#5719)
  • Add global spell check via the ‘typos’ GitHub action (#5720)
  • Ensure probing reads are block size aligned (#5727)
  • Multiple bug fixes around the latency counter for block devices (#5712, #5750, #5762, #5763)
  • Replace unsound static mut with once_cell (#5772)


Many thanks to everyone who has contributed to our release:


See the GitHub Release for the release assets.