Cloud Hypervisor v40.0 Released!

Posted June 21, 2024 by Cloud Hypervisor Team ‐ 2 min read

This release has been tracked in our roadmap project as iteration v40.0. The following user visible changes have been made:

Support for Restoring File Descriptor Backed Network Devices

It is now possible to pass file descriptors over the HTTP API (and using ch-remote) when restoring to update the file descriptors for network devices. This enables snapshot & restore functionality for guests using macvtap or other file descriptor backed network devices. (#6286)

Notable Bug Fixes

  • Default values have been removed from required fields in the OpenAPI metadata (#6495)
  • The help syntax of ch-remote remove-device has been improved (#6456)
  • A double close of file descriptors has been fixed when using --serial (#6486)
  • To prevent loops a limit on the nesting level for QCOW2 backing files has been introduced (#6482)
  • Boot time performance has been improved with multiple cores by avoiding cpuid instructions and by seeding the in kernel file descriptor table (#6498, #6478)
  • L1 cache details are more likely to be propagated into the guest (#6523)
  • The default topology for guests now uses multiple cores rather than sockets (#6504)


Many thanks to everyone who has contributed to our release:


See the GitHub Release for the release assets.