Cloud Hypervisor v31.0 Released!

Posted April 6, 2023 by Cloud Hypervisor Team ‐ 2 min read

This release has been tracked in our roadmap project as iteration v31.0. The following user visible changes have been made:

Update to Latest acpi_tables

Adapted to the latest acpi_tables. There has been significant API changes in the crate.

Update Reference Kernel to 6.2

Updated the recommended guest kernel version from 6.1.6 to 6.2.

Improvements on Console SIGWINCH Handler

A separate thread had been created to capture the SIGWINCH signal and resize the guest console. Now the thread is skipped if the console is not resizable.

Two completely different code paths existed for handling console resizing, one for tty and the other for pty. That makes the understanding of the console handling code unnecessarily complicated. Now the code paths are unified. Both tty and pty are supported in single SIGWINCH handler. And the new handler can works with kernel versions earlier than v5.5.

Remove Directory Support from MemoryZoneConfig::file

Setting a directory to MemoryZoneConfig::file is no longer supported.

Before this change, user can set a directory to file of the --memory-zone option. In that case, a temporary file will be created as the backing file for the mmap(2) operation. This functionality has been unnecessary since we had the native support for hugepages and allocating anonymous shared memory.

Documentation Improvements

  • Various improvements in API document
  • Improvements in Doc comments
  • Updated Slack channel information in README

Notable Bug Fixes

  • Fixed the offset setting while removing the entire mapping of vhost-user FS client.
  • Fixed the ShutdownVmm and Shutdown commands to call the correct API endpoint.


Many thanks to everyone who has contributed to our release:


See the GitHub Release for the release assets.