Cloud Hypervisor v19.0 Released!

Posted October 14, 2021 by Cloud Hypervisor Team ‐ 2 min read

This release has been tracked through the v19.0 project.

Improved PTY handling for serial and virtio-console

The PTY support for serial has been enhanced with improved buffering when the the PTY is not yet connected to. Using virtio-console with PTY now results in the console being resized if the PTY window is also resized.

PCI boot time optimisations

Multiple optimisations have been made to the PCI handling resulting in significant improvements in the boot time of the guest.

Improved TDX support

When using the latest TDVF firmware the ACPI tables created by the VMM are now exposed via the firmware to the guest.

Live migration enhancements

Live migration support has been enhanced to support migration with virtio-mem based memory hotplug and the virtio-balloon device now supports live migration.

virtio-mem support with vfio-user

The use of vfio-user userspaces devices can now be used in conjunction with virtio-mem based memory hotplug and unplug.

AArch64 for virtio-iommu

A paravirtualised IOMMU can now be used on the AArch64 platform.

Notable bug fixes

  • ACPI hotplugged memory is correctly restored after a live migration or snapshot/restore (#3165)
  • Multiple devices from the same IOMMU group can be passed through via VFIO (#3078 #3113)
  • Live migration with large blocks of memory was buggy due to an in issue in the underlying crate (#3157)


Many thanks to everyone who has contributed to our release:


See the GitHub Release for the release assets.