Cloud Hypervisor v18.0 Released!

Posted September 9, 2021 by Cloud Hypervisor Team ‐ 2 min read

This release has been tracked through the v18.0 project.

Experimental User Device (vfio-user) support

Experimental support for running PCI devices in userspace via vfio-user has been included. This allows the use of the SPDK NVMe vfio-user controller with Cloud Hypervisor. This is enabled by --user-device on the command line.

Migration support for vhost-user devices

Devices exposed into the VM via vhost-user can now be migrated using the live migration support. This requires support from the backend however the commonly used DPDK vhost-user backend does support this.

VHDX disk image support

Images using the VHDX disk image format can now be used with Cloud Hypervisor.

Device pass through on MSHV hypervisor

When running on the MSHV hypervisor it is possible to pass through devices from the host through to the guest (e.g with --device)

AArch64 for support virtio-mem

The reference Linux kernel we recommend for using with Cloud Hypervisor now supports virtio-mem on AArch64.

Live migration on MSHV hypervisor

Live migration is now supported when running on the MSHV hypervisor including efficient tracking of dirty pages.

AArch64 CPU topology support

The CPU topology (as configured through --cpu topology=) can now be configured on AArch64 platforms and is conveyed through either ACPI or device tree.

Power button support on AArch64

Use of the ACPI power button (e.g ch-remote --api-socket=<API socket> power-button) is now supported when running on AArch64.

Notable bug fixes

  • Using two PTY outputs e.g. --serial pty --console pty now works correctly (#3012)
  • TTY input is now always sent to the correct destination (#3005)
  • The boot is no longer blocked when using a unattached PTY on the serial console (#3004)
  • Live migration is now supported on AArch64 (#3049)
  • Ensure signal handlers are run on the correct thread (#3069)


Many thanks to everyone who has contributed to our release:


See the GitHub Release for the release assets.