Be notified of new releases
Create your free GitHub account today to subscribe to this repository for new releases and build software alongside 40 million developers.Sign up
This release has been tracked through the 0.2.0 project.
cloud-hypervisor version 0.2.0 include:
Network device offloading
As part of our general effort to offload paravirtualized I/O to external
processes, we added support for
vhost-user-net backends. This
cloud-hypervisor users to plug a
vhost-user based networking device
(e.g. DPDK) into the VMM as their virtio network backend.
Minimal hardware-reduced ACPI
In order to properly implement and guest reset and shutdown, we implemented
a minimal version of the hardware-reduced ACPI specification. Together with
a tiny I/O port based ACPI device, this allows
cloud-hypervisor guests to
cleanly reboot and shutdown.
The ACPI implementation is a
cloud-hypervisor build time option that is
enabled by default.
Debug I/O port
Based on the Firecracker idea of using a dedicated I/O port to measure guest
boot times, we added support for logging guest events through the
PC debug port. This allows, among other things, for granular guest boot time
measurements. See our debug port documentation
for more details.
Improved direct device assignment
We fixed a major performance issue with our initial VFIO implementation: When
enabling VT-d through the KVM and VFIO APIs, our guest memory writes and reads
were (in many cases) not cached. After correctly tagging the guest memory from
cloud-hypervisor we're now able to reach the expected performance from
directly assigned devices.
Improved shared filesystem
Ubuntu bionic based CI
Thanks to our simple KVM firmware
improvements, we are now able to boot Ubuntu bionic images. We added those to
our CI pipeline.
This release has been tracked through the 0.1.0 project.
cloud-hypervisor version 0.1.0 include:
We added support for the virtio-fs shared file
system, allowing for an efficient and reliable way of sharing a filesystem
between the host and the
See our filesystem sharing
documentation for more details on how to use virtio-fs with
Initial direct device assignment support
VFIO (Virtual Function I/O) is a kernel framework that exposes direct device
access to userspace.
cloud-hypervisor uses VFIO to directly assign host
physical devices into its guest.
See our VFIO
documentation for more detail on how to directly assign host devices to
cloud-hypervisor supports a so-called split IRQ chip implementation by
implementing support for the IOAPIC.
By moving part of the IRQ chip implementation from kernel space to user space,
the IRQ chip emulation does not always run in a fully privileged mode.
Virtual persistent memory
virtio-pmem implementation emulates a virtual persistent memory device
cloud-hypervisor can e.g. boot from. Booting from a
allows to bypass the guest page cache and improve the guest memory footprint.
Linux kernel bzImage
cloud-hypervisor linux kernel loader now supports direct kernel boot from
bzImage kernel images, which is usually the format that Linux distributions
use to ship their kernels. For example, this allows for booting from the host
distribution kernel image.
Console over virtio
cloud-hypervisor now exposes a
virtio-console device to the guest. Although
using this device as a guest console can potentially cut some early boot
messages, it can reduce the guest boot time and provides a complete console
virtio-console device is enabled by default for the guest console.
Switching back to the legacy serial port is done by selecting
--serial tty --console off from the command line.
We now run all unit tests from all our crates directly from our CI.
Integration tests parallelization
The CI cycle run time has been significantly reduced by refactoring our
integration tests; allowing them to all be run in parallel.