8.9 KiB
v0.3.0
This release has been tracked through the 0.3.0 project.
Highlights for cloud-hypervisor version 0.3.0 include:
Block device offloading
We continue to work on offloading paravirtualized I/O to external processes,
and we added support for
vhost-user-blk backends.
This enables cloud-hypervisor users to plug a vhost-user based block device
like SPDK) into the VMM as their paravirtualized storage
backend.
Network device backend
The previous release provided support for vhost-user-net backends. Now we also provide a TAP based vhost-user-net backend, implemented in Rust. Together with the vhost-user-net device implementation, this will eventually become the Cloud Hypervisor default paravirtualized networking architecture.
Virtual sockets
In order to more efficiently and securely communicate between host and guest, we added an hybrid implementation of the VSOCK socket address family over virtio. Credits go to the Firecracker project as our implementation is a copy of theirs.
HTTP based API
In anticipation of the need to support asynchronous operations to Cloud Hypervisor guests (e.g. resources hotplug and guest migration), we added a HTTP based API to the VMM. The API will be more extensively documented during the next release cycle.
Memory mapped virtio transport
In order to support potential PCI-free use cases, we added support for the virtio MMIO transport layer. This will allow us to support simple, minimal guest configurations that do not require a PCI bus emulation.
Paravirtualized IOMMU
As we want to improve our nested guests support, we added support for exposing a paravirtualized IOMMU device through virtio. This allows for a safer nested virtio and directly assigned devices support.
To add the IOMMU support, we had to make some CLI changes for Cloud Hypervisor
users to be able to specify if devices had to be handled through this virtual
IOMMU or not. In particular, the --disk option now expects disk paths to be
prefixed with a path= string, and supports an optional iommu=[on|off]
setting.
Ubuntu 19.10
With the latest hypervisor firmware, we can now support the latest Ubuntu 19.10 (Eoan Ermine) cloud images.
Large memory guests
After simplifying and changing our guest address space handling, we can now support guests with large amount of memory (more than 64GB).
v0.2.0
This release has been tracked through the 0.2.0 project.
Highlights for 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
enables 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 0x80 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
We added shared memory region with DAX support to our virtio-fs shared file system. This provides better shared filesystem IO performance with a smaller guest memory footprint.
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.
v0.1.0
This release has been tracked through the 0.1.0 project.
Highlights for cloud-hypervisor version 0.1.0 include:
Shared filesystem
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 cloud-hypervisor guest.
See our filesystem sharing
documentation for more details on how to use virtio-fs with cloud-hypervisor.
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 guests.
Userspace IOAPIC
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
The virtio-pmem implementation emulates a virtual persistent memory device
that cloud-hypervisor can e.g. boot from. Booting from a virtio-pmem device
allows to bypass the guest page cache and improve the guest memory footprint.
Linux kernel bzImage
The 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
implementation.
The 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.
Unit testing
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.