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Cloud Hypervisor Releases Version v35.0 of Open Source Virtual Machine Monitor

Cloud Hypervisor, an open-source Virtual Machine Monitor (VMM), has announced the release of version v35.0. This VMM runs on top of the KVM hypervisor and the Microsoft Hypervisor (MSHV). The primary focus of the Cloud Hypervisor project is to enable the running of modern cloud workloads on specific, common hardware architectures. Cloud workloads, in this context, refer to those run by customers within a Cloud Service Provider. This includes modern operating systems with most I/O handled by paravirtualized devices (such as virtio), no requirement for legacy devices, and 64-bit CPUs.

Implemented in Rust and based on the Rust VMM crates, Cloud Hypervisor offers several user-visible changes and improvements in this release. Some of the notable updates include:

  • virtio-vsock Support for Linux Guest Kernel v6.3+: With the kernel version 6.3 and newer, a vsock packet can now be included in a single descriptor, rather than being split over two descriptors. The virtio-vsock implementation in Cloud Hypervisor now supports both situations.

  • User Specified Serial Number for virtio-block: A new option called serial has been added to the --block command, allowing users to specify a serial number for block devices that will be visible to the guest.

  • vCPU TSC Frequency Included in Migration State: This enhancement ensures successful migration between hosts with different TSC frequencies when the guest is running with TSC as the source of timekeeping.

In addition to these improvements, the release also includes several bug fixes, addressing issues like concurrent CPU resizing, handling of APIC EOI messages for MSHV, memory offset calculations, spell check, block device alignment, and latency counter for block devices.

The release of version v35.0 of Cloud Hypervisor is the result of contributions from various contributors, including Alyssa Ross, Anatol Belski, Bo Chen, Christian Blichmann, Jianyong Wu, Jinank Jain, Julian Stecklina, Omer Faruk Bayram, Philipp Schuster, Rob Bradford, Ruslan Mstoi, Thomas Barrett, Wei Liu, Yi Wang, and zhongbingnan.

For more details about the release and the Cloud Hypervisor project, visit the Cloud Hypervisor v35.0 release page.