diff --git a/content/en/blog/v50.1/index.md b/content/en/blog/v50.1/index.md new file mode 100644 index 0000000..0f52a84 --- /dev/null +++ b/content/en/blog/v50.1/index.md @@ -0,0 +1,31 @@ +--- +title: "Cloud Hypervisor v50.1 Released!" +date: 2026-02-20T01:21:45Z +draft: false +contributors: [Cloud Hypervisor Team] +--- +This is a point release containing security fixes and bug fixes. + +Security Fixes +-------------- + +This release fixes a security vulnerability in disk image handling. +Details can be found in [GHSA-jmr4-g2hv-mjj6](https://github.com/cloud-hypervisor/cloud-hypervisor/security/advisories/GHSA-jmr4-g2hv-mjj6). + +* A new `backing_files=on|off` option has been added to `--disk` to + explicitly control whether QCOW2 backing files are permitted. This + defaults to `off` to prevent the loading of backing files entirely. + (#7685) +* Explicit image type specification via the user interface, removing + reliance on format autodetection (#7728). +* Prevent sector-zero writes for autodetected raw images (#7728). + +Bug Fixes +--------- + +* Fix various inconsistencies in our OpenAPI specification file + (#7716, #7726) +* Fix QCOW2 thread safety for multiple virtio queues + (`num_queues > 1`) (#7661) +### Download + See the GitHub Release for the release assets. diff --git a/content/en/blog/v51.0/index.md b/content/en/blog/v51.0/index.md new file mode 100644 index 0000000..f048c6d --- /dev/null +++ b/content/en/blog/v51.0/index.md @@ -0,0 +1,135 @@ +--- +title: "Cloud Hypervisor v51.0 Released!" +date: 2026-02-20T01:34:50Z +draft: false +contributors: [Cloud Hypervisor Team] +--- +This release has been tracked in [v51.0 group](https://github.com/orgs/cloud-hypervisor/projects/6/views/6?filterQuery=release%3A%22Release+51%22) of our [roadmap project](https://github.com/orgs/cloud-hypervisor/projects/6/). + +Security Fixes +-------------- + +This release fixes a security vulnerability in disk image handling. +Details can be found in [GHSA-jmr4-g2hv-mjj6](https://github.com/cloud-hypervisor/cloud-hypervisor/security/advisories/GHSA-jmr4-g2hv-mjj6). + +* A new `backing_files=on|off` option has been added to `--disk` to + explicitly control whether QCOW2 backing files are permitted. This + defaults to `off` to prevent the loading of backing files entirely. + (#7685) +* Explicit image type specification via the user interface, removing + reliance on format autodetection (#7728). +* Prevent sector-zero writes for autodetected raw images (#7728). + +Significant QCOW2 v3 Improvements +--------------------------------- + +A large number of QCOW2 v3 specification features have been implemented: + +* RAW backing file support for QCOW2 overlays (#7570) +* Zero bit in L2 entries (#7627) +* Incompatible feature bit validation (#7612) +* Dirty bit support (#7636) +* Variable refcount widths (1 to 64-bit) (#7633) +* Corrupt bit detection and marking (#7639) +* Autoclear feature bits handling (#7648) +* Thread safety fix for multiple virtio queues (`num_queues > 1`) + (#7661) +* Correct zero-fill for reads beyond backing file size (#7678) +* Live disk resize support (#7687) + +ACPI Generic Initiator Support +------------------------------ + +ACPI Generic Initiator Affinity (SRAT Type 5) support has been added +to associate VFIO-PCI devices with dedicated memory/CPU-less NUMA +nodes. This enables the guest OS to make NUMA-aware memory allocation +decisions for device workloads. A new `device_id` parameter has been +added to `--numa` for specifying VFIO devices. (#7626) + +Block Device DISCARD and WRITE_ZEROES Support +--------------------------------------------- + +The `virtio-blk` device now supports `DISCARD` and `WRITE_ZEROES` +operations for QCOW2 and RAW image formats. This enables thin +provisioning and efficient space reclamation when guests trim +filesystems. A new `sparse=on|off` option has been added to `--disk` to +control disk space management: `sparse=on` (default) enables thin +provisioning with space reclamation, while `sparse=off` provides thick +provisioning with consistent I/O latency. (#7666) + +Notable Performance Improvements +-------------------------------- + +* Transparent Huge Pages (THP) support has been extended to cover + anonymous shared memory (`shared=on`) via `madvise`. Previously, THP + was only used for non-shared memory. (#7646) +* The `vhost-user-net` device now uses the default set of vhost-user + virtio features, including `VIRTIO_F_RING_INDIRECT_DESC`, which + provides a performance improvement. (#7653) + +MSHV Support Improvements +------------------------- + +* Optimize CPU state update after emulation by only updating special + registers when changed (#7603) +* Enable SMT for guests with `threads_per_core > 1` (#7668) +* Stub `save_data_tables()` to unblock VM pause/resume (#7692) +* Handle `GHCB_INFO_SPECIAL_DBGPRINT` VMG exit in SEV-SNP guest exit + handler (#7703) +* Fix CVM boot failure on MSHV (#7548) +* Fix CPU topology detection for multithreaded configurations (#7576) + +Notable Bug Fixes +----------------- + +* Fix VFIO device hot-remove leaving group and container file + descriptors open, preventing re-add (#7676) +* Fix snapshot restore when backing file is on read-only storage with + `shared=false` (#7674) +* Enforce `VIRTIO_BLK_F_RO` even if guest does not negotiate it + (#7705) +* Fix read-only block device FLUSH requests from OVMF preventing VMs + from booting (#7706) +* Fix vhost-user device not properly dropping unowned file descriptors + (#7679) +* Fix `vhost-user-block` `get_config` interoperability (#7617) +* Fix vsock TOCTOU race condition by copying packet header from guest + memory before processing (#7530) +* Fix vsock handling of large TX packets spanning multiple data + descriptors (#7680) +* Add `gettid()` to all seccomp filters (#7596) +* Fix MAC address parsing that wrongly allowed `+` instead of hex + characters (#7579) +* Improve UUID parse error message and `--net` fd help text (#7702) +* Fix various inconsistencies in our OpenAPI specification file + (#7716, #7726) +* Various documentation fixes (#7602, #7606) + +Contributors +------------ + +Many thanks to everyone who has contributed to our release: + +* Aastha Rawat +* Alyssa Ross +* Anatol Belski +* Anirudh Rayabharam +* Bo Chen +* Champ-Goblem +* Changyuan Lyu +* Damian Barabonkov +* Demi Marie Obenour +* Leander Kohler +* Muminul Islam +* Philipp Schuster +* Rob Bradford +* Rowen-Ye +* Saravanan D +* Stanislav Kinsburskii +* Thomas Leroy +* Wei Liu +* Yi Wang +* Zhibin Li +* stevenhorsman +### Download + See the GitHub Release for the release assets.