OpenBSD 8.0 Releases with 64-VM Support and Drops Loongson Architecture

OpenBSD 8.0, the 61st release of the Unix-like operating system, has been published with significant virtualization enhancements and updated software components. Developer Bryan Steele posted a summary of the release highlights on Mastodon, noting that the round version number does not indicate a radical departure from previous iterations of the project.

The new version expands the capabilities of the VMM/VMD hypervisor to support multiprocessor virtual machines with up to 64 virtual CPUs in each guest environment. On x86-64 systems, the kernel virtual memory address space has increased from 4 GB to 512 GB, a change designed to accommodate GPUs with large amounts of video random access memory.

Technical Changes and Component Updates

OpenBSD 8.0 introduces hibernation support for Arm64 machines and enables the use of CPU AES instructions for faster encrypted swap on both x86-64 and Arm64 platforms. The release includes updates to the qwx driver for Qualcomm Wi-Fi 6 hardware, improving wireless connectivity options for users with compatible network interface cards.

Software components have been upgraded to OpenSSH 10.6 and LibreSSL 4.4.0. The default C compiler is now Clang/LLVM 22, which is also used for the SPARC64 edition. However, this update comes with the significant change of dropping support for the Loongson architecture entirely, removing compatibility for that specific hardware lineage.

Security Context and Historical Background

The release of OpenBSD 8.0 follows a recent high-profile security incident involving a decades-old shared-memory bug. Researchers from California described how this flaw, when chained with a separate kernel vulnerability, allowed attackers to gain local root access. Both issues were addressed in the previous OpenBSD 7.9 release through errata 026 and 018.

Project leader Theo de Raadt forked OpenBSD from NetBSD 1.0 in 1995, with the first release occurring in July 1996. This makes version 8.0 close to the project’s 30th anniversary. According to proof-of-concept code on GitHub, the shared-memory bug existed in the original BSD codebase inherited by both OpenBSD and NetBSD, explaining the presence of a 37-year-old flaw.

What should you do?

Users running older versions of OpenBSD should verify they have applied the latest errata from version 7.9 to mitigate the recently disclosed shared-memory and kernel flaws. Administrators planning to upgrade to version 8.0 should review the hardware compatibility list, particularly if they rely on Loongson-based systems, as support has been removed.

What to do and how to stay safe: OpenBSD

• Verify that your current OpenBSD installation includes errata 026 and 018 to patch the shared-memory and kernel vulnerabilities.
• Test virtual machine workloads in a non-production environment before migrating to OpenBSD 8.0 to ensure compatibility with the new VMM/VMD hypervisor settings.
• Review hardware requirements for Arm64 and x86-64 systems to confirm support for the new hibernation and encrypted swap features.
• Monitor official OpenBSD channels for any post-release errata, as the initial list contains only four fixes for the new version.

Step-by-step guide: Mobile Device Security: How to Protect Data Beyond Passwords

General security guidance from the Threat Times newsroom. It is not confirmed advice from the organisations named in this story.

Frequently asked questions

Does OpenBSD 8.0 still support the Loongson architecture?

No, OpenBSD 8.0 drops support for the Loongson architecture, though it continues to support SPARC64 with the new Clang/LLVM 22 compiler.

What virtualization improvements are included in OpenBSD 8.0?

The VMM/VMD hypervisor now supports multiprocessor VMs with up to 64 virtual CPUs per guest, and the x86-64 kernel address space is expanded to 512 GB.

Was the recent shared-memory bug fixed in OpenBSD 8.0?

No, the shared-memory bug and associated kernel flaw were fixed in the previous release, OpenBSD 7.9, via errata 026 and 018.