Following the [1]Windows Subsystem for Linux 3.0.2 release with support for running WSL2 now on very large servers and also experimental sparse VHD storage support, Microsoft has now released a new version of the WSL2 Linux kernel as their downstream kernel configuration tailored for WSL2 usage.

Microsoft's WSL2 Linux kernel continues to be a modified copy of the current Linux 6.18 LTS kernel. The new linux-msft-wsl-6.18.54.1 kernel release has updated against the upstream Linux 6.18.54 release for incorporating all of the latest bug/security fixes. Plus it's pulled in and updated a number of the patches it carries for working optimally in the WSL2 confines.

One of the new features of this kernel release is native fence sharing for DXGKRNL, Microsoft's out-of-tree kernel driver used for the DirectX graphics support. The DXGKRNL native fence sharing support is described in [2]this patch as:

"Native fence create/open now use the global vmbus channel with the channel lock held, and return the host global sync object via an explicit out-parameter instead of overloading device_handle, so the guest device handle is preserved for later open. Copy results to user-mode before publishing the handle so a failed copy_to_user cannot leave a handle user-mode can still see. Drop the extra kref_get after hmgrtable_assign_handle to match dxgkio_create_sync_object refcounting."

The linux-msft-wsl-6.18.54.1 kernel also re-enables Direct Rendering Manager (DRM) and VGEM kernel support, PPP support is restored, ISO9660 support is now built-in rather than as a kernel module, and BPF LSM support is enabled by default.

More details on the updated WSL2 Linux kernel flavor via [3]GitHub .



[1] https://www.phoronix.com/news/Microsoft-WSL-3.0.2

[2] https://github.com/microsoft/WSL2-Linux-Kernel/commit/5cf9490c151001504dc61136137469d9ba4a69e1

[3] https://github.com/microsoft/WSL2-Linux-Kernel/releases/tag/linux-msft-wsl-6.18.54.1