The Compute Express Link (CXL) changes have been merged for the in-development Linux 6.18 kernel.
The headline feature of the CXL subsystem update for Linux 6.18 is mainlining Poison Injection support. CXL Poison Injection is used for testing the error handling and reliability of CXL memory devices. Via a DebugFS interface, user-space can submit physical address(es) to “poison” for checking the hardware response and software-handled errors. This is primarily useful for testing both of the CXL software and hardware handling to different behavior.
The CXL updates for Linux 6.18 also include fixing CXL access coordinates when onlining CXL memory, CXL delayed downstream port enumeration and initialization, and various other updates.
More details on the CXL changes for the Linux 6.18 kernel, which is expected to be the 2025 LTS kernel version, can be found via this merge.
