The RISC-V CPU architecture feature updates have now been submitted and merged for the nearly-over Linux 6.14 merge window.
Most notable this cycle on the RISC-V architecture side is adding support for the T-Head Vector Extensions. The Linux kernel now supports exposing these T-Head Vector Extensions to user-space on systems implementing support for them.
The XuanTie XTheadVector extension is a non-standard, non-conforming extension for adding 32 vector registers and 6 unprivileged CSRs. XTHeadVector is derived from the RISC-V Vector 0.7.1 extension. The patches working out this T-Head Vector Extensions support has been in the works the past number of months but now mainlined.
Linux 6.14 also adds mitigations for the GhostWrite vulnerability… The vulnerability affects the XTHeadVector instruction set. The mitigation is disabling this newly-added support. GhostWrite was announced back in August as one of the first notable RISC-V CPU vulnerabilities.
More details on all of the Linux 6.14 RISC-V changes via this pull.
