RISC-V Enabling Generic CPU Vulnerabilities Reporting

While RISC-V processors don't need to worry about Meltdown and Spectre or have any other severe CPU vulnerabilities at the moment, with the upcoming Linux 6.12 kernel the RISC-V code is set to enable the generic CPU vulnerabilities support.

The generic CPU vulnerabilities support reports the various vulnerabilities and whether the running system/CPU is affected by the vulnerabilities and if so the mitigation status. This is conveniently exposed under /sys/devices/system/cpu/vulnerabilities across x86/x86_64, ARM, AArch64, and other architectures. But so far hasn't been exposed under RISC-V.

As RISC-V adoption rises there will likely be more security researchers poking at RISC-V processors in looking for security vulnerabilities. There's been some hardware/implementation specific ones already like the recent GhostWrite vulnerability. So with time it's pretty inevitable that some security issues for RISC-V needing software mitigations will come to light.

Plus enabling the generic CPU vulnerabilities support now will at least make it clear to users that they are not affected by the current batch of CPU vulnerabilities. "Not affected" will be conveyed to the users when running Linux 5.12+ with the current vulnerabilities exposed under this generic CPU vulnerability reporting.

The patch has made it into RISC-V's "for-next" Git branch this week and thus destined for the upcoming Linux 6.12 merge window barring any last minute change of course.