Context: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/about/ https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/... Writes to arbitrary

Context: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/about/ https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/... Writes to arbitrary MSR are still allowed by linux, but it'll squawk a warning with the PID from what poked the MSR. What has been preventing writing to MSR is microcode updates (loaded via Linux via initram/firmware, or via the vendor in a BIOS update), such as the one(s) in response to plundervolt https://plundervolt.com/ https://plundervolt.com/ Writing to the plundervolt-related MSR was particularly helpful to undervolt a thermal-throttled laptop. So! Can either downgrade the BIOS and/or rollback the microcode that your distro is loading during boot.