July 2024 Update on Instability Reports on Intel Core Processors
community.intel.comIt astounds me that CPUs can be patched. Can anyone comment on how that works?
This explains it well: https://wiki.archlinux.org/title/Microcode
to be slightly facetious, x86 machine code is an interpreted language
That's more than just slightly facetious. In a modern x86 CPU, the bulk of instructions are translated to micro-ops by fixed-function logic, and the micro-ops are executed directly. That's very far from interpretation.
Some instructions (legacy or more complex instructions, especially the ones you'd find in OS code) are implemented by microcode, and that microcode can be patched.
Microcode also plays a role during CPU initialization, which is when configuration registers are set (which may disable some functionality that turns out to be buggy). Or, as in this case, in power management.