As I understand the microcode updates get installed by Linux distros and Windows by updates. Microcodes are loaded by the CPU at every boot. The question is, h

As I understand the microcode updates get installed by Linux distros and Windows by updates. Microcodes are loaded by the CPU at every boot. The question is, how can one check if the CPU already got the microcode update? Can a OS running inside a VM (over Intel VT ring-1) patch the CPU's microcode? (e.g. Linux host, and Win guest patches CPU's microcode) Nothing seems impossible anymore.