On 01/09/2018 05:06 PM, Thomas Gleixner wrote: > This is for the case where we need to set feature flags late, like, for > example, after late microcode patch has been loaded which has enabled > new CPUID bits. > > This has no effect on alternatives patching.
In other words, if you use late microcode loading for getting IBRS, you don't get ALTERNATIVE patching and its benefits? I'll also profess some microcode ignorance here. Is "late microcode patching" *all* of the stuff we do from the OS, or do we have early and late Linux loading in addition to what the BIOS can do?
