I started to look at the IBRS series and this thing really needs a thorough treatment with a steam blaster.
So I started that effort by integrating it proper into the existing spectre_v2 command line parsing and mitigation method selection. It's not having any of the actual IBRS bits yet and is completely untested, but I wanted to send it out before falling completely asleep so the folks still awake can take a look and comment or expand/modify. The first patch is from Boris to simplify the cpu feature bits sync after a late microcode load, but it's not yet used. I just added it for reference so people can see where this is heading. I'll continue on that tomorrow morning after picking up a few patches here and there. Applies on top of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/pti Thanks, tglx