On Wed, Jan 10, 2018 at 09:27:59AM +0000, David Woodhouse wrote: > > The only question I have is if retpoline works at all on SKL (with ucode > > update); BDW needs the ucode update for retpoline to work because of the > > RSB fallback. > > As I understand it, Skylake is never getting the IBRS_ATT (all the > time) feature. That is for future CPUs only.
Ah, so then I got confused by your earlier email. So retpoline will work on SKL, but it will, like BDW need the ucode update? > I don't know why you're calling that 'IBRS=2'; are you getting confused > by Andrea's distro horridness? Yes, continuation of the nomenclature of that earlier thread. Still, point remains, do we ever need that MSR fiddling dynamic IBRS stuff now that we have retpolines? I would prefer to not have it if there is no compelling reason for it.
