* Linus Torvalds: > On Thu, Jan 4, 2018 at 9:56 AM, Tim Chen <tim.c.c...@linux.intel.com> wrote: >> >> Speculation on Skylake and later requires these patches ("dynamic IBRS") >> be used instead of retpoline[1]. > > Can somebody explain this part? > > I was assuming that retpoline would work around this issue on all uarchs. > > This seems to say "retpoline does nothing on Skylake+"
Retpoline also looks incompatible with CET, so future Intel CPUs will eventually need a different approach anyway.