On Sun, Jan 21, 2018 at 2:00 PM, David Woodhouse <dwmw2@xxxxxxxxxxxxx> wrote: >> >> The patches do things like add the garbage MSR writes to the kernel >> entry/exit points. That's insane. That says "we're trying to protect >> the kernel". We already have retpoline there, with less overhead. > > You're looking at IBRS usage, not IBPB. They are different things. Ehh. Odd intel naming detail. If you look at this series, it very much does that kernel entry/exit stuff. It was patch 10/10, iirc. In fact, the patch I was replying to was explicitly setting that garbage up. And I really don't want to see these garbage patches just mindlessly sent around. Linus