On Tue, May 3, 2016 at 2:28 PM, Dave Hansen <dave.han...@intel.com> wrote: >> >> So we won't init MPX on those... > > Yes, and as long as such a processor doesn't exist today and never > exists in the future or the folks that buy such a processor truly don't > care about MPX, that's fine to do. I'm just a bit nervous about the > whole "never exists in the future" part.
I don't think we need to care. If a CPU doesn't support SMEP, there really is no reason for us to ever support MPX either. It's not like there is a clamoring for MPX support in the first place (have you ever heard of anybody actually asking for or using it?), and quite frankly, it's a _lot_ more complicated from a CPU core side than SMEP (which is trivial). So if Intel ever releases a CPU with MPX but without SMEP, nobody will ever care about the MPX part being useless. Linus