Re: [RFC 09/10] x86/enter: Create macros to restrict/unrestrict Indirect Branch Speculation

From: Andi Kleen
Date: Tue Jan 23 2018 - 17:50:12 EST


> Not sure. Maybe to start, the answer might be to allow it to be set for
> the ultra-paranoid, but in general don't enable it by default. Having it
> enabled would be an alternative to someone deciding to disable SMT, since
> that would have even more of a performance impact.

I agree. A reasonable strategy would be to only enable it for
processes that have dumpable disabled. This should be already set for
high value processes like GPG, and allows others to opt-in if
they need to.

-Andi