4 ms·
Yes, on some processors basically it's as if all userspace was recompiled to use retpolines. Enabling STIBP promises that one thread cannot influence the indire
by bonzini 8y ago
Yes, on some processors basically it's as if all userspace was recompiled to use retpolines. Enabling STIBP promises that one thread cannot influence the indirect branch predictor's operation when the sibling runs; on those processors the indirect branch predictor is completely disabled, which is an inefficient but valid way to implement STIBP semantics.