> A solution to this issue was proposed, whereby Xen synchronises siblings > on vmexit/entry, so we are never executing code in two different > privilege levels. Getting this working would make it safe to continue > using hyperthreading even in the presence of L1TF. Obviously, its going > to come in perf hit, but compared to disabling hyperthreading, all its > got to do is beat a 60% perf hit to make it the preferable option for > making your system L1TF-proof.
Could you shed some light what tests were done where that 60% performance hit was observed? We have performed intensive stress-tests to confirm this but according to our findings turning off hyper-threading is actually improving performance on all machines we tested thus far. Thanks, Tamas _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
