Motivated by a 25% performance degradation seen on an Intel Xeon Scalable dual socket server due to Indirect Branch Restricted Speculation (IBRS), Red Hat's Waiman Long has been working on a patch series to update the IBRS handling in different conditions for affected Intel processors on Linux.
Red Hat engineers are working to deal with Indirect Branch Restricted Speculation (IBRS) being too costly for mitigating Spectre V2 and Retbleed on older Intel Xeon Scalable processors