Following Retbleed, The Combined CPU Security Mitigation Impact For AMD Zen 2 / Ryzen 9 3950X

Following the July disclosure of the Retbleed CPU security vulnerability affecting older processors and an AMD change made in August, here is a fresh look at the performance impact of the Retbleed mitigations on Linux, including if opting for the IBPB-based Retbleed mitigation, and the accumulated CPU security mitigation impact for Zen 2 with the flagship Ryzen 9 3950X processor.