Looking At The LVI Mitigation Impact On Intel Cascade Lake Refresh

As we've seen from the recent LLVM LVI tests on the Intel Core i9 and further back when looking at the GNU toolchain mitigations, the performance hit when enabling this mitigation is very sizable. The extent of the impact really depends upon the particular code-base for the number of additional LFENCE instructions that may now be needed. For crypto benchmarks like Cryptopp and SMHasher, the overhead of the LVI option is very apparent.