Linux 7.4 Kernel Crypto Library Enjoying Optimized AES Implementations On x86 & RISC-V

The latest Linux kernel cryptographic subsystem performance work carried out by Google engineer Eric Biggers is migrating x86/x86_64 and RISC-V optimized implementations of different AES modes into the lib/crypto kernel crypto library to enjoy faster performance there. Merged for the Linux 7.4 kernel, Biggers migrated the x86/x86_64 and RISC-V optimized implementations of AES modes ECB, CBC, CBC-CTS, CTR, XCTR, XTS into the kernel crypto library space. In turn the library APIs are now properly accelerated on those architectures while also still accelerating crypto_skcipher usage too. On Intel/AMD x86_64 CPUs this means making use of AVX optimized code as well as AES-NI instructions. The Linux kernel crypto expert explained that beyond the acceleration from these optimized implementations, it also removes a lot of redundant glue code and code duplication. Separately in the crypto library updates for Linux 7.4, open-source developer Stian Halseth authored an optimized AES-XTS implementation for SPARC64. The new implementation is making use of SPARC's crypto opcodes. Seeing new SPARC crypto optimizations wasn't what I was expecting to write about in 2026... The full list of now-merged crypto library updates for Linux 7.4 can be found via this pull request.