[riscv-CMOs:master] New Comment on Issue #48 How to discover the information of cache block size by software?
By brucehoult:

My understanding of the intent of the RVA ISA Profiles is that Linux distros will target an RVA profile. At some point going forward that will be RVA22.

As far as I know, x86_64 Linux distributions still support the original 2003 Athlon 64s. They don't assume anything like AVX or even the BMI1/BMI2 (Intel) or ABM (AMD) bit manipulation extensions.

RVA20 aka RV64GC should be a supported baseline forever.