RISC-V is not an IP core, just an instruction set architecture.
Any implementation of it has the exact same patent minefield to navigate as any other ISA. Most of the patents are around implementation techniques not instruction set.
Any implementation of it has the exact same patent minefield to navigate as any other ISA. Most of the patents are around implementation techniques not instruction set.
https://riscv.org/technical/specifications/risc-v-genealogy/
Of course, the various extensions might violate current patents (I would guess that packed SIMD and cryptography extensions are particularly at risk). But the basic ISA does not use anything that was not already widely adopted by 2003.
Besides that, engineers in large companies are told to explicitly not look up any patents so they won't be accused of willful infringement.