It was just with Linux 5.17 that its RISC-V code adds “sv48” support for being able to handle more system memory by offering 48-bit virtual address space support. Now for Linux 5.17 there is “sv57” support prepared for 57-bit virtual address space support with five level page table handling.
Queued up in the Linux RISC-V’s “for-next” branch over the past week is support for the sv57 extension this royalty-free processor ISA. RISC-V sv57 allows for 57-bit page-based virtual memory system support for cases where the sv48 support is insufficient. The sv57 extension adds the fifth level of the page table.