Difference between risc-v "access fault" and "page fault"

access fault

To put it simply access fault It happened in PMP When testing . It means that the processor uses memory without permission . Occurs at least user On machines in mode , Because in machine In mode , The processor can access all the memory . So only M Mode processors may not be able to pass PMP Check . Besides ,access fault It may be due to PMA（ Physical memory properties ） The inspection fails , This also applies to M Pattern .

page fault

When a processor attempts to use memory that it may have permission to use , But the memory block is not yet available , It usually produces page fault.page fault Can only occur when there is Supervisor On machines in mode , Because the virtual memory system needs Supervisor Pattern .