WALLY-mmu-sv39-svadu-svnapot-svpbmt fails in ImperasDV

Created by: davidharrishmc

There is a discrepancy between Wally and ImperasDV on

WALLY-mmu-sv39-svadu-svnapot-svpbmt

Invoke with run-elf.bash --elf /home/harris/cvw/tests/riscof/work/wally-riscv-arch-test/rv64i_m/privilege/src/WALLY-mmu-sv39-svadu-svnapot-svpbmt-01.S/ref/ref.elf --verbose

Wally reads the page successfully, while ImperasDV takes a page fault. ImperasDV was correct because the PTE is 0x80000000200800DF, which should be NAPOT but doesn't have pte.ppn[3] = 1. I fixed the test by changing the PTE to 0x80000000200820DF with ppn[3] = 1.

This is a real bug in Wally caused by not examine ppn[3:0] to detect and fault on reserved NAPOT page types.