Invalid NAPOT settings cause page faults, not access exceptions

riscv/mmu.cc

@@ -357,7 +357,7 @@ reg_t mmu_t::s2xlate(reg_t gva, reg_t gpa, access_type type, access_type trap_ty
 
       int napot_bits = ((pte & PTE_N) ? (clz(ppn) + 1) : 0);
       if (((pte & PTE_N) && (ppn == 0 || i != 0)) || (napot_bits != 0 && napot_bits != 4))
-        throw_access_exception(gva, trap_type);
+        break;
 
       reg_t page_base = ((ppn & ~((reg_t(1) << napot_bits) - 1))
                         | (vpn & ((reg_t(1) << napot_bits) - 1))
@@ -437,7 +437,7 @@ reg_t mmu_t::walk(reg_t addr, access_type type, reg_t mode, bool virt, bool mxr)
 
       int napot_bits = ((pte & PTE_N) ? (clz(ppn) + 1) : 0);
       if (((pte & PTE_N) && (ppn == 0 || i != 0)) || (napot_bits != 0 && napot_bits != 4))
-        throw_access_exception(addr, type);
+        break;
 
       reg_t page_base = ((ppn & ~((reg_t(1) << napot_bits) - 1))
                         | (vpn & ((reg_t(1) << napot_bits) - 1))