why Foundation Model can not produce Address size fault，Translation fault， Access flag fault？

Hi，

     I  want  to produce an exception in Foundation Model to test my ARMV8 U-boot. But when I set AF bit to 0 in last level page table entry, and want to produce an Access Flag exception, it failed, the same happened to Address size fault and Translation fault.  But when I set AP bit(access ) , the permission fault can be reported to exception handler which I added to start.S.

     I'm wondering if the Hardware page table walk in Foundation model can not report exception in handling page table entry? Cause permission fault is produced in TLB not in hardware page table walk.

    Can anybody help me? Thanks very much in advance.