5.5.2.4.8.2 Page table protection
The page table protection mechanism is applied to virtual addresses during their translation to real addresses.
The page table protection mechanism controls access to virtual storage by using the page protection bit in
each page-table entry and segment-table entry. Protection can be applied to a single page or an entire
segment (a collection of contiguous pages). Once the ASCE is located, the following dynamic address
translation is used to translate virtual address to a real address. Page table protection (for a page or a segment)
is applied at this stage. The first diagram illustrates the DAT process for 31-bit addresses and the second
diagram for the 64-bit addresses.
112