pt2tab_index
idx = pt2tab_index(sva);
count = (pt2tab_index(eva) - idx + 1) * sizeof(pt2_entry_t);
end = pt2tab_index(VM_MAXUSER_ADDRESS);
start = pt2tab_index(KERNBASE) * sizeof(pt2_entry_t);
end = (pt2tab_index(0xFFFFFFFF) + 1) * sizeof(pt2_entry_t);
return (pt2tab + pt2tab_index(va));