_PAGES_PER_SEGMENT
#define _PAGES_PER_REGION3 (_PAGES_PER_SEGMENT * _CRST_ENTRIES)
slot->base_gfn <= ALIGN_DOWN(f->gfn, _PAGES_PER_SEGMENT) &&
slot->base_gfn + slot->npages >= ALIGN(f->gfn + 1, _PAGES_PER_SEGMENT);