VM_LEVEL_0_PSIND
KASSERT(rv->pages->psind == VM_LEVEL_0_PSIND,
rv->pages->psind = VM_LEVEL_0_PSIND - 1;
rv->pages->psind < VM_LEVEL_0_PSIND,
KASSERT(rv->pages->psind == VM_LEVEL_0_PSIND - 1,
rv->pages->psind = VM_LEVEL_0_PSIND;