pglvl_pgtbl_pte_off
pte += pglvl_pgtbl_pte_off(domain->pglvl, base, lvl);
pte += pglvl_pgtbl_pte_off(domain->pglvl, base, lvl);
idx = pglvl_pgtbl_pte_off(pglvl, base, i) +
int pglvl_pgtbl_pte_off(int pglvl, iommu_gaddr_t base, int lvl);