page_set_storage_key
page_set_storage_key(init_pfn << PAGE_SHIFT,
page_set_storage_key(real, PAGE_DEFAULT_KEY, 1);
page_set_storage_key(pte_origin(pte), nkey.skey, 0);
page_set_storage_key(pte_origin(new), page_get_storage_key(pte_origin(old)), 1);
page_set_storage_key(large_crste_to_phys(*crstep, gfn), skey.skey, !nq);
page_set_storage_key(pte_origin(*ptep), skey.skey, !nq);
page_set_storage_key(paddr, skey.skey, !nq);
page_set_storage_key(pte_origin(*ptep), PAGE_DEFAULT_KEY, 1);
page_set_storage_key(addr, PAGE_DEFAULT_KEY, 1);
page_set_storage_key(start, PAGE_DEFAULT_KEY, 1);