__dat_ptep_xchg
union pgste __must_check __dat_ptep_xchg(union pte *ptep, union pgste pgste, union pte new,
pgste = __dat_ptep_xchg(ptep, pgste, new, gfn, asce, has_skeys);
pgste = __dat_ptep_xchg(ptep, pgste, newpte, gpa_to_gfn(raddr), sg->asce, uses_skeys(sg));
pgste = __dat_ptep_xchg(ptep, pgste, new, gfn, walk->asce, uses_skeys(p->gmap));
return __dat_ptep_xchg(ptep, pgste, newpte, gfn, gmap->asce, uses_skeys(gmap));