s390/mm: fix huge pte soft dirty copying

If the pmd is soft dirty we must mark the pte as soft dirty (and not dirty).
This fixes some cases for guest migration with huge page backings.

Cc: <[email protected]> # 4.8
Fixes: bc29b7a ("s390/mm: clean up pte/pmd encoding")
Reviewed-by: Christian Borntraeger <[email protected]>
Reviewed-by: Gerald Schaefer <[email protected]>
Signed-off-by: Janosch Frank <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>

Author: frankjaa

arch/s390/mm/hugetlbpage.c

@@ -117,7 +117,7 @@ static inline pte_t __rste_to_pte(unsigned long rste)
 					     _PAGE_YOUNG);
 #ifdef CONFIG_MEM_SOFT_DIRTY
 		pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_SOFT_DIRTY,
-					     _PAGE_DIRTY);
+					     _PAGE_SOFT_DIRTY);
 #endif
 		pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_NOEXEC,
 					     _PAGE_NOEXEC);