KVM: s390/mm: Properly reset no-dat

commit 27072b8e18a73ffeffb1c140939023915a35134b upstream.

When the CMMA state needs to be reset, the no-dat bit also needs to be
reset. Failure to do so could cause issues in the guest, since the
guest expects the bit to be cleared after a reset.

Cc: <stable@vger.kernel.org>
Reviewed-by: Nico Boehr <nrb@linux.ibm.com>
Message-ID: <20231109123624.37314-1-imbrenda@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 783e07934a3d9d6053b7c1750236414ea17c034e..74fce7c454843d37113599c35f9bc2e04f5c59f7 100644 (file)
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -667,7 +667,7 @@ void ptep_zap_unused(struct mm_struct *mm, unsigned long addr,
                pte_clear(mm, addr, ptep);
        }
        if (reset)
-               pgste_val(pgste) &= ~_PGSTE_GPS_USAGE_MASK;
+               pgste_val(pgste) &= ~(_PGSTE_GPS_USAGE_MASK | _PGSTE_GPS_NODAT);
        pgste_set_unlock(ptep, pgste);
        preempt_enable();
 }