KVM: s390/mm: Properly reset no-dat

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>

diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 3bd2ab2a9a3449a411145a938d65a0b1f9a5ad62..5cb92941540b32bea8e908863c3364a0f61230c5 100644 (file)
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -756,7 +756,7 @@ 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();
 }