[PATCH v1 1/1] KVM: s390/mm: Properly reset no-dat

From: Claudio Imbrenda
Date: Thu Nov 09 2023 - 07:36:39 EST


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.

Signed-off-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
---
arch/s390/mm/pgtable.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 3bd2ab2a9a34..5cb92941540b 100644
--- 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();
}
--
2.41.0