s390/mm: push rte protection down to shadow pte

Just like we already do with ste protection, let's take rte protection
into account. This way, the host pte doesn't have to be mapped writable.

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

arch/s390/kvm/gaccess.c

@@ -966,6 +966,7 @@ static int kvm_s390_shadow_tables(struct gmap *sg, unsigned long saddr,
 	int rc;
 
 	*fake = 0;
+	*dat_protection = 0;
 	parent = sg->parent;
 	vaddr.addr = saddr;
 	asce.val = sg->orig_asce;
@@ -1008,6 +1009,8 @@ static int kvm_s390_shadow_tables(struct gmap *sg, unsigned long saddr,
 			return PGM_TRANSLATION_SPEC;
 		if (vaddr.rsx01 < rfte.tf || vaddr.rsx01 > rfte.tl)
 			return PGM_REGION_SECOND_TRANS;
+		if (sg->edat_level >= 1)
+			*dat_protection |= rfte.p;
 		rc = gmap_shadow_r2t(sg, saddr, rfte.val);
 		if (rc)
 			return rc;
@@ -1026,6 +1029,9 @@ static int kvm_s390_shadow_tables(struct gmap *sg, unsigned long saddr,
 			return PGM_TRANSLATION_SPEC;
 		if (vaddr.rtx01 < rste.tf || vaddr.rtx01 > rste.tl)
 			return PGM_REGION_THIRD_TRANS;
+		if (sg->edat_level >= 1)
+			*dat_protection |= rste.p;
+		rste.p |= *dat_protection;
 		rc = gmap_shadow_r3t(sg, saddr, rste.val);
 		if (rc)
 			return rc;
@@ -1045,18 +1051,19 @@ static int kvm_s390_shadow_tables(struct gmap *sg, unsigned long saddr,
 		if (rtte.cr && asce.p && sg->edat_level >= 2)
 			return PGM_TRANSLATION_SPEC;
 		if (rtte.fc && sg->edat_level >= 2) {
-			bool prot = rtte.fc1.p;
-
+			*dat_protection |= rtte.fc0.p;
 			*fake = 1;
 			ptr = rtte.fc1.rfaa << 31UL;
 			rtte.val = ptr;
-			rtte.fc0.p = prot;
 			goto shadow_sgt;
 		}
 		if (vaddr.sx01 < rtte.fc0.tf || vaddr.sx01 > rtte.fc0.tl)
 			return PGM_SEGMENT_TRANSLATION;
+		if (sg->edat_level >= 1)
+			*dat_protection |= rtte.fc0.p;
 		ptr = rtte.fc0.sto << 12UL;
 shadow_sgt:
+		rtte.fc0.p |= *dat_protection;
 		rc = gmap_shadow_sgt(sg, saddr, rtte.val, *fake);
 		if (rc)
 			return rc;
@@ -1080,18 +1087,16 @@ shadow_sgt:
 			return PGM_TRANSLATION_SPEC;
 		if (ste.cs && asce.p)
 			return PGM_TRANSLATION_SPEC;
-		*dat_protection = ste.fc0.p;
+		*dat_protection |= ste.fc0.p;
 		if (ste.fc && sg->edat_level >= 1) {
-			bool prot = ste.fc1.p;
-
 			*fake = 1;
 			ptr = ste.fc1.sfaa << 20UL;
 			ste.val = ptr;
-			ste.fc0.p = prot;
 			goto shadow_pgt;
 		}
 		ptr = ste.fc0.pto << 11UL;
 shadow_pgt:
+		ste.fc0.p |= *dat_protection;
 		rc = gmap_shadow_pgt(sg, saddr, ste.val, *fake);
 		if (rc)
 			return rc;