s390x/mmu: Add EDAT2 translation support

This only adds basic support to the DAT translation, but no EDAT2 support
for TCG. E.g., the gdbstub under kvm uses this function, too, to
translate virtual addresses.

Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>

target/s390x/mmu_helper.c

@@ -120,6 +120,7 @@ static int mmu_translate_asce(CPUS390XState *env, target_ulong vaddr,
 {
     const bool edat1 = (env->cregs[0] & CR0_EDAT) &&
                        s390_has_feat(S390_FEAT_EDAT);
+    const bool edat2 = edat1 && s390_has_feat(S390_FEAT_EDAT_2);
     const int asce_tl = asce & ASCE_TABLE_LENGTH;
     const int asce_p = asce & ASCE_PRIVATE_SPACE;
     hwaddr gaddr = asce & ASCE_ORIGIN;
@@ -217,13 +218,21 @@ static int mmu_translate_asce(CPUS390XState *env, target_ulong vaddr,
         if ((entry & REGION_ENTRY_TT) != REGION_ENTRY_TT_REGION3) {
             return PGM_TRANS_SPEC;
         }
-        if (VADDR_SEGMENT_TL(vaddr) < (entry & REGION_ENTRY_TF) >> 6 ||
-            VADDR_SEGMENT_TL(vaddr) > (entry & REGION_ENTRY_TL)) {
-            return PGM_SEGMENT_TRANS;
+        if (edat2 && (entry & REGION3_ENTRY_CR) && asce_p) {
+            return PGM_TRANS_SPEC;
         }
         if (edat1 && (entry & REGION_ENTRY_P)) {
             *flags &= ~PAGE_WRITE;
         }
+        if (edat2 && (entry & REGION3_ENTRY_FC)) {
+            *raddr = (entry & REGION3_ENTRY_RFAA) |
+                     (vaddr & ~REGION3_ENTRY_RFAA);
+            return 0;
+        }
+        if (VADDR_SEGMENT_TL(vaddr) < (entry & REGION_ENTRY_TF) >> 6 ||
+            VADDR_SEGMENT_TL(vaddr) > (entry & REGION_ENTRY_TL)) {
+            return PGM_SEGMENT_TRANS;
+        }
         gaddr = (entry & REGION_ENTRY_ORIGIN) + VADDR_SEGMENT_TX(vaddr) * 8;
         /* fall through */
     case ASCE_TYPE_SEGMENT: