4 files changed, 44 insertions, 0 deletions
diff --git a/target/s390x/helper.h b/target/s390x/helper.h
index 5780bb5090..385ce9af71 100644
--- a/target/s390x/helper.h
+++ b/target/s390x/helper.h
@@ -14,6 +14,7 @@ DEF_HELPER_FLAGS_4(divu64, TCG_CALL_NO_WG, i64, env, i64, i64, i64)
 DEF_HELPER_4(srst, i64, env, i64, i64, i64)
 DEF_HELPER_4(clst, i64, env, i64, i64, i64)
 DEF_HELPER_FLAGS_4(mvn, TCG_CALL_NO_WG, void, env, i32, i64, i64)
+DEF_HELPER_FLAGS_4(mvo, TCG_CALL_NO_WG, void, env, i32, i64, i64)
 DEF_HELPER_FLAGS_4(mvpg, TCG_CALL_NO_WG, i32, env, i64, i64, i64)
 DEF_HELPER_4(mvst, i64, env, i64, i64, i64)
 DEF_HELPER_4(ex, void, env, i32, i64, i64)
diff --git a/target/s390x/insn-data.def b/target/s390x/insn-data.def
index cbb91bbe71..45aaf11e61 100644
--- a/target/s390x/insn-data.def
+++ b/target/s390x/insn-data.def
@@ -582,6 +582,10 @@
     C(0xb254, MVPG,    RRE,   Z,   r1_o, r2_o, 0, 0, mvpg, 0)
 /* MOVE STRING */
     C(0xb255, MVST,    RRE,   Z,   r1_o, r2_o, 0, 0, mvst, 0)
+/* MOVE WITH OFFSET */
+    /* Really format SS_b, but we pack both lengths into one argument
+       for the helper call, so we might as well leave one 8-bit field.  */
+    C(0xf100, MVO,     SS_a,  Z,   la1, a2, 0, 0, mvo, 0)
 
 /* MULTIPLY */
     C(0x1c00, MR,      RR_a,  Z,   r1p1_32s, r2_32s, new, r1_D32, mul, 0)
diff --git a/target/s390x/mem_helper.c b/target/s390x/mem_helper.c
index f80b7a5f06..facac4b6d7 100644
--- a/target/s390x/mem_helper.c
+++ b/target/s390x/mem_helper.c
@@ -256,6 +256,37 @@ void HELPER(mvn)(CPUS390XState *env, uint32_t l, uint64_t dest, uint64_t src)
     }
 }
 
+/* move with offset  */
+void HELPER(mvo)(CPUS390XState *env, uint32_t l, uint64_t dest, uint64_t src)
+{
+    uintptr_t ra = GETPC();
+    int len_dest = l >> 4;
+    int len_src = l & 0xf;
+    uint8_t byte_dest, byte_src;
+    int i;
+
+    src += len_src;
+    dest += len_dest;
+
+    /* Handle rightmost byte */
+    byte_src = cpu_ldub_data_ra(env, src, ra);
+    byte_dest = cpu_ldub_data_ra(env, dest, ra);
+    byte_dest = (byte_dest & 0x0f) | (byte_src << 4);
+    cpu_stb_data_ra(env, dest, byte_dest, ra);
+
+    /* Process remaining bytes from right to left */
+    for (i = 1; i <= len_dest; i++) {
+        byte_dest = byte_src >> 4;
+        if (len_src - i >= 0) {
+            byte_src = cpu_ldub_data_ra(env, src - i, ra);
+        } else {
+            byte_src = 0;
+        }
+        byte_dest |= byte_src << 4;
+        cpu_stb_data_ra(env, dest - i, byte_dest, ra);
+    }
+}
+
 /* compare unsigned byte arrays */
 static uint32_t do_helper_clc(CPUS390XState *env, uint32_t l, uint64_t s1,
                               uint64_t s2, uintptr_t ra)
diff --git a/target/s390x/translate.c b/target/s390x/translate.c
index 7b42c0267d..7be1c70837 100644
--- a/target/s390x/translate.c
+++ b/target/s390x/translate.c
@@ -2996,6 +2996,14 @@ static ExitStatus op_mvn(DisasContext *s, DisasOps *o)
     return NO_EXIT;
 }
 
+static ExitStatus op_mvo(DisasContext *s, DisasOps *o)
+{
+    TCGv_i32 l = tcg_const_i32(get_field(s->fields, l1));
+    gen_helper_mvo(cpu_env, l, o->addr1, o->in2);
+    tcg_temp_free_i32(l);
+    return NO_EXIT;
+}
+
 static ExitStatus op_mvpg(DisasContext *s, DisasOps *o)
 {
     gen_helper_mvpg(cc_op, cpu_env, regs[0], o->in1, o->in2);