diff --git a/target/mips/cpu.h b/target/mips/cpu.h
index c218ccc..7cf1b49 100644
--- a/target/mips/cpu.h
+++ b/target/mips/cpu.h
@@ -961,7 +961,7 @@ struct CPUMIPSState {
 /*
  * CP0 Register 19
  */
-    int32_t CP0_WatchHi[8];
+    uint64_t CP0_WatchHi[8];
 #define CP0WH_ASID 16
 /*
  * CP0 Register 20
diff --git a/target/mips/helper.h b/target/mips/helper.h
index 7b8ad74..5b1f8bb 100644
--- a/target/mips/helper.h
+++ b/target/mips/helper.h
@@ -78,6 +78,7 @@ DEF_HELPER_1(mfc0_maar, tl, env)
 DEF_HELPER_1(mfhc0_maar, tl, env)
 DEF_HELPER_2(mfc0_watchlo, tl, env, i32)
 DEF_HELPER_2(mfc0_watchhi, tl, env, i32)
+DEF_HELPER_2(mfhc0_watchhi, tl, env, i32)
 DEF_HELPER_1(mfc0_debug, tl, env)
 DEF_HELPER_1(mftc0_debug, tl, env)
 #ifdef TARGET_MIPS64
@@ -89,6 +90,7 @@ DEF_HELPER_1(dmfc0_tcschefback, tl, env)
 DEF_HELPER_1(dmfc0_lladdr, tl, env)
 DEF_HELPER_1(dmfc0_maar, tl, env)
 DEF_HELPER_2(dmfc0_watchlo, tl, env, i32)
+DEF_HELPER_2(dmfc0_watchhi, tl, env, i32)
 DEF_HELPER_1(dmfc0_saar, tl, env)
 #endif /* TARGET_MIPS64 */
 
@@ -159,6 +161,7 @@ DEF_HELPER_2(mthc0_maar, void, env, tl)
 DEF_HELPER_2(mtc0_maari, void, env, tl)
 DEF_HELPER_3(mtc0_watchlo, void, env, tl, i32)
 DEF_HELPER_3(mtc0_watchhi, void, env, tl, i32)
+DEF_HELPER_3(mthc0_watchhi, void, env, tl, i32)
 DEF_HELPER_2(mtc0_xcontext, void, env, tl)
 DEF_HELPER_2(mtc0_framemask, void, env, tl)
 DEF_HELPER_2(mtc0_debug, void, env, tl)
diff --git a/target/mips/machine.c b/target/mips/machine.c
index c139239..8d5b18b 100644
--- a/target/mips/machine.c
+++ b/target/mips/machine.c
@@ -212,8 +212,8 @@ const VMStateDescription vmstate_tlb = {
 
 const VMStateDescription vmstate_mips_cpu = {
     .name = "cpu",
-    .version_id = 18,
-    .minimum_version_id = 18,
+    .version_id = 19,
+    .minimum_version_id = 19,
     .post_load = cpu_post_load,
     .fields = (VMStateField[]) {
         /* Active TC */
@@ -296,7 +296,7 @@ const VMStateDescription vmstate_mips_cpu = {
         VMSTATE_INT32(env.CP0_MAARI, MIPSCPU),
         VMSTATE_UINTTL(env.lladdr, MIPSCPU),
         VMSTATE_UINTTL_ARRAY(env.CP0_WatchLo, MIPSCPU, 8),
-        VMSTATE_INT32_ARRAY(env.CP0_WatchHi, MIPSCPU, 8),
+        VMSTATE_UINT64_ARRAY(env.CP0_WatchHi, MIPSCPU, 8),
         VMSTATE_UINTTL(env.CP0_XContext, MIPSCPU),
         VMSTATE_INT32(env.CP0_Framemask, MIPSCPU),
         VMSTATE_INT32(env.CP0_Debug, MIPSCPU),
diff --git a/target/mips/op_helper.c b/target/mips/op_helper.c
index 79d44da..7425a88 100644
--- a/target/mips/op_helper.c
+++ b/target/mips/op_helper.c
@@ -945,7 +945,12 @@ target_ulong helper_mfc0_watchlo(CPUMIPSState *env, uint32_t sel)
 
 target_ulong helper_mfc0_watchhi(CPUMIPSState *env, uint32_t sel)
 {
-    return env->CP0_WatchHi[sel];
+    return (int32_t) env->CP0_WatchHi[sel];
+}
+
+target_ulong helper_mfhc0_watchhi(CPUMIPSState *env, uint32_t sel)
+{
+    return env->CP0_WatchHi[sel] >> 32;
 }
 
 target_ulong helper_mfc0_debug(CPUMIPSState *env)
@@ -1016,6 +1021,11 @@ target_ulong helper_dmfc0_watchlo(CPUMIPSState *env, uint32_t sel)
     return env->CP0_WatchLo[sel];
 }
 
+target_ulong helper_dmfc0_watchhi(CPUMIPSState *env, uint32_t sel)
+{
+    return env->CP0_WatchHi[sel];
+}
+
 target_ulong helper_dmfc0_saar(CPUMIPSState *env)
 {
     if ((env->CP0_SAARI & 0x3f) < 2) {
@@ -1869,11 +1879,20 @@ void helper_mtc0_watchlo(CPUMIPSState *env, target_ulong arg1, uint32_t sel)
 
 void helper_mtc0_watchhi(CPUMIPSState *env, target_ulong arg1, uint32_t sel)
 {
-    int mask = 0x40000FF8 | (env->CP0_EntryHi_ASID_mask << CP0WH_ASID);
+    uint64_t mask = 0x40000FF8 | (env->CP0_EntryHi_ASID_mask << CP0WH_ASID);
+    if ((env->CP0_Config5 >> CP0C5_MI) & 1) {
+        mask |= 0xFFFFFFFF00000000ULL; /* MMID */
+    }
     env->CP0_WatchHi[sel] = arg1 & mask;
     env->CP0_WatchHi[sel] &= ~(env->CP0_WatchHi[sel] & arg1 & 0x7);
 }
 
+void helper_mthc0_watchhi(CPUMIPSState *env, target_ulong arg1, uint32_t sel)
+{
+    env->CP0_WatchHi[sel] = ((uint64_t) (arg1) << 32) |
+                            (env->CP0_WatchHi[sel] & 0x00000000ffffffffULL);
+}
+
 void helper_mtc0_xcontext(CPUMIPSState *env, target_ulong arg1)
 {
     target_ulong mask = (1ULL << (env->SEGBITS - 7)) - 1;
diff --git a/target/mips/translate.c b/target/mips/translate.c
index efe75e6..d51330c 100644
--- a/target/mips/translate.c
+++ b/target/mips/translate.c
@@ -2547,6 +2547,7 @@ typedef struct DisasContext {
     bool nan2008;
     bool abs2008;
     bool saar;
+    bool mi;
 } DisasContext;
 
 #define DISAS_STOP       DISAS_TARGET_0
@@ -6783,6 +6784,25 @@ static void gen_mfhc0(DisasContext *ctx, TCGv arg, int reg, int sel)
             goto cp0_unimplemented;
         }
         break;
+    case CP0_REGISTER_19:
+        switch (sel) {
+        case CP0_REG19__WATCHHI0:
+        case CP0_REG19__WATCHHI1:
+        case CP0_REG19__WATCHHI2:
+        case CP0_REG19__WATCHHI3:
+        case CP0_REG19__WATCHHI4:
+        case CP0_REG19__WATCHHI5:
+        case CP0_REG19__WATCHHI6:
+        case CP0_REG19__WATCHHI7:
+            /* upper 32 bits are only available when Config5MI != 0 */
+            CP0_CHECK(ctx->mi);
+            gen_mfhc0_load64(arg, offsetof(CPUMIPSState, CP0_WatchHi[sel]), 0);
+            register_name = "WatchHi";
+            break;
+        default:
+            goto cp0_unimplemented;
+        }
+        break;
     case CP0_REGISTER_28:
         switch (sel) {
         case 0:
@@ -6869,6 +6889,25 @@ static void gen_mthc0(DisasContext *ctx, TCGv arg, int reg, int sel)
             goto cp0_unimplemented;
         }
         break;
+    case CP0_REGISTER_19:
+        switch (sel) {
+        case CP0_REG19__WATCHHI0:
+        case CP0_REG19__WATCHHI1:
+        case CP0_REG19__WATCHHI2:
+        case CP0_REG19__WATCHHI3:
+        case CP0_REG19__WATCHHI4:
+        case CP0_REG19__WATCHHI5:
+        case CP0_REG19__WATCHHI6:
+        case CP0_REG19__WATCHHI7:
+            /* upper 32 bits are only available when Config5MI != 0 */
+            CP0_CHECK(ctx->mi);
+            gen_helper_0e1i(mthc0_watchhi, arg, sel);
+            register_name = "WatchHi";
+            break;
+        default:
+            goto cp0_unimplemented;
+        }
+        break;
     case CP0_REGISTER_28:
         switch (sel) {
         case 0:
@@ -8922,7 +8961,7 @@ static void gen_dmfc0(DisasContext *ctx, TCGv arg, int reg, int sel)
         case CP0_REG19__WATCHHI6:
         case CP0_REG19__WATCHHI7:
             CP0_CHECK(ctx->CP0_Config1 & (1 << CP0C1_WR));
-            gen_helper_1e0i(mfc0_watchhi, arg, sel);
+            gen_helper_1e0i(dmfc0_watchhi, arg, sel);
             register_name = "WatchHi";
             break;
         default:
@@ -30727,6 +30766,7 @@ static void mips_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
     ctx->mrp = (env->CP0_Config5 >> CP0C5_MRP) & 1;
     ctx->nan2008 = (env->active_fpu.fcr31 >> FCR31_NAN2008) & 1;
     ctx->abs2008 = (env->active_fpu.fcr31 >> FCR31_ABS2008) & 1;
+    ctx->mi = (env->CP0_Config5 >> CP0C5_MI) & 1;
     restore_cpu_state(env, ctx);
 #ifdef CONFIG_USER_ONLY
         ctx->mem_idx = MIPS_HFLAG_UM;
