diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index c46bb5a5c0..9f618e120a 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -2718,6 +2718,7 @@ static void arm_max_initfn(Object *obj)
 
             t = cpu->isar.id_mmfr4;
             t = FIELD_DP32(t, ID_MMFR4, HPDS, 1); /* AA32HPD */
+            t = FIELD_DP32(t, ID_MMFR4, AC2, 1); /* ACTLR2, HACTLR2 */
             cpu->isar.id_mmfr4 = t;
         }
 #endif
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index c6af3290ca..b4c83a1cb5 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -3531,6 +3531,11 @@ static inline bool isar_feature_aa32_hpd(const ARMISARegisters *id)
     return FIELD_EX32(id->id_mmfr4, ID_MMFR4, HPDS) != 0;
 }
 
+static inline bool isar_feature_aa32_ac2(const ARMISARegisters *id)
+{
+    return FIELD_EX32(id->id_mmfr4, ID_MMFR4, AC2) != 0;
+}
+
 /*
  * 64-bit feature tests via id registers.
  */
diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c
index 8430d43294..0929401a4d 100644
--- a/target/arm/cpu64.c
+++ b/target/arm/cpu64.c
@@ -703,6 +703,10 @@ static void aarch64_max_initfn(Object *obj)
         u = FIELD_DP32(u, ID_MMFR3, PAN, 2); /* ATS1E1 */
         cpu->isar.id_mmfr3 = u;
 
+        u = cpu->isar.id_mmfr4;
+        u = FIELD_DP32(u, ID_MMFR4, AC2, 1); /* ACTLR2, HACTLR2 */
+        cpu->isar.id_mmfr4 = u;
+
         u = cpu->isar.id_aa64dfr0;
         u = FIELD_DP64(u, ID_AA64DFR0, PMUVER, 5); /* v8.4-PMU */
         cpu->isar.id_aa64dfr0 = u;
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 19d749a191..1ac09f387e 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -6862,6 +6862,27 @@ static const ARMCPRegInfo ats1cp_reginfo[] = {
 };
 #endif
 
+/*
+ * ACTLR2 and HACTLR2 map to ACTLR_EL1[63:32] and
+ * ACTLR_EL2[63:32]. They exist only if the ID_MMFR4.AC2 field
+ * is non-zero, which is never for ARMv7, optionally in ARMv8
+ * and mandatorily for ARMv8.2 and up.
+ * ACTLR2 is banked for S and NS if EL3 is AArch32. Since QEMU's
+ * implementation is RAZ/WI we can ignore this detail, as we
+ * do for ACTLR.
+ */
+static const ARMCPRegInfo actlr2_hactlr2_reginfo[] = {
+    { .name = "ACTLR2", .state = ARM_CP_STATE_AA32,
+      .cp = 15, .opc1 = 0, .crn = 1, .crm = 0, .opc2 = 3,
+      .access = PL1_RW, .type = ARM_CP_CONST,
+      .resetvalue = 0 },
+    { .name = "HACTLR2", .state = ARM_CP_STATE_AA32,
+      .cp = 15, .opc1 = 4, .crn = 1, .crm = 0, .opc2 = 3,
+      .access = PL2_RW, .type = ARM_CP_CONST,
+      .resetvalue = 0 },
+    REGINFO_SENTINEL
+};
+
 void register_cp_regs_for_features(ARMCPU *cpu)
 {
     /* Register all the coprocessor registers based on feature bits */
@@ -7623,15 +7644,8 @@ void register_cp_regs_for_features(ARMCPU *cpu)
             REGINFO_SENTINEL
         };
         define_arm_cp_regs(cpu, auxcr_reginfo);
-        if (arm_feature(env, ARM_FEATURE_V8)) {
-            /* HACTLR2 maps to ACTLR_EL2[63:32] and is not in ARMv7 */
-            ARMCPRegInfo hactlr2_reginfo = {
-                .name = "HACTLR2", .state = ARM_CP_STATE_AA32,
-                .cp = 15, .opc1 = 4, .crn = 1, .crm = 0, .opc2 = 3,
-                .access = PL2_RW, .type = ARM_CP_CONST,
-                .resetvalue = 0
-            };
-            define_one_arm_cp_reg(cpu, &hactlr2_reginfo);
+        if (cpu_isar_feature(aa32_ac2, cpu)) {
+            define_arm_cp_regs(cpu, actlr2_hactlr2_reginfo);
         }
     }