diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 65c8d6855ec..9bbfdcf6758 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -557,7 +557,7 @@ struct RISCVCPUClass {
 
     DeviceRealize parent_realize;
     ResettablePhases parent_phases;
-    RISCVMXL misa_mxl_max;  /* max mxl for this cpu */
+    RISCVCPUDef *def;
 };
 
 static inline int riscv_has_ext(CPURISCVState *env, target_ulong ext)
diff --git a/hw/riscv/boot.c b/hw/riscv/boot.c
index 765b9e2b1ab..828a867be39 100644
--- a/hw/riscv/boot.c
+++ b/hw/riscv/boot.c
@@ -37,7 +37,7 @@
 bool riscv_is_32bit(RISCVHartArrayState *harts)
 {
     RISCVCPUClass *mcc = RISCV_CPU_GET_CLASS(&harts->harts[0]);
-    return mcc->misa_mxl_max == MXL_RV32;
+    return mcc->def->misa_mxl_max == MXL_RV32;
 }
 
 /*
diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 3bd2bff1328..25132e57380 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -357,7 +357,7 @@ void riscv_cpu_set_misa_ext(CPURISCVState *env, uint32_t ext)
 
 int riscv_cpu_max_xlen(RISCVCPUClass *mcc)
 {
-    return 16 << mcc->misa_mxl_max;
+    return 16 << mcc->def->misa_mxl_max;
 }
 
 #ifndef CONFIG_USER_ONLY
@@ -1055,7 +1055,7 @@ static void riscv_cpu_reset_hold(Object *obj, ResetType type)
         mcc->parent_phases.hold(obj, type);
     }
 #ifndef CONFIG_USER_ONLY
-    env->misa_mxl = mcc->misa_mxl_max;
+    env->misa_mxl = mcc->def->misa_mxl_max;
     env->priv = PRV_M;
     env->mstatus &= ~(MSTATUS_MIE | MSTATUS_MPRV);
     if (env->misa_mxl > MXL_RV32) {
@@ -1457,7 +1457,7 @@ static void riscv_cpu_init(Object *obj)
     RISCVCPU *cpu = RISCV_CPU(obj);
     CPURISCVState *env = &cpu->env;
 
-    env->misa_mxl = mcc->misa_mxl_max;
+    env->misa_mxl = mcc->def->misa_mxl_max;
 
 #ifndef CONFIG_USER_ONLY
     qdev_init_gpio_in(DEVICE(obj), riscv_cpu_set_irq,
@@ -1554,7 +1554,7 @@ static void riscv_cpu_validate_misa_mxl(RISCVCPUClass *mcc)
     CPUClass *cc = CPU_CLASS(mcc);
 
     /* Validate that MISA_MXL is set properly. */
-    switch (mcc->misa_mxl_max) {
+    switch (mcc->def->misa_mxl_max) {
 #ifdef TARGET_RISCV64
     case MXL_RV64:
     case MXL_RV128:
@@ -3079,12 +3079,24 @@ static void riscv_cpu_common_class_init(ObjectClass *c, void *data)
     device_class_set_props(dc, riscv_cpu_properties);
 }
 
+static void riscv_cpu_class_base_init(ObjectClass *c, void *data)
+{
+    RISCVCPUClass *mcc = RISCV_CPU_CLASS(c);
+    RISCVCPUClass *pcc = RISCV_CPU_CLASS(object_class_get_parent(c));
+
+    if (pcc->def) {
+        mcc->def = g_memdup2(pcc->def, sizeof(*pcc->def));
+    } else {
+        mcc->def = g_new0(RISCVCPUDef, 1);
+    }
+}
+
 static void riscv_cpu_class_init(ObjectClass *c, void *data)
 {
     RISCVCPUClass *mcc = RISCV_CPU_CLASS(c);
     const RISCVCPUDef *def = data;
 
-    mcc->misa_mxl_max = def->misa_mxl_max;
+    mcc->def->misa_mxl_max = def->misa_mxl_max;
     riscv_cpu_validate_misa_mxl(mcc);
 }
 
@@ -3235,6 +3247,7 @@ static const TypeInfo riscv_cpu_type_infos[] = {
         .abstract = true,
         .class_size = sizeof(RISCVCPUClass),
         .class_init = riscv_cpu_common_class_init,
+        .class_base_init = riscv_cpu_class_base_init,
     },
     {
         .name = TYPE_RISCV_DYNAMIC_CPU,
diff --git a/target/riscv/gdbstub.c b/target/riscv/gdbstub.c
index 18e88f416af..1934f919c01 100644
--- a/target/riscv/gdbstub.c
+++ b/target/riscv/gdbstub.c
@@ -62,7 +62,7 @@ int riscv_cpu_gdb_read_register(CPUState *cs, GByteArray *mem_buf, int n)
         return 0;
     }
 
-    switch (mcc->misa_mxl_max) {
+    switch (mcc->def->misa_mxl_max) {
     case MXL_RV32:
         return gdb_get_reg32(mem_buf, tmp);
     case MXL_RV64:
@@ -82,7 +82,7 @@ int riscv_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
     int length = 0;
     target_ulong tmp;
 
-    switch (mcc->misa_mxl_max) {
+    switch (mcc->def->misa_mxl_max) {
     case MXL_RV32:
         tmp = (int32_t)ldl_p(mem_buf);
         length = 4;
@@ -359,7 +359,7 @@ void riscv_cpu_register_gdb_regs_for_features(CPUState *cs)
                                  ricsv_gen_dynamic_vector_feature(cs, cs->gdb_num_regs),
                                  0);
     }
-    switch (mcc->misa_mxl_max) {
+    switch (mcc->def->misa_mxl_max) {
     case MXL_RV32:
         gdb_register_coprocessor(cs, riscv_gdb_get_virtual,
                                  riscv_gdb_set_virtual,
diff --git a/target/riscv/kvm/kvm-cpu.c b/target/riscv/kvm/kvm-cpu.c
index 0f4997a9186..d7e6970a670 100644
--- a/target/riscv/kvm/kvm-cpu.c
+++ b/target/riscv/kvm/kvm-cpu.c
@@ -1997,22 +1997,19 @@ static void kvm_cpu_accel_register_types(void)
 }
 type_init(kvm_cpu_accel_register_types);
 
-static void riscv_host_cpu_class_init(ObjectClass *c, void *data)
-{
-    RISCVCPUClass *mcc = RISCV_CPU_CLASS(c);
-
-#if defined(TARGET_RISCV32)
-    mcc->misa_mxl_max = MXL_RV32;
-#elif defined(TARGET_RISCV64)
-    mcc->misa_mxl_max = MXL_RV64;
-#endif
-}
-
 static const TypeInfo riscv_kvm_cpu_type_infos[] = {
     {
         .name = TYPE_RISCV_CPU_HOST,
         .parent = TYPE_RISCV_CPU,
-        .class_init = riscv_host_cpu_class_init,
+#if defined(TARGET_RISCV32)
+        .class_data = &((const RISCVCPUDef) {
+            .misa_mxl_max = MXL_RV32,
+        },
+#elif defined(TARGET_RISCV64)
+        .class_data = &((const RISCVCPUDef) {
+            .misa_mxl_max = MXL_RV64,
+        },
+#endif
     }
 };
 
diff --git a/target/riscv/machine.c b/target/riscv/machine.c
index 889e2b65701..df2d5bad8d6 100644
--- a/target/riscv/machine.c
+++ b/target/riscv/machine.c
@@ -170,7 +170,7 @@ static bool rv128_needed(void *opaque)
 {
     RISCVCPUClass *mcc = RISCV_CPU_GET_CLASS(opaque);
 
-    return mcc->misa_mxl_max == MXL_RV128;
+    return mcc->def->misa_mxl_max == MXL_RV128;
 }
 
 static const VMStateDescription vmstate_rv128 = {
diff --git a/target/riscv/tcg/tcg-cpu.c b/target/riscv/tcg/tcg-cpu.c
index 2f93e2dd285..b43bd3d35b7 100644
--- a/target/riscv/tcg/tcg-cpu.c
+++ b/target/riscv/tcg/tcg-cpu.c
@@ -581,7 +581,7 @@ void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
         return;
     }
 
-    if (mcc->misa_mxl_max != MXL_RV32 && cpu->cfg.ext_zcf) {
+    if (mcc->def->misa_mxl_max != MXL_RV32 && cpu->cfg.ext_zcf) {
         error_setg(errp, "Zcf extension is only relevant to RV32");
         return;
     }
@@ -678,7 +678,7 @@ void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
         return;
     }
 
-    if (mcc->misa_mxl_max == MXL_RV32 && cpu->cfg.ext_svukte) {
+    if (mcc->def->misa_mxl_max == MXL_RV32 && cpu->cfg.ext_svukte) {
         error_setg(errp, "svukte is not supported for RV32");
         return;
     }
@@ -916,7 +916,7 @@ static void cpu_enable_zc_implied_rules(RISCVCPU *cpu)
         cpu_cfg_ext_auto_update(cpu, CPU_CFG_OFFSET(ext_zcmp), true);
         cpu_cfg_ext_auto_update(cpu, CPU_CFG_OFFSET(ext_zcmt), true);
 
-        if (riscv_has_ext(env, RVF) && mcc->misa_mxl_max == MXL_RV32) {
+        if (riscv_has_ext(env, RVF) && mcc->def->misa_mxl_max == MXL_RV32) {
             cpu_cfg_ext_auto_update(cpu, CPU_CFG_OFFSET(ext_zcf), true);
         }
     }
@@ -925,7 +925,7 @@ static void cpu_enable_zc_implied_rules(RISCVCPU *cpu)
     if (riscv_has_ext(env, RVC) && env->priv_ver >= PRIV_VERSION_1_12_0) {
         cpu_cfg_ext_auto_update(cpu, CPU_CFG_OFFSET(ext_zca), true);
 
-        if (riscv_has_ext(env, RVF) && mcc->misa_mxl_max == MXL_RV32) {
+        if (riscv_has_ext(env, RVF) && mcc->def->misa_mxl_max == MXL_RV32) {
             cpu_cfg_ext_auto_update(cpu, CPU_CFG_OFFSET(ext_zcf), true);
         }
 
@@ -1049,7 +1049,7 @@ static bool riscv_tcg_cpu_realize(CPUState *cs, Error **errp)
         return false;
     }
 
-    if (mcc->misa_mxl_max >= MXL_RV128 && qemu_tcg_mttcg_enabled()) {
+    if (mcc->def->misa_mxl_max >= MXL_RV128 && qemu_tcg_mttcg_enabled()) {
         /* Missing 128-bit aligned atomics */
         error_setg(errp,
                    "128-bit RISC-V currently does not work with Multi "
diff --git a/target/riscv/translate.c b/target/riscv/translate.c
index d6651f244f6..e22ecd11565 100644
--- a/target/riscv/translate.c
+++ b/target/riscv/translate.c
@@ -1282,7 +1282,7 @@ static void riscv_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
     ctx->cfg_vta_all_1s = cpu->cfg.rvv_ta_all_1s;
     ctx->vstart_eq_zero = FIELD_EX32(tb_flags, TB_FLAGS, VSTART_EQ_ZERO);
     ctx->vl_eq_vlmax = FIELD_EX32(tb_flags, TB_FLAGS, VL_EQ_VLMAX);
-    ctx->misa_mxl_max = mcc->misa_mxl_max;
+    ctx->misa_mxl_max = mcc->def->misa_mxl_max;
     ctx->xl = FIELD_EX32(tb_flags, TB_FLAGS, XL);
     ctx->address_xl = FIELD_EX32(tb_flags, TB_FLAGS, AXL);
     ctx->cs = cs;
