target/riscv/cpu.c: add riscv_cpu_validate_misa_mxl()

Let's remove more code that is open coded in riscv_cpu_realize() and put
it into a helper. Let's also add an error message instead of just
asserting out if env->misa_mxl_max != env->misa_mlx.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20230517135714.211809-9-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

target/riscv/cpu.c

@@ -910,6 +910,33 @@ static void riscv_cpu_disable_priv_spec_isa_exts(RISCVCPU *cpu)
     }
 }
 
+static void riscv_cpu_validate_misa_mxl(RISCVCPU *cpu, Error **errp)
+{
+    RISCVCPUClass *mcc = RISCV_CPU_GET_CLASS(cpu);
+    CPUClass *cc = CPU_CLASS(mcc);
+    CPURISCVState *env = &cpu->env;
+
+    /* Validate that MISA_MXL is set properly. */
+    switch (env->misa_mxl_max) {
+#ifdef TARGET_RISCV64
+    case MXL_RV64:
+    case MXL_RV128:
+        cc->gdb_core_xml_file = "riscv-64bit-cpu.xml";
+        break;
+#endif
+    case MXL_RV32:
+        cc->gdb_core_xml_file = "riscv-32bit-cpu.xml";
+        break;
+    default:
+        g_assert_not_reached();
+    }
+
+    if (env->misa_mxl_max != env->misa_mxl) {
+        error_setg(errp, "misa_mxl_max must be equal to misa_mxl");
+        return;
+    }
+}
+
 /*
  * Check consistency between chosen extensions while setting
  * cpu->cfg accordingly.
@@ -1232,7 +1259,6 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
     RISCVCPU *cpu = RISCV_CPU(dev);
     CPURISCVState *env = &cpu->env;
     RISCVCPUClass *mcc = RISCV_CPU_GET_CLASS(dev);
-    CPUClass *cc = CPU_CLASS(mcc);
     Error *local_err = NULL;
 
     cpu_exec_realizefn(cs, &local_err);
@@ -1241,6 +1267,12 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
         return;
     }
 
+    riscv_cpu_validate_misa_mxl(cpu, &local_err);
+    if (local_err != NULL) {
+        error_propagate(errp, local_err);
+        return;
+    }
+
     riscv_cpu_validate_priv_spec(cpu, &local_err);
     if (local_err != NULL) {
         error_propagate(errp, local_err);
@@ -1269,22 +1301,6 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
     }
 #endif /* CONFIG_USER_ONLY */
 
-    /* Validate that MISA_MXL is set properly. */
-    switch (env->misa_mxl_max) {
-#ifdef TARGET_RISCV64
-    case MXL_RV64:
-    case MXL_RV128:
-        cc->gdb_core_xml_file = "riscv-64bit-cpu.xml";
-        break;
-#endif
-    case MXL_RV32:
-        cc->gdb_core_xml_file = "riscv-32bit-cpu.xml";
-        break;
-    default:
-        g_assert_not_reached();
-    }
-    assert(env->misa_mxl_max == env->misa_mxl);
-
     riscv_cpu_validate_set_extensions(cpu, &local_err);
     if (local_err != NULL) {
         error_propagate(errp, local_err);