The logic, to check if the specified CPU type is supported in
machine_run_board_init(), is independent enough. Factor it out into
helper is_cpu_type_supported(). machine_run_board_init() looks a bit
clean with this. Since we're here, @machine_class is renamed to @mc
to avoid multiple line spanning of code. The error messages and comments
are tweaked a bit either.

No functional change intended.

Signed-off-by: Gavin Shan <gshan@redhat.com>
---
v6: 'const MachineState *' in is_cpu_type_supported()     (Phil)
    Clearer hint if only one valid CPU is supported       (Phil)
---
 hw/core/machine.c | 88 +++++++++++++++++++++++++++--------------------
 1 file changed, 50 insertions(+), 38 deletions(-)

diff --git a/hw/core/machine.c b/hw/core/machine.c
index 5b45dbbbd5..d19aec11a3 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -1387,13 +1387,57 @@ out:
     return r;
 }
 
+static void is_cpu_type_supported(const MachineState *machine, Error **errp)
+{
+    MachineClass *mc = MACHINE_GET_CLASS(machine);
+    ObjectClass *oc = object_class_by_name(machine->cpu_type);
+    CPUClass *cc;
+    int i;
+
+    /*
+     * Check if the user specified CPU type is supported when the valid
+     * CPU types have been determined. Note that the user specified CPU
+     * type is provided through '-cpu' option.
+     */
+    if (mc->valid_cpu_types && machine->cpu_type) {
+        for (i = 0; mc->valid_cpu_types[i]; i++) {
+            if (object_class_dynamic_cast(oc, mc->valid_cpu_types[i])) {
+                break;
+            }
+        }
+
+        /* The user specified CPU type isn't valid */
+        if (!mc->valid_cpu_types[i]) {
+            error_setg(errp, "Invalid CPU type: %s", machine->cpu_type);
+            if (!mc->valid_cpu_types[1]) {
+                error_append_hint(errp, "The only valid type is: %s",
+                                  mc->valid_cpu_types[0]);
+            } else {
+                error_append_hint(errp, "The valid types are: %s",
+                                  mc->valid_cpu_types[0]);
+            }
+
+            for (i = 1; mc->valid_cpu_types[i]; i++) {
+                error_append_hint(errp, ", %s", mc->valid_cpu_types[i]);
+            }
+
+            error_append_hint(errp, "\n");
+            return;
+        }
+    }
+
+    /* Check if CPU type is deprecated and warn if so */
+    cc = CPU_CLASS(oc);
+    if (cc && cc->deprecation_note) {
+        warn_report("CPU model %s is deprecated -- %s",
+                    machine->cpu_type, cc->deprecation_note);
+    }
+}
 
 void machine_run_board_init(MachineState *machine, const char *mem_path, Error **errp)
 {
     ERRP_GUARD();
     MachineClass *machine_class = MACHINE_GET_CLASS(machine);
-    ObjectClass *oc = object_class_by_name(machine->cpu_type);
-    CPUClass *cc;
     Error *local_err = NULL;
 
     /* This checkpoint is required by replay to separate prior clock
@@ -1449,42 +1493,10 @@ void machine_run_board_init(MachineState *machine, const char *mem_path, Error *
         machine->ram = machine_consume_memdev(machine, machine->memdev);
     }
 
-    /* If the machine supports the valid_cpu_types check and the user
-     * specified a CPU with -cpu check here that the user CPU is supported.
-     */
-    if (machine_class->valid_cpu_types && machine->cpu_type) {
-        int i;
-
-        for (i = 0; machine_class->valid_cpu_types[i]; i++) {
-            if (object_class_dynamic_cast(oc,
-                                          machine_class->valid_cpu_types[i])) {
-                /* The user specified CPU is in the valid field, we are
-                 * good to go.
-                 */
-                break;
-            }
-        }
-
-        if (!machine_class->valid_cpu_types[i]) {
-            /* The user specified CPU is not valid */
-            error_setg(&local_err, "Invalid CPU type: %s", machine->cpu_type);
-            error_append_hint(&local_err, "The valid types are: %s",
-                              machine_class->valid_cpu_types[0]);
-            for (i = 1; machine_class->valid_cpu_types[i]; i++) {
-                error_append_hint(&local_err, ", %s",
-                                  machine_class->valid_cpu_types[i]);
-            }
-            error_append_hint(&local_err, "\n");
-
-            error_propagate(errp, local_err);
-        }
-    }
-
-    /* Check if CPU type is deprecated and warn if so */
-    cc = CPU_CLASS(oc);
-    if (cc && cc->deprecation_note) {
-        warn_report("CPU model %s is deprecated -- %s", machine->cpu_type,
-                    cc->deprecation_note);
+    /* Check if the CPU type is supported */
+    is_cpu_type_supported(machine, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
     }
 
     if (machine->cgs) {
-- 
2.41.0