target-unicore32: Detect attempt to instantiate non-CPU type in cpu_init()

Consolidate model checking into a new uc32_cpu_class_by_name().

If the name matches an existing type, also check whether that type is
actually (a sub-type of) TYPE_UNICORE32_CPU.

This fixes, e.g., -cpu puv3_dma asserting.

Cc: qemu-stable@nongnu.org
Signed-off-by: NAndreas Färber <afaerber@suse.de>

target-unicore32/cpu.c

@@ -22,6 +22,21 @@ static inline void set_feature(CPUUniCore32State *env, int feature)
 
 /* CPU models */
 
+static ObjectClass *uc32_cpu_class_by_name(const char *cpu_model)
+{
+    ObjectClass *oc;
+
+    if (cpu_model == NULL) {
+        return NULL;
+    }
+
+    oc = object_class_by_name(cpu_model);
+    if (oc != NULL && !object_class_dynamic_cast(oc, TYPE_UNICORE32_CPU)) {
+        oc = NULL;
+    }
+    return oc;
+}
+
 typedef struct UniCore32CPUInfo {
     const char *name;
     void (*instance_init)(Object *obj);
@@ -80,6 +95,13 @@ static void uc32_cpu_initfn(Object *obj)
     tlb_flush(env, 1);
 }
 
+static void uc32_cpu_class_init(ObjectClass *oc, void *data)
+{
+    CPUClass *cc = CPU_CLASS(oc);
+
+    cc->class_by_name = uc32_cpu_class_by_name;
+}
+
 static void uc32_register_cpu_type(const UniCore32CPUInfo *info)
 {
     TypeInfo type_info = {
@@ -98,6 +120,7 @@ static const TypeInfo uc32_cpu_type_info = {
     .instance_init = uc32_cpu_initfn,
     .abstract = true,
     .class_size = sizeof(UniCore32CPUClass),
+    .class_init = uc32_cpu_class_init,
 };
 
 static void uc32_cpu_register_types(void)

target-unicore32/helper.c

@@ -29,12 +29,14 @@ CPUUniCore32State *uc32_cpu_init(const char *cpu_model)
 {
     UniCore32CPU *cpu;
     CPUUniCore32State *env;
+    ObjectClass *oc;
     static int inited = 1;
 
-    if (object_class_by_name(cpu_model) == NULL) {
+    oc = cpu_class_by_name(TYPE_UNICORE32_CPU, cpu_model);
+    if (oc == NULL) {
         return NULL;
     }
-    cpu = UNICORE32_CPU(object_new(cpu_model));
+    cpu = UNICORE32_CPU(object_new(object_class_get_name(oc)));
     env = &cpu->env;
 
     if (inited) {