target/loongarch: Fix loongarch_cpu_class_by_name

The cpu_model argument may already have the '-loongarch-cpu' suffix,
e.g. when using the default for the LS7A1000 machine.  If that fails,
try again with the suffix.  Validate that the object created by the
function is derived from the proper base class.

Signed-off-by: Xiaojuan Yang <yangxiaojuan@loongson.cn>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220715060740.1500628-2-yangxiaojuan@loongson.cn>
[rth: Try without and then with the suffix, to avoid testsuite breakage.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 15 insertions, 5 deletions

diff --git a/target/loongarch/cpu.c b/target/loongarch/cpu.c
index e21715592a..5573468a7d 100644
--- a/target/loongarch/cpu.c
+++ b/target/loongarch/cpu.c
@@ -571,12 +571,22 @@ static void loongarch_cpu_init(Object *obj)
 static ObjectClass *loongarch_cpu_class_by_name(const char *cpu_model)
 {
     ObjectClass *oc;
-    char *typename;
 
-    typename = g_strdup_printf(LOONGARCH_CPU_TYPE_NAME("%s"), cpu_model);
-    oc = object_class_by_name(typename);
-    g_free(typename);
-    return oc;
+    oc = object_class_by_name(cpu_model);
+    if (!oc) {
+        g_autofree char *typename 
+            = g_strdup_printf(LOONGARCH_CPU_TYPE_NAME("%s"), cpu_model);
+        oc = object_class_by_name(typename);
+        if (!oc) {
+            return NULL;
+        }
+    }
+
+    if (object_class_dynamic_cast(oc, TYPE_LOONGARCH_CPU)
+        && !object_class_is_abstract(oc)) {
+        return oc;
+    }
+    return NULL;
 }
 
 void loongarch_cpu_dump_state(CPUState *cs, FILE *f, int flags)