qom/cpu: move cpu_model null check to cpu_class_by_name()

and clean every implementation.

Suggested-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20170917232842.14544-1-f4bug@amsat.org>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Artyom Tarasenko <atar4qemu@gmail.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/qom/cpu.c b/qom/cpu.c
index 94fa8fe005..54c9452b1c 100644
--- a/qom/cpu.c
+++ b/qom/cpu.c
@@ -316,7 +316,12 @@ static bool cpu_common_has_work(CPUState *cs)
 
 ObjectClass *cpu_class_by_name(const char *typename, const char *cpu_model)
 {
-    CPUClass *cc = CPU_CLASS(object_class_by_name(typename));
+    CPUClass *cc;
+
+    if (!cpu_model) {
+        return NULL;
+    }
+    cc = CPU_CLASS(object_class_by_name(typename));
 
     return cc->class_by_name(cpu_model);
 }