[Qemu-devel] [PATCH 5/7] cpu: Let architectures set CPU class name format

[Eduardo Habkost <ehabkost@redhat.com>]

Instead of requiring every architecture to implement a
class_by_name function, let them set a format string at
CPUClass::class_name_format.

This will let us get rid of at least 16 class_by_name functions
in the next commits.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
 include/qom/cpu.h | 12 ++++++++++++
 qom/cpu.c         | 18 ++++++++++++++++--
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/include/qom/cpu.h b/include/qom/cpu.h
index fefd5c26b0..eda6a46b82 100644
--- a/include/qom/cpu.h
+++ b/include/qom/cpu.h
@@ -163,7 +163,19 @@ typedef struct CPUClass {
     DeviceClass parent_class;
     /*< public >*/
 
+    /* The following fields configure CPU model name -> QOM type translation: */
+
+    /*
+     * arch-specific CPU model -> QOM type translation function.
+     * Optional if @class_name_format is set.
+     */
     ObjectClass *(*class_by_name)(const char *cpu_model);
+    /*
+     * Format string for g_strdup_printf(), used to generate the CPU
+     * class name.
+     */
+    const char *class_name_format;
+
     void (*parse_features)(const char *typename, char *str, Error **errp);
 
     void (*reset)(CPUState *cpu);
diff --git a/qom/cpu.c b/qom/cpu.c
index b971a56242..1fa64941b6 100644
--- a/qom/cpu.c
+++ b/qom/cpu.c
@@ -286,9 +286,23 @@ static bool cpu_common_has_work(CPUState *cs)
 CPUClass *cpu_class_by_name(const char *typename, const char *cpu_model)
 {
     CPUClass *cc = CPU_CLASS(object_class_by_name(typename));
+    ObjectClass *oc;
+    char *class_name;
 
-    assert(cpu_model && cc->class_by_name);
-    return CPU_CLASS(cc->class_by_name(cpu_model));
+    assert(cpu_model);
+    if (cc->class_by_name) {
+        return CPU_CLASS(cc->class_by_name(cpu_model));
+    }
+
+    assert(cc->class_name_format);
+    class_name = g_strdup_printf(cc->class_name_format, cpu_model);
+    oc = object_class_by_name(class_name);
+    g_free(class_name);
+    if (!oc || !object_class_dynamic_cast(oc, typename) ||
+        object_class_is_abstract(oc)) {
+        return NULL;
+    }
+    return CPU_CLASS(oc);
 }
 
 static void cpu_common_parse_features(const char *typename, char *features,
-- 
2.18.0.rc1.1.g3f1ff2140