[RFC 19/41] hw/cpu/cluster: Wrap TCG related ops and props into CONFIG_TCG

[Zhao Liu <zhao1.liu@xxxxxxxxxxxxxxx>]

From: Zhao Liu <zhao1.liu@xxxxxxxxx>

Currenltly cpu-cluster is used in TCG case to organize CPUs with the
same type.

Wrap 2 things into TCG specific areas:
1. cluster-id:

   The cluster-id in TCG case is global, since no higher topology
   container above cluster. To simplify the logic of cluster topology
   in virtualization, move the cluster-id into CONFIG_TCG, then it
   won't be exposed in cli.

2. CPU collection in realize():

   In TCG case, the CPUs are added into cluster directly via child<>
   property. But in virtualization case, the CPU topology will be built
   via topology tree. Thus, wrap CPU collection as the TCG operation.

Signed-off-by: Zhao Liu <zhao1.liu@xxxxxxxxx>
---
 hw/cpu/cluster.c         | 30 +++++++++++++++++++++++++-----
 include/hw/cpu/cluster.h | 22 ++++++++++++++++++++--
 2 files changed, 45 insertions(+), 7 deletions(-)

diff --git a/hw/cpu/cluster.c b/hw/cpu/cluster.c
index fd978a543e40..340cfad9f8f1 100644
--- a/hw/cpu/cluster.c
+++ b/hw/cpu/cluster.c
@@ -26,7 +26,9 @@
 #include "qapi/error.h"
 
 static Property cpu_cluster_properties[] = {
+#ifdef CONFIG_TCG
     DEFINE_PROP_UINT32("cluster-id", CPUCluster, cluster_id, 0),
+#endif
     DEFINE_PROP_END_OF_LIST()
 };
 
@@ -47,18 +49,17 @@ static int add_cpu_to_cluster(Object *obj, void *opaque)
     return 0;
 }
 
-static void cpu_cluster_realize(DeviceState *dev, Error **errp)
+static void cpu_cluster_common_collect_cpus(CPUCluster *cluster, Error **errp)
 {
     /* Iterate through all our CPU children and set their cluster_index */
-    CPUCluster *cluster = CPU_CLUSTER(dev);
-    Object *cluster_obj = OBJECT(dev);
+    Object *cluster_obj = OBJECT(cluster);
     CallbackData cbdata = {
         .cluster = cluster,
         .cpu_count = 0,
     };
 
-    if (cluster->cluster_id >= MAX_CLUSTERS) {
-        error_setg(errp, "cluster-id must be less than %d", MAX_CLUSTERS);
+    if (cluster->cluster_id >= MAX_TCG_CLUSTERS) {
+        error_setg(errp, "cluster-id must be less than %d", MAX_TCG_CLUSTERS);
         return;
     }
 
@@ -73,15 +74,34 @@ static void cpu_cluster_realize(DeviceState *dev, Error 
**errp)
     assert(cbdata.cpu_count > 0);
 }
 
+static const struct TCGClusterOps common_cluster_tcg_ops = {
+    .collect_cpus = cpu_cluster_common_collect_cpus,
+};
+
+static void cpu_cluster_realize(DeviceState *dev, Error **errp)
+{
+    CPUCluster *cluster = CPU_CLUSTER(dev);
+    CPUClusterClass *cc = CPU_CLUSTER_GET_CLASS(dev);
+
+    if (cc->tcg_clu_ops->collect_cpus) {
+        cc->tcg_clu_ops->collect_cpus(cluster, errp);
+    }
+}
+
 static void cpu_cluster_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
+    CPUClusterClass *cc = CPU_CLUSTER_CLASS(klass);
 
     device_class_set_props(dc, cpu_cluster_properties);
     dc->realize = cpu_cluster_realize;
 
     /* This is not directly for users, CPU children must be attached by code */
     dc->user_creatable = false;
+
+#ifdef CONFIG_TCG
+    cc->tcg_clu_ops = &common_cluster_tcg_ops;
+#endif
 }
 
 static const TypeInfo cpu_cluster_type_info = {
diff --git a/include/hw/cpu/cluster.h b/include/hw/cpu/cluster.h
index 644b87350268..c038f05ddc9f 100644
--- a/include/hw/cpu/cluster.h
+++ b/include/hw/cpu/cluster.h
@@ -55,13 +55,31 @@
  */
 
 #define TYPE_CPU_CLUSTER "cpu-cluster"
-OBJECT_DECLARE_SIMPLE_TYPE(CPUCluster, CPU_CLUSTER)
+OBJECT_DECLARE_TYPE(CPUCluster, CPUClusterClass, CPU_CLUSTER)
 
 /*
  * This limit is imposed by TCG, which puts the cluster ID into an
  * 8 bit field (and uses all-1s for the default "not in any cluster").
  */
-#define MAX_CLUSTERS 255
+#define MAX_TCG_CLUSTERS 255
+
+struct TCGClusterOps {
+    /**
+     * @collect_cpus: Iterate children CPUs and set cluser_index.
+     *
+     * Called when the cluster is realized.
+     */
+    void (*collect_cpus)(CPUCluster *cluster, Error **errp);
+};
+
+struct CPUClusterClass {
+    /*< private >*/
+    DeviceClass parent_class;
+
+    /*< public >*/
+    /* when TCG is not available, this pointer is NULL */
+    const struct TCGClusterOps *tcg_clu_ops;
+};
 
 /**
  * CPUCluster:
-- 
2.34.1