[RFC 30/41] hw/core/slot: Check topology child to be added under CPU slot

[Zhao Liu <zhao1.liu@xxxxxxxxxxxxxxx>]

From: Zhao Liu <zhao1.liu@xxxxxxxxx>

Implement CPUTopoClass.check_topo_child() in cpu-slot to be compatible
with the limitations of the current smp topology.

Signed-off-by: Zhao Liu <zhao1.liu@xxxxxxxxx>
---
 hw/core/cpu-slot.c         | 37 +++++++++++++++++++++++++++++++++++++
 hw/core/cpu-topo.c         |  2 +-
 include/hw/core/cpu-slot.h |  2 ++
 include/hw/core/cpu-topo.h |  1 +
 4 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/hw/core/cpu-slot.c b/hw/core/cpu-slot.c
index e8e6f4d25532..2a796ad5b6e7 100644
--- a/hw/core/cpu-slot.c
+++ b/hw/core/cpu-slot.c
@@ -21,6 +21,7 @@
 #include "qemu/osdep.h"
 
 #include "hw/core/cpu-slot.h"
+#include "qapi/error.h"
 
 static inline
 CPUTopoStatEntry *get_topo_stat_entry(CPUTopoStat *stat,
@@ -94,6 +95,37 @@ static void cpu_slot_update_topo_info(CPUTopoState *root, CPUTopoState *child,
     }
 }
 
+static void cpu_slot_check_topo_support(CPUTopoState *root, CPUTopoState *child,
+                                        Error **errp)
+{
+    CPUSlot *slot = CPU_SLOT(root);
+    CPUTopoLevel child_level = CPU_TOPO_LEVEL(child);
+
+    if (!test_bit(child_level, slot->supported_levels)) {
+        error_setg(errp, "cpu topo: the level %s is not supported",
+                   cpu_topo_level_to_string(child_level));
+        return;
+    }
+
+    /*
+     * Currently we doesn't support hybrid topology. For SMP topology,
+     * each child under the same parent are same type.
+     */
+    if (child->parent->num_children) {
+        CPUTopoState *sibling = QTAILQ_FIRST(&child->parent->children);
+        const char *sibling_type = object_get_typename(OBJECT(sibling));
+        const char *child_type = object_get_typename(OBJECT(child));
+
+        if (strcmp(sibling_type, child_type)) {
+            error_setg(errp, "Invalid smp topology: different CPU "
+                       "topology types (%s child vs %s sibling) "
+                       "under the same parent (%s).",
+                       child_type, sibling_type,
+                       object_get_typename(OBJECT(child->parent)));
+        }
+    }
+}
+
 static void cpu_slot_class_init(ObjectClass *oc, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(oc);
@@ -104,6 +136,7 @@ static void cpu_slot_class_init(ObjectClass *oc, void *data)
 
     tc->level = CPU_TOPO_ROOT;
     tc->update_topo_info = cpu_slot_update_topo_info;
+    tc->check_topo_child = cpu_slot_check_topo_support;
 }
 
 static void cpu_slot_instance_init(Object *obj)
@@ -112,6 +145,10 @@ static void cpu_slot_instance_init(Object *obj)
 
     QTAILQ_INIT(&slot->cores);
     set_bit(CPU_TOPO_ROOT, slot->stat.curr_levels);
+
+    /* Set all levels by default. */
+    bitmap_fill(slot->supported_levels, USER_AVAIL_LEVEL_NUM);
+    clear_bit(CPU_TOPO_UNKNOWN, slot->supported_levels);
 }
 
 static const TypeInfo cpu_slot_type_info = {
diff --git a/hw/core/cpu-topo.c b/hw/core/cpu-topo.c
index 687a4cc566ec..351112ca7a73 100644
--- a/hw/core/cpu-topo.c
+++ b/hw/core/cpu-topo.c
@@ -24,7 +24,7 @@
 #include "hw/qdev-properties.h"
 #include "qapi/error.h"
 
-static const char *cpu_topo_level_to_string(CPUTopoLevel level)
+const char *cpu_topo_level_to_string(CPUTopoLevel level)
 {
     switch (level) {
     case CPU_TOPO_UNKNOWN:
diff --git a/include/hw/core/cpu-slot.h b/include/hw/core/cpu-slot.h
index fa2bd4af247d..7bf51988afb3 100644
--- a/include/hw/core/cpu-slot.h
+++ b/include/hw/core/cpu-slot.h
@@ -77,6 +77,7 @@ OBJECT_DECLARE_SIMPLE_TYPE(CPUSlot, CPU_SLOT)
  *     queues for other topology levels to facilitate traversal
  *     when necessary.
  * @stat: Statistical topology information for topology tree.
+ * @supported_levels: Supported topology levels for topology tree.
  */
 struct CPUSlot {
     /*< private >*/
@@ -85,6 +86,7 @@ struct CPUSlot {
     /*< public >*/
     QTAILQ_HEAD(, CPUCore) cores;
     CPUTopoStat stat;
+    DECLARE_BITMAP(supported_levels, USER_AVAIL_LEVEL_NUM);
 };
 
 #endif /* CPU_SLOT_H */
diff --git a/include/hw/core/cpu-topo.h b/include/hw/core/cpu-topo.h
index 453bacbb558b..d27da0335c42 100644
--- a/include/hw/core/cpu-topo.h
+++ b/include/hw/core/cpu-topo.h
@@ -102,5 +102,6 @@ int cpu_topo_child_foreach(CPUTopoState *topo, unsigned long *levels,
 int cpu_topo_child_foreach_recursive(CPUTopoState *topo,
                                      unsigned long *levels,
                                      topo_fn fn, void *opaque);
+const char *cpu_topo_level_to_string(CPUTopoLevel level);
 
 #endif /* CPU_TOPO_H */
-- 
2.34.1