From: Zhao Liu <zhao1....@intel.com>
Topology index is used to identify the topology child under the same
parent topology device.
This field corresponds to the topology sub index (e.g., socket-id/
core-id/thread-id) used for addressing.
Signed-off-by: Zhao Liu <zhao1....@intel.com>
---
hw/core/cpu-topo.c | 77 ++++++++++++++++++++++++++++++++++++++
include/hw/core/cpu-topo.h | 6 +++
2 files changed, 83 insertions(+)
diff --git a/hw/core/cpu-topo.c b/hw/core/cpu-topo.c
index 4428b979a5dc..3e0c183388d8 100644
--- a/hw/core/cpu-topo.c
+++ b/hw/core/cpu-topo.c
@@ -50,6 +50,66 @@ static const char *cpu_topo_level_to_string(CPUTopoLevel
level)
return NULL;
}
+static void cpu_topo_refresh_free_child_index(CPUTopoState *topo)
+{
+ CPUTopoState *child;
+
+ /*
+ * Fast way: Assume that the index grows sequentially and that there
+ * are no "index hole" in the previous children.
+ *
+ * The previous check on num_children ensures that free_child_index + 1
+ * does not hit the max_children limit.
+ */
+ if (topo->free_child_index + 1 == topo->num_children) {
+ topo->free_child_index++;
+ return;
+ }
+
+ /* Slow way: Search the "index hole". The index hole must be found. */
+ for (int index = 0; index < topo->num_children; index++) {
+ bool existed = false;
+
+ QTAILQ_FOREACH(child, &topo->children, sibling) {
+ if (child->index == index) {
+ existed = true;
+ break;
+ }
+ }
+
+ if (!existed) {
+ topo->free_child_index = index;
+ return;
+ }
+ }
+}
+
+static void cpu_topo_validate_index(CPUTopoState *topo, Error **errp)
+{
+ CPUTopoState *parent = topo->parent, *child;
+
+ if (topo->index < 0) {
+ error_setg(errp, "Invalid topology index (%d).",
+ topo->index);
+ return;
+ }
+
+ if (parent->max_children && topo->index >= parent->max_children) {
+ error_setg(errp, "Invalid topology index (%d): "
+ "The maximum index is %d.",
+ topo->index, parent->max_children);
+ return;
+ }
+
+ QTAILQ_FOREACH(child, &topo->children, sibling) {
+ if (child->index == topo->index) {
+ error_setg(errp, "Duplicate topology index (%d)",
+ topo->index);
+ return;
+ }
+ }
+}
+
static void cpu_topo_build_hierarchy(CPUTopoState *topo, Error **errp)
{
CPUTopoState *parent = topo->parent;
@@ -80,7 +140,18 @@ static void cpu_topo_build_hierarchy(CPUTopoState *topo,
Error **errp)
}
parent->num_children++;
+ if (topo->index == UNASSIGNED_TOPO_INDEX) {
+ topo->index = parent->free_child_index;
+ } else if (topo->index != parent->free_child_index) {
+ /* The index has been set, then we need to validate it. */
+ cpu_topo_validate_index(topo, errp);
+ if (*errp) {
+ return;
+ }
+ }
+
QTAILQ_INSERT_TAIL(&parent->children, topo, sibling);
+ cpu_topo_refresh_free_child_index(parent);
}
static void cpu_topo_set_parent(CPUTopoState *topo, Error **errp)
@@ -135,6 +206,10 @@ static void cpu_topo_destroy_hierarchy(CPUTopoState *topo)
QTAILQ_REMOVE(&parent->children, topo, sibling);
parent->num_children--;
+ if (topo->index < parent->free_child_index) {
+ parent->free_child_index = topo->index;
+ }
+
if (!parent->num_children) {
parent->child_level = CPU_TOPO_UNKNOWN;
}
@@ -180,6 +255,8 @@ static void cpu_topo_instance_init(Object *obj)
CPUTopoState *topo = CPU_TOPO(obj);
QTAILQ_INIT(&topo->children);
+ topo->index = UNASSIGNED_TOPO_INDEX;
+ topo->free_child_index = 0;
topo->child_level = CPU_TOPO_UNKNOWN;
}
diff --git a/include/hw/core/cpu-topo.h b/include/hw/core/cpu-topo.h
index ebcbdd854da5..c0dfff9dc63b 100644
--- a/include/hw/core/cpu-topo.h
+++ b/include/hw/core/cpu-topo.h
@@ -24,6 +24,8 @@
#include "hw/qdev-core.h"
#include "qemu/queue.h"
+#define UNASSIGNED_TOPO_INDEX -1
+
typedef enum CPUTopoLevel {
CPU_TOPO_UNKNOWN,
CPU_TOPO_THREAD,
@@ -53,6 +55,8 @@ struct CPUTopoClass {
/**
* CPUTopoState:
+ * @index: Topology index within parent's topology queue.
+ * @free_child_index: Cached free index to be specified for next child.
* @num_children: Number of topology children under this topology device.
* @max_children: Maximum number of children allowed to be inserted under
* this topology device.
@@ -66,6 +70,8 @@ struct CPUTopoState {
DeviceState parent_obj;
/*< public >*/
+ int index;
+ int free_child_index;
int num_children;
int max_children;
CPUTopoLevel child_level;
--
2.34.1
