1 files changed, 96 insertions, 0 deletions
diff --git a/hw/core/machine.c b/hw/core/machine.c
index 2482c630c1..420c8c4d16 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -389,6 +389,102 @@ HotpluggableCPUList *machine_query_hotpluggable_cpus(MachineState *machine)
     return head;
 }
 
+/**
+ * machine_set_cpu_numa_node:
+ * @machine: machine object to modify
+ * @props: specifies which cpu objects to assign to
+ *         numa node specified by @props.node_id
+ * @errp: if an error occurs, a pointer to an area to store the error
+ *
+ * Associate NUMA node specified by @props.node_id with cpu slots that
+ * match socket/core/thread-ids specified by @props. It's recommended to use
+ * query-hotpluggable-cpus.props values to specify affected cpu slots,
+ * which would lead to exact 1:1 mapping of cpu slots to NUMA node.
+ *
+ * However for CLI convenience it's possible to pass in subset of properties,
+ * which would affect all cpu slots that match it.
+ * Ex for pc machine:
+ *    -smp 4,cores=2,sockets=2 -numa node,nodeid=0 -numa node,nodeid=1 \
+ *    -numa cpu,node-id=0,socket_id=0 \
+ *    -numa cpu,node-id=1,socket_id=1
+ * will assign all child cores of socket 0 to node 0 and
+ * of socket 1 to node 1.
+ *
+ * On attempt of reassigning (already assigned) cpu slot to another NUMA node,
+ * return error.
+ * Empty subset is disallowed and function will return with error in this case.
+ */
+void machine_set_cpu_numa_node(MachineState *machine,
+                               const CpuInstanceProperties *props, Error **errp)
+{
+    MachineClass *mc = MACHINE_GET_CLASS(machine);
+    bool match = false;
+    int i;
+
+    if (!mc->possible_cpu_arch_ids) {
+        error_setg(errp, "mapping of CPUs to NUMA node is not supported");
+        return;
+    }
+
+    /* disabling node mapping is not supported, forbid it */
+    assert(props->has_node_id);
+
+    /* force board to initialize possible_cpus if it hasn't been done yet */
+    mc->possible_cpu_arch_ids(machine);
+
+    for (i = 0; i < machine->possible_cpus->len; i++) {
+        CPUArchId *slot = &machine->possible_cpus->cpus[i];
+
+        /* reject unsupported by board properties */
+        if (props->has_thread_id && !slot->props.has_thread_id) {
+            error_setg(errp, "thread-id is not supported");
+            return;
+        }
+
+        if (props->has_core_id && !slot->props.has_core_id) {
+            error_setg(errp, "core-id is not supported");
+            return;
+        }
+
+        if (props->has_socket_id && !slot->props.has_socket_id) {
+            error_setg(errp, "socket-id is not supported");
+            return;
+        }
+
+        /* skip slots with explicit mismatch */
+        if (props->has_thread_id && props->thread_id != slot->props.thread_id) {
+                continue;
+        }
+
+        if (props->has_core_id && props->core_id != slot->props.core_id) {
+                continue;
+        }
+
+        if (props->has_socket_id && props->socket_id != slot->props.socket_id) {
+                continue;
+        }
+
+        /* reject assignment if slot is already assigned, for compatibility
+         * of legacy cpu_index mapping with SPAPR core based mapping do not
+         * error out if cpu thread and matched core have the same node-id */
+        if (slot->props.has_node_id &&
+            slot->props.node_id != props->node_id) {
+            error_setg(errp, "CPU is already assigned to node-id: %" PRId64,
+                       slot->props.node_id);
+            return;
+        }
+
+        /* assign slot to node as it's matched '-numa cpu' key */
+        match = true;
+        slot->props.node_id = props->node_id;
+        slot->props.has_node_id = props->has_node_id;
+    }
+
+    if (!match) {
+        error_setg(errp, "no match found");
+    }
+}
+
 static void machine_class_init(ObjectClass *oc, void *data)
 {
     MachineClass *mc = MACHINE_CLASS(oc);