stats: Move QMP commands from monitor/ to stats/

This moves these commands from MAINTAINERS section "QMP" to new
section "Stats".  Status is Orphan.  Volunteers welcome!

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20230124121946.1139465-23-armbru@redhat.com>

2 files changed, 163 insertions, 0 deletions

diff --git a/stats/meson.build b/stats/meson.build
new file mode 100644
index 0000000000..4ddb4d096b
--- /dev/null
+++ b/stats/meson.build
@@ -0,0 +1 @@
+softmmu_ss.add(files('stats-qmp-cmds.c'))
diff --git a/stats/stats-qmp-cmds.c b/stats/stats-qmp-cmds.c
new file mode 100644
index 0000000000..bc973747fb
--- /dev/null
+++ b/stats/stats-qmp-cmds.c
@@ -0,0 +1,162 @@
+/*
+ * QMP commands related to stats
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * (at your option) any later version.
+ */
+
+#include "qemu/osdep.h"
+#include "sysemu/stats.h"
+#include "qapi/qapi-commands-stats.h"
+#include "qemu/queue.h"
+#include "qapi/error.h"
+
+typedef struct StatsCallbacks {
+    StatsProvider provider;
+    StatRetrieveFunc *stats_cb;
+    SchemaRetrieveFunc *schemas_cb;
+    QTAILQ_ENTRY(StatsCallbacks) next;
+} StatsCallbacks;
+
+static QTAILQ_HEAD(, StatsCallbacks) stats_callbacks =
+    QTAILQ_HEAD_INITIALIZER(stats_callbacks);
+
+void add_stats_callbacks(StatsProvider provider,
+                         StatRetrieveFunc *stats_fn,
+                         SchemaRetrieveFunc *schemas_fn)
+{
+    StatsCallbacks *entry = g_new(StatsCallbacks, 1);
+    entry->provider = provider;
+    entry->stats_cb = stats_fn;
+    entry->schemas_cb = schemas_fn;
+
+    QTAILQ_INSERT_TAIL(&stats_callbacks, entry, next);
+}
+
+static bool invoke_stats_cb(StatsCallbacks *entry,
+                            StatsResultList **stats_results,
+                            StatsFilter *filter, StatsRequest *request,
+                            Error **errp)
+{
+    ERRP_GUARD();
+    strList *targets = NULL;
+    strList *names = NULL;
+
+    if (request) {
+        if (request->provider != entry->provider) {
+            return true;
+        }
+        if (request->has_names && !request->names) {
+            return true;
+        }
+        names = request->has_names ? request->names : NULL;
+    }
+
+    switch (filter->target) {
+    case STATS_TARGET_VM:
+        break;
+    case STATS_TARGET_VCPU:
+        if (filter->u.vcpu.has_vcpus) {
+            if (!filter->u.vcpu.vcpus) {
+                /* No targets allowed?  Return no statistics.  */
+                return true;
+            }
+            targets = filter->u.vcpu.vcpus;
+        }
+        break;
+    default:
+        abort();
+    }
+
+    entry->stats_cb(stats_results, filter->target, names, targets, errp);
+    if (*errp) {
+        qapi_free_StatsResultList(*stats_results);
+        *stats_results = NULL;
+        return false;
+    }
+    return true;
+}
+
+StatsResultList *qmp_query_stats(StatsFilter *filter, Error **errp)
+{
+    StatsResultList *stats_results = NULL;
+    StatsCallbacks *entry;
+    StatsRequestList *request;
+
+    QTAILQ_FOREACH(entry, &stats_callbacks, next) {
+        if (filter->has_providers) {
+            for (request = filter->providers; request; request = request->next) {
+                if (!invoke_stats_cb(entry, &stats_results, filter,
+                                     request->value, errp)) {
+                    break;
+                }
+            }
+        } else {
+            if (!invoke_stats_cb(entry, &stats_results, filter, NULL, errp)) {
+                break;
+            }
+        }
+    }
+
+    return stats_results;
+}
+
+StatsSchemaList *qmp_query_stats_schemas(bool has_provider,
+                                         StatsProvider provider,
+                                         Error **errp)
+{
+    ERRP_GUARD();
+    StatsSchemaList *stats_results = NULL;
+    StatsCallbacks *entry;
+
+    QTAILQ_FOREACH(entry, &stats_callbacks, next) {
+        if (!has_provider || provider == entry->provider) {
+            entry->schemas_cb(&stats_results, errp);
+            if (*errp) {
+                qapi_free_StatsSchemaList(stats_results);
+                return NULL;
+            }
+        }
+    }
+
+    return stats_results;
+}
+
+void add_stats_entry(StatsResultList **stats_results, StatsProvider provider,
+                     const char *qom_path, StatsList *stats_list)
+{
+    StatsResult *entry = g_new0(StatsResult, 1);
+
+    entry->provider = provider;
+    entry->qom_path = g_strdup(qom_path);
+    entry->stats = stats_list;
+
+    QAPI_LIST_PREPEND(*stats_results, entry);
+}
+
+void add_stats_schema(StatsSchemaList **schema_results,
+                      StatsProvider provider, StatsTarget target,
+                      StatsSchemaValueList *stats_list)
+{
+    StatsSchema *entry = g_new0(StatsSchema, 1);
+
+    entry->provider = provider;
+    entry->target = target;
+    entry->stats = stats_list;
+    QAPI_LIST_PREPEND(*schema_results, entry);
+}
+
+bool apply_str_list_filter(const char *string, strList *list)
+{
+    strList *str_list = NULL;
+
+    if (!list) {
+        return true;
+    }
+    for (str_list = list; str_list; str_list = str_list->next) {
+        if (g_str_equal(string, str_list->value)) {
+            return true;
+        }
+    }
+    return false;
+}