Introduce a simple filtering of statistics, that allows to retrieve
statistics for a subset of the guest vCPUs. This will be used for
example by the HMP monitor, in order to retrieve the statistics
for the currently selected CPU.
Example:
{ "execute": "query-stats",
"arguments": {
"target": "vcpu",
"vcpus": [ "/machine/unattached/device[2]",
"/machine/unattached/device[4]" ] } }
Extracted from a patch by Mark Kanda.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
v3->v4: renamed str_in_list to apply_str_list_filter
handle empty filter early by avoiding the query altogether
accel/kvm/kvm-all.c | 9 +++++++--
include/monitor/stats.h | 11 ++++++++++-
monitor/qmp-cmds.c | 34 +++++++++++++++++++++++++++++++++-
qapi/stats.json | 24 +++++++++++++++++++-----
4 files changed, 69 insertions(+), 9 deletions(-)
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 6a6bbe2994..3ee431a431 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -2311,7 +2311,8 @@ bool kvm_dirty_ring_enabled(void)
return kvm_state->kvm_dirty_ring_size ? true : false;
}
-static void query_stats_cb(StatsResultList **result, StatsTarget target, Error
**errp);
+static void query_stats_cb(StatsResultList **result, StatsTarget target,
+ strList *targets, Error **errp);
static void query_stats_schemas_cb(StatsSchemaList **result, Error **errp);
static int kvm_init(MachineState *ms)
@@ -4049,7 +4050,8 @@ static void query_stats_schema_vcpu(CPUState *cpu,
run_on_cpu_data data)
close(stats_fd);
}
-static void query_stats_cb(StatsResultList **result, StatsTarget target, Error
**errp)
+static void query_stats_cb(StatsResultList **result, StatsTarget target,
+ strList *targets, Error **errp)
{
KVMState *s = kvm_state;
CPUState *cpu;
@@ -4073,6 +4075,9 @@ static void query_stats_cb(StatsResultList **result,
StatsTarget target, Error *
stats_args.result.stats = result;
stats_args.errp = errp;
CPU_FOREACH(cpu) {
+ if (!apply_str_list_filter(cpu->parent_obj.canonical_path,
targets)) {
+ continue;
+ }
run_on_cpu(cpu, query_stats_vcpu,
RUN_ON_CPU_HOST_PTR(&stats_args));
}
break;
diff --git a/include/monitor/stats.h b/include/monitor/stats.h
index 912eeadb2f..8c50feeaa9 100644
--- a/include/monitor/stats.h
+++ b/include/monitor/stats.h
@@ -11,7 +11,7 @@
#include "qapi/qapi-types-stats.h"
typedef void StatRetrieveFunc(StatsResultList **result, StatsTarget target,
- Error **errp);
+ strList *targets, Error **errp);
typedef void SchemaRetrieveFunc(StatsSchemaList **result, Error **errp);
/*
@@ -31,4 +31,13 @@ void add_stats_entry(StatsResultList **, StatsProvider,
const char *id,
void add_stats_schema(StatsSchemaList **, StatsProvider, StatsTarget,
StatsSchemaValueList *);
+/*
+ * True if a string matches the filter passed to the stats_fn callabck,
+ * false otherwise.
+ *
+ * Note that an empty list means no filtering, i.e. all strings will
+ * return true.
+ */
+bool apply_str_list_filter(const char *string, strList *list);
+
#endif /* STATS_H */
diff --git a/monitor/qmp-cmds.c b/monitor/qmp-cmds.c
index d65c5f0257..ebf6f49446 100644
--- a/monitor/qmp-cmds.c
+++ b/monitor/qmp-cmds.c
@@ -466,11 +466,28 @@ void add_stats_callbacks(StatRetrieveFunc *stats_fn,
StatsResultList *qmp_query_stats(StatsFilter *filter, Error **errp)
{
StatsResultList *stats_results = NULL;
+ strList *targets = NULL;
StatsCallbacks *entry;
ERRP_GUARD();
+ 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 NULL;
+ }
+ targets = filter->u.vcpu.vcpus;
+ }
+ break;
+ default:
+ abort();
+ }
+
QTAILQ_FOREACH(entry, &stats_callbacks, next) {
- entry->stats_cb(&stats_results, filter->target, errp);
+ entry->stats_cb(&stats_results, filter->target, targets, errp);
if (*errp) {
qapi_free_StatsResultList(stats_results);
return NULL;
@@ -523,3 +540,18 @@ void add_stats_schema(StatsSchemaList **schema_results,
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;
+}
diff --git a/qapi/stats.json b/qapi/stats.json
index 1129ba49bc..e8ed907793 100644
--- a/qapi/stats.json
+++ b/qapi/stats.json
@@ -69,15 +69,29 @@
'data': [ 'vm', 'vcpu' ] }
##
-# @StatsFilter:
+# @StatsVCPUFilter:
#
-# The arguments to the query-stats command; specifies a target for which to
-# request statistics.
+# @vcpus: list of QOM paths for the desired vCPU objects.
#
# Since: 7.1
##
-{ 'struct': 'StatsFilter',
- 'data': { 'target': 'StatsTarget' } }
+{ 'struct': 'StatsVCPUFilter',
+ 'data': { '*vcpus': [ 'str' ] } }
+
+##
+# @StatsFilter:
+#
+# The arguments to the query-stats command; specifies a target for which to
+# request statistics and optionally the required subset of information for
+# that target:
+# - which vCPUs to request statistics for
+#
+# Since: 7.1
+##
+{ 'union': 'StatsFilter',
+ 'base': { 'target': 'StatsTarget' },
+ 'discriminator': 'target',
+ 'data': { 'vcpu': 'StatsVCPUFilter' } }
##
# @StatsValue:
--
2.36.0
