cf7405bc02
Allow retrieving only a subset of statistics. This can be useful
for example in order to plot a subset of the statistics many times
a second: KVM publishes ~40 statistics for each vCPU on x86; retrieving
and serializing all of them would be useless.
Another use will be in HMP in the following patch; implementing the
filter in the backend is easy enough that it was deemed okay to make
this a public interface.
Example:
{ "execute": "query-stats",
"arguments": {
"target": "vcpu",
"vcpus": [ "/machine/unattached/device[2]",
"/machine/unattached/device[4]" ],
"providers": [
{ "provider": "kvm",
"names": [ "l1d_flush", "exits" ] } } }
{ "return": {
"vcpus": [
{ "path": "/machine/unattached/device[2]"
"providers": [
{ "provider": "kvm",
"stats": [ { "name": "l1d_flush", "value": 41213 },
{ "name": "exits", "value": 74291 } ] } ] },
{ "path": "/machine/unattached/device[4]"
"providers": [
{ "provider": "kvm",
"stats": [ { "name": "l1d_flush", "value": 16132 },
{ "name": "exits", "value": 57922 } ] } ] } ] } }
Extracted from a patch by Mark Kanda.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
46 lines
1.4 KiB
C
46 lines
1.4 KiB
C
/*
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* Copyright (c) 2022 Oracle and/or its affiliates.
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*
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* This work is licensed under the terms of the GNU GPL, version 2.
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* See the COPYING file in the top-level directory.
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*/
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#ifndef STATS_H
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#define STATS_H
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#include "qapi/qapi-types-stats.h"
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typedef void StatRetrieveFunc(StatsResultList **result, StatsTarget target,
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strList *names, strList *targets, Error **errp);
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typedef void SchemaRetrieveFunc(StatsSchemaList **result, Error **errp);
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/*
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* Register callbacks for the QMP query-stats command.
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*
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* @provider: stats provider checked against QMP command arguments
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* @stats_fn: routine to query stats:
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* @schema_fn: routine to query stat schemas:
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*/
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void add_stats_callbacks(StatsProvider provider,
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StatRetrieveFunc *stats_fn,
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SchemaRetrieveFunc *schemas_fn);
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/*
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* Helper routines for adding stats entries to the results lists.
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*/
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void add_stats_entry(StatsResultList **, StatsProvider, const char *id,
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StatsList *stats_list);
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void add_stats_schema(StatsSchemaList **, StatsProvider, StatsTarget,
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StatsSchemaValueList *);
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/*
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* True if a string matches the filter passed to the stats_fn callabck,
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* false otherwise.
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*
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* Note that an empty list means no filtering, i.e. all strings will
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* return true.
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*/
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bool apply_str_list_filter(const char *string, strList *list);
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#endif /* STATS_H */
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