1/*
2 * QEMU block throttling group infrastructure
3 *
4 * Copyright (C) Nodalink, EURL. 2014
5 * Copyright (C) Igalia, S.L. 2015
6 *
7 * Authors:
8 * Benoît Canet <benoit.canet@nodalink.com>
9 * Alberto Garcia <berto@igalia.com>
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License as
13 * published by the Free Software Foundation; either version 2 or
14 * (at your option) version 3 of the License.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, see <http://www.gnu.org/licenses/>.
23 */
24
25#ifndef THROTTLE_GROUPS_H
26#define THROTTLE_GROUPS_H
27
28#include "qemu/throttle.h"
29#include "block/block_int.h"
30
31/* The ThrottleGroupMember structure indicates membership in a ThrottleGroup
32 * and holds related data.
33 */
34
35typedef struct ThrottleGroupMember {
36 AioContext *aio_context;
37 /* throttled_reqs_lock protects the CoQueues for throttled requests. */
38 CoMutex throttled_reqs_lock;
39 CoQueue throttled_reqs[2];
40
41 /* Nonzero if the I/O limits are currently being ignored; generally
42 * it is zero. Accessed with atomic operations.
43 */
44 unsigned int io_limits_disabled;
45
46 /* Number of pending throttle_group_restart_queue_entry() coroutines.
47 * Accessed with atomic operations.
48 */
49 unsigned int restart_pending;
50
51 /* The following fields are protected by the ThrottleGroup lock.
52 * See the ThrottleGroup documentation for details.
53 * throttle_state tells us if I/O limits are configured. */
54 ThrottleState *throttle_state;
55 ThrottleTimers throttle_timers;
56 unsigned pending_reqs[2];
57 QLIST_ENTRY(ThrottleGroupMember) round_robin;
58
59} ThrottleGroupMember;
60
61#define TYPE_THROTTLE_GROUP "throttle-group"
62#define THROTTLE_GROUP(obj) OBJECT_CHECK(ThrottleGroup, (obj), TYPE_THROTTLE_GROUP)
63
64const char *throttle_group_get_name(ThrottleGroupMember *tgm);
65
66ThrottleState *throttle_group_incref(const char *name);
67void throttle_group_unref(ThrottleState *ts);
68
69void throttle_group_config(ThrottleGroupMember *tgm, ThrottleConfig *cfg);
70void throttle_group_get_config(ThrottleGroupMember *tgm, ThrottleConfig *cfg);
71
72void throttle_group_register_tgm(ThrottleGroupMember *tgm,
73 const char *groupname,
74 AioContext *ctx);
75void throttle_group_unregister_tgm(ThrottleGroupMember *tgm);
76void throttle_group_restart_tgm(ThrottleGroupMember *tgm);
77
78void coroutine_fn throttle_group_co_io_limits_intercept(ThrottleGroupMember *tgm,
79 unsigned int bytes,
80 bool is_write);
81void throttle_group_attach_aio_context(ThrottleGroupMember *tgm,
82 AioContext *new_context);
83void throttle_group_detach_aio_context(ThrottleGroupMember *tgm);
84/*
85 * throttle_group_exists() must be called under the global
86 * mutex.
87 */
88bool throttle_group_exists(const char *name);
89
90#endif
91