Merge remote-tracking branch 'remotes/alistair/tags/pull-riscv-to-apply-20210304...
[qemu.git] / block / throttle-groups.c
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 * BenoƮt 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 #include "qemu/osdep.h"
26 #include "sysemu/block-backend.h"
27 #include "block/throttle-groups.h"
28 #include "qemu/throttle-options.h"
29 #include "qemu/main-loop.h"
30 #include "qemu/queue.h"
31 #include "qemu/thread.h"
32 #include "sysemu/qtest.h"
33 #include "qapi/error.h"
34 #include "qapi/qapi-visit-block-core.h"
35 #include "qom/object.h"
36 #include "qom/object_interfaces.h"
37
38 static void throttle_group_obj_init(Object *obj);
39 static void throttle_group_obj_complete(UserCreatable *obj, Error **errp);
40 static void timer_cb(ThrottleGroupMember *tgm, bool is_write);
41
42 /* The ThrottleGroup structure (with its ThrottleState) is shared
43 * among different ThrottleGroupMembers and it's independent from
44 * AioContext, so in order to use it from different threads it needs
45 * its own locking.
46 *
47 * This locking is however handled internally in this file, so it's
48 * transparent to outside users.
49 *
50 * The whole ThrottleGroup structure is private and invisible to
51 * outside users, that only use it through its ThrottleState.
52 *
53 * In addition to the ThrottleGroup structure, ThrottleGroupMember has
54 * fields that need to be accessed by other members of the group and
55 * therefore also need to be protected by this lock. Once a
56 * ThrottleGroupMember is registered in a group those fields can be accessed
57 * by other threads any time.
58 *
59 * Again, all this is handled internally and is mostly transparent to
60 * the outside. The 'throttle_timers' field however has an additional
61 * constraint because it may be temporarily invalid (see for example
62 * blk_set_aio_context()). Therefore in this file a thread will
63 * access some other ThrottleGroupMember's timers only after verifying that
64 * that ThrottleGroupMember has throttled requests in the queue.
65 */
66 struct ThrottleGroup {
67 Object parent_obj;
68
69 /* refuse individual property change if initialization is complete */
70 bool is_initialized;
71 char *name; /* This is constant during the lifetime of the group */
72
73 QemuMutex lock; /* This lock protects the following four fields */
74 ThrottleState ts;
75 QLIST_HEAD(, ThrottleGroupMember) head;
76 ThrottleGroupMember *tokens[2];
77 bool any_timer_armed[2];
78 QEMUClockType clock_type;
79
80 /* This field is protected by the global QEMU mutex */
81 QTAILQ_ENTRY(ThrottleGroup) list;
82 };
83
84 /* This is protected by the global QEMU mutex */
85 static QTAILQ_HEAD(, ThrottleGroup) throttle_groups =
86 QTAILQ_HEAD_INITIALIZER(throttle_groups);
87
88
89 /* This function reads throttle_groups and must be called under the global
90 * mutex.
91 */
92 static ThrottleGroup *throttle_group_by_name(const char *name)
93 {
94 ThrottleGroup *iter;
95
96 /* Look for an existing group with that name */
97 QTAILQ_FOREACH(iter, &throttle_groups, list) {
98 if (!g_strcmp0(name, iter->name)) {
99 return iter;
100 }
101 }
102
103 return NULL;
104 }
105
106 /* This function reads throttle_groups and must be called under the global
107 * mutex.
108 */
109 bool throttle_group_exists(const char *name)
110 {
111 return throttle_group_by_name(name) != NULL;
112 }
113
114 /* Increments the reference count of a ThrottleGroup given its name.
115 *
116 * If no ThrottleGroup is found with the given name a new one is
117 * created.
118 *
119 * This function edits throttle_groups and must be called under the global
120 * mutex.
121 *
122 * @name: the name of the ThrottleGroup
123 * @ret: the ThrottleState member of the ThrottleGroup
124 */
125 ThrottleState *throttle_group_incref(const char *name)
126 {
127 ThrottleGroup *tg = NULL;
128
129 /* Look for an existing group with that name */
130 tg = throttle_group_by_name(name);
131
132 if (tg) {
133 object_ref(OBJECT(tg));
134 } else {
135 /* Create a new one if not found */
136 /* new ThrottleGroup obj will have a refcnt = 1 */
137 tg = THROTTLE_GROUP(object_new(TYPE_THROTTLE_GROUP));
138 tg->name = g_strdup(name);
139 throttle_group_obj_complete(USER_CREATABLE(tg), &error_abort);
140 }
141
142 return &tg->ts;
143 }
144
145 /* Decrease the reference count of a ThrottleGroup.
146 *
147 * When the reference count reaches zero the ThrottleGroup is
148 * destroyed.
149 *
150 * This function edits throttle_groups and must be called under the global
151 * mutex.
152 *
153 * @ts: The ThrottleGroup to unref, given by its ThrottleState member
154 */
155 void throttle_group_unref(ThrottleState *ts)
156 {
157 ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
158 object_unref(OBJECT(tg));
159 }
160
161 /* Get the name from a ThrottleGroupMember's group. The name (and the pointer)
162 * is guaranteed to remain constant during the lifetime of the group.
163 *
164 * @tgm: a ThrottleGroupMember
165 * @ret: the name of the group.
166 */
167 const char *throttle_group_get_name(ThrottleGroupMember *tgm)
168 {
169 ThrottleGroup *tg = container_of(tgm->throttle_state, ThrottleGroup, ts);
170 return tg->name;
171 }
172
173 /* Return the next ThrottleGroupMember in the round-robin sequence, simulating
174 * a circular list.
175 *
176 * This assumes that tg->lock is held.
177 *
178 * @tgm: the current ThrottleGroupMember
179 * @ret: the next ThrottleGroupMember in the sequence
180 */
181 static ThrottleGroupMember *throttle_group_next_tgm(ThrottleGroupMember *tgm)
182 {
183 ThrottleState *ts = tgm->throttle_state;
184 ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
185 ThrottleGroupMember *next = QLIST_NEXT(tgm, round_robin);
186
187 if (!next) {
188 next = QLIST_FIRST(&tg->head);
189 }
190
191 return next;
192 }
193
194 /*
195 * Return whether a ThrottleGroupMember has pending requests.
196 *
197 * This assumes that tg->lock is held.
198 *
199 * @tgm: the ThrottleGroupMember
200 * @is_write: the type of operation (read/write)
201 * @ret: whether the ThrottleGroupMember has pending requests.
202 */
203 static inline bool tgm_has_pending_reqs(ThrottleGroupMember *tgm,
204 bool is_write)
205 {
206 return tgm->pending_reqs[is_write];
207 }
208
209 /* Return the next ThrottleGroupMember in the round-robin sequence with pending
210 * I/O requests.
211 *
212 * This assumes that tg->lock is held.
213 *
214 * @tgm: the current ThrottleGroupMember
215 * @is_write: the type of operation (read/write)
216 * @ret: the next ThrottleGroupMember with pending requests, or tgm if
217 * there is none.
218 */
219 static ThrottleGroupMember *next_throttle_token(ThrottleGroupMember *tgm,
220 bool is_write)
221 {
222 ThrottleState *ts = tgm->throttle_state;
223 ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
224 ThrottleGroupMember *token, *start;
225
226 /* If this member has its I/O limits disabled then it means that
227 * it's being drained. Skip the round-robin search and return tgm
228 * immediately if it has pending requests. Otherwise we could be
229 * forcing it to wait for other member's throttled requests. */
230 if (tgm_has_pending_reqs(tgm, is_write) &&
231 qatomic_read(&tgm->io_limits_disabled)) {
232 return tgm;
233 }
234
235 start = token = tg->tokens[is_write];
236
237 /* get next bs round in round robin style */
238 token = throttle_group_next_tgm(token);
239 while (token != start && !tgm_has_pending_reqs(token, is_write)) {
240 token = throttle_group_next_tgm(token);
241 }
242
243 /* If no IO are queued for scheduling on the next round robin token
244 * then decide the token is the current tgm because chances are
245 * the current tgm got the current request queued.
246 */
247 if (token == start && !tgm_has_pending_reqs(token, is_write)) {
248 token = tgm;
249 }
250
251 /* Either we return the original TGM, or one with pending requests */
252 assert(token == tgm || tgm_has_pending_reqs(token, is_write));
253
254 return token;
255 }
256
257 /* Check if the next I/O request for a ThrottleGroupMember needs to be
258 * throttled or not. If there's no timer set in this group, set one and update
259 * the token accordingly.
260 *
261 * This assumes that tg->lock is held.
262 *
263 * @tgm: the current ThrottleGroupMember
264 * @is_write: the type of operation (read/write)
265 * @ret: whether the I/O request needs to be throttled or not
266 */
267 static bool throttle_group_schedule_timer(ThrottleGroupMember *tgm,
268 bool is_write)
269 {
270 ThrottleState *ts = tgm->throttle_state;
271 ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
272 ThrottleTimers *tt = &tgm->throttle_timers;
273 bool must_wait;
274
275 if (qatomic_read(&tgm->io_limits_disabled)) {
276 return false;
277 }
278
279 /* Check if any of the timers in this group is already armed */
280 if (tg->any_timer_armed[is_write]) {
281 return true;
282 }
283
284 must_wait = throttle_schedule_timer(ts, tt, is_write);
285
286 /* If a timer just got armed, set tgm as the current token */
287 if (must_wait) {
288 tg->tokens[is_write] = tgm;
289 tg->any_timer_armed[is_write] = true;
290 }
291
292 return must_wait;
293 }
294
295 /* Start the next pending I/O request for a ThrottleGroupMember. Return whether
296 * any request was actually pending.
297 *
298 * @tgm: the current ThrottleGroupMember
299 * @is_write: the type of operation (read/write)
300 */
301 static bool coroutine_fn throttle_group_co_restart_queue(ThrottleGroupMember *tgm,
302 bool is_write)
303 {
304 bool ret;
305
306 qemu_co_mutex_lock(&tgm->throttled_reqs_lock);
307 ret = qemu_co_queue_next(&tgm->throttled_reqs[is_write]);
308 qemu_co_mutex_unlock(&tgm->throttled_reqs_lock);
309
310 return ret;
311 }
312
313 /* Look for the next pending I/O request and schedule it.
314 *
315 * This assumes that tg->lock is held.
316 *
317 * @tgm: the current ThrottleGroupMember
318 * @is_write: the type of operation (read/write)
319 */
320 static void schedule_next_request(ThrottleGroupMember *tgm, bool is_write)
321 {
322 ThrottleState *ts = tgm->throttle_state;
323 ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
324 bool must_wait;
325 ThrottleGroupMember *token;
326
327 /* Check if there's any pending request to schedule next */
328 token = next_throttle_token(tgm, is_write);
329 if (!tgm_has_pending_reqs(token, is_write)) {
330 return;
331 }
332
333 /* Set a timer for the request if it needs to be throttled */
334 must_wait = throttle_group_schedule_timer(token, is_write);
335
336 /* If it doesn't have to wait, queue it for immediate execution */
337 if (!must_wait) {
338 /* Give preference to requests from the current tgm */
339 if (qemu_in_coroutine() &&
340 throttle_group_co_restart_queue(tgm, is_write)) {
341 token = tgm;
342 } else {
343 ThrottleTimers *tt = &token->throttle_timers;
344 int64_t now = qemu_clock_get_ns(tg->clock_type);
345 timer_mod(tt->timers[is_write], now);
346 tg->any_timer_armed[is_write] = true;
347 }
348 tg->tokens[is_write] = token;
349 }
350 }
351
352 /* Check if an I/O request needs to be throttled, wait and set a timer
353 * if necessary, and schedule the next request using a round robin
354 * algorithm.
355 *
356 * @tgm: the current ThrottleGroupMember
357 * @bytes: the number of bytes for this I/O
358 * @is_write: the type of operation (read/write)
359 */
360 void coroutine_fn throttle_group_co_io_limits_intercept(ThrottleGroupMember *tgm,
361 int64_t bytes,
362 bool is_write)
363 {
364 bool must_wait;
365 ThrottleGroupMember *token;
366 ThrottleGroup *tg = container_of(tgm->throttle_state, ThrottleGroup, ts);
367
368 assert(bytes >= 0);
369
370 qemu_mutex_lock(&tg->lock);
371
372 /* First we check if this I/O has to be throttled. */
373 token = next_throttle_token(tgm, is_write);
374 must_wait = throttle_group_schedule_timer(token, is_write);
375
376 /* Wait if there's a timer set or queued requests of this type */
377 if (must_wait || tgm->pending_reqs[is_write]) {
378 tgm->pending_reqs[is_write]++;
379 qemu_mutex_unlock(&tg->lock);
380 qemu_co_mutex_lock(&tgm->throttled_reqs_lock);
381 qemu_co_queue_wait(&tgm->throttled_reqs[is_write],
382 &tgm->throttled_reqs_lock);
383 qemu_co_mutex_unlock(&tgm->throttled_reqs_lock);
384 qemu_mutex_lock(&tg->lock);
385 tgm->pending_reqs[is_write]--;
386 }
387
388 /* The I/O will be executed, so do the accounting */
389 throttle_account(tgm->throttle_state, is_write, bytes);
390
391 /* Schedule the next request */
392 schedule_next_request(tgm, is_write);
393
394 qemu_mutex_unlock(&tg->lock);
395 }
396
397 typedef struct {
398 ThrottleGroupMember *tgm;
399 bool is_write;
400 } RestartData;
401
402 static void coroutine_fn throttle_group_restart_queue_entry(void *opaque)
403 {
404 RestartData *data = opaque;
405 ThrottleGroupMember *tgm = data->tgm;
406 ThrottleState *ts = tgm->throttle_state;
407 ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
408 bool is_write = data->is_write;
409 bool empty_queue;
410
411 empty_queue = !throttle_group_co_restart_queue(tgm, is_write);
412
413 /* If the request queue was empty then we have to take care of
414 * scheduling the next one */
415 if (empty_queue) {
416 qemu_mutex_lock(&tg->lock);
417 schedule_next_request(tgm, is_write);
418 qemu_mutex_unlock(&tg->lock);
419 }
420
421 g_free(data);
422
423 qatomic_dec(&tgm->restart_pending);
424 aio_wait_kick();
425 }
426
427 static void throttle_group_restart_queue(ThrottleGroupMember *tgm, bool is_write)
428 {
429 Coroutine *co;
430 RestartData *rd = g_new0(RestartData, 1);
431
432 rd->tgm = tgm;
433 rd->is_write = is_write;
434
435 /* This function is called when a timer is fired or when
436 * throttle_group_restart_tgm() is called. Either way, there can
437 * be no timer pending on this tgm at this point */
438 assert(!timer_pending(tgm->throttle_timers.timers[is_write]));
439
440 qatomic_inc(&tgm->restart_pending);
441
442 co = qemu_coroutine_create(throttle_group_restart_queue_entry, rd);
443 aio_co_enter(tgm->aio_context, co);
444 }
445
446 void throttle_group_restart_tgm(ThrottleGroupMember *tgm)
447 {
448 int i;
449
450 if (tgm->throttle_state) {
451 for (i = 0; i < 2; i++) {
452 QEMUTimer *t = tgm->throttle_timers.timers[i];
453 if (timer_pending(t)) {
454 /* If there's a pending timer on this tgm, fire it now */
455 timer_del(t);
456 timer_cb(tgm, i);
457 } else {
458 /* Else run the next request from the queue manually */
459 throttle_group_restart_queue(tgm, i);
460 }
461 }
462 }
463 }
464
465 /* Update the throttle configuration for a particular group. Similar
466 * to throttle_config(), but guarantees atomicity within the
467 * throttling group.
468 *
469 * @tgm: a ThrottleGroupMember that is a member of the group
470 * @cfg: the configuration to set
471 */
472 void throttle_group_config(ThrottleGroupMember *tgm, ThrottleConfig *cfg)
473 {
474 ThrottleState *ts = tgm->throttle_state;
475 ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
476 qemu_mutex_lock(&tg->lock);
477 throttle_config(ts, tg->clock_type, cfg);
478 qemu_mutex_unlock(&tg->lock);
479
480 throttle_group_restart_tgm(tgm);
481 }
482
483 /* Get the throttle configuration from a particular group. Similar to
484 * throttle_get_config(), but guarantees atomicity within the
485 * throttling group.
486 *
487 * @tgm: a ThrottleGroupMember that is a member of the group
488 * @cfg: the configuration will be written here
489 */
490 void throttle_group_get_config(ThrottleGroupMember *tgm, ThrottleConfig *cfg)
491 {
492 ThrottleState *ts = tgm->throttle_state;
493 ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
494 qemu_mutex_lock(&tg->lock);
495 throttle_get_config(ts, cfg);
496 qemu_mutex_unlock(&tg->lock);
497 }
498
499 /* ThrottleTimers callback. This wakes up a request that was waiting
500 * because it had been throttled.
501 *
502 * @tgm: the ThrottleGroupMember whose request had been throttled
503 * @is_write: the type of operation (read/write)
504 */
505 static void timer_cb(ThrottleGroupMember *tgm, bool is_write)
506 {
507 ThrottleState *ts = tgm->throttle_state;
508 ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
509
510 /* The timer has just been fired, so we can update the flag */
511 qemu_mutex_lock(&tg->lock);
512 tg->any_timer_armed[is_write] = false;
513 qemu_mutex_unlock(&tg->lock);
514
515 /* Run the request that was waiting for this timer */
516 throttle_group_restart_queue(tgm, is_write);
517 }
518
519 static void read_timer_cb(void *opaque)
520 {
521 timer_cb(opaque, false);
522 }
523
524 static void write_timer_cb(void *opaque)
525 {
526 timer_cb(opaque, true);
527 }
528
529 /* Register a ThrottleGroupMember from the throttling group, also initializing
530 * its timers and updating its throttle_state pointer to point to it. If a
531 * throttling group with that name does not exist yet, it will be created.
532 *
533 * This function edits throttle_groups and must be called under the global
534 * mutex.
535 *
536 * @tgm: the ThrottleGroupMember to insert
537 * @groupname: the name of the group
538 * @ctx: the AioContext to use
539 */
540 void throttle_group_register_tgm(ThrottleGroupMember *tgm,
541 const char *groupname,
542 AioContext *ctx)
543 {
544 int i;
545 ThrottleState *ts = throttle_group_incref(groupname);
546 ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
547
548 tgm->throttle_state = ts;
549 tgm->aio_context = ctx;
550 qatomic_set(&tgm->restart_pending, 0);
551
552 QEMU_LOCK_GUARD(&tg->lock);
553 /* If the ThrottleGroup is new set this ThrottleGroupMember as the token */
554 for (i = 0; i < 2; i++) {
555 if (!tg->tokens[i]) {
556 tg->tokens[i] = tgm;
557 }
558 }
559
560 QLIST_INSERT_HEAD(&tg->head, tgm, round_robin);
561
562 throttle_timers_init(&tgm->throttle_timers,
563 tgm->aio_context,
564 tg->clock_type,
565 read_timer_cb,
566 write_timer_cb,
567 tgm);
568 qemu_co_mutex_init(&tgm->throttled_reqs_lock);
569 qemu_co_queue_init(&tgm->throttled_reqs[0]);
570 qemu_co_queue_init(&tgm->throttled_reqs[1]);
571 }
572
573 /* Unregister a ThrottleGroupMember from its group, removing it from the list,
574 * destroying the timers and setting the throttle_state pointer to NULL.
575 *
576 * The ThrottleGroupMember must not have pending throttled requests, so the
577 * caller has to drain them first.
578 *
579 * The group will be destroyed if it's empty after this operation.
580 *
581 * @tgm the ThrottleGroupMember to remove
582 */
583 void throttle_group_unregister_tgm(ThrottleGroupMember *tgm)
584 {
585 ThrottleState *ts = tgm->throttle_state;
586 ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
587 ThrottleGroupMember *token;
588 int i;
589
590 if (!ts) {
591 /* Discard already unregistered tgm */
592 return;
593 }
594
595 /* Wait for throttle_group_restart_queue_entry() coroutines to finish */
596 AIO_WAIT_WHILE(tgm->aio_context, qatomic_read(&tgm->restart_pending) > 0);
597
598 WITH_QEMU_LOCK_GUARD(&tg->lock) {
599 for (i = 0; i < 2; i++) {
600 assert(tgm->pending_reqs[i] == 0);
601 assert(qemu_co_queue_empty(&tgm->throttled_reqs[i]));
602 assert(!timer_pending(tgm->throttle_timers.timers[i]));
603 if (tg->tokens[i] == tgm) {
604 token = throttle_group_next_tgm(tgm);
605 /* Take care of the case where this is the last tgm in the group */
606 if (token == tgm) {
607 token = NULL;
608 }
609 tg->tokens[i] = token;
610 }
611 }
612
613 /* remove the current tgm from the list */
614 QLIST_REMOVE(tgm, round_robin);
615 throttle_timers_destroy(&tgm->throttle_timers);
616 }
617
618 throttle_group_unref(&tg->ts);
619 tgm->throttle_state = NULL;
620 }
621
622 void throttle_group_attach_aio_context(ThrottleGroupMember *tgm,
623 AioContext *new_context)
624 {
625 ThrottleTimers *tt = &tgm->throttle_timers;
626 throttle_timers_attach_aio_context(tt, new_context);
627 tgm->aio_context = new_context;
628 }
629
630 void throttle_group_detach_aio_context(ThrottleGroupMember *tgm)
631 {
632 ThrottleGroup *tg = container_of(tgm->throttle_state, ThrottleGroup, ts);
633 ThrottleTimers *tt = &tgm->throttle_timers;
634 int i;
635
636 /* Requests must have been drained */
637 assert(tgm->pending_reqs[0] == 0 && tgm->pending_reqs[1] == 0);
638 assert(qemu_co_queue_empty(&tgm->throttled_reqs[0]));
639 assert(qemu_co_queue_empty(&tgm->throttled_reqs[1]));
640
641 /* Kick off next ThrottleGroupMember, if necessary */
642 WITH_QEMU_LOCK_GUARD(&tg->lock) {
643 for (i = 0; i < 2; i++) {
644 if (timer_pending(tt->timers[i])) {
645 tg->any_timer_armed[i] = false;
646 schedule_next_request(tgm, i);
647 }
648 }
649 }
650
651 throttle_timers_detach_aio_context(tt);
652 tgm->aio_context = NULL;
653 }
654
655 #undef THROTTLE_OPT_PREFIX
656 #define THROTTLE_OPT_PREFIX "x-"
657
658 /* Helper struct and array for QOM property setter/getter */
659 typedef struct {
660 const char *name;
661 BucketType type;
662 enum {
663 AVG,
664 MAX,
665 BURST_LENGTH,
666 IOPS_SIZE,
667 } category;
668 } ThrottleParamInfo;
669
670 static ThrottleParamInfo properties[] = {
671 {
672 THROTTLE_OPT_PREFIX QEMU_OPT_IOPS_TOTAL,
673 THROTTLE_OPS_TOTAL, AVG,
674 },
675 {
676 THROTTLE_OPT_PREFIX QEMU_OPT_IOPS_TOTAL_MAX,
677 THROTTLE_OPS_TOTAL, MAX,
678 },
679 {
680 THROTTLE_OPT_PREFIX QEMU_OPT_IOPS_TOTAL_MAX_LENGTH,
681 THROTTLE_OPS_TOTAL, BURST_LENGTH,
682 },
683 {
684 THROTTLE_OPT_PREFIX QEMU_OPT_IOPS_READ,
685 THROTTLE_OPS_READ, AVG,
686 },
687 {
688 THROTTLE_OPT_PREFIX QEMU_OPT_IOPS_READ_MAX,
689 THROTTLE_OPS_READ, MAX,
690 },
691 {
692 THROTTLE_OPT_PREFIX QEMU_OPT_IOPS_READ_MAX_LENGTH,
693 THROTTLE_OPS_READ, BURST_LENGTH,
694 },
695 {
696 THROTTLE_OPT_PREFIX QEMU_OPT_IOPS_WRITE,
697 THROTTLE_OPS_WRITE, AVG,
698 },
699 {
700 THROTTLE_OPT_PREFIX QEMU_OPT_IOPS_WRITE_MAX,
701 THROTTLE_OPS_WRITE, MAX,
702 },
703 {
704 THROTTLE_OPT_PREFIX QEMU_OPT_IOPS_WRITE_MAX_LENGTH,
705 THROTTLE_OPS_WRITE, BURST_LENGTH,
706 },
707 {
708 THROTTLE_OPT_PREFIX QEMU_OPT_BPS_TOTAL,
709 THROTTLE_BPS_TOTAL, AVG,
710 },
711 {
712 THROTTLE_OPT_PREFIX QEMU_OPT_BPS_TOTAL_MAX,
713 THROTTLE_BPS_TOTAL, MAX,
714 },
715 {
716 THROTTLE_OPT_PREFIX QEMU_OPT_BPS_TOTAL_MAX_LENGTH,
717 THROTTLE_BPS_TOTAL, BURST_LENGTH,
718 },
719 {
720 THROTTLE_OPT_PREFIX QEMU_OPT_BPS_READ,
721 THROTTLE_BPS_READ, AVG,
722 },
723 {
724 THROTTLE_OPT_PREFIX QEMU_OPT_BPS_READ_MAX,
725 THROTTLE_BPS_READ, MAX,
726 },
727 {
728 THROTTLE_OPT_PREFIX QEMU_OPT_BPS_READ_MAX_LENGTH,
729 THROTTLE_BPS_READ, BURST_LENGTH,
730 },
731 {
732 THROTTLE_OPT_PREFIX QEMU_OPT_BPS_WRITE,
733 THROTTLE_BPS_WRITE, AVG,
734 },
735 {
736 THROTTLE_OPT_PREFIX QEMU_OPT_BPS_WRITE_MAX,
737 THROTTLE_BPS_WRITE, MAX,
738 },
739 {
740 THROTTLE_OPT_PREFIX QEMU_OPT_BPS_WRITE_MAX_LENGTH,
741 THROTTLE_BPS_WRITE, BURST_LENGTH,
742 },
743 {
744 THROTTLE_OPT_PREFIX QEMU_OPT_IOPS_SIZE,
745 0, IOPS_SIZE,
746 }
747 };
748
749 /* This function edits throttle_groups and must be called under the global
750 * mutex */
751 static void throttle_group_obj_init(Object *obj)
752 {
753 ThrottleGroup *tg = THROTTLE_GROUP(obj);
754
755 tg->clock_type = QEMU_CLOCK_REALTIME;
756 if (qtest_enabled()) {
757 /* For testing block IO throttling only */
758 tg->clock_type = QEMU_CLOCK_VIRTUAL;
759 }
760 tg->is_initialized = false;
761 qemu_mutex_init(&tg->lock);
762 throttle_init(&tg->ts);
763 QLIST_INIT(&tg->head);
764 }
765
766 /* This function edits throttle_groups and must be called under the global
767 * mutex */
768 static void throttle_group_obj_complete(UserCreatable *obj, Error **errp)
769 {
770 ThrottleGroup *tg = THROTTLE_GROUP(obj);
771 ThrottleConfig cfg;
772
773 /* set group name to object id if it exists */
774 if (!tg->name && tg->parent_obj.parent) {
775 tg->name = g_strdup(object_get_canonical_path_component(OBJECT(obj)));
776 }
777 /* We must have a group name at this point */
778 assert(tg->name);
779
780 /* error if name is duplicate */
781 if (throttle_group_exists(tg->name)) {
782 error_setg(errp, "A group with this name already exists");
783 return;
784 }
785
786 /* check validity */
787 throttle_get_config(&tg->ts, &cfg);
788 if (!throttle_is_valid(&cfg, errp)) {
789 return;
790 }
791 throttle_config(&tg->ts, tg->clock_type, &cfg);
792 QTAILQ_INSERT_TAIL(&throttle_groups, tg, list);
793 tg->is_initialized = true;
794 }
795
796 /* This function edits throttle_groups and must be called under the global
797 * mutex */
798 static void throttle_group_obj_finalize(Object *obj)
799 {
800 ThrottleGroup *tg = THROTTLE_GROUP(obj);
801 if (tg->is_initialized) {
802 QTAILQ_REMOVE(&throttle_groups, tg, list);
803 }
804 qemu_mutex_destroy(&tg->lock);
805 g_free(tg->name);
806 }
807
808 static void throttle_group_set(Object *obj, Visitor *v, const char * name,
809 void *opaque, Error **errp)
810
811 {
812 ThrottleGroup *tg = THROTTLE_GROUP(obj);
813 ThrottleConfig *cfg;
814 ThrottleParamInfo *info = opaque;
815 int64_t value;
816
817 /* If we have finished initialization, don't accept individual property
818 * changes through QOM. Throttle configuration limits must be set in one
819 * transaction, as certain combinations are invalid.
820 */
821 if (tg->is_initialized) {
822 error_setg(errp, "Property cannot be set after initialization");
823 return;
824 }
825
826 if (!visit_type_int64(v, name, &value, errp)) {
827 return;
828 }
829 if (value < 0) {
830 error_setg(errp, "Property values cannot be negative");
831 return;
832 }
833
834 cfg = &tg->ts.cfg;
835 switch (info->category) {
836 case AVG:
837 cfg->buckets[info->type].avg = value;
838 break;
839 case MAX:
840 cfg->buckets[info->type].max = value;
841 break;
842 case BURST_LENGTH:
843 if (value > UINT_MAX) {
844 error_setg(errp, "%s value must be in the" "range [0, %u]",
845 info->name, UINT_MAX);
846 return;
847 }
848 cfg->buckets[info->type].burst_length = value;
849 break;
850 case IOPS_SIZE:
851 cfg->op_size = value;
852 break;
853 }
854 }
855
856 static void throttle_group_get(Object *obj, Visitor *v, const char *name,
857 void *opaque, Error **errp)
858 {
859 ThrottleGroup *tg = THROTTLE_GROUP(obj);
860 ThrottleConfig cfg;
861 ThrottleParamInfo *info = opaque;
862 int64_t value;
863
864 throttle_get_config(&tg->ts, &cfg);
865 switch (info->category) {
866 case AVG:
867 value = cfg.buckets[info->type].avg;
868 break;
869 case MAX:
870 value = cfg.buckets[info->type].max;
871 break;
872 case BURST_LENGTH:
873 value = cfg.buckets[info->type].burst_length;
874 break;
875 case IOPS_SIZE:
876 value = cfg.op_size;
877 break;
878 }
879
880 visit_type_int64(v, name, &value, errp);
881 }
882
883 static void throttle_group_set_limits(Object *obj, Visitor *v,
884 const char *name, void *opaque,
885 Error **errp)
886
887 {
888 ThrottleGroup *tg = THROTTLE_GROUP(obj);
889 ThrottleConfig cfg;
890 ThrottleLimits *argp;
891 Error *local_err = NULL;
892
893 if (!visit_type_ThrottleLimits(v, name, &argp, errp)) {
894 return;
895 }
896 qemu_mutex_lock(&tg->lock);
897 throttle_get_config(&tg->ts, &cfg);
898 throttle_limits_to_config(argp, &cfg, &local_err);
899 if (local_err) {
900 goto unlock;
901 }
902 throttle_config(&tg->ts, tg->clock_type, &cfg);
903
904 unlock:
905 qemu_mutex_unlock(&tg->lock);
906 qapi_free_ThrottleLimits(argp);
907 error_propagate(errp, local_err);
908 return;
909 }
910
911 static void throttle_group_get_limits(Object *obj, Visitor *v,
912 const char *name, void *opaque,
913 Error **errp)
914 {
915 ThrottleGroup *tg = THROTTLE_GROUP(obj);
916 ThrottleConfig cfg;
917 ThrottleLimits arg = { 0 };
918 ThrottleLimits *argp = &arg;
919
920 qemu_mutex_lock(&tg->lock);
921 throttle_get_config(&tg->ts, &cfg);
922 qemu_mutex_unlock(&tg->lock);
923
924 throttle_config_to_limits(&cfg, argp);
925
926 visit_type_ThrottleLimits(v, name, &argp, errp);
927 }
928
929 static bool throttle_group_can_be_deleted(UserCreatable *uc)
930 {
931 return OBJECT(uc)->ref == 1;
932 }
933
934 static void throttle_group_obj_class_init(ObjectClass *klass, void *class_data)
935 {
936 size_t i = 0;
937 UserCreatableClass *ucc = USER_CREATABLE_CLASS(klass);
938
939 ucc->complete = throttle_group_obj_complete;
940 ucc->can_be_deleted = throttle_group_can_be_deleted;
941
942 /* individual properties */
943 for (i = 0; i < sizeof(properties) / sizeof(ThrottleParamInfo); i++) {
944 object_class_property_add(klass,
945 properties[i].name,
946 "int",
947 throttle_group_get,
948 throttle_group_set,
949 NULL, &properties[i]);
950 }
951
952 /* ThrottleLimits */
953 object_class_property_add(klass,
954 "limits", "ThrottleLimits",
955 throttle_group_get_limits,
956 throttle_group_set_limits,
957 NULL, NULL);
958 }
959
960 static const TypeInfo throttle_group_info = {
961 .name = TYPE_THROTTLE_GROUP,
962 .parent = TYPE_OBJECT,
963 .class_init = throttle_group_obj_class_init,
964 .instance_size = sizeof(ThrottleGroup),
965 .instance_init = throttle_group_obj_init,
966 .instance_finalize = throttle_group_obj_finalize,
967 .interfaces = (InterfaceInfo[]) {
968 { TYPE_USER_CREATABLE },
969 { }
970 },
971 };
972
973 static void throttle_groups_init(void)
974 {
975 type_register_static(&throttle_group_info);
976 }
977
978 type_init(throttle_groups_init);