xref: /openbmc/qemu/util/async.c (revision aae1746c726d6cc54e555bcca21e1eb5b56c21bf)
1  /*
2   * Data plane event loop
3   *
4   * Copyright (c) 2003-2008 Fabrice Bellard
5   * Copyright (c) 2009-2017 QEMU contributors
6   *
7   * Permission is hereby granted, free of charge, to any person obtaining a copy
8   * of this software and associated documentation files (the "Software"), to deal
9   * in the Software without restriction, including without limitation the rights
10   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11   * copies of the Software, and to permit persons to whom the Software is
12   * furnished to do so, subject to the following conditions:
13   *
14   * The above copyright notice and this permission notice shall be included in
15   * all copies or substantial portions of the Software.
16   *
17   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20   * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23   * THE SOFTWARE.
24   */
25  
26  #include "qemu/osdep.h"
27  #include "qapi/error.h"
28  #include "block/aio.h"
29  #include "block/thread-pool.h"
30  #include "qemu/main-loop.h"
31  #include "qemu/atomic.h"
32  #include "qemu/rcu_queue.h"
33  #include "block/raw-aio.h"
34  #include "qemu/coroutine_int.h"
35  #include "qemu/coroutine-tls.h"
36  #include "sysemu/cpu-timers.h"
37  #include "trace.h"
38  
39  /***********************************************************/
40  /* bottom halves (can be seen as timers which expire ASAP) */
41  
42  /* QEMUBH::flags values */
43  enum {
44      /* Already enqueued and waiting for aio_bh_poll() */
45      BH_PENDING   = (1 << 0),
46  
47      /* Invoke the callback */
48      BH_SCHEDULED = (1 << 1),
49  
50      /* Delete without invoking callback */
51      BH_DELETED   = (1 << 2),
52  
53      /* Delete after invoking callback */
54      BH_ONESHOT   = (1 << 3),
55  
56      /* Schedule periodically when the event loop is idle */
57      BH_IDLE      = (1 << 4),
58  };
59  
60  struct QEMUBH {
61      AioContext *ctx;
62      const char *name;
63      QEMUBHFunc *cb;
64      void *opaque;
65      QSLIST_ENTRY(QEMUBH) next;
66      unsigned flags;
67  };
68  
69  /* Called concurrently from any thread */
70  static void aio_bh_enqueue(QEMUBH *bh, unsigned new_flags)
71  {
72      AioContext *ctx = bh->ctx;
73      unsigned old_flags;
74  
75      /*
76       * The memory barrier implicit in qatomic_fetch_or makes sure that:
77       * 1. idle & any writes needed by the callback are done before the
78       *    locations are read in the aio_bh_poll.
79       * 2. ctx is loaded before the callback has a chance to execute and bh
80       *    could be freed.
81       */
82      old_flags = qatomic_fetch_or(&bh->flags, BH_PENDING | new_flags);
83      if (!(old_flags & BH_PENDING)) {
84          QSLIST_INSERT_HEAD_ATOMIC(&ctx->bh_list, bh, next);
85      }
86  
87      aio_notify(ctx);
88      /*
89       * Workaround for record/replay.
90       * vCPU execution should be suspended when new BH is set.
91       * This is needed to avoid guest timeouts caused
92       * by the long cycles of the execution.
93       */
94      icount_notify_exit();
95  }
96  
97  /* Only called from aio_bh_poll() and aio_ctx_finalize() */
98  static QEMUBH *aio_bh_dequeue(BHList *head, unsigned *flags)
99  {
100      QEMUBH *bh = QSLIST_FIRST_RCU(head);
101  
102      if (!bh) {
103          return NULL;
104      }
105  
106      QSLIST_REMOVE_HEAD(head, next);
107  
108      /*
109       * The qatomic_and is paired with aio_bh_enqueue().  The implicit memory
110       * barrier ensures that the callback sees all writes done by the scheduling
111       * thread.  It also ensures that the scheduling thread sees the cleared
112       * flag before bh->cb has run, and thus will call aio_notify again if
113       * necessary.
114       */
115      *flags = qatomic_fetch_and(&bh->flags,
116                                ~(BH_PENDING | BH_SCHEDULED | BH_IDLE));
117      return bh;
118  }
119  
120  void aio_bh_schedule_oneshot_full(AioContext *ctx, QEMUBHFunc *cb,
121                                    void *opaque, const char *name)
122  {
123      QEMUBH *bh;
124      bh = g_new(QEMUBH, 1);
125      *bh = (QEMUBH){
126          .ctx = ctx,
127          .cb = cb,
128          .opaque = opaque,
129          .name = name,
130      };
131      aio_bh_enqueue(bh, BH_SCHEDULED | BH_ONESHOT);
132  }
133  
134  QEMUBH *aio_bh_new_full(AioContext *ctx, QEMUBHFunc *cb, void *opaque,
135                          const char *name)
136  {
137      QEMUBH *bh;
138      bh = g_new(QEMUBH, 1);
139      *bh = (QEMUBH){
140          .ctx = ctx,
141          .cb = cb,
142          .opaque = opaque,
143          .name = name,
144      };
145      return bh;
146  }
147  
148  void aio_bh_call(QEMUBH *bh)
149  {
150      bh->cb(bh->opaque);
151  }
152  
153  /* Multiple occurrences of aio_bh_poll cannot be called concurrently. */
154  int aio_bh_poll(AioContext *ctx)
155  {
156      BHListSlice slice;
157      BHListSlice *s;
158      int ret = 0;
159  
160      QSLIST_MOVE_ATOMIC(&slice.bh_list, &ctx->bh_list);
161      QSIMPLEQ_INSERT_TAIL(&ctx->bh_slice_list, &slice, next);
162  
163      while ((s = QSIMPLEQ_FIRST(&ctx->bh_slice_list))) {
164          QEMUBH *bh;
165          unsigned flags;
166  
167          bh = aio_bh_dequeue(&s->bh_list, &flags);
168          if (!bh) {
169              QSIMPLEQ_REMOVE_HEAD(&ctx->bh_slice_list, next);
170              continue;
171          }
172  
173          if ((flags & (BH_SCHEDULED | BH_DELETED)) == BH_SCHEDULED) {
174              /* Idle BHs don't count as progress */
175              if (!(flags & BH_IDLE)) {
176                  ret = 1;
177              }
178              aio_bh_call(bh);
179          }
180          if (flags & (BH_DELETED | BH_ONESHOT)) {
181              g_free(bh);
182          }
183      }
184  
185      return ret;
186  }
187  
188  void qemu_bh_schedule_idle(QEMUBH *bh)
189  {
190      aio_bh_enqueue(bh, BH_SCHEDULED | BH_IDLE);
191  }
192  
193  void qemu_bh_schedule(QEMUBH *bh)
194  {
195      aio_bh_enqueue(bh, BH_SCHEDULED);
196  }
197  
198  /* This func is async.
199   */
200  void qemu_bh_cancel(QEMUBH *bh)
201  {
202      qatomic_and(&bh->flags, ~BH_SCHEDULED);
203  }
204  
205  /* This func is async.The bottom half will do the delete action at the finial
206   * end.
207   */
208  void qemu_bh_delete(QEMUBH *bh)
209  {
210      aio_bh_enqueue(bh, BH_DELETED);
211  }
212  
213  static int64_t aio_compute_bh_timeout(BHList *head, int timeout)
214  {
215      QEMUBH *bh;
216  
217      QSLIST_FOREACH_RCU(bh, head, next) {
218          if ((bh->flags & (BH_SCHEDULED | BH_DELETED)) == BH_SCHEDULED) {
219              if (bh->flags & BH_IDLE) {
220                  /* idle bottom halves will be polled at least
221                   * every 10ms */
222                  timeout = 10000000;
223              } else {
224                  /* non-idle bottom halves will be executed
225                   * immediately */
226                  return 0;
227              }
228          }
229      }
230  
231      return timeout;
232  }
233  
234  int64_t
235  aio_compute_timeout(AioContext *ctx)
236  {
237      BHListSlice *s;
238      int64_t deadline;
239      int timeout = -1;
240  
241      timeout = aio_compute_bh_timeout(&ctx->bh_list, timeout);
242      if (timeout == 0) {
243          return 0;
244      }
245  
246      QSIMPLEQ_FOREACH(s, &ctx->bh_slice_list, next) {
247          timeout = aio_compute_bh_timeout(&s->bh_list, timeout);
248          if (timeout == 0) {
249              return 0;
250          }
251      }
252  
253      deadline = timerlistgroup_deadline_ns(&ctx->tlg);
254      if (deadline == 0) {
255          return 0;
256      } else {
257          return qemu_soonest_timeout(timeout, deadline);
258      }
259  }
260  
261  static gboolean
262  aio_ctx_prepare(GSource *source, gint    *timeout)
263  {
264      AioContext *ctx = (AioContext *) source;
265  
266      qatomic_set(&ctx->notify_me, qatomic_read(&ctx->notify_me) | 1);
267  
268      /*
269       * Write ctx->notify_me before computing the timeout
270       * (reading bottom half flags, etc.).  Pairs with
271       * smp_mb in aio_notify().
272       */
273      smp_mb();
274  
275      /* We assume there is no timeout already supplied */
276      *timeout = qemu_timeout_ns_to_ms(aio_compute_timeout(ctx));
277  
278      if (aio_prepare(ctx)) {
279          *timeout = 0;
280      }
281  
282      return *timeout == 0;
283  }
284  
285  static gboolean
286  aio_ctx_check(GSource *source)
287  {
288      AioContext *ctx = (AioContext *) source;
289      QEMUBH *bh;
290      BHListSlice *s;
291  
292      /* Finish computing the timeout before clearing the flag.  */
293      qatomic_store_release(&ctx->notify_me, qatomic_read(&ctx->notify_me) & ~1);
294      aio_notify_accept(ctx);
295  
296      QSLIST_FOREACH_RCU(bh, &ctx->bh_list, next) {
297          if ((bh->flags & (BH_SCHEDULED | BH_DELETED)) == BH_SCHEDULED) {
298              return true;
299          }
300      }
301  
302      QSIMPLEQ_FOREACH(s, &ctx->bh_slice_list, next) {
303          QSLIST_FOREACH_RCU(bh, &s->bh_list, next) {
304              if ((bh->flags & (BH_SCHEDULED | BH_DELETED)) == BH_SCHEDULED) {
305                  return true;
306              }
307          }
308      }
309      return aio_pending(ctx) || (timerlistgroup_deadline_ns(&ctx->tlg) == 0);
310  }
311  
312  static gboolean
313  aio_ctx_dispatch(GSource     *source,
314                   GSourceFunc  callback,
315                   gpointer     user_data)
316  {
317      AioContext *ctx = (AioContext *) source;
318  
319      assert(callback == NULL);
320      aio_dispatch(ctx);
321      return true;
322  }
323  
324  static void
325  aio_ctx_finalize(GSource     *source)
326  {
327      AioContext *ctx = (AioContext *) source;
328      QEMUBH *bh;
329      unsigned flags;
330  
331      thread_pool_free(ctx->thread_pool);
332  
333  #ifdef CONFIG_LINUX_AIO
334      if (ctx->linux_aio) {
335          laio_detach_aio_context(ctx->linux_aio, ctx);
336          laio_cleanup(ctx->linux_aio);
337          ctx->linux_aio = NULL;
338      }
339  #endif
340  
341  #ifdef CONFIG_LINUX_IO_URING
342      if (ctx->linux_io_uring) {
343          luring_detach_aio_context(ctx->linux_io_uring, ctx);
344          luring_cleanup(ctx->linux_io_uring);
345          ctx->linux_io_uring = NULL;
346      }
347  #endif
348  
349      assert(QSLIST_EMPTY(&ctx->scheduled_coroutines));
350      qemu_bh_delete(ctx->co_schedule_bh);
351  
352      /* There must be no aio_bh_poll() calls going on */
353      assert(QSIMPLEQ_EMPTY(&ctx->bh_slice_list));
354  
355      while ((bh = aio_bh_dequeue(&ctx->bh_list, &flags))) {
356          /*
357           * qemu_bh_delete() must have been called on BHs in this AioContext. In
358           * many cases memory leaks, hangs, or inconsistent state occur when a
359           * BH is leaked because something still expects it to run.
360           *
361           * If you hit this, fix the lifecycle of the BH so that
362           * qemu_bh_delete() and any associated cleanup is called before the
363           * AioContext is finalized.
364           */
365          if (unlikely(!(flags & BH_DELETED))) {
366              fprintf(stderr, "%s: BH '%s' leaked, aborting...\n",
367                      __func__, bh->name);
368              abort();
369          }
370  
371          g_free(bh);
372      }
373  
374      aio_set_event_notifier(ctx, &ctx->notifier, false, NULL, NULL, NULL);
375      event_notifier_cleanup(&ctx->notifier);
376      qemu_rec_mutex_destroy(&ctx->lock);
377      qemu_lockcnt_destroy(&ctx->list_lock);
378      timerlistgroup_deinit(&ctx->tlg);
379      aio_context_destroy(ctx);
380  }
381  
382  static GSourceFuncs aio_source_funcs = {
383      aio_ctx_prepare,
384      aio_ctx_check,
385      aio_ctx_dispatch,
386      aio_ctx_finalize
387  };
388  
389  GSource *aio_get_g_source(AioContext *ctx)
390  {
391      aio_context_use_g_source(ctx);
392      g_source_ref(&ctx->source);
393      return &ctx->source;
394  }
395  
396  ThreadPool *aio_get_thread_pool(AioContext *ctx)
397  {
398      if (!ctx->thread_pool) {
399          ctx->thread_pool = thread_pool_new(ctx);
400      }
401      return ctx->thread_pool;
402  }
403  
404  #ifdef CONFIG_LINUX_AIO
405  LinuxAioState *aio_setup_linux_aio(AioContext *ctx, Error **errp)
406  {
407      if (!ctx->linux_aio) {
408          ctx->linux_aio = laio_init(errp);
409          if (ctx->linux_aio) {
410              laio_attach_aio_context(ctx->linux_aio, ctx);
411          }
412      }
413      return ctx->linux_aio;
414  }
415  
416  LinuxAioState *aio_get_linux_aio(AioContext *ctx)
417  {
418      assert(ctx->linux_aio);
419      return ctx->linux_aio;
420  }
421  #endif
422  
423  #ifdef CONFIG_LINUX_IO_URING
424  LuringState *aio_setup_linux_io_uring(AioContext *ctx, Error **errp)
425  {
426      if (ctx->linux_io_uring) {
427          return ctx->linux_io_uring;
428      }
429  
430      ctx->linux_io_uring = luring_init(errp);
431      if (!ctx->linux_io_uring) {
432          return NULL;
433      }
434  
435      luring_attach_aio_context(ctx->linux_io_uring, ctx);
436      return ctx->linux_io_uring;
437  }
438  
439  LuringState *aio_get_linux_io_uring(AioContext *ctx)
440  {
441      assert(ctx->linux_io_uring);
442      return ctx->linux_io_uring;
443  }
444  #endif
445  
446  void aio_notify(AioContext *ctx)
447  {
448      /*
449       * Write e.g. bh->flags before writing ctx->notified.  Pairs with smp_mb in
450       * aio_notify_accept.
451       */
452      smp_wmb();
453      qatomic_set(&ctx->notified, true);
454  
455      /*
456       * Write ctx->notified before reading ctx->notify_me.  Pairs
457       * with smp_mb in aio_ctx_prepare or aio_poll.
458       */
459      smp_mb();
460      if (qatomic_read(&ctx->notify_me)) {
461          event_notifier_set(&ctx->notifier);
462      }
463  }
464  
465  void aio_notify_accept(AioContext *ctx)
466  {
467      qatomic_set(&ctx->notified, false);
468  
469      /*
470       * Write ctx->notified before reading e.g. bh->flags.  Pairs with smp_wmb
471       * in aio_notify.
472       */
473      smp_mb();
474  }
475  
476  static void aio_timerlist_notify(void *opaque, QEMUClockType type)
477  {
478      aio_notify(opaque);
479  }
480  
481  static void aio_context_notifier_cb(EventNotifier *e)
482  {
483      AioContext *ctx = container_of(e, AioContext, notifier);
484  
485      event_notifier_test_and_clear(&ctx->notifier);
486  }
487  
488  /* Returns true if aio_notify() was called (e.g. a BH was scheduled) */
489  static bool aio_context_notifier_poll(void *opaque)
490  {
491      EventNotifier *e = opaque;
492      AioContext *ctx = container_of(e, AioContext, notifier);
493  
494      return qatomic_read(&ctx->notified);
495  }
496  
497  static void aio_context_notifier_poll_ready(EventNotifier *e)
498  {
499      /* Do nothing, we just wanted to kick the event loop */
500  }
501  
502  static void co_schedule_bh_cb(void *opaque)
503  {
504      AioContext *ctx = opaque;
505      QSLIST_HEAD(, Coroutine) straight, reversed;
506  
507      QSLIST_MOVE_ATOMIC(&reversed, &ctx->scheduled_coroutines);
508      QSLIST_INIT(&straight);
509  
510      while (!QSLIST_EMPTY(&reversed)) {
511          Coroutine *co = QSLIST_FIRST(&reversed);
512          QSLIST_REMOVE_HEAD(&reversed, co_scheduled_next);
513          QSLIST_INSERT_HEAD(&straight, co, co_scheduled_next);
514      }
515  
516      while (!QSLIST_EMPTY(&straight)) {
517          Coroutine *co = QSLIST_FIRST(&straight);
518          QSLIST_REMOVE_HEAD(&straight, co_scheduled_next);
519          trace_aio_co_schedule_bh_cb(ctx, co);
520          aio_context_acquire(ctx);
521  
522          /* Protected by write barrier in qemu_aio_coroutine_enter */
523          qatomic_set(&co->scheduled, NULL);
524          qemu_aio_coroutine_enter(ctx, co);
525          aio_context_release(ctx);
526      }
527  }
528  
529  AioContext *aio_context_new(Error **errp)
530  {
531      int ret;
532      AioContext *ctx;
533  
534      ctx = (AioContext *) g_source_new(&aio_source_funcs, sizeof(AioContext));
535      QSLIST_INIT(&ctx->bh_list);
536      QSIMPLEQ_INIT(&ctx->bh_slice_list);
537      aio_context_setup(ctx);
538  
539      ret = event_notifier_init(&ctx->notifier, false);
540      if (ret < 0) {
541          error_setg_errno(errp, -ret, "Failed to initialize event notifier");
542          goto fail;
543      }
544      g_source_set_can_recurse(&ctx->source, true);
545      qemu_lockcnt_init(&ctx->list_lock);
546  
547      ctx->co_schedule_bh = aio_bh_new(ctx, co_schedule_bh_cb, ctx);
548      QSLIST_INIT(&ctx->scheduled_coroutines);
549  
550      aio_set_event_notifier(ctx, &ctx->notifier,
551                             false,
552                             aio_context_notifier_cb,
553                             aio_context_notifier_poll,
554                             aio_context_notifier_poll_ready);
555  #ifdef CONFIG_LINUX_AIO
556      ctx->linux_aio = NULL;
557  #endif
558  
559  #ifdef CONFIG_LINUX_IO_URING
560      ctx->linux_io_uring = NULL;
561  #endif
562  
563      ctx->thread_pool = NULL;
564      qemu_rec_mutex_init(&ctx->lock);
565      timerlistgroup_init(&ctx->tlg, aio_timerlist_notify, ctx);
566  
567      ctx->poll_ns = 0;
568      ctx->poll_max_ns = 0;
569      ctx->poll_grow = 0;
570      ctx->poll_shrink = 0;
571  
572      ctx->aio_max_batch = 0;
573  
574      ctx->thread_pool_min = 0;
575      ctx->thread_pool_max = THREAD_POOL_MAX_THREADS_DEFAULT;
576  
577      return ctx;
578  fail:
579      g_source_destroy(&ctx->source);
580      return NULL;
581  }
582  
583  void aio_co_schedule(AioContext *ctx, Coroutine *co)
584  {
585      trace_aio_co_schedule(ctx, co);
586      const char *scheduled = qatomic_cmpxchg(&co->scheduled, NULL,
587                                             __func__);
588  
589      if (scheduled) {
590          fprintf(stderr,
591                  "%s: Co-routine was already scheduled in '%s'\n",
592                  __func__, scheduled);
593          abort();
594      }
595  
596      /* The coroutine might run and release the last ctx reference before we
597       * invoke qemu_bh_schedule().  Take a reference to keep ctx alive until
598       * we're done.
599       */
600      aio_context_ref(ctx);
601  
602      QSLIST_INSERT_HEAD_ATOMIC(&ctx->scheduled_coroutines,
603                                co, co_scheduled_next);
604      qemu_bh_schedule(ctx->co_schedule_bh);
605  
606      aio_context_unref(ctx);
607  }
608  
609  typedef struct AioCoRescheduleSelf {
610      Coroutine *co;
611      AioContext *new_ctx;
612  } AioCoRescheduleSelf;
613  
614  static void aio_co_reschedule_self_bh(void *opaque)
615  {
616      AioCoRescheduleSelf *data = opaque;
617      aio_co_schedule(data->new_ctx, data->co);
618  }
619  
620  void coroutine_fn aio_co_reschedule_self(AioContext *new_ctx)
621  {
622      AioContext *old_ctx = qemu_get_current_aio_context();
623  
624      if (old_ctx != new_ctx) {
625          AioCoRescheduleSelf data = {
626              .co = qemu_coroutine_self(),
627              .new_ctx = new_ctx,
628          };
629          /*
630           * We can't directly schedule the coroutine in the target context
631           * because this would be racy: The other thread could try to enter the
632           * coroutine before it has yielded in this one.
633           */
634          aio_bh_schedule_oneshot(old_ctx, aio_co_reschedule_self_bh, &data);
635          qemu_coroutine_yield();
636      }
637  }
638  
639  void aio_co_wake(struct Coroutine *co)
640  {
641      AioContext *ctx;
642  
643      /* Read coroutine before co->ctx.  Matches smp_wmb in
644       * qemu_coroutine_enter.
645       */
646      smp_read_barrier_depends();
647      ctx = qatomic_read(&co->ctx);
648  
649      aio_co_enter(ctx, co);
650  }
651  
652  void aio_co_enter(AioContext *ctx, struct Coroutine *co)
653  {
654      if (ctx != qemu_get_current_aio_context()) {
655          aio_co_schedule(ctx, co);
656          return;
657      }
658  
659      if (qemu_in_coroutine()) {
660          Coroutine *self = qemu_coroutine_self();
661          assert(self != co);
662          QSIMPLEQ_INSERT_TAIL(&self->co_queue_wakeup, co, co_queue_next);
663      } else {
664          aio_context_acquire(ctx);
665          qemu_aio_coroutine_enter(ctx, co);
666          aio_context_release(ctx);
667      }
668  }
669  
670  void aio_context_ref(AioContext *ctx)
671  {
672      g_source_ref(&ctx->source);
673  }
674  
675  void aio_context_unref(AioContext *ctx)
676  {
677      g_source_unref(&ctx->source);
678  }
679  
680  void aio_context_acquire(AioContext *ctx)
681  {
682      qemu_rec_mutex_lock(&ctx->lock);
683  }
684  
685  void aio_context_release(AioContext *ctx)
686  {
687      qemu_rec_mutex_unlock(&ctx->lock);
688  }
689  
690  QEMU_DEFINE_STATIC_CO_TLS(AioContext *, my_aiocontext)
691  
692  AioContext *qemu_get_current_aio_context(void)
693  {
694      AioContext *ctx = get_my_aiocontext();
695      if (ctx) {
696          return ctx;
697      }
698      if (qemu_mutex_iothread_locked()) {
699          /* Possibly in a vCPU thread.  */
700          return qemu_get_aio_context();
701      }
702      return NULL;
703  }
704  
705  void qemu_set_current_aio_context(AioContext *ctx)
706  {
707      assert(!get_my_aiocontext());
708      set_my_aiocontext(ctx);
709  }
710  
711  void aio_context_set_thread_pool_params(AioContext *ctx, int64_t min,
712                                          int64_t max, Error **errp)
713  {
714  
715      if (min > max || !max || min > INT_MAX || max > INT_MAX) {
716          error_setg(errp, "bad thread-pool-min/thread-pool-max values");
717          return;
718      }
719  
720      ctx->thread_pool_min = min;
721      ctx->thread_pool_max = max;
722  
723      if (ctx->thread_pool) {
724          thread_pool_update_params(ctx->thread_pool, ctx);
725      }
726  }
727