1c2b38b27SPaolo Bonzini /* 2c2b38b27SPaolo Bonzini * Data plane event loop 3c2b38b27SPaolo Bonzini * 4c2b38b27SPaolo Bonzini * Copyright (c) 2003-2008 Fabrice Bellard 5c2b38b27SPaolo Bonzini * Copyright (c) 2009-2017 QEMU contributors 6c2b38b27SPaolo Bonzini * 7c2b38b27SPaolo Bonzini * Permission is hereby granted, free of charge, to any person obtaining a copy 8c2b38b27SPaolo Bonzini * of this software and associated documentation files (the "Software"), to deal 9c2b38b27SPaolo Bonzini * in the Software without restriction, including without limitation the rights 10c2b38b27SPaolo Bonzini * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 11c2b38b27SPaolo Bonzini * copies of the Software, and to permit persons to whom the Software is 12c2b38b27SPaolo Bonzini * furnished to do so, subject to the following conditions: 13c2b38b27SPaolo Bonzini * 14c2b38b27SPaolo Bonzini * The above copyright notice and this permission notice shall be included in 15c2b38b27SPaolo Bonzini * all copies or substantial portions of the Software. 16c2b38b27SPaolo Bonzini * 17c2b38b27SPaolo Bonzini * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 18c2b38b27SPaolo Bonzini * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 19c2b38b27SPaolo Bonzini * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 20c2b38b27SPaolo Bonzini * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 21c2b38b27SPaolo Bonzini * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 22c2b38b27SPaolo Bonzini * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 23c2b38b27SPaolo Bonzini * THE SOFTWARE. 24c2b38b27SPaolo Bonzini */ 25c2b38b27SPaolo Bonzini 26c2b38b27SPaolo Bonzini #include "qemu/osdep.h" 27c2b38b27SPaolo Bonzini #include "qapi/error.h" 28c2b38b27SPaolo Bonzini #include "block/aio.h" 29c2b38b27SPaolo Bonzini #include "block/thread-pool.h" 30c2b38b27SPaolo Bonzini #include "qemu/main-loop.h" 31c2b38b27SPaolo Bonzini #include "qemu/atomic.h" 328c6b0356SStefan Hajnoczi #include "qemu/rcu_queue.h" 33c2b38b27SPaolo Bonzini #include "block/raw-aio.h" 340c330a73SPaolo Bonzini #include "qemu/coroutine_int.h" 35*47b74464SStefan Hajnoczi #include "qemu/coroutine-tls.h" 360c330a73SPaolo Bonzini #include "trace.h" 37c2b38b27SPaolo Bonzini 38c2b38b27SPaolo Bonzini /***********************************************************/ 39c2b38b27SPaolo Bonzini /* bottom halves (can be seen as timers which expire ASAP) */ 40c2b38b27SPaolo Bonzini 418c6b0356SStefan Hajnoczi /* QEMUBH::flags values */ 428c6b0356SStefan Hajnoczi enum { 438c6b0356SStefan Hajnoczi /* Already enqueued and waiting for aio_bh_poll() */ 448c6b0356SStefan Hajnoczi BH_PENDING = (1 << 0), 458c6b0356SStefan Hajnoczi 468c6b0356SStefan Hajnoczi /* Invoke the callback */ 478c6b0356SStefan Hajnoczi BH_SCHEDULED = (1 << 1), 488c6b0356SStefan Hajnoczi 498c6b0356SStefan Hajnoczi /* Delete without invoking callback */ 508c6b0356SStefan Hajnoczi BH_DELETED = (1 << 2), 518c6b0356SStefan Hajnoczi 528c6b0356SStefan Hajnoczi /* Delete after invoking callback */ 538c6b0356SStefan Hajnoczi BH_ONESHOT = (1 << 3), 548c6b0356SStefan Hajnoczi 558c6b0356SStefan Hajnoczi /* Schedule periodically when the event loop is idle */ 568c6b0356SStefan Hajnoczi BH_IDLE = (1 << 4), 578c6b0356SStefan Hajnoczi }; 588c6b0356SStefan Hajnoczi 59c2b38b27SPaolo Bonzini struct QEMUBH { 60c2b38b27SPaolo Bonzini AioContext *ctx; 610f08586cSStefan Hajnoczi const char *name; 62c2b38b27SPaolo Bonzini QEMUBHFunc *cb; 63c2b38b27SPaolo Bonzini void *opaque; 648c6b0356SStefan Hajnoczi QSLIST_ENTRY(QEMUBH) next; 658c6b0356SStefan Hajnoczi unsigned flags; 66c2b38b27SPaolo Bonzini }; 67c2b38b27SPaolo Bonzini 688c6b0356SStefan Hajnoczi /* Called concurrently from any thread */ 698c6b0356SStefan Hajnoczi static void aio_bh_enqueue(QEMUBH *bh, unsigned new_flags) 708c6b0356SStefan Hajnoczi { 718c6b0356SStefan Hajnoczi AioContext *ctx = bh->ctx; 728c6b0356SStefan Hajnoczi unsigned old_flags; 738c6b0356SStefan Hajnoczi 748c6b0356SStefan Hajnoczi /* 75d73415a3SStefan Hajnoczi * The memory barrier implicit in qatomic_fetch_or makes sure that: 768c6b0356SStefan Hajnoczi * 1. idle & any writes needed by the callback are done before the 778c6b0356SStefan Hajnoczi * locations are read in the aio_bh_poll. 788c6b0356SStefan Hajnoczi * 2. ctx is loaded before the callback has a chance to execute and bh 798c6b0356SStefan Hajnoczi * could be freed. 808c6b0356SStefan Hajnoczi */ 81d73415a3SStefan Hajnoczi old_flags = qatomic_fetch_or(&bh->flags, BH_PENDING | new_flags); 828c6b0356SStefan Hajnoczi if (!(old_flags & BH_PENDING)) { 838c6b0356SStefan Hajnoczi QSLIST_INSERT_HEAD_ATOMIC(&ctx->bh_list, bh, next); 848c6b0356SStefan Hajnoczi } 858c6b0356SStefan Hajnoczi 868c6b0356SStefan Hajnoczi aio_notify(ctx); 878c6b0356SStefan Hajnoczi } 888c6b0356SStefan Hajnoczi 898c6b0356SStefan Hajnoczi /* Only called from aio_bh_poll() and aio_ctx_finalize() */ 908c6b0356SStefan Hajnoczi static QEMUBH *aio_bh_dequeue(BHList *head, unsigned *flags) 918c6b0356SStefan Hajnoczi { 928c6b0356SStefan Hajnoczi QEMUBH *bh = QSLIST_FIRST_RCU(head); 938c6b0356SStefan Hajnoczi 948c6b0356SStefan Hajnoczi if (!bh) { 958c6b0356SStefan Hajnoczi return NULL; 968c6b0356SStefan Hajnoczi } 978c6b0356SStefan Hajnoczi 988c6b0356SStefan Hajnoczi QSLIST_REMOVE_HEAD(head, next); 998c6b0356SStefan Hajnoczi 1008c6b0356SStefan Hajnoczi /* 101d73415a3SStefan Hajnoczi * The qatomic_and is paired with aio_bh_enqueue(). The implicit memory 1028c6b0356SStefan Hajnoczi * barrier ensures that the callback sees all writes done by the scheduling 1038c6b0356SStefan Hajnoczi * thread. It also ensures that the scheduling thread sees the cleared 1048c6b0356SStefan Hajnoczi * flag before bh->cb has run, and thus will call aio_notify again if 1058c6b0356SStefan Hajnoczi * necessary. 1068c6b0356SStefan Hajnoczi */ 107d73415a3SStefan Hajnoczi *flags = qatomic_fetch_and(&bh->flags, 1088c6b0356SStefan Hajnoczi ~(BH_PENDING | BH_SCHEDULED | BH_IDLE)); 1098c6b0356SStefan Hajnoczi return bh; 1108c6b0356SStefan Hajnoczi } 1118c6b0356SStefan Hajnoczi 1120f08586cSStefan Hajnoczi void aio_bh_schedule_oneshot_full(AioContext *ctx, QEMUBHFunc *cb, 1130f08586cSStefan Hajnoczi void *opaque, const char *name) 114c2b38b27SPaolo Bonzini { 115c2b38b27SPaolo Bonzini QEMUBH *bh; 116c2b38b27SPaolo Bonzini bh = g_new(QEMUBH, 1); 117c2b38b27SPaolo Bonzini *bh = (QEMUBH){ 118c2b38b27SPaolo Bonzini .ctx = ctx, 119c2b38b27SPaolo Bonzini .cb = cb, 120c2b38b27SPaolo Bonzini .opaque = opaque, 1210f08586cSStefan Hajnoczi .name = name, 122c2b38b27SPaolo Bonzini }; 1238c6b0356SStefan Hajnoczi aio_bh_enqueue(bh, BH_SCHEDULED | BH_ONESHOT); 124c2b38b27SPaolo Bonzini } 125c2b38b27SPaolo Bonzini 1260f08586cSStefan Hajnoczi QEMUBH *aio_bh_new_full(AioContext *ctx, QEMUBHFunc *cb, void *opaque, 1270f08586cSStefan Hajnoczi const char *name) 128c2b38b27SPaolo Bonzini { 129c2b38b27SPaolo Bonzini QEMUBH *bh; 130c2b38b27SPaolo Bonzini bh = g_new(QEMUBH, 1); 131c2b38b27SPaolo Bonzini *bh = (QEMUBH){ 132c2b38b27SPaolo Bonzini .ctx = ctx, 133c2b38b27SPaolo Bonzini .cb = cb, 134c2b38b27SPaolo Bonzini .opaque = opaque, 1350f08586cSStefan Hajnoczi .name = name, 136c2b38b27SPaolo Bonzini }; 137c2b38b27SPaolo Bonzini return bh; 138c2b38b27SPaolo Bonzini } 139c2b38b27SPaolo Bonzini 140c2b38b27SPaolo Bonzini void aio_bh_call(QEMUBH *bh) 141c2b38b27SPaolo Bonzini { 142c2b38b27SPaolo Bonzini bh->cb(bh->opaque); 143c2b38b27SPaolo Bonzini } 144c2b38b27SPaolo Bonzini 1458c6b0356SStefan Hajnoczi /* Multiple occurrences of aio_bh_poll cannot be called concurrently. */ 146c2b38b27SPaolo Bonzini int aio_bh_poll(AioContext *ctx) 147c2b38b27SPaolo Bonzini { 1488c6b0356SStefan Hajnoczi BHListSlice slice; 1498c6b0356SStefan Hajnoczi BHListSlice *s; 1508c6b0356SStefan Hajnoczi int ret = 0; 151c2b38b27SPaolo Bonzini 1528c6b0356SStefan Hajnoczi QSLIST_MOVE_ATOMIC(&slice.bh_list, &ctx->bh_list); 1538c6b0356SStefan Hajnoczi QSIMPLEQ_INSERT_TAIL(&ctx->bh_slice_list, &slice, next); 1548c6b0356SStefan Hajnoczi 1558c6b0356SStefan Hajnoczi while ((s = QSIMPLEQ_FIRST(&ctx->bh_slice_list))) { 1568c6b0356SStefan Hajnoczi QEMUBH *bh; 1578c6b0356SStefan Hajnoczi unsigned flags; 1588c6b0356SStefan Hajnoczi 1598c6b0356SStefan Hajnoczi bh = aio_bh_dequeue(&s->bh_list, &flags); 1608c6b0356SStefan Hajnoczi if (!bh) { 1618c6b0356SStefan Hajnoczi QSIMPLEQ_REMOVE_HEAD(&ctx->bh_slice_list, next); 1628c6b0356SStefan Hajnoczi continue; 1638c6b0356SStefan Hajnoczi } 1648c6b0356SStefan Hajnoczi 1658c6b0356SStefan Hajnoczi if ((flags & (BH_SCHEDULED | BH_DELETED)) == BH_SCHEDULED) { 166c2b38b27SPaolo Bonzini /* Idle BHs don't count as progress */ 1678c6b0356SStefan Hajnoczi if (!(flags & BH_IDLE)) { 168c2b38b27SPaolo Bonzini ret = 1; 169c2b38b27SPaolo Bonzini } 170c2b38b27SPaolo Bonzini aio_bh_call(bh); 171c2b38b27SPaolo Bonzini } 1728c6b0356SStefan Hajnoczi if (flags & (BH_DELETED | BH_ONESHOT)) { 173c2b38b27SPaolo Bonzini g_free(bh); 174c2b38b27SPaolo Bonzini } 175c2b38b27SPaolo Bonzini } 1768c6b0356SStefan Hajnoczi 177c2b38b27SPaolo Bonzini return ret; 178c2b38b27SPaolo Bonzini } 179c2b38b27SPaolo Bonzini 180c2b38b27SPaolo Bonzini void qemu_bh_schedule_idle(QEMUBH *bh) 181c2b38b27SPaolo Bonzini { 1828c6b0356SStefan Hajnoczi aio_bh_enqueue(bh, BH_SCHEDULED | BH_IDLE); 183c2b38b27SPaolo Bonzini } 184c2b38b27SPaolo Bonzini 185c2b38b27SPaolo Bonzini void qemu_bh_schedule(QEMUBH *bh) 186c2b38b27SPaolo Bonzini { 1878c6b0356SStefan Hajnoczi aio_bh_enqueue(bh, BH_SCHEDULED); 188c2b38b27SPaolo Bonzini } 189c2b38b27SPaolo Bonzini 190c2b38b27SPaolo Bonzini /* This func is async. 191c2b38b27SPaolo Bonzini */ 192c2b38b27SPaolo Bonzini void qemu_bh_cancel(QEMUBH *bh) 193c2b38b27SPaolo Bonzini { 194d73415a3SStefan Hajnoczi qatomic_and(&bh->flags, ~BH_SCHEDULED); 195c2b38b27SPaolo Bonzini } 196c2b38b27SPaolo Bonzini 197c2b38b27SPaolo Bonzini /* This func is async.The bottom half will do the delete action at the finial 198c2b38b27SPaolo Bonzini * end. 199c2b38b27SPaolo Bonzini */ 200c2b38b27SPaolo Bonzini void qemu_bh_delete(QEMUBH *bh) 201c2b38b27SPaolo Bonzini { 2028c6b0356SStefan Hajnoczi aio_bh_enqueue(bh, BH_DELETED); 203c2b38b27SPaolo Bonzini } 204c2b38b27SPaolo Bonzini 2058c6b0356SStefan Hajnoczi static int64_t aio_compute_bh_timeout(BHList *head, int timeout) 206c2b38b27SPaolo Bonzini { 207c2b38b27SPaolo Bonzini QEMUBH *bh; 208c2b38b27SPaolo Bonzini 2098c6b0356SStefan Hajnoczi QSLIST_FOREACH_RCU(bh, head, next) { 2108c6b0356SStefan Hajnoczi if ((bh->flags & (BH_SCHEDULED | BH_DELETED)) == BH_SCHEDULED) { 2118c6b0356SStefan Hajnoczi if (bh->flags & BH_IDLE) { 212c2b38b27SPaolo Bonzini /* idle bottom halves will be polled at least 213c2b38b27SPaolo Bonzini * every 10ms */ 214c2b38b27SPaolo Bonzini timeout = 10000000; 215c2b38b27SPaolo Bonzini } else { 216c2b38b27SPaolo Bonzini /* non-idle bottom halves will be executed 217c2b38b27SPaolo Bonzini * immediately */ 218c2b38b27SPaolo Bonzini return 0; 219c2b38b27SPaolo Bonzini } 220c2b38b27SPaolo Bonzini } 221c2b38b27SPaolo Bonzini } 222c2b38b27SPaolo Bonzini 2238c6b0356SStefan Hajnoczi return timeout; 2248c6b0356SStefan Hajnoczi } 2258c6b0356SStefan Hajnoczi 2268c6b0356SStefan Hajnoczi int64_t 2278c6b0356SStefan Hajnoczi aio_compute_timeout(AioContext *ctx) 2288c6b0356SStefan Hajnoczi { 2298c6b0356SStefan Hajnoczi BHListSlice *s; 2308c6b0356SStefan Hajnoczi int64_t deadline; 2318c6b0356SStefan Hajnoczi int timeout = -1; 2328c6b0356SStefan Hajnoczi 2338c6b0356SStefan Hajnoczi timeout = aio_compute_bh_timeout(&ctx->bh_list, timeout); 2348c6b0356SStefan Hajnoczi if (timeout == 0) { 2358c6b0356SStefan Hajnoczi return 0; 2368c6b0356SStefan Hajnoczi } 2378c6b0356SStefan Hajnoczi 2388c6b0356SStefan Hajnoczi QSIMPLEQ_FOREACH(s, &ctx->bh_slice_list, next) { 2398c6b0356SStefan Hajnoczi timeout = aio_compute_bh_timeout(&s->bh_list, timeout); 2408c6b0356SStefan Hajnoczi if (timeout == 0) { 2418c6b0356SStefan Hajnoczi return 0; 2428c6b0356SStefan Hajnoczi } 2438c6b0356SStefan Hajnoczi } 2448c6b0356SStefan Hajnoczi 245c2b38b27SPaolo Bonzini deadline = timerlistgroup_deadline_ns(&ctx->tlg); 246c2b38b27SPaolo Bonzini if (deadline == 0) { 247c2b38b27SPaolo Bonzini return 0; 248c2b38b27SPaolo Bonzini } else { 249c2b38b27SPaolo Bonzini return qemu_soonest_timeout(timeout, deadline); 250c2b38b27SPaolo Bonzini } 251c2b38b27SPaolo Bonzini } 252c2b38b27SPaolo Bonzini 253c2b38b27SPaolo Bonzini static gboolean 254c2b38b27SPaolo Bonzini aio_ctx_prepare(GSource *source, gint *timeout) 255c2b38b27SPaolo Bonzini { 256c2b38b27SPaolo Bonzini AioContext *ctx = (AioContext *) source; 257c2b38b27SPaolo Bonzini 258d73415a3SStefan Hajnoczi qatomic_set(&ctx->notify_me, qatomic_read(&ctx->notify_me) | 1); 2595710a3e0SPaolo Bonzini 2605710a3e0SPaolo Bonzini /* 2615710a3e0SPaolo Bonzini * Write ctx->notify_me before computing the timeout 2625710a3e0SPaolo Bonzini * (reading bottom half flags, etc.). Pairs with 2635710a3e0SPaolo Bonzini * smp_mb in aio_notify(). 2645710a3e0SPaolo Bonzini */ 2655710a3e0SPaolo Bonzini smp_mb(); 266c2b38b27SPaolo Bonzini 267c2b38b27SPaolo Bonzini /* We assume there is no timeout already supplied */ 268c2b38b27SPaolo Bonzini *timeout = qemu_timeout_ns_to_ms(aio_compute_timeout(ctx)); 269c2b38b27SPaolo Bonzini 270c2b38b27SPaolo Bonzini if (aio_prepare(ctx)) { 271c2b38b27SPaolo Bonzini *timeout = 0; 272c2b38b27SPaolo Bonzini } 273c2b38b27SPaolo Bonzini 274c2b38b27SPaolo Bonzini return *timeout == 0; 275c2b38b27SPaolo Bonzini } 276c2b38b27SPaolo Bonzini 277c2b38b27SPaolo Bonzini static gboolean 278c2b38b27SPaolo Bonzini aio_ctx_check(GSource *source) 279c2b38b27SPaolo Bonzini { 280c2b38b27SPaolo Bonzini AioContext *ctx = (AioContext *) source; 281c2b38b27SPaolo Bonzini QEMUBH *bh; 2828c6b0356SStefan Hajnoczi BHListSlice *s; 283c2b38b27SPaolo Bonzini 2845710a3e0SPaolo Bonzini /* Finish computing the timeout before clearing the flag. */ 285d73415a3SStefan Hajnoczi qatomic_store_release(&ctx->notify_me, qatomic_read(&ctx->notify_me) & ~1); 286c2b38b27SPaolo Bonzini aio_notify_accept(ctx); 287c2b38b27SPaolo Bonzini 2888c6b0356SStefan Hajnoczi QSLIST_FOREACH_RCU(bh, &ctx->bh_list, next) { 2898c6b0356SStefan Hajnoczi if ((bh->flags & (BH_SCHEDULED | BH_DELETED)) == BH_SCHEDULED) { 290c2b38b27SPaolo Bonzini return true; 291c2b38b27SPaolo Bonzini } 292c2b38b27SPaolo Bonzini } 2938c6b0356SStefan Hajnoczi 2948c6b0356SStefan Hajnoczi QSIMPLEQ_FOREACH(s, &ctx->bh_slice_list, next) { 2958c6b0356SStefan Hajnoczi QSLIST_FOREACH_RCU(bh, &s->bh_list, next) { 2968c6b0356SStefan Hajnoczi if ((bh->flags & (BH_SCHEDULED | BH_DELETED)) == BH_SCHEDULED) { 2978c6b0356SStefan Hajnoczi return true; 2988c6b0356SStefan Hajnoczi } 2998c6b0356SStefan Hajnoczi } 3008c6b0356SStefan Hajnoczi } 301c2b38b27SPaolo Bonzini return aio_pending(ctx) || (timerlistgroup_deadline_ns(&ctx->tlg) == 0); 302c2b38b27SPaolo Bonzini } 303c2b38b27SPaolo Bonzini 304c2b38b27SPaolo Bonzini static gboolean 305c2b38b27SPaolo Bonzini aio_ctx_dispatch(GSource *source, 306c2b38b27SPaolo Bonzini GSourceFunc callback, 307c2b38b27SPaolo Bonzini gpointer user_data) 308c2b38b27SPaolo Bonzini { 309c2b38b27SPaolo Bonzini AioContext *ctx = (AioContext *) source; 310c2b38b27SPaolo Bonzini 311c2b38b27SPaolo Bonzini assert(callback == NULL); 312a153bf52SPaolo Bonzini aio_dispatch(ctx); 313c2b38b27SPaolo Bonzini return true; 314c2b38b27SPaolo Bonzini } 315c2b38b27SPaolo Bonzini 316c2b38b27SPaolo Bonzini static void 317c2b38b27SPaolo Bonzini aio_ctx_finalize(GSource *source) 318c2b38b27SPaolo Bonzini { 319c2b38b27SPaolo Bonzini AioContext *ctx = (AioContext *) source; 3208c6b0356SStefan Hajnoczi QEMUBH *bh; 3218c6b0356SStefan Hajnoczi unsigned flags; 322c2b38b27SPaolo Bonzini 323c2b38b27SPaolo Bonzini thread_pool_free(ctx->thread_pool); 324c2b38b27SPaolo Bonzini 325c2b38b27SPaolo Bonzini #ifdef CONFIG_LINUX_AIO 326c2b38b27SPaolo Bonzini if (ctx->linux_aio) { 327c2b38b27SPaolo Bonzini laio_detach_aio_context(ctx->linux_aio, ctx); 328c2b38b27SPaolo Bonzini laio_cleanup(ctx->linux_aio); 329c2b38b27SPaolo Bonzini ctx->linux_aio = NULL; 330c2b38b27SPaolo Bonzini } 331c2b38b27SPaolo Bonzini #endif 332c2b38b27SPaolo Bonzini 333fcb7a4a4SAarushi Mehta #ifdef CONFIG_LINUX_IO_URING 334fcb7a4a4SAarushi Mehta if (ctx->linux_io_uring) { 335fcb7a4a4SAarushi Mehta luring_detach_aio_context(ctx->linux_io_uring, ctx); 336fcb7a4a4SAarushi Mehta luring_cleanup(ctx->linux_io_uring); 337fcb7a4a4SAarushi Mehta ctx->linux_io_uring = NULL; 338fcb7a4a4SAarushi Mehta } 339fcb7a4a4SAarushi Mehta #endif 340fcb7a4a4SAarushi Mehta 3410c330a73SPaolo Bonzini assert(QSLIST_EMPTY(&ctx->scheduled_coroutines)); 3420c330a73SPaolo Bonzini qemu_bh_delete(ctx->co_schedule_bh); 3430c330a73SPaolo Bonzini 3448c6b0356SStefan Hajnoczi /* There must be no aio_bh_poll() calls going on */ 3458c6b0356SStefan Hajnoczi assert(QSIMPLEQ_EMPTY(&ctx->bh_slice_list)); 346c2b38b27SPaolo Bonzini 3478c6b0356SStefan Hajnoczi while ((bh = aio_bh_dequeue(&ctx->bh_list, &flags))) { 348023ca420SStefan Hajnoczi /* 349023ca420SStefan Hajnoczi * qemu_bh_delete() must have been called on BHs in this AioContext. In 350023ca420SStefan Hajnoczi * many cases memory leaks, hangs, or inconsistent state occur when a 351023ca420SStefan Hajnoczi * BH is leaked because something still expects it to run. 352023ca420SStefan Hajnoczi * 353023ca420SStefan Hajnoczi * If you hit this, fix the lifecycle of the BH so that 354023ca420SStefan Hajnoczi * qemu_bh_delete() and any associated cleanup is called before the 355023ca420SStefan Hajnoczi * AioContext is finalized. 356023ca420SStefan Hajnoczi */ 357023ca420SStefan Hajnoczi if (unlikely(!(flags & BH_DELETED))) { 358023ca420SStefan Hajnoczi fprintf(stderr, "%s: BH '%s' leaked, aborting...\n", 359023ca420SStefan Hajnoczi __func__, bh->name); 360023ca420SStefan Hajnoczi abort(); 361023ca420SStefan Hajnoczi } 362c2b38b27SPaolo Bonzini 3638c6b0356SStefan Hajnoczi g_free(bh); 364c2b38b27SPaolo Bonzini } 365c2b38b27SPaolo Bonzini 366826cc324SStefan Hajnoczi aio_set_event_notifier(ctx, &ctx->notifier, false, NULL, NULL, NULL); 367c2b38b27SPaolo Bonzini event_notifier_cleanup(&ctx->notifier); 368c2b38b27SPaolo Bonzini qemu_rec_mutex_destroy(&ctx->lock); 369c2b38b27SPaolo Bonzini qemu_lockcnt_destroy(&ctx->list_lock); 370c2b38b27SPaolo Bonzini timerlistgroup_deinit(&ctx->tlg); 371cd0a6d2bSJie Wang aio_context_destroy(ctx); 372c2b38b27SPaolo Bonzini } 373c2b38b27SPaolo Bonzini 374c2b38b27SPaolo Bonzini static GSourceFuncs aio_source_funcs = { 375c2b38b27SPaolo Bonzini aio_ctx_prepare, 376c2b38b27SPaolo Bonzini aio_ctx_check, 377c2b38b27SPaolo Bonzini aio_ctx_dispatch, 378c2b38b27SPaolo Bonzini aio_ctx_finalize 379c2b38b27SPaolo Bonzini }; 380c2b38b27SPaolo Bonzini 381c2b38b27SPaolo Bonzini GSource *aio_get_g_source(AioContext *ctx) 382c2b38b27SPaolo Bonzini { 383ba607ca8SStefan Hajnoczi aio_context_use_g_source(ctx); 384c2b38b27SPaolo Bonzini g_source_ref(&ctx->source); 385c2b38b27SPaolo Bonzini return &ctx->source; 386c2b38b27SPaolo Bonzini } 387c2b38b27SPaolo Bonzini 388c2b38b27SPaolo Bonzini ThreadPool *aio_get_thread_pool(AioContext *ctx) 389c2b38b27SPaolo Bonzini { 390c2b38b27SPaolo Bonzini if (!ctx->thread_pool) { 391c2b38b27SPaolo Bonzini ctx->thread_pool = thread_pool_new(ctx); 392c2b38b27SPaolo Bonzini } 393c2b38b27SPaolo Bonzini return ctx->thread_pool; 394c2b38b27SPaolo Bonzini } 395c2b38b27SPaolo Bonzini 396c2b38b27SPaolo Bonzini #ifdef CONFIG_LINUX_AIO 397ed6e2161SNishanth Aravamudan LinuxAioState *aio_setup_linux_aio(AioContext *ctx, Error **errp) 398c2b38b27SPaolo Bonzini { 399c2b38b27SPaolo Bonzini if (!ctx->linux_aio) { 400ed6e2161SNishanth Aravamudan ctx->linux_aio = laio_init(errp); 401ed6e2161SNishanth Aravamudan if (ctx->linux_aio) { 402c2b38b27SPaolo Bonzini laio_attach_aio_context(ctx->linux_aio, ctx); 403c2b38b27SPaolo Bonzini } 404ed6e2161SNishanth Aravamudan } 405ed6e2161SNishanth Aravamudan return ctx->linux_aio; 406ed6e2161SNishanth Aravamudan } 407ed6e2161SNishanth Aravamudan 408ed6e2161SNishanth Aravamudan LinuxAioState *aio_get_linux_aio(AioContext *ctx) 409ed6e2161SNishanth Aravamudan { 410ed6e2161SNishanth Aravamudan assert(ctx->linux_aio); 411c2b38b27SPaolo Bonzini return ctx->linux_aio; 412c2b38b27SPaolo Bonzini } 413c2b38b27SPaolo Bonzini #endif 414c2b38b27SPaolo Bonzini 415fcb7a4a4SAarushi Mehta #ifdef CONFIG_LINUX_IO_URING 416fcb7a4a4SAarushi Mehta LuringState *aio_setup_linux_io_uring(AioContext *ctx, Error **errp) 417fcb7a4a4SAarushi Mehta { 418fcb7a4a4SAarushi Mehta if (ctx->linux_io_uring) { 419fcb7a4a4SAarushi Mehta return ctx->linux_io_uring; 420fcb7a4a4SAarushi Mehta } 421fcb7a4a4SAarushi Mehta 422fcb7a4a4SAarushi Mehta ctx->linux_io_uring = luring_init(errp); 423fcb7a4a4SAarushi Mehta if (!ctx->linux_io_uring) { 424fcb7a4a4SAarushi Mehta return NULL; 425fcb7a4a4SAarushi Mehta } 426fcb7a4a4SAarushi Mehta 427fcb7a4a4SAarushi Mehta luring_attach_aio_context(ctx->linux_io_uring, ctx); 428fcb7a4a4SAarushi Mehta return ctx->linux_io_uring; 429fcb7a4a4SAarushi Mehta } 430fcb7a4a4SAarushi Mehta 431fcb7a4a4SAarushi Mehta LuringState *aio_get_linux_io_uring(AioContext *ctx) 432fcb7a4a4SAarushi Mehta { 433fcb7a4a4SAarushi Mehta assert(ctx->linux_io_uring); 434fcb7a4a4SAarushi Mehta return ctx->linux_io_uring; 435fcb7a4a4SAarushi Mehta } 436fcb7a4a4SAarushi Mehta #endif 437fcb7a4a4SAarushi Mehta 438c2b38b27SPaolo Bonzini void aio_notify(AioContext *ctx) 439c2b38b27SPaolo Bonzini { 440601829f8SStefan Hajnoczi /* 441601829f8SStefan Hajnoczi * Write e.g. bh->flags before writing ctx->notified. Pairs with smp_mb in 442601829f8SStefan Hajnoczi * aio_notify_accept. 443601829f8SStefan Hajnoczi */ 444601829f8SStefan Hajnoczi smp_wmb(); 445d73415a3SStefan Hajnoczi qatomic_set(&ctx->notified, true); 446601829f8SStefan Hajnoczi 447601829f8SStefan Hajnoczi /* 448601829f8SStefan Hajnoczi * Write ctx->notified before reading ctx->notify_me. Pairs 4495710a3e0SPaolo Bonzini * with smp_mb in aio_ctx_prepare or aio_poll. 450c2b38b27SPaolo Bonzini */ 451c2b38b27SPaolo Bonzini smp_mb(); 452d73415a3SStefan Hajnoczi if (qatomic_read(&ctx->notify_me)) { 453c2b38b27SPaolo Bonzini event_notifier_set(&ctx->notifier); 454c2b38b27SPaolo Bonzini } 455c2b38b27SPaolo Bonzini } 456c2b38b27SPaolo Bonzini 457c2b38b27SPaolo Bonzini void aio_notify_accept(AioContext *ctx) 458c2b38b27SPaolo Bonzini { 459d73415a3SStefan Hajnoczi qatomic_set(&ctx->notified, false); 460601829f8SStefan Hajnoczi 461601829f8SStefan Hajnoczi /* 462601829f8SStefan Hajnoczi * Write ctx->notified before reading e.g. bh->flags. Pairs with smp_wmb 463601829f8SStefan Hajnoczi * in aio_notify. 464601829f8SStefan Hajnoczi */ 465601829f8SStefan Hajnoczi smp_mb(); 466c2b38b27SPaolo Bonzini } 467c2b38b27SPaolo Bonzini 4683f53bc61SPaolo Bonzini static void aio_timerlist_notify(void *opaque, QEMUClockType type) 469c2b38b27SPaolo Bonzini { 470c2b38b27SPaolo Bonzini aio_notify(opaque); 471c2b38b27SPaolo Bonzini } 472c2b38b27SPaolo Bonzini 473601829f8SStefan Hajnoczi static void aio_context_notifier_cb(EventNotifier *e) 474c2b38b27SPaolo Bonzini { 475601829f8SStefan Hajnoczi AioContext *ctx = container_of(e, AioContext, notifier); 476601829f8SStefan Hajnoczi 477601829f8SStefan Hajnoczi event_notifier_test_and_clear(&ctx->notifier); 478c2b38b27SPaolo Bonzini } 479c2b38b27SPaolo Bonzini 480c2b38b27SPaolo Bonzini /* Returns true if aio_notify() was called (e.g. a BH was scheduled) */ 481c13be5a1SStefan Hajnoczi static bool aio_context_notifier_poll(void *opaque) 482c2b38b27SPaolo Bonzini { 483c2b38b27SPaolo Bonzini EventNotifier *e = opaque; 484c2b38b27SPaolo Bonzini AioContext *ctx = container_of(e, AioContext, notifier); 485c2b38b27SPaolo Bonzini 486d73415a3SStefan Hajnoczi return qatomic_read(&ctx->notified); 487c2b38b27SPaolo Bonzini } 488c2b38b27SPaolo Bonzini 489826cc324SStefan Hajnoczi static void aio_context_notifier_poll_ready(EventNotifier *e) 490826cc324SStefan Hajnoczi { 491826cc324SStefan Hajnoczi /* Do nothing, we just wanted to kick the event loop */ 492826cc324SStefan Hajnoczi } 493826cc324SStefan Hajnoczi 4940c330a73SPaolo Bonzini static void co_schedule_bh_cb(void *opaque) 4950c330a73SPaolo Bonzini { 4960c330a73SPaolo Bonzini AioContext *ctx = opaque; 4970c330a73SPaolo Bonzini QSLIST_HEAD(, Coroutine) straight, reversed; 4980c330a73SPaolo Bonzini 4990c330a73SPaolo Bonzini QSLIST_MOVE_ATOMIC(&reversed, &ctx->scheduled_coroutines); 5000c330a73SPaolo Bonzini QSLIST_INIT(&straight); 5010c330a73SPaolo Bonzini 5020c330a73SPaolo Bonzini while (!QSLIST_EMPTY(&reversed)) { 5030c330a73SPaolo Bonzini Coroutine *co = QSLIST_FIRST(&reversed); 5040c330a73SPaolo Bonzini QSLIST_REMOVE_HEAD(&reversed, co_scheduled_next); 5050c330a73SPaolo Bonzini QSLIST_INSERT_HEAD(&straight, co, co_scheduled_next); 5060c330a73SPaolo Bonzini } 5070c330a73SPaolo Bonzini 5080c330a73SPaolo Bonzini while (!QSLIST_EMPTY(&straight)) { 5090c330a73SPaolo Bonzini Coroutine *co = QSLIST_FIRST(&straight); 5100c330a73SPaolo Bonzini QSLIST_REMOVE_HEAD(&straight, co_scheduled_next); 5110c330a73SPaolo Bonzini trace_aio_co_schedule_bh_cb(ctx, co); 5121919631eSPaolo Bonzini aio_context_acquire(ctx); 5136133b39fSJeff Cody 5146133b39fSJeff Cody /* Protected by write barrier in qemu_aio_coroutine_enter */ 515d73415a3SStefan Hajnoczi qatomic_set(&co->scheduled, NULL); 5166808ae04SSergio Lopez qemu_aio_coroutine_enter(ctx, co); 5171919631eSPaolo Bonzini aio_context_release(ctx); 5180c330a73SPaolo Bonzini } 5190c330a73SPaolo Bonzini } 5200c330a73SPaolo Bonzini 521c2b38b27SPaolo Bonzini AioContext *aio_context_new(Error **errp) 522c2b38b27SPaolo Bonzini { 523c2b38b27SPaolo Bonzini int ret; 524c2b38b27SPaolo Bonzini AioContext *ctx; 525c2b38b27SPaolo Bonzini 526c2b38b27SPaolo Bonzini ctx = (AioContext *) g_source_new(&aio_source_funcs, sizeof(AioContext)); 5278c6b0356SStefan Hajnoczi QSLIST_INIT(&ctx->bh_list); 5288c6b0356SStefan Hajnoczi QSIMPLEQ_INIT(&ctx->bh_slice_list); 529c2b38b27SPaolo Bonzini aio_context_setup(ctx); 530c2b38b27SPaolo Bonzini 531c2b38b27SPaolo Bonzini ret = event_notifier_init(&ctx->notifier, false); 532c2b38b27SPaolo Bonzini if (ret < 0) { 533c2b38b27SPaolo Bonzini error_setg_errno(errp, -ret, "Failed to initialize event notifier"); 534c2b38b27SPaolo Bonzini goto fail; 535c2b38b27SPaolo Bonzini } 536c2b38b27SPaolo Bonzini g_source_set_can_recurse(&ctx->source, true); 537c2b38b27SPaolo Bonzini qemu_lockcnt_init(&ctx->list_lock); 5380c330a73SPaolo Bonzini 5390c330a73SPaolo Bonzini ctx->co_schedule_bh = aio_bh_new(ctx, co_schedule_bh_cb, ctx); 5400c330a73SPaolo Bonzini QSLIST_INIT(&ctx->scheduled_coroutines); 5410c330a73SPaolo Bonzini 542c2b38b27SPaolo Bonzini aio_set_event_notifier(ctx, &ctx->notifier, 543c2b38b27SPaolo Bonzini false, 544601829f8SStefan Hajnoczi aio_context_notifier_cb, 545826cc324SStefan Hajnoczi aio_context_notifier_poll, 546826cc324SStefan Hajnoczi aio_context_notifier_poll_ready); 547c2b38b27SPaolo Bonzini #ifdef CONFIG_LINUX_AIO 548c2b38b27SPaolo Bonzini ctx->linux_aio = NULL; 549c2b38b27SPaolo Bonzini #endif 550fcb7a4a4SAarushi Mehta 551fcb7a4a4SAarushi Mehta #ifdef CONFIG_LINUX_IO_URING 552fcb7a4a4SAarushi Mehta ctx->linux_io_uring = NULL; 553fcb7a4a4SAarushi Mehta #endif 554fcb7a4a4SAarushi Mehta 555c2b38b27SPaolo Bonzini ctx->thread_pool = NULL; 556c2b38b27SPaolo Bonzini qemu_rec_mutex_init(&ctx->lock); 557c2b38b27SPaolo Bonzini timerlistgroup_init(&ctx->tlg, aio_timerlist_notify, ctx); 558c2b38b27SPaolo Bonzini 559c2b38b27SPaolo Bonzini ctx->poll_ns = 0; 560c2b38b27SPaolo Bonzini ctx->poll_max_ns = 0; 561c2b38b27SPaolo Bonzini ctx->poll_grow = 0; 562c2b38b27SPaolo Bonzini ctx->poll_shrink = 0; 563c2b38b27SPaolo Bonzini 5641793ad02SStefano Garzarella ctx->aio_max_batch = 0; 5651793ad02SStefano Garzarella 566c2b38b27SPaolo Bonzini return ctx; 567c2b38b27SPaolo Bonzini fail: 568c2b38b27SPaolo Bonzini g_source_destroy(&ctx->source); 569c2b38b27SPaolo Bonzini return NULL; 570c2b38b27SPaolo Bonzini } 571c2b38b27SPaolo Bonzini 5720c330a73SPaolo Bonzini void aio_co_schedule(AioContext *ctx, Coroutine *co) 5730c330a73SPaolo Bonzini { 5740c330a73SPaolo Bonzini trace_aio_co_schedule(ctx, co); 575d73415a3SStefan Hajnoczi const char *scheduled = qatomic_cmpxchg(&co->scheduled, NULL, 5766133b39fSJeff Cody __func__); 5776133b39fSJeff Cody 5786133b39fSJeff Cody if (scheduled) { 5796133b39fSJeff Cody fprintf(stderr, 5806133b39fSJeff Cody "%s: Co-routine was already scheduled in '%s'\n", 5816133b39fSJeff Cody __func__, scheduled); 5826133b39fSJeff Cody abort(); 5836133b39fSJeff Cody } 5846133b39fSJeff Cody 585f0f81002SStefan Hajnoczi /* The coroutine might run and release the last ctx reference before we 586f0f81002SStefan Hajnoczi * invoke qemu_bh_schedule(). Take a reference to keep ctx alive until 587f0f81002SStefan Hajnoczi * we're done. 588f0f81002SStefan Hajnoczi */ 589f0f81002SStefan Hajnoczi aio_context_ref(ctx); 590f0f81002SStefan Hajnoczi 5910c330a73SPaolo Bonzini QSLIST_INSERT_HEAD_ATOMIC(&ctx->scheduled_coroutines, 5920c330a73SPaolo Bonzini co, co_scheduled_next); 5930c330a73SPaolo Bonzini qemu_bh_schedule(ctx->co_schedule_bh); 594f0f81002SStefan Hajnoczi 595f0f81002SStefan Hajnoczi aio_context_unref(ctx); 5960c330a73SPaolo Bonzini } 5970c330a73SPaolo Bonzini 59826b0b698SKevin Wolf typedef struct AioCoRescheduleSelf { 59926b0b698SKevin Wolf Coroutine *co; 60026b0b698SKevin Wolf AioContext *new_ctx; 60126b0b698SKevin Wolf } AioCoRescheduleSelf; 60226b0b698SKevin Wolf 60326b0b698SKevin Wolf static void aio_co_reschedule_self_bh(void *opaque) 60426b0b698SKevin Wolf { 60526b0b698SKevin Wolf AioCoRescheduleSelf *data = opaque; 60626b0b698SKevin Wolf aio_co_schedule(data->new_ctx, data->co); 60726b0b698SKevin Wolf } 60826b0b698SKevin Wolf 60926b0b698SKevin Wolf void coroutine_fn aio_co_reschedule_self(AioContext *new_ctx) 61026b0b698SKevin Wolf { 61126b0b698SKevin Wolf AioContext *old_ctx = qemu_get_current_aio_context(); 61226b0b698SKevin Wolf 61326b0b698SKevin Wolf if (old_ctx != new_ctx) { 61426b0b698SKevin Wolf AioCoRescheduleSelf data = { 61526b0b698SKevin Wolf .co = qemu_coroutine_self(), 61626b0b698SKevin Wolf .new_ctx = new_ctx, 61726b0b698SKevin Wolf }; 61826b0b698SKevin Wolf /* 61926b0b698SKevin Wolf * We can't directly schedule the coroutine in the target context 62026b0b698SKevin Wolf * because this would be racy: The other thread could try to enter the 62126b0b698SKevin Wolf * coroutine before it has yielded in this one. 62226b0b698SKevin Wolf */ 62326b0b698SKevin Wolf aio_bh_schedule_oneshot(old_ctx, aio_co_reschedule_self_bh, &data); 62426b0b698SKevin Wolf qemu_coroutine_yield(); 62526b0b698SKevin Wolf } 62626b0b698SKevin Wolf } 62726b0b698SKevin Wolf 6280c330a73SPaolo Bonzini void aio_co_wake(struct Coroutine *co) 6290c330a73SPaolo Bonzini { 6300c330a73SPaolo Bonzini AioContext *ctx; 6310c330a73SPaolo Bonzini 6320c330a73SPaolo Bonzini /* Read coroutine before co->ctx. Matches smp_wmb in 6330c330a73SPaolo Bonzini * qemu_coroutine_enter. 6340c330a73SPaolo Bonzini */ 6350c330a73SPaolo Bonzini smp_read_barrier_depends(); 636d73415a3SStefan Hajnoczi ctx = qatomic_read(&co->ctx); 6370c330a73SPaolo Bonzini 6388865852eSFam Zheng aio_co_enter(ctx, co); 6398865852eSFam Zheng } 6408865852eSFam Zheng 6418865852eSFam Zheng void aio_co_enter(AioContext *ctx, struct Coroutine *co) 6428865852eSFam Zheng { 6430c330a73SPaolo Bonzini if (ctx != qemu_get_current_aio_context()) { 6440c330a73SPaolo Bonzini aio_co_schedule(ctx, co); 6450c330a73SPaolo Bonzini return; 6460c330a73SPaolo Bonzini } 6470c330a73SPaolo Bonzini 6480c330a73SPaolo Bonzini if (qemu_in_coroutine()) { 6490c330a73SPaolo Bonzini Coroutine *self = qemu_coroutine_self(); 6500c330a73SPaolo Bonzini assert(self != co); 6510c330a73SPaolo Bonzini QSIMPLEQ_INSERT_TAIL(&self->co_queue_wakeup, co, co_queue_next); 6520c330a73SPaolo Bonzini } else { 6530c330a73SPaolo Bonzini aio_context_acquire(ctx); 6548865852eSFam Zheng qemu_aio_coroutine_enter(ctx, co); 6550c330a73SPaolo Bonzini aio_context_release(ctx); 6560c330a73SPaolo Bonzini } 6570c330a73SPaolo Bonzini } 6580c330a73SPaolo Bonzini 659c2b38b27SPaolo Bonzini void aio_context_ref(AioContext *ctx) 660c2b38b27SPaolo Bonzini { 661c2b38b27SPaolo Bonzini g_source_ref(&ctx->source); 662c2b38b27SPaolo Bonzini } 663c2b38b27SPaolo Bonzini 664c2b38b27SPaolo Bonzini void aio_context_unref(AioContext *ctx) 665c2b38b27SPaolo Bonzini { 666c2b38b27SPaolo Bonzini g_source_unref(&ctx->source); 667c2b38b27SPaolo Bonzini } 668c2b38b27SPaolo Bonzini 669c2b38b27SPaolo Bonzini void aio_context_acquire(AioContext *ctx) 670c2b38b27SPaolo Bonzini { 671c2b38b27SPaolo Bonzini qemu_rec_mutex_lock(&ctx->lock); 672c2b38b27SPaolo Bonzini } 673c2b38b27SPaolo Bonzini 674c2b38b27SPaolo Bonzini void aio_context_release(AioContext *ctx) 675c2b38b27SPaolo Bonzini { 676c2b38b27SPaolo Bonzini qemu_rec_mutex_unlock(&ctx->lock); 677c2b38b27SPaolo Bonzini } 6785f50be9bSPaolo Bonzini 679*47b74464SStefan Hajnoczi QEMU_DEFINE_STATIC_CO_TLS(AioContext *, my_aiocontext) 6805f50be9bSPaolo Bonzini 6815f50be9bSPaolo Bonzini AioContext *qemu_get_current_aio_context(void) 6825f50be9bSPaolo Bonzini { 683*47b74464SStefan Hajnoczi AioContext *ctx = get_my_aiocontext(); 684*47b74464SStefan Hajnoczi if (ctx) { 685*47b74464SStefan Hajnoczi return ctx; 6865f50be9bSPaolo Bonzini } 6875f50be9bSPaolo Bonzini if (qemu_mutex_iothread_locked()) { 6885f50be9bSPaolo Bonzini /* Possibly in a vCPU thread. */ 6895f50be9bSPaolo Bonzini return qemu_get_aio_context(); 6905f50be9bSPaolo Bonzini } 6915f50be9bSPaolo Bonzini return NULL; 6925f50be9bSPaolo Bonzini } 6935f50be9bSPaolo Bonzini 6945f50be9bSPaolo Bonzini void qemu_set_current_aio_context(AioContext *ctx) 6955f50be9bSPaolo Bonzini { 696*47b74464SStefan Hajnoczi assert(!get_my_aiocontext()); 697*47b74464SStefan Hajnoczi set_my_aiocontext(ctx); 6985f50be9bSPaolo Bonzini } 699