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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 | /* * QEMU System Emulator * * Copyright (c) 2003-2008 Fabrice Bellard * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ #include "qemu/osdep.h" #include "qapi/error.h" #include "qemu/cutils.h" #include "qemu/timer.h" #include "sysemu/cpu-timers.h" #include "sysemu/replay.h" #include "qemu/main-loop.h" #include "block/aio.h" #include "block/thread-pool.h" #include "qemu/error-report.h" #include "qemu/queue.h" #include "qom/object.h" #ifndef _WIN32 #include <sys/wait.h> #endif #ifndef _WIN32 /* If we have signalfd, we mask out the signals we want to handle and then * use signalfd to listen for them. We rely on whatever the current signal * handler is to dispatch the signals when we receive them. */ /* * Disable CFI checks. * We are going to call a signal handler directly. Such handler may or may not * have been defined in our binary, so there's no guarantee that the pointer * used to set the handler is a cfi-valid pointer. Since the handlers are * stored in kernel memory, changing the handler to an attacker-defined * function requires being able to call a sigaction() syscall, * which is not as easy as overwriting a pointer in memory. */ QEMU_DISABLE_CFI static void sigfd_handler(void *opaque) { int fd = (intptr_t)opaque; struct qemu_signalfd_siginfo info; struct sigaction action; ssize_t len; while (1) { len = RETRY_ON_EINTR(read(fd, &info, sizeof(info))); if (len == -1 && errno == EAGAIN) { break; } if (len != sizeof(info)) { error_report("read from sigfd returned %zd: %s", len, g_strerror(errno)); return; } sigaction(info.ssi_signo, NULL, &action); if ((action.sa_flags & SA_SIGINFO) && action.sa_sigaction) { sigaction_invoke(&action, &info); } else if (action.sa_handler) { action.sa_handler(info.ssi_signo); } } } static int qemu_signal_init(Error **errp) { int sigfd; sigset_t set; /* * SIG_IPI must be blocked in the main thread and must not be caught * by sigwait() in the signal thread. Otherwise, the cpu thread will * not catch it reliably. */ sigemptyset(&set); sigaddset(&set, SIG_IPI); sigaddset(&set, SIGIO); sigaddset(&set, SIGALRM); sigaddset(&set, SIGBUS); /* SIGINT cannot be handled via signalfd, so that ^C can be used * to interrupt QEMU when it is being run under gdb. SIGHUP and * SIGTERM are also handled asynchronously, even though it is not * strictly necessary, because they use the same handler as SIGINT. */ pthread_sigmask(SIG_BLOCK, &set, NULL); sigdelset(&set, SIG_IPI); sigfd = qemu_signalfd(&set); if (sigfd == -1) { error_setg_errno(errp, errno, "failed to create signalfd"); return -errno; } g_unix_set_fd_nonblocking(sigfd, true, NULL); qemu_set_fd_handler(sigfd, sigfd_handler, NULL, (void *)(intptr_t)sigfd); return 0; } #else /* _WIN32 */ static int qemu_signal_init(Error **errp) { return 0; } #endif static AioContext *qemu_aio_context; static QEMUBH *qemu_notify_bh; static void notify_event_cb(void *opaque) { /* No need to do anything; this bottom half is only used to * kick the kernel out of ppoll/poll/WaitForMultipleObjects. */ } AioContext *qemu_get_aio_context(void) { return qemu_aio_context; } void qemu_notify_event(void) { if (!qemu_aio_context) { return; } qemu_bh_schedule(qemu_notify_bh); } static GArray *gpollfds; int qemu_init_main_loop(Error **errp) { int ret; GSource *src; init_clocks(qemu_timer_notify_cb); ret = qemu_signal_init(errp); if (ret) { return ret; } qemu_aio_context = aio_context_new(errp); if (!qemu_aio_context) { return -EMFILE; } qemu_set_current_aio_context(qemu_aio_context); qemu_notify_bh = qemu_bh_new(notify_event_cb, NULL); gpollfds = g_array_new(FALSE, FALSE, sizeof(GPollFD)); src = aio_get_g_source(qemu_aio_context); g_source_set_name(src, "aio-context"); g_source_attach(src, NULL); g_source_unref(src); src = iohandler_get_g_source(); g_source_set_name(src, "io-handler"); g_source_attach(src, NULL); g_source_unref(src); return 0; } static void main_loop_update_params(EventLoopBase *base, Error **errp) { ERRP_GUARD(); if (!qemu_aio_context) { error_setg(errp, "qemu aio context not ready"); return; } aio_context_set_aio_params(qemu_aio_context, base->aio_max_batch); aio_context_set_thread_pool_params(qemu_aio_context, base->thread_pool_min, base->thread_pool_max, errp); } MainLoop *mloop; static void main_loop_init(EventLoopBase *base, Error **errp) { MainLoop *m = MAIN_LOOP(base); if (mloop) { error_setg(errp, "only one main-loop instance allowed"); return; } main_loop_update_params(base, errp); mloop = m; return; } static bool main_loop_can_be_deleted(EventLoopBase *base) { return false; } static void main_loop_class_init(ObjectClass *oc, void *class_data) { EventLoopBaseClass *bc = EVENT_LOOP_BASE_CLASS(oc); bc->init = main_loop_init; bc->update_params = main_loop_update_params; bc->can_be_deleted = main_loop_can_be_deleted; } static const TypeInfo main_loop_info = { .name = TYPE_MAIN_LOOP, .parent = TYPE_EVENT_LOOP_BASE, .class_init = main_loop_class_init, .instance_size = sizeof(MainLoop), }; static void main_loop_register_types(void) { type_register_static(&main_loop_info); } type_init(main_loop_register_types) static int max_priority; #ifndef _WIN32 static int glib_pollfds_idx; static int glib_n_poll_fds; static void glib_pollfds_fill(int64_t *cur_timeout) { GMainContext *context = g_main_context_default(); int timeout = 0; int64_t timeout_ns; int n; g_main_context_prepare(context, &max_priority); glib_pollfds_idx = gpollfds->len; n = glib_n_poll_fds; do { GPollFD *pfds; glib_n_poll_fds = n; g_array_set_size(gpollfds, glib_pollfds_idx + glib_n_poll_fds); pfds = &g_array_index(gpollfds, GPollFD, glib_pollfds_idx); n = g_main_context_query(context, max_priority, &timeout, pfds, glib_n_poll_fds); } while (n != glib_n_poll_fds); if (timeout < 0) { timeout_ns = -1; } else { timeout_ns = (int64_t)timeout * (int64_t)SCALE_MS; } *cur_timeout = qemu_soonest_timeout(timeout_ns, *cur_timeout); } static void glib_pollfds_poll(void) { GMainContext *context = g_main_context_default(); GPollFD *pfds = &g_array_index(gpollfds, GPollFD, glib_pollfds_idx); if (g_main_context_check(context, max_priority, pfds, glib_n_poll_fds)) { g_main_context_dispatch(context); } } #define MAX_MAIN_LOOP_SPIN (1000) static int os_host_main_loop_wait(int64_t timeout) { GMainContext *context = g_main_context_default(); int ret; g_main_context_acquire(context); glib_pollfds_fill(&timeout); bql_unlock(); replay_mutex_unlock(); ret = qemu_poll_ns((GPollFD *)gpollfds->data, gpollfds->len, timeout); replay_mutex_lock(); bql_lock(); glib_pollfds_poll(); g_main_context_release(context); return ret; } #else /***********************************************************/ /* Polling handling */ typedef struct PollingEntry { PollingFunc *func; void *opaque; struct PollingEntry *next; } PollingEntry; static PollingEntry *first_polling_entry; int qemu_add_polling_cb(PollingFunc *func, void *opaque) { PollingEntry **ppe, *pe; pe = g_new0(PollingEntry, 1); pe->func = func; pe->opaque = opaque; for(ppe = &first_polling_entry; *ppe != NULL; ppe = &(*ppe)->next); *ppe = pe; return 0; } void qemu_del_polling_cb(PollingFunc *func, void *opaque) { PollingEntry **ppe, *pe; for(ppe = &first_polling_entry; *ppe != NULL; ppe = &(*ppe)->next) { pe = *ppe; if (pe->func == func && pe->opaque == opaque) { *ppe = pe->next; g_free(pe); break; } } } /***********************************************************/ /* Wait objects support */ typedef struct WaitObjects { int num; int revents[MAXIMUM_WAIT_OBJECTS]; HANDLE events[MAXIMUM_WAIT_OBJECTS]; WaitObjectFunc *func[MAXIMUM_WAIT_OBJECTS]; void *opaque[MAXIMUM_WAIT_OBJECTS]; } WaitObjects; static WaitObjects wait_objects = {0}; int qemu_add_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque) { int i; WaitObjects *w = &wait_objects; if (w->num >= MAXIMUM_WAIT_OBJECTS) { return -1; } for (i = 0; i < w->num; i++) { /* check if the same handle is added twice */ if (w->events[i] == handle) { return -1; } } w->events[w->num] = handle; w->func[w->num] = func; w->opaque[w->num] = opaque; w->revents[w->num] = 0; w->num++; return 0; } void qemu_del_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque) { int i, found; WaitObjects *w = &wait_objects; found = 0; for (i = 0; i < w->num; i++) { if (w->events[i] == handle) { found = 1; } if (found && i < (MAXIMUM_WAIT_OBJECTS - 1)) { w->events[i] = w->events[i + 1]; w->func[i] = w->func[i + 1]; w->opaque[i] = w->opaque[i + 1]; w->revents[i] = w->revents[i + 1]; } } if (found) { w->num--; } } static int pollfds_fill(GArray *pollfds, fd_set *rfds, fd_set *wfds, fd_set *xfds) { int nfds = -1; int i; for (i = 0; i < pollfds->len; i++) { GPollFD *pfd = &g_array_index(pollfds, GPollFD, i); int fd = pfd->fd; int events = pfd->events; if (events & G_IO_IN) { FD_SET(fd, rfds); nfds = MAX(nfds, fd); } if (events & G_IO_OUT) { FD_SET(fd, wfds); nfds = MAX(nfds, fd); } if (events & G_IO_PRI) { FD_SET(fd, xfds); nfds = MAX(nfds, fd); } } return nfds; } static void pollfds_poll(GArray *pollfds, int nfds, fd_set *rfds, fd_set *wfds, fd_set *xfds) { int i; for (i = 0; i < pollfds->len; i++) { GPollFD *pfd = &g_array_index(pollfds, GPollFD, i); int fd = pfd->fd; int revents = 0; if (FD_ISSET(fd, rfds)) { revents |= G_IO_IN; } if (FD_ISSET(fd, wfds)) { revents |= G_IO_OUT; } if (FD_ISSET(fd, xfds)) { revents |= G_IO_PRI; } pfd->revents = revents & pfd->events; } } static int os_host_main_loop_wait(int64_t timeout) { GMainContext *context = g_main_context_default(); GPollFD poll_fds[1024 * 2]; /* this is probably overkill */ int select_ret = 0; int g_poll_ret, ret, i, n_poll_fds; PollingEntry *pe; WaitObjects *w = &wait_objects; gint poll_timeout; int64_t poll_timeout_ns; static struct timeval tv0; fd_set rfds, wfds, xfds; int nfds; g_main_context_acquire(context); /* XXX: need to suppress polling by better using win32 events */ ret = 0; for (pe = first_polling_entry; pe != NULL; pe = pe->next) { ret |= pe->func(pe->opaque); } if (ret != 0) { g_main_context_release(context); return ret; } FD_ZERO(&rfds); FD_ZERO(&wfds); FD_ZERO(&xfds); nfds = pollfds_fill(gpollfds, &rfds, &wfds, &xfds); if (nfds >= 0) { select_ret = select(nfds + 1, &rfds, &wfds, &xfds, &tv0); if (select_ret != 0) { timeout = 0; } if (select_ret > 0) { pollfds_poll(gpollfds, nfds, &rfds, &wfds, &xfds); } } g_main_context_prepare(context, &max_priority); n_poll_fds = g_main_context_query(context, max_priority, &poll_timeout, poll_fds, ARRAY_SIZE(poll_fds)); g_assert(n_poll_fds + w->num <= ARRAY_SIZE(poll_fds)); for (i = 0; i < w->num; i++) { poll_fds[n_poll_fds + i].fd = (DWORD_PTR)w->events[i]; poll_fds[n_poll_fds + i].events = G_IO_IN; } if (poll_timeout < 0) { poll_timeout_ns = -1; } else { poll_timeout_ns = (int64_t)poll_timeout * (int64_t)SCALE_MS; } poll_timeout_ns = qemu_soonest_timeout(poll_timeout_ns, timeout); bql_unlock(); replay_mutex_unlock(); g_poll_ret = qemu_poll_ns(poll_fds, n_poll_fds + w->num, poll_timeout_ns); replay_mutex_lock(); bql_lock(); if (g_poll_ret > 0) { for (i = 0; i < w->num; i++) { w->revents[i] = poll_fds[n_poll_fds + i].revents; } for (i = 0; i < w->num; i++) { if (w->revents[i] && w->func[i]) { w->func[i](w->opaque[i]); } } } if (g_main_context_check(context, max_priority, poll_fds, n_poll_fds)) { g_main_context_dispatch(context); } g_main_context_release(context); return select_ret || g_poll_ret; } #endif static NotifierList main_loop_poll_notifiers = NOTIFIER_LIST_INITIALIZER(main_loop_poll_notifiers); void main_loop_poll_add_notifier(Notifier *notify) { notifier_list_add(&main_loop_poll_notifiers, notify); } void main_loop_poll_remove_notifier(Notifier *notify) { notifier_remove(notify); } void main_loop_wait(int nonblocking) { MainLoopPoll mlpoll = { .state = MAIN_LOOP_POLL_FILL, .timeout = UINT32_MAX, .pollfds = gpollfds, }; int ret; int64_t timeout_ns; if (nonblocking) { mlpoll.timeout = 0; } /* poll any events */ g_array_set_size(gpollfds, 0); /* reset for new iteration */ /* XXX: separate device handlers from system ones */ notifier_list_notify(&main_loop_poll_notifiers, &mlpoll); if (mlpoll.timeout == UINT32_MAX) { timeout_ns = -1; } else { timeout_ns = (uint64_t)mlpoll.timeout * (int64_t)(SCALE_MS); } timeout_ns = qemu_soonest_timeout(timeout_ns, timerlistgroup_deadline_ns( &main_loop_tlg)); ret = os_host_main_loop_wait(timeout_ns); mlpoll.state = ret < 0 ? MAIN_LOOP_POLL_ERR : MAIN_LOOP_POLL_OK; notifier_list_notify(&main_loop_poll_notifiers, &mlpoll); if (icount_enabled()) { /* * CPU thread can infinitely wait for event after * missing the warp */ icount_start_warp_timer(); } qemu_clock_run_all_timers(); } /* Functions to operate on the main QEMU AioContext. */ QEMUBH *qemu_bh_new_full(QEMUBHFunc *cb, void *opaque, const char *name, MemReentrancyGuard *reentrancy_guard) { return aio_bh_new_full(qemu_aio_context, cb, opaque, name, reentrancy_guard); } /* * Functions to operate on the I/O handler AioContext. * This context runs on top of main loop. We can't reuse qemu_aio_context * because iohandlers mustn't be polled by aio_poll(qemu_aio_context). */ static AioContext *iohandler_ctx; static void iohandler_init(void) { if (!iohandler_ctx) { iohandler_ctx = aio_context_new(&error_abort); } } AioContext *iohandler_get_aio_context(void) { iohandler_init(); return iohandler_ctx; } GSource *iohandler_get_g_source(void) { iohandler_init(); return aio_get_g_source(iohandler_ctx); } void qemu_set_fd_handler(int fd, IOHandler *fd_read, IOHandler *fd_write, void *opaque) { iohandler_init(); aio_set_fd_handler(iohandler_ctx, fd, fd_read, fd_write, NULL, NULL, opaque); } void event_notifier_set_handler(EventNotifier *e, EventNotifierHandler *handler) { iohandler_init(); aio_set_event_notifier(iohandler_ctx, e, handler, NULL, NULL); } |