1 /* SPDX-License-Identifier: BSD-3-Clause 2 * Copyright(c) 2018 Intel Corporation 3 */ 4 5 #include <string.h> 6 #include <unistd.h> 7 #include <fcntl.h> 8 #include <signal.h> 9 #include <sys/socket.h> 10 #include <linux/netlink.h> 11 12 #include <rte_string_fns.h> 13 #include <rte_log.h> 14 #include <rte_compat.h> 15 #include <rte_dev.h> 16 #include <rte_malloc.h> 17 #include <rte_interrupts.h> 18 #include <rte_alarm.h> 19 #include <rte_bus.h> 20 #include <rte_eal.h> 21 #include <rte_spinlock.h> 22 #include <rte_errno.h> 23 24 #include "eal_private.h" 25 26 static struct rte_intr_handle *intr_handle; 27 static rte_rwlock_t monitor_lock = RTE_RWLOCK_INITIALIZER; 28 static uint32_t monitor_refcount; 29 static bool hotplug_handle; 30 31 #define EAL_UEV_MSG_LEN 4096 32 #define EAL_UEV_MSG_ELEM_LEN 128 33 34 /* 35 * spinlock for device hot-unplug failure handling. If it try to access bus or 36 * device, such as handle sigbus on bus or handle memory failure for device 37 * just need to use this lock. It could protect the bus and the device to avoid 38 * race condition. 39 */ 40 static rte_spinlock_t failure_handle_lock = RTE_SPINLOCK_INITIALIZER; 41 42 static struct sigaction sigbus_action_old; 43 44 static int sigbus_need_recover; 45 46 static void dev_uev_handler(__rte_unused void *param); 47 48 /* identify the system layer which reports this event. */ 49 enum eal_dev_event_subsystem { 50 EAL_DEV_EVENT_SUBSYSTEM_PCI, /* PCI bus device event */ 51 EAL_DEV_EVENT_SUBSYSTEM_UIO, /* UIO driver device event */ 52 EAL_DEV_EVENT_SUBSYSTEM_VFIO, /* VFIO driver device event */ 53 EAL_DEV_EVENT_SUBSYSTEM_MAX 54 }; 55 56 static void 57 sigbus_action_recover(void) 58 { 59 if (sigbus_need_recover) { 60 sigaction(SIGBUS, &sigbus_action_old, NULL); 61 sigbus_need_recover = 0; 62 } 63 } 64 65 static void sigbus_handler(int signum, siginfo_t *info, 66 void *ctx __rte_unused) 67 { 68 int ret; 69 70 RTE_LOG(DEBUG, EAL, "Thread catch SIGBUS, fault address:%p\n", 71 info->si_addr); 72 73 rte_spinlock_lock(&failure_handle_lock); 74 ret = rte_bus_sigbus_handler(info->si_addr); 75 rte_spinlock_unlock(&failure_handle_lock); 76 if (ret == -1) { 77 rte_exit(EXIT_FAILURE, 78 "Failed to handle SIGBUS for hot-unplug, " 79 "(rte_errno: %s)!", strerror(rte_errno)); 80 } else if (ret == 1) { 81 if (sigbus_action_old.sa_flags == SA_SIGINFO 82 && sigbus_action_old.sa_sigaction) { 83 (*(sigbus_action_old.sa_sigaction))(signum, 84 info, ctx); 85 } else if (sigbus_action_old.sa_flags != SA_SIGINFO 86 && sigbus_action_old.sa_handler) { 87 (*(sigbus_action_old.sa_handler))(signum); 88 } else { 89 rte_exit(EXIT_FAILURE, 90 "Failed to handle generic SIGBUS!"); 91 } 92 } 93 94 RTE_LOG(DEBUG, EAL, "Success to handle SIGBUS for hot-unplug!\n"); 95 } 96 97 static int cmp_dev_name(const struct rte_device *dev, 98 const void *_name) 99 { 100 const char *name = _name; 101 102 return strcmp(dev->name, name); 103 } 104 105 static int 106 dev_uev_socket_fd_create(void) 107 { 108 struct sockaddr_nl addr; 109 int ret, fd; 110 111 fd = socket(PF_NETLINK, SOCK_RAW | SOCK_CLOEXEC | SOCK_NONBLOCK, 112 NETLINK_KOBJECT_UEVENT); 113 if (fd < 0) { 114 RTE_LOG(ERR, EAL, "create uevent fd failed.\n"); 115 return -1; 116 } 117 118 memset(&addr, 0, sizeof(addr)); 119 addr.nl_family = AF_NETLINK; 120 addr.nl_pid = 0; 121 addr.nl_groups = 0xffffffff; 122 123 ret = bind(fd, (struct sockaddr *) &addr, sizeof(addr)); 124 if (ret < 0) { 125 RTE_LOG(ERR, EAL, "Failed to bind uevent socket.\n"); 126 goto err; 127 } 128 129 if (rte_intr_fd_set(intr_handle, fd)) 130 goto err; 131 132 return 0; 133 err: 134 close(fd); 135 fd = -1; 136 return ret; 137 } 138 139 struct rte_dev_event { 140 enum rte_dev_event_type type; /**< device event type */ 141 int subsystem; /**< subsystem id */ 142 char *devname; /**< device name */ 143 }; 144 145 static int 146 dev_uev_parse(const char *buf, struct rte_dev_event *event, int length) 147 { 148 char action[EAL_UEV_MSG_ELEM_LEN]; 149 char subsystem[EAL_UEV_MSG_ELEM_LEN]; 150 char pci_slot_name[EAL_UEV_MSG_ELEM_LEN]; 151 int i = 0; 152 153 memset(action, 0, EAL_UEV_MSG_ELEM_LEN); 154 memset(subsystem, 0, EAL_UEV_MSG_ELEM_LEN); 155 memset(pci_slot_name, 0, EAL_UEV_MSG_ELEM_LEN); 156 157 while (i < length) { 158 for (; i < length; i++) { 159 if (*buf) 160 break; 161 buf++; 162 } 163 if (i >= length) 164 break; 165 166 /** 167 * check device uevent from kernel side, no need to check 168 * uevent from udev. 169 */ 170 if (!strncmp(buf, "libudev", 7)) { 171 buf += 7; 172 i += 7; 173 return -1; 174 } 175 if (!strncmp(buf, "ACTION=", 7)) { 176 buf += 7; 177 i += 7; 178 strlcpy(action, buf, sizeof(action)); 179 } else if (!strncmp(buf, "SUBSYSTEM=", 10)) { 180 buf += 10; 181 i += 10; 182 strlcpy(subsystem, buf, sizeof(subsystem)); 183 } else if (!strncmp(buf, "PCI_SLOT_NAME=", 14)) { 184 buf += 14; 185 i += 14; 186 strlcpy(pci_slot_name, buf, sizeof(subsystem)); 187 event->devname = strdup(pci_slot_name); 188 } 189 for (; i < length; i++) { 190 if (*buf == '\0') 191 break; 192 buf++; 193 } 194 } 195 196 /* parse the subsystem layer */ 197 if (!strncmp(subsystem, "uio", 3)) 198 event->subsystem = EAL_DEV_EVENT_SUBSYSTEM_UIO; 199 else if (!strncmp(subsystem, "pci", 3)) 200 event->subsystem = EAL_DEV_EVENT_SUBSYSTEM_PCI; 201 else if (!strncmp(subsystem, "vfio", 4)) 202 event->subsystem = EAL_DEV_EVENT_SUBSYSTEM_VFIO; 203 else 204 goto err; 205 206 /* parse the action type */ 207 if (!strncmp(action, "add", 3)) 208 event->type = RTE_DEV_EVENT_ADD; 209 else if (!strncmp(action, "remove", 6)) 210 event->type = RTE_DEV_EVENT_REMOVE; 211 else 212 goto err; 213 return 0; 214 err: 215 free(event->devname); 216 return -1; 217 } 218 219 static void 220 dev_delayed_unregister(void *param) 221 { 222 rte_intr_callback_unregister(intr_handle, dev_uev_handler, param); 223 if (rte_intr_fd_get(intr_handle) >= 0) { 224 close(rte_intr_fd_get(intr_handle)); 225 rte_intr_fd_set(intr_handle, -1); 226 } 227 } 228 229 static void 230 dev_uev_handler(__rte_unused void *param) 231 { 232 struct rte_dev_event uevent; 233 int ret; 234 char buf[EAL_UEV_MSG_LEN]; 235 struct rte_bus *bus; 236 struct rte_device *dev; 237 const char *busname = ""; 238 239 memset(&uevent, 0, sizeof(struct rte_dev_event)); 240 memset(buf, 0, EAL_UEV_MSG_LEN); 241 242 if (rte_intr_fd_get(intr_handle) < 0) 243 return; 244 245 ret = recv(rte_intr_fd_get(intr_handle), buf, EAL_UEV_MSG_LEN, 246 MSG_DONTWAIT); 247 if (ret < 0 && errno == EAGAIN) 248 return; 249 else if (ret <= 0) { 250 /* connection is closed or broken, can not up again. */ 251 RTE_LOG(ERR, EAL, "uevent socket connection is broken.\n"); 252 rte_eal_alarm_set(1, dev_delayed_unregister, NULL); 253 return; 254 } 255 256 ret = dev_uev_parse(buf, &uevent, EAL_UEV_MSG_LEN); 257 if (ret < 0) { 258 RTE_LOG(DEBUG, EAL, "Ignoring uevent '%s'\n", buf); 259 return; 260 } 261 262 RTE_LOG(DEBUG, EAL, "receive uevent(name:%s, type:%d, subsystem:%d)\n", 263 uevent.devname, uevent.type, uevent.subsystem); 264 265 switch (uevent.subsystem) { 266 case EAL_DEV_EVENT_SUBSYSTEM_PCI: 267 case EAL_DEV_EVENT_SUBSYSTEM_UIO: 268 busname = "pci"; 269 break; 270 default: 271 break; 272 } 273 274 if (uevent.devname) { 275 if (uevent.type == RTE_DEV_EVENT_REMOVE && hotplug_handle) { 276 rte_spinlock_lock(&failure_handle_lock); 277 bus = rte_bus_find_by_name(busname); 278 if (bus == NULL) { 279 RTE_LOG(ERR, EAL, "Cannot find bus (%s)\n", 280 busname); 281 goto failure_handle_err; 282 } 283 284 dev = bus->find_device(NULL, cmp_dev_name, 285 uevent.devname); 286 if (dev == NULL) { 287 RTE_LOG(ERR, EAL, "Cannot find device (%s) on " 288 "bus (%s)\n", uevent.devname, busname); 289 goto failure_handle_err; 290 } 291 292 ret = bus->hot_unplug_handler(dev); 293 if (ret) { 294 RTE_LOG(ERR, EAL, "Can not handle hot-unplug " 295 "for device (%s)\n", dev->name); 296 } 297 rte_spinlock_unlock(&failure_handle_lock); 298 } 299 rte_dev_event_callback_process(uevent.devname, uevent.type); 300 free(uevent.devname); 301 } 302 303 return; 304 305 failure_handle_err: 306 rte_spinlock_unlock(&failure_handle_lock); 307 free(uevent.devname); 308 } 309 310 int 311 rte_dev_event_monitor_start(void) 312 { 313 int ret = 0; 314 315 rte_rwlock_write_lock(&monitor_lock); 316 317 if (monitor_refcount) { 318 monitor_refcount++; 319 goto exit; 320 } 321 322 intr_handle = rte_intr_instance_alloc(RTE_INTR_INSTANCE_F_PRIVATE); 323 if (intr_handle == NULL) { 324 RTE_LOG(ERR, EAL, "Fail to allocate intr_handle\n"); 325 goto exit; 326 } 327 328 ret = rte_intr_type_set(intr_handle, RTE_INTR_HANDLE_DEV_EVENT); 329 if (ret) 330 goto exit; 331 332 ret = rte_intr_fd_set(intr_handle, -1); 333 if (ret) 334 goto exit; 335 336 ret = dev_uev_socket_fd_create(); 337 if (ret) { 338 RTE_LOG(ERR, EAL, "error create device event fd.\n"); 339 goto exit; 340 } 341 342 ret = rte_intr_callback_register(intr_handle, dev_uev_handler, NULL); 343 344 if (ret) { 345 close(rte_intr_fd_get(intr_handle)); 346 goto exit; 347 } 348 349 monitor_refcount++; 350 351 exit: 352 if (ret) { 353 rte_intr_instance_free(intr_handle); 354 intr_handle = NULL; 355 } 356 rte_rwlock_write_unlock(&monitor_lock); 357 return ret; 358 } 359 360 int 361 rte_dev_event_monitor_stop(void) 362 { 363 int ret = 0; 364 365 rte_rwlock_write_lock(&monitor_lock); 366 367 if (!monitor_refcount) { 368 RTE_LOG(ERR, EAL, "device event monitor already stopped\n"); 369 goto exit; 370 } 371 372 if (monitor_refcount > 1) { 373 monitor_refcount--; 374 goto exit; 375 } 376 377 ret = rte_intr_callback_unregister(intr_handle, dev_uev_handler, 378 (void *)-1); 379 if (ret < 0) { 380 RTE_LOG(ERR, EAL, "fail to unregister uevent callback.\n"); 381 goto exit; 382 } 383 384 close(rte_intr_fd_get(intr_handle)); 385 rte_intr_instance_free(intr_handle); 386 intr_handle = NULL; 387 388 monitor_refcount--; 389 390 exit: 391 rte_rwlock_write_unlock(&monitor_lock); 392 393 return ret; 394 } 395 396 int 397 dev_sigbus_handler_register(void) 398 { 399 sigset_t mask; 400 struct sigaction action; 401 402 rte_errno = 0; 403 404 if (sigbus_need_recover) 405 return 0; 406 407 sigemptyset(&mask); 408 sigaddset(&mask, SIGBUS); 409 action.sa_flags = SA_SIGINFO; 410 action.sa_mask = mask; 411 action.sa_sigaction = sigbus_handler; 412 sigbus_need_recover = !sigaction(SIGBUS, &action, &sigbus_action_old); 413 414 return rte_errno; 415 } 416 417 int 418 dev_sigbus_handler_unregister(void) 419 { 420 rte_errno = 0; 421 422 sigbus_action_recover(); 423 424 return rte_errno; 425 } 426 427 int 428 rte_dev_hotplug_handle_enable(void) 429 { 430 int ret = 0; 431 432 ret = dev_sigbus_handler_register(); 433 if (ret < 0) 434 RTE_LOG(ERR, EAL, 435 "fail to register sigbus handler for devices.\n"); 436 437 hotplug_handle = true; 438 439 return ret; 440 } 441 442 int 443 rte_dev_hotplug_handle_disable(void) 444 { 445 int ret = 0; 446 447 ret = dev_sigbus_handler_unregister(); 448 if (ret < 0) 449 RTE_LOG(ERR, EAL, 450 "fail to unregister sigbus handler for devices.\n"); 451 452 hotplug_handle = false; 453 454 return ret; 455 } 456