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