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 close(rte_intr_fd_get(intr_handle)); 224 rte_intr_fd_set(intr_handle, -1); 225 } 226 227 static void 228 dev_uev_handler(__rte_unused void *param) 229 { 230 struct rte_dev_event uevent; 231 int ret; 232 char buf[EAL_UEV_MSG_LEN]; 233 struct rte_bus *bus; 234 struct rte_device *dev; 235 const char *busname = ""; 236 237 memset(&uevent, 0, sizeof(struct rte_dev_event)); 238 memset(buf, 0, EAL_UEV_MSG_LEN); 239 240 ret = recv(rte_intr_fd_get(intr_handle), buf, EAL_UEV_MSG_LEN, 241 MSG_DONTWAIT); 242 if (ret < 0 && errno == EAGAIN) 243 return; 244 else if (ret <= 0) { 245 /* connection is closed or broken, can not up again. */ 246 RTE_LOG(ERR, EAL, "uevent socket connection is broken.\n"); 247 rte_eal_alarm_set(1, dev_delayed_unregister, NULL); 248 return; 249 } 250 251 ret = dev_uev_parse(buf, &uevent, EAL_UEV_MSG_LEN); 252 if (ret < 0) { 253 RTE_LOG(DEBUG, EAL, "Ignoring uevent '%s'\n", buf); 254 return; 255 } 256 257 RTE_LOG(DEBUG, EAL, "receive uevent(name:%s, type:%d, subsystem:%d)\n", 258 uevent.devname, uevent.type, uevent.subsystem); 259 260 switch (uevent.subsystem) { 261 case EAL_DEV_EVENT_SUBSYSTEM_PCI: 262 case EAL_DEV_EVENT_SUBSYSTEM_UIO: 263 busname = "pci"; 264 break; 265 default: 266 break; 267 } 268 269 if (uevent.devname) { 270 if (uevent.type == RTE_DEV_EVENT_REMOVE && hotplug_handle) { 271 rte_spinlock_lock(&failure_handle_lock); 272 bus = rte_bus_find_by_name(busname); 273 if (bus == NULL) { 274 RTE_LOG(ERR, EAL, "Cannot find bus (%s)\n", 275 busname); 276 goto failure_handle_err; 277 } 278 279 dev = bus->find_device(NULL, cmp_dev_name, 280 uevent.devname); 281 if (dev == NULL) { 282 RTE_LOG(ERR, EAL, "Cannot find device (%s) on " 283 "bus (%s)\n", uevent.devname, busname); 284 goto failure_handle_err; 285 } 286 287 ret = bus->hot_unplug_handler(dev); 288 if (ret) { 289 RTE_LOG(ERR, EAL, "Can not handle hot-unplug " 290 "for device (%s)\n", dev->name); 291 } 292 rte_spinlock_unlock(&failure_handle_lock); 293 } 294 rte_dev_event_callback_process(uevent.devname, uevent.type); 295 free(uevent.devname); 296 } 297 298 return; 299 300 failure_handle_err: 301 rte_spinlock_unlock(&failure_handle_lock); 302 free(uevent.devname); 303 } 304 305 int 306 rte_dev_event_monitor_start(void) 307 { 308 int ret = 0; 309 310 rte_rwlock_write_lock(&monitor_lock); 311 312 if (monitor_refcount) { 313 monitor_refcount++; 314 goto exit; 315 } 316 317 intr_handle = rte_intr_instance_alloc(RTE_INTR_INSTANCE_F_PRIVATE); 318 if (intr_handle == NULL) { 319 RTE_LOG(ERR, EAL, "Fail to allocate intr_handle\n"); 320 goto exit; 321 } 322 323 if (rte_intr_type_set(intr_handle, RTE_INTR_HANDLE_DEV_EVENT)) 324 goto exit; 325 326 if (rte_intr_fd_set(intr_handle, -1)) 327 goto exit; 328 329 ret = dev_uev_socket_fd_create(); 330 if (ret) { 331 RTE_LOG(ERR, EAL, "error create device event fd.\n"); 332 goto exit; 333 } 334 335 ret = rte_intr_callback_register(intr_handle, dev_uev_handler, NULL); 336 337 if (ret) { 338 close(rte_intr_fd_get(intr_handle)); 339 goto exit; 340 } 341 342 monitor_refcount++; 343 344 exit: 345 rte_intr_instance_free(intr_handle); 346 rte_rwlock_write_unlock(&monitor_lock); 347 return ret; 348 } 349 350 int 351 rte_dev_event_monitor_stop(void) 352 { 353 int ret = 0; 354 355 rte_rwlock_write_lock(&monitor_lock); 356 357 if (!monitor_refcount) { 358 RTE_LOG(ERR, EAL, "device event monitor already stopped\n"); 359 goto exit; 360 } 361 362 if (monitor_refcount > 1) { 363 monitor_refcount--; 364 goto exit; 365 } 366 367 ret = rte_intr_callback_unregister(intr_handle, dev_uev_handler, 368 (void *)-1); 369 if (ret < 0) { 370 RTE_LOG(ERR, EAL, "fail to unregister uevent callback.\n"); 371 goto exit; 372 } 373 374 close(rte_intr_fd_get(intr_handle)); 375 rte_intr_instance_free(intr_handle); 376 377 monitor_refcount--; 378 379 exit: 380 rte_rwlock_write_unlock(&monitor_lock); 381 382 return ret; 383 } 384 385 int 386 dev_sigbus_handler_register(void) 387 { 388 sigset_t mask; 389 struct sigaction action; 390 391 rte_errno = 0; 392 393 if (sigbus_need_recover) 394 return 0; 395 396 sigemptyset(&mask); 397 sigaddset(&mask, SIGBUS); 398 action.sa_flags = SA_SIGINFO; 399 action.sa_mask = mask; 400 action.sa_sigaction = sigbus_handler; 401 sigbus_need_recover = !sigaction(SIGBUS, &action, &sigbus_action_old); 402 403 return rte_errno; 404 } 405 406 int 407 dev_sigbus_handler_unregister(void) 408 { 409 rte_errno = 0; 410 411 sigbus_action_recover(); 412 413 return rte_errno; 414 } 415 416 int 417 rte_dev_hotplug_handle_enable(void) 418 { 419 int ret = 0; 420 421 ret = dev_sigbus_handler_register(); 422 if (ret < 0) 423 RTE_LOG(ERR, EAL, 424 "fail to register sigbus handler for devices.\n"); 425 426 hotplug_handle = true; 427 428 return ret; 429 } 430 431 int 432 rte_dev_hotplug_handle_disable(void) 433 { 434 int ret = 0; 435 436 ret = dev_sigbus_handler_unregister(); 437 if (ret < 0) 438 RTE_LOG(ERR, EAL, 439 "fail to unregister sigbus handler for devices.\n"); 440 441 hotplug_handle = false; 442 443 return ret; 444 } 445