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 /** 164 * check device uevent from kernel side, no need to check 165 * uevent from udev. 166 */ 167 if (!strncmp(buf, "libudev", 7)) { 168 buf += 7; 169 i += 7; 170 return -1; 171 } 172 if (!strncmp(buf, "ACTION=", 7)) { 173 buf += 7; 174 i += 7; 175 strlcpy(action, buf, sizeof(action)); 176 } else if (!strncmp(buf, "SUBSYSTEM=", 10)) { 177 buf += 10; 178 i += 10; 179 strlcpy(subsystem, buf, sizeof(subsystem)); 180 } else if (!strncmp(buf, "PCI_SLOT_NAME=", 14)) { 181 buf += 14; 182 i += 14; 183 strlcpy(pci_slot_name, buf, sizeof(subsystem)); 184 event->devname = strdup(pci_slot_name); 185 } 186 for (; i < length; i++) { 187 if (*buf == '\0') 188 break; 189 buf++; 190 } 191 } 192 193 /* parse the subsystem layer */ 194 if (!strncmp(subsystem, "uio", 3)) 195 event->subsystem = EAL_DEV_EVENT_SUBSYSTEM_UIO; 196 else if (!strncmp(subsystem, "pci", 3)) 197 event->subsystem = EAL_DEV_EVENT_SUBSYSTEM_PCI; 198 else if (!strncmp(subsystem, "vfio", 4)) 199 event->subsystem = EAL_DEV_EVENT_SUBSYSTEM_VFIO; 200 else 201 goto err; 202 203 /* parse the action type */ 204 if (!strncmp(action, "add", 3)) 205 event->type = RTE_DEV_EVENT_ADD; 206 else if (!strncmp(action, "remove", 6)) 207 event->type = RTE_DEV_EVENT_REMOVE; 208 else 209 goto err; 210 return 0; 211 err: 212 free(event->devname); 213 return -1; 214 } 215 216 static void 217 dev_delayed_unregister(void *param) 218 { 219 rte_intr_callback_unregister(intr_handle, dev_uev_handler, param); 220 close(rte_intr_fd_get(intr_handle)); 221 rte_intr_fd_set(intr_handle, -1); 222 } 223 224 static void 225 dev_uev_handler(__rte_unused void *param) 226 { 227 struct rte_dev_event uevent; 228 int ret; 229 char buf[EAL_UEV_MSG_LEN]; 230 struct rte_bus *bus; 231 struct rte_device *dev; 232 const char *busname = ""; 233 234 memset(&uevent, 0, sizeof(struct rte_dev_event)); 235 memset(buf, 0, EAL_UEV_MSG_LEN); 236 237 ret = recv(rte_intr_fd_get(intr_handle), buf, EAL_UEV_MSG_LEN, 238 MSG_DONTWAIT); 239 if (ret < 0 && errno == EAGAIN) 240 return; 241 else if (ret <= 0) { 242 /* connection is closed or broken, can not up again. */ 243 RTE_LOG(ERR, EAL, "uevent socket connection is broken.\n"); 244 rte_eal_alarm_set(1, dev_delayed_unregister, NULL); 245 return; 246 } 247 248 ret = dev_uev_parse(buf, &uevent, EAL_UEV_MSG_LEN); 249 if (ret < 0) { 250 RTE_LOG(DEBUG, EAL, "Ignoring uevent '%s'\n", buf); 251 return; 252 } 253 254 RTE_LOG(DEBUG, EAL, "receive uevent(name:%s, type:%d, subsystem:%d)\n", 255 uevent.devname, uevent.type, uevent.subsystem); 256 257 switch (uevent.subsystem) { 258 case EAL_DEV_EVENT_SUBSYSTEM_PCI: 259 case EAL_DEV_EVENT_SUBSYSTEM_UIO: 260 busname = "pci"; 261 break; 262 default: 263 break; 264 } 265 266 if (uevent.devname) { 267 if (uevent.type == RTE_DEV_EVENT_REMOVE && hotplug_handle) { 268 rte_spinlock_lock(&failure_handle_lock); 269 bus = rte_bus_find_by_name(busname); 270 if (bus == NULL) { 271 RTE_LOG(ERR, EAL, "Cannot find bus (%s)\n", 272 busname); 273 goto failure_handle_err; 274 } 275 276 dev = bus->find_device(NULL, cmp_dev_name, 277 uevent.devname); 278 if (dev == NULL) { 279 RTE_LOG(ERR, EAL, "Cannot find device (%s) on " 280 "bus (%s)\n", uevent.devname, busname); 281 goto failure_handle_err; 282 } 283 284 ret = bus->hot_unplug_handler(dev); 285 if (ret) { 286 RTE_LOG(ERR, EAL, "Can not handle hot-unplug " 287 "for device (%s)\n", dev->name); 288 } 289 rte_spinlock_unlock(&failure_handle_lock); 290 } 291 rte_dev_event_callback_process(uevent.devname, uevent.type); 292 free(uevent.devname); 293 } 294 295 return; 296 297 failure_handle_err: 298 rte_spinlock_unlock(&failure_handle_lock); 299 free(uevent.devname); 300 } 301 302 int 303 rte_dev_event_monitor_start(void) 304 { 305 int ret = 0; 306 307 rte_rwlock_write_lock(&monitor_lock); 308 309 if (monitor_refcount) { 310 monitor_refcount++; 311 goto exit; 312 } 313 314 intr_handle = rte_intr_instance_alloc(RTE_INTR_INSTANCE_F_PRIVATE); 315 if (intr_handle == NULL) { 316 RTE_LOG(ERR, EAL, "Fail to allocate intr_handle\n"); 317 goto exit; 318 } 319 320 if (rte_intr_type_set(intr_handle, RTE_INTR_HANDLE_DEV_EVENT)) 321 goto exit; 322 323 if (rte_intr_fd_set(intr_handle, -1)) 324 goto exit; 325 326 ret = dev_uev_socket_fd_create(); 327 if (ret) { 328 RTE_LOG(ERR, EAL, "error create device event fd.\n"); 329 goto exit; 330 } 331 332 ret = rte_intr_callback_register(intr_handle, dev_uev_handler, NULL); 333 334 if (ret) { 335 close(rte_intr_fd_get(intr_handle)); 336 goto exit; 337 } 338 339 monitor_refcount++; 340 341 exit: 342 rte_intr_instance_free(intr_handle); 343 rte_rwlock_write_unlock(&monitor_lock); 344 return ret; 345 } 346 347 int 348 rte_dev_event_monitor_stop(void) 349 { 350 int ret = 0; 351 352 rte_rwlock_write_lock(&monitor_lock); 353 354 if (!monitor_refcount) { 355 RTE_LOG(ERR, EAL, "device event monitor already stopped\n"); 356 goto exit; 357 } 358 359 if (monitor_refcount > 1) { 360 monitor_refcount--; 361 goto exit; 362 } 363 364 ret = rte_intr_callback_unregister(intr_handle, dev_uev_handler, 365 (void *)-1); 366 if (ret < 0) { 367 RTE_LOG(ERR, EAL, "fail to unregister uevent callback.\n"); 368 goto exit; 369 } 370 371 close(rte_intr_fd_get(intr_handle)); 372 rte_intr_instance_free(intr_handle); 373 374 monitor_refcount--; 375 376 exit: 377 rte_rwlock_write_unlock(&monitor_lock); 378 379 return ret; 380 } 381 382 int 383 dev_sigbus_handler_register(void) 384 { 385 sigset_t mask; 386 struct sigaction action; 387 388 rte_errno = 0; 389 390 if (sigbus_need_recover) 391 return 0; 392 393 sigemptyset(&mask); 394 sigaddset(&mask, SIGBUS); 395 action.sa_flags = SA_SIGINFO; 396 action.sa_mask = mask; 397 action.sa_sigaction = sigbus_handler; 398 sigbus_need_recover = !sigaction(SIGBUS, &action, &sigbus_action_old); 399 400 return rte_errno; 401 } 402 403 int 404 dev_sigbus_handler_unregister(void) 405 { 406 rte_errno = 0; 407 408 sigbus_action_recover(); 409 410 return rte_errno; 411 } 412 413 int 414 rte_dev_hotplug_handle_enable(void) 415 { 416 int ret = 0; 417 418 ret = dev_sigbus_handler_register(); 419 if (ret < 0) 420 RTE_LOG(ERR, EAL, 421 "fail to register sigbus handler for devices.\n"); 422 423 hotplug_handle = true; 424 425 return ret; 426 } 427 428 int 429 rte_dev_hotplug_handle_disable(void) 430 { 431 int ret = 0; 432 433 ret = dev_sigbus_handler_unregister(); 434 if (ret < 0) 435 RTE_LOG(ERR, EAL, 436 "fail to unregister sigbus handler for devices.\n"); 437 438 hotplug_handle = false; 439 440 return ret; 441 } 442