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 .type = RTE_INTR_HANDLE_DEV_EVENT, 28 .fd = -1, 29 }; 30 static rte_rwlock_t monitor_lock = RTE_RWLOCK_INITIALIZER; 31 static uint32_t monitor_refcount; 32 static bool hotplug_handle; 33 34 #define EAL_UEV_MSG_LEN 4096 35 #define EAL_UEV_MSG_ELEM_LEN 128 36 37 /* 38 * spinlock for device hot-unplug failure handling. If it try to access bus or 39 * device, such as handle sigbus on bus or handle memory failure for device 40 * just need to use this lock. It could protect the bus and the device to avoid 41 * race condition. 42 */ 43 static rte_spinlock_t failure_handle_lock = RTE_SPINLOCK_INITIALIZER; 44 45 static struct sigaction sigbus_action_old; 46 47 static int sigbus_need_recover; 48 49 static void dev_uev_handler(__rte_unused void *param); 50 51 /* identify the system layer which reports this event. */ 52 enum eal_dev_event_subsystem { 53 EAL_DEV_EVENT_SUBSYSTEM_PCI, /* PCI bus device event */ 54 EAL_DEV_EVENT_SUBSYSTEM_UIO, /* UIO driver device event */ 55 EAL_DEV_EVENT_SUBSYSTEM_VFIO, /* VFIO driver device event */ 56 EAL_DEV_EVENT_SUBSYSTEM_MAX 57 }; 58 59 static void 60 sigbus_action_recover(void) 61 { 62 if (sigbus_need_recover) { 63 sigaction(SIGBUS, &sigbus_action_old, NULL); 64 sigbus_need_recover = 0; 65 } 66 } 67 68 static void sigbus_handler(int signum, siginfo_t *info, 69 void *ctx __rte_unused) 70 { 71 int ret; 72 73 RTE_LOG(DEBUG, EAL, "Thread catch SIGBUS, fault address:%p\n", 74 info->si_addr); 75 76 rte_spinlock_lock(&failure_handle_lock); 77 ret = rte_bus_sigbus_handler(info->si_addr); 78 rte_spinlock_unlock(&failure_handle_lock); 79 if (ret == -1) { 80 rte_exit(EXIT_FAILURE, 81 "Failed to handle SIGBUS for hot-unplug, " 82 "(rte_errno: %s)!", strerror(rte_errno)); 83 } else if (ret == 1) { 84 if (sigbus_action_old.sa_flags == SA_SIGINFO 85 && sigbus_action_old.sa_sigaction) { 86 (*(sigbus_action_old.sa_sigaction))(signum, 87 info, ctx); 88 } else if (sigbus_action_old.sa_flags != SA_SIGINFO 89 && sigbus_action_old.sa_handler) { 90 (*(sigbus_action_old.sa_handler))(signum); 91 } else { 92 rte_exit(EXIT_FAILURE, 93 "Failed to handle generic SIGBUS!"); 94 } 95 } 96 97 RTE_LOG(DEBUG, EAL, "Success to handle SIGBUS for hot-unplug!\n"); 98 } 99 100 static int cmp_dev_name(const struct rte_device *dev, 101 const void *_name) 102 { 103 const char *name = _name; 104 105 return strcmp(dev->name, name); 106 } 107 108 static int 109 dev_uev_socket_fd_create(void) 110 { 111 struct sockaddr_nl addr; 112 int ret; 113 114 intr_handle.fd = socket(PF_NETLINK, SOCK_RAW | SOCK_CLOEXEC | 115 SOCK_NONBLOCK, 116 NETLINK_KOBJECT_UEVENT); 117 if (intr_handle.fd < 0) { 118 RTE_LOG(ERR, EAL, "create uevent fd failed.\n"); 119 return -1; 120 } 121 122 memset(&addr, 0, sizeof(addr)); 123 addr.nl_family = AF_NETLINK; 124 addr.nl_pid = 0; 125 addr.nl_groups = 0xffffffff; 126 127 ret = bind(intr_handle.fd, (struct sockaddr *) &addr, sizeof(addr)); 128 if (ret < 0) { 129 RTE_LOG(ERR, EAL, "Failed to bind uevent socket.\n"); 130 goto err; 131 } 132 133 return 0; 134 err: 135 close(intr_handle.fd); 136 intr_handle.fd = -1; 137 return ret; 138 } 139 140 struct rte_dev_event { 141 enum rte_dev_event_type type; /**< device event type */ 142 int subsystem; /**< subsystem id */ 143 char *devname; /**< device name */ 144 }; 145 146 static int 147 dev_uev_parse(const char *buf, struct rte_dev_event *event, int length) 148 { 149 char action[EAL_UEV_MSG_ELEM_LEN]; 150 char subsystem[EAL_UEV_MSG_ELEM_LEN]; 151 char pci_slot_name[EAL_UEV_MSG_ELEM_LEN]; 152 int i = 0; 153 154 memset(action, 0, EAL_UEV_MSG_ELEM_LEN); 155 memset(subsystem, 0, EAL_UEV_MSG_ELEM_LEN); 156 memset(pci_slot_name, 0, EAL_UEV_MSG_ELEM_LEN); 157 158 while (i < length) { 159 for (; i < length; i++) { 160 if (*buf) 161 break; 162 buf++; 163 } 164 /** 165 * check device uevent from kernel side, no need to check 166 * uevent from udev. 167 */ 168 if (!strncmp(buf, "libudev", 7)) { 169 buf += 7; 170 i += 7; 171 return -1; 172 } 173 if (!strncmp(buf, "ACTION=", 7)) { 174 buf += 7; 175 i += 7; 176 strlcpy(action, buf, sizeof(action)); 177 } else if (!strncmp(buf, "SUBSYSTEM=", 10)) { 178 buf += 10; 179 i += 10; 180 strlcpy(subsystem, buf, sizeof(subsystem)); 181 } else if (!strncmp(buf, "PCI_SLOT_NAME=", 14)) { 182 buf += 14; 183 i += 14; 184 strlcpy(pci_slot_name, buf, sizeof(subsystem)); 185 event->devname = strdup(pci_slot_name); 186 } 187 for (; i < length; i++) { 188 if (*buf == '\0') 189 break; 190 buf++; 191 } 192 } 193 194 /* parse the subsystem layer */ 195 if (!strncmp(subsystem, "uio", 3)) 196 event->subsystem = EAL_DEV_EVENT_SUBSYSTEM_UIO; 197 else if (!strncmp(subsystem, "pci", 3)) 198 event->subsystem = EAL_DEV_EVENT_SUBSYSTEM_PCI; 199 else if (!strncmp(subsystem, "vfio", 4)) 200 event->subsystem = EAL_DEV_EVENT_SUBSYSTEM_VFIO; 201 else 202 goto err; 203 204 /* parse the action type */ 205 if (!strncmp(action, "add", 3)) 206 event->type = RTE_DEV_EVENT_ADD; 207 else if (!strncmp(action, "remove", 6)) 208 event->type = RTE_DEV_EVENT_REMOVE; 209 else 210 goto err; 211 return 0; 212 err: 213 free(event->devname); 214 return -1; 215 } 216 217 static void 218 dev_delayed_unregister(void *param) 219 { 220 rte_intr_callback_unregister(&intr_handle, dev_uev_handler, param); 221 close(intr_handle.fd); 222 intr_handle.fd = -1; 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 ret = recv(intr_handle.fd, buf, EAL_UEV_MSG_LEN, 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 ret = dev_uev_socket_fd_create(); 315 if (ret) { 316 RTE_LOG(ERR, EAL, "error create device event fd.\n"); 317 goto exit; 318 } 319 320 ret = rte_intr_callback_register(&intr_handle, dev_uev_handler, NULL); 321 322 if (ret) { 323 RTE_LOG(ERR, EAL, "fail to register uevent callback.\n"); 324 close(intr_handle.fd); 325 intr_handle.fd = -1; 326 goto exit; 327 } 328 329 monitor_refcount++; 330 331 exit: 332 rte_rwlock_write_unlock(&monitor_lock); 333 return ret; 334 } 335 336 int 337 rte_dev_event_monitor_stop(void) 338 { 339 int ret = 0; 340 341 rte_rwlock_write_lock(&monitor_lock); 342 343 if (!monitor_refcount) { 344 RTE_LOG(ERR, EAL, "device event monitor already stopped\n"); 345 goto exit; 346 } 347 348 if (monitor_refcount > 1) { 349 monitor_refcount--; 350 goto exit; 351 } 352 353 ret = rte_intr_callback_unregister(&intr_handle, dev_uev_handler, 354 (void *)-1); 355 if (ret < 0) { 356 RTE_LOG(ERR, EAL, "fail to unregister uevent callback.\n"); 357 goto exit; 358 } 359 360 close(intr_handle.fd); 361 intr_handle.fd = -1; 362 363 monitor_refcount--; 364 365 exit: 366 rte_rwlock_write_unlock(&monitor_lock); 367 368 return ret; 369 } 370 371 int 372 dev_sigbus_handler_register(void) 373 { 374 sigset_t mask; 375 struct sigaction action; 376 377 rte_errno = 0; 378 379 if (sigbus_need_recover) 380 return 0; 381 382 sigemptyset(&mask); 383 sigaddset(&mask, SIGBUS); 384 action.sa_flags = SA_SIGINFO; 385 action.sa_mask = mask; 386 action.sa_sigaction = sigbus_handler; 387 sigbus_need_recover = !sigaction(SIGBUS, &action, &sigbus_action_old); 388 389 return rte_errno; 390 } 391 392 int 393 dev_sigbus_handler_unregister(void) 394 { 395 rte_errno = 0; 396 397 sigbus_action_recover(); 398 399 return rte_errno; 400 } 401 402 int 403 rte_dev_hotplug_handle_enable(void) 404 { 405 int ret = 0; 406 407 ret = dev_sigbus_handler_register(); 408 if (ret < 0) 409 RTE_LOG(ERR, EAL, 410 "fail to register sigbus handler for devices.\n"); 411 412 hotplug_handle = true; 413 414 return ret; 415 } 416 417 int 418 rte_dev_hotplug_handle_disable(void) 419 { 420 int ret = 0; 421 422 ret = dev_sigbus_handler_unregister(); 423 if (ret < 0) 424 RTE_LOG(ERR, EAL, 425 "fail to unregister sigbus handler for devices.\n"); 426 427 hotplug_handle = false; 428 429 return ret; 430 } 431