src/vnet/session/segment_manager.c

   1 /*
   2  * Copyright (c) 2017 Cisco and/or its affiliates.
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15
  16 #include <vnet/session/segment_manager.h>
  17 #include <vnet/session/session.h>
  18 #include <vnet/session/application.h>
  19
  20 /**
  21  * Counter used to build segment names
  22  */
  23 u32 segment_name_counter = 0;
  24
  25 /**
  26  * Pool of segment managers
  27  */
  28 segment_manager_t *segment_managers = 0;
  29
  30 /*
  31  * Pool of segment manager properties
  32  */
  33 static segment_manager_properties_t *segment_manager_properties_pool;
  34
  35 /**
  36  * Process private segment index
  37  */
  38 u32 *private_segment_indices;
  39
  40 /**
  41  * Default fifo and segment size. TODO config.
  42  */
  43 u32 default_fifo_size = 1 << 16;
  44 u32 default_segment_size = 1 << 20;
  45
  46 segment_manager_properties_t *
  47 segment_manager_properties_alloc (void)
  48 {
  49   segment_manager_properties_t *props;
  50   pool_get (segment_manager_properties_pool, props);
  51   memset (props, 0, sizeof (*props));
  52   props->add_segment_size = default_segment_size;
  53   props->rx_fifo_size = default_fifo_size;
  54   props->tx_fifo_size = default_fifo_size;
  55   return props;
  56 }
  57
  58 void
  59 segment_manager_properties_free (segment_manager_properties_t * props)
  60 {
  61   pool_put (segment_manager_properties_pool, props);
  62   memset (props, 0xFB, sizeof (*props));
  63 }
  64
  65 segment_manager_properties_t *
  66 segment_manager_properties_get (u32 smp_index)
  67 {
  68   if (pool_is_free_index (segment_manager_properties_pool, smp_index))
  69     return 0;
  70   return pool_elt_at_index (segment_manager_properties_pool, smp_index);
  71 }
  72
  73 u32
  74 segment_manager_properties_index (segment_manager_properties_t * p)
  75 {
  76   return p - segment_manager_properties_pool;
  77 }
  78
  79 svm_fifo_segment_private_t *
  80 segment_manager_get_segment (u32 segment_index)
  81 {
  82   return svm_fifo_segment_get_segment (segment_index);
  83 }
  84
  85 void
  86 segment_manager_get_segment_info (u32 index, u8 ** name, u32 * size)
  87 {
  88   svm_fifo_segment_private_t *s;
  89   s = svm_fifo_segment_get_segment (index);
  90   *name = s->ssvm.name;
  91   *size = s->ssvm.ssvm_size;
  92 }
  93
  94 always_inline int
  95 segment_manager_add_segment_i (segment_manager_t * sm, u32 segment_size,
  96                                u32 protected_space)
  97 {
  98   svm_fifo_segment_create_args_t _ca = { 0 }, *ca = &_ca;
  99   segment_manager_properties_t *props;
 100
 101   props = segment_manager_properties_get (sm->properties_index);
 102
 103   /* Not configured for addition of new segments and not first */
 104   if (!props->add_segment && !segment_size)
 105     {
 106       clib_warning ("cannot allocate new segment");
 107       return VNET_API_ERROR_INVALID_VALUE;
 108     }
 109
 110   ca->segment_size = segment_size ? segment_size : props->add_segment_size;
 111   ca->rx_fifo_size = props->rx_fifo_size;
 112   ca->tx_fifo_size = props->tx_fifo_size;
 113   ca->preallocated_fifo_pairs = props->preallocated_fifo_pairs;
 114   ca->seg_protected_space = protected_space ? protected_space : 0;
 115
 116   if (props->segment_type != SSVM_N_SEGMENT_TYPES)
 117     {
 118       ca->segment_name = (char *) format (0, "%d-%d%c", getpid (),
 119                                           segment_name_counter++, 0);
 120       ca->segment_type = props->segment_type;
 121       if (svm_fifo_segment_create (ca))
 122         {
 123           clib_warning ("svm_fifo_segment_create ('%s', %d) failed",
 124                         ca->segment_name, ca->segment_size);
 125           return VNET_API_ERROR_SVM_SEGMENT_CREATE_FAIL;
 126         }
 127       vec_free (ca->segment_name);
 128     }
 129   else
 130     {
 131       u32 rx_fifo_size, tx_fifo_size;
 132       u32 rx_rounded_data_size, tx_rounded_data_size;
 133       u32 approx_segment_count;
 134       u64 approx_total_size;
 135
 136       ca->segment_name = "process-private-segment";
 137       ca->private_segment_count = props->private_segment_count;
 138
 139       /* Calculate space requirements */
 140       rx_rounded_data_size = (1 << (max_log2 (ca->rx_fifo_size)));
 141       tx_rounded_data_size = (1 << (max_log2 (ca->tx_fifo_size)));
 142
 143       rx_fifo_size = sizeof (svm_fifo_t) + rx_rounded_data_size;
 144       tx_fifo_size = sizeof (svm_fifo_t) + tx_rounded_data_size;
 145
 146       approx_total_size = (u64) ca->preallocated_fifo_pairs
 147         * (rx_fifo_size + tx_fifo_size);
 148       approx_segment_count = (approx_total_size + protected_space
 149                               + (ca->segment_size -
 150                                  1)) / (u64) ca->segment_size;
 151
 152       /* The user asked us to figure it out... */
 153       if (ca->private_segment_count == 0
 154           || approx_segment_count < ca->private_segment_count)
 155         {
 156           ca->private_segment_count = approx_segment_count;
 157         }
 158       /* Follow directions, but issue a warning */
 159       else if (approx_segment_count < ca->private_segment_count)
 160         {
 161           clib_warning ("Honoring segment count %u, calculated count was %u",
 162                         ca->private_segment_count, approx_segment_count);
 163         }
 164       else if (approx_segment_count > ca->private_segment_count)
 165         {
 166           clib_warning ("Segment count too low %u, calculated %u.",
 167                         ca->private_segment_count, approx_segment_count);
 168           return VNET_API_ERROR_INVALID_VALUE;
 169         }
 170
 171       if (svm_fifo_segment_create_process_private (ca))
 172         clib_warning ("Failed to create process private segment");
 173
 174       ASSERT (vec_len (ca->new_segment_indices));
 175     }
 176
 177   vec_append (sm->segment_indices, ca->new_segment_indices);
 178   vec_free (ca->new_segment_indices);
 179   return 0;
 180 }
 181
 182 int
 183 segment_manager_add_segment (segment_manager_t * sm)
 184 {
 185   return segment_manager_add_segment_i (sm, 0, 0);
 186 }
 187
 188 segment_manager_t *
 189 segment_manager_new ()
 190 {
 191   segment_manager_t *sm;
 192   pool_get (segment_managers, sm);
 193   memset (sm, 0, sizeof (*sm));
 194   return sm;
 195 }
 196
 197 /**
 198  * Initializes segment manager based on options provided.
 199  * Returns error if svm segment allocation fails.
 200  */
 201 int
 202 segment_manager_init (segment_manager_t * sm, u32 props_index,
 203                       u32 first_seg_size, u32 evt_q_size)
 204 {
 205   u32 protected_space;
 206   int rv;
 207
 208   sm->properties_index = props_index;
 209
 210   protected_space = max_pow2 (sizeof (svm_queue_t)
 211                               + evt_q_size * sizeof (session_fifo_event_t));
 212   protected_space = round_pow2_u64 (protected_space, CLIB_CACHE_LINE_BYTES);
 213   first_seg_size = first_seg_size > 0 ? first_seg_size : default_segment_size;
 214   rv = segment_manager_add_segment_i (sm, first_seg_size, protected_space);
 215   if (rv)
 216     {
 217       clib_warning ("Failed to allocate segment");
 218       return rv;
 219     }
 220
 221   clib_spinlock_init (&sm->lockp);
 222   return 0;
 223 }
 224
 225 u8
 226 segment_manager_has_fifos (segment_manager_t * sm)
 227 {
 228   svm_fifo_segment_private_t *segment;
 229   int i;
 230
 231   for (i = 0; i < vec_len (sm->segment_indices); i++)
 232     {
 233       segment = svm_fifo_segment_get_segment (sm->segment_indices[i]);
 234       if (CLIB_DEBUG && i && !svm_fifo_segment_has_fifos (segment)
 235           && !(segment->h->flags & FIFO_SEGMENT_F_IS_PREALLOCATED))
 236         clib_warning ("segment %d has no fifos!", sm->segment_indices[i]);
 237       if (svm_fifo_segment_has_fifos (segment))
 238         return 1;
 239     }
 240   return 0;
 241 }
 242
 243 static u8
 244 segment_manager_app_detached (segment_manager_t * sm)
 245 {
 246   return (sm->app_index == SEGMENT_MANAGER_INVALID_APP_INDEX);
 247 }
 248
 249 void
 250 segment_manager_app_detach (segment_manager_t * sm)
 251 {
 252   sm->app_index = SEGMENT_MANAGER_INVALID_APP_INDEX;
 253 }
 254
 255 static void
 256 segment_manager_del_segment (segment_manager_t * sm, u32 segment_index)
 257 {
 258   svm_fifo_segment_private_t *fifo_segment;
 259   u32 svm_segment_index;
 260   clib_spinlock_lock (&sm->lockp);
 261   svm_segment_index = vec_elt (sm->segment_indices, segment_index);
 262   fifo_segment = svm_fifo_segment_get_segment (svm_segment_index);
 263   if (!fifo_segment
 264       || ((fifo_segment->h->flags & FIFO_SEGMENT_F_IS_PREALLOCATED)
 265           && !segment_manager_app_detached (sm)))
 266     {
 267       clib_spinlock_unlock (&sm->lockp);
 268       return;
 269     }
 270   svm_fifo_segment_delete (fifo_segment);
 271   vec_del1 (sm->segment_indices, segment_index);
 272   clib_spinlock_unlock (&sm->lockp);
 273 }
 274
 275 /**
 276  * Initiate disconnects for all sessions 'owned' by a segment manager
 277  */
 278 void
 279 segment_manager_del_sessions (segment_manager_t * sm)
 280 {
 281   int j;
 282   svm_fifo_segment_private_t *fifo_segment;
 283   svm_fifo_t *fifo;
 284
 285   ASSERT (vec_len (sm->segment_indices));
 286
 287   /* Across all fifo segments used by the server */
 288   for (j = 0; j < vec_len (sm->segment_indices); j++)
 289     {
 290       fifo_segment = svm_fifo_segment_get_segment (sm->segment_indices[j]);
 291       fifo = svm_fifo_segment_get_fifo_list (fifo_segment);
 292
 293       /*
 294        * Remove any residual sessions from the session lookup table
 295        * Don't bother deleting the individual fifos, we're going to
 296        * throw away the fifo segment in a minute.
 297        */
 298       while (fifo)
 299         {
 300           u32 session_index, thread_index;
 301           stream_session_t *session;
 302
 303           session_index = fifo->master_session_index;
 304           thread_index = fifo->master_thread_index;
 305           session = session_get (session_index, thread_index);
 306
 307           /* Instead of directly removing the session call disconnect */
 308           if (session->session_state != SESSION_STATE_CLOSED)
 309             {
 310               session->session_state = SESSION_STATE_CLOSED;
 311               session_send_session_evt_to_thread (session_handle (session),
 312                                                   FIFO_EVENT_DISCONNECT,
 313                                                   thread_index);
 314             }
 315           fifo = fifo->next;
 316         }
 317
 318       /* Instead of removing the segment, test when cleaning up disconnected
 319        * sessions if the segment can be removed.
 320        */
 321     }
 322 }
 323
 324 /**
 325  * Removes segment manager.
 326  *
 327  * Since the fifos allocated in the segment keep backpointers to the sessions
 328  * prior to removing the segment, we call session disconnect. This
 329  * subsequently propagates into transport.
 330  */
 331 void
 332 segment_manager_del (segment_manager_t * sm)
 333 {
 334   int i;
 335
 336   ASSERT (!segment_manager_has_fifos (sm)
 337           && segment_manager_app_detached (sm));
 338
 339   /* If we have empty preallocated segments that haven't been removed, remove
 340    * them now. Apart from that, the first segment in the first segment manager
 341    * is not removed when all fifos are removed. It can only be removed when
 342    * the manager is explicitly deleted/detached by the app. */
 343   for (i = vec_len (sm->segment_indices) - 1; i >= 0; i--)
 344     {
 345       if (CLIB_DEBUG)
 346         {
 347           svm_fifo_segment_private_t *segment;
 348           segment = svm_fifo_segment_get_segment (sm->segment_indices[i]);
 349           ASSERT (!svm_fifo_segment_has_fifos (segment));
 350         }
 351       segment_manager_del_segment (sm, i);
 352     }
 353   clib_spinlock_free (&sm->lockp);
 354   if (CLIB_DEBUG)
 355     memset (sm, 0xfe, sizeof (*sm));
 356   pool_put (segment_managers, sm);
 357 }
 358
 359 void
 360 segment_manager_init_del (segment_manager_t * sm)
 361 {
 362   segment_manager_app_detach (sm);
 363   if (segment_manager_has_fifos (sm))
 364     segment_manager_del_sessions (sm);
 365   else
 366     {
 367       ASSERT (!sm->first_is_protected || segment_manager_app_detached (sm));
 368       segment_manager_del (sm);
 369     }
 370 }
 371
 372 int
 373 segment_manager_alloc_session_fifos (segment_manager_t * sm,
 374                                      svm_fifo_t ** rx_fifo,
 375                                      svm_fifo_t ** tx_fifo,
 376                                      u32 * fifo_segment_index)
 377 {
 378   svm_fifo_segment_private_t *fifo_segment;
 379   segment_manager_properties_t *props;
 380   u32 fifo_size, sm_index;
 381   u8 added_a_segment = 0;
 382   int i;
 383
 384   ASSERT (vec_len (sm->segment_indices));
 385
 386   /* Make sure we don't have multiple threads trying to allocate segments
 387    * at the same time. */
 388   clib_spinlock_lock (&sm->lockp);
 389
 390   /* Allocate svm fifos */
 391   props = segment_manager_properties_get (sm->properties_index);
 392 again:
 393   for (i = 0; i < vec_len (sm->segment_indices); i++)
 394     {
 395       *fifo_segment_index = vec_elt (sm->segment_indices, i);
 396       fifo_segment = svm_fifo_segment_get_segment (*fifo_segment_index);
 397
 398       fifo_size = props->rx_fifo_size;
 399       fifo_size = (fifo_size == 0) ? default_fifo_size : fifo_size;
 400       *rx_fifo = svm_fifo_segment_alloc_fifo (fifo_segment, fifo_size,
 401                                               FIFO_SEGMENT_RX_FREELIST);
 402
 403       fifo_size = props->tx_fifo_size;
 404       fifo_size = (fifo_size == 0) ? default_fifo_size : fifo_size;
 405       *tx_fifo = svm_fifo_segment_alloc_fifo (fifo_segment, fifo_size,
 406                                               FIFO_SEGMENT_TX_FREELIST);
 407
 408       if (*rx_fifo == 0)
 409         {
 410           /* This would be very odd, but handle it... */
 411           if (*tx_fifo != 0)
 412             {
 413               svm_fifo_segment_free_fifo (fifo_segment, *tx_fifo,
 414                                           FIFO_SEGMENT_TX_FREELIST);
 415               *tx_fifo = 0;
 416             }
 417           continue;
 418         }
 419       if (*tx_fifo == 0)
 420         {
 421           if (*rx_fifo != 0)
 422             {
 423               svm_fifo_segment_free_fifo (fifo_segment, *rx_fifo,
 424                                           FIFO_SEGMENT_RX_FREELIST);
 425               *rx_fifo = 0;
 426             }
 427           continue;
 428         }
 429       break;
 430     }
 431
 432   /* See if we're supposed to create another segment */
 433   if (*rx_fifo == 0)
 434     {
 435       if (props->add_segment && !props->segment_type)
 436         {
 437           if (added_a_segment)
 438             {
 439               clib_warning ("added a segment, still can't allocate a fifo");
 440               clib_spinlock_unlock (&sm->lockp);
 441               return SESSION_ERROR_NEW_SEG_NO_SPACE;
 442             }
 443
 444           if (segment_manager_add_segment (sm))
 445             {
 446               clib_spinlock_unlock (&sm->lockp);
 447               return VNET_API_ERROR_URI_FIFO_CREATE_FAILED;
 448             }
 449
 450           added_a_segment = 1;
 451           goto again;
 452         }
 453       else
 454         {
 455           clib_warning ("No space to allocate fifos!");
 456           clib_spinlock_unlock (&sm->lockp);
 457           return SESSION_ERROR_NO_SPACE;
 458         }
 459     }
 460
 461   /* Backpointers to segment manager */
 462   sm_index = segment_manager_index (sm);
 463   (*tx_fifo)->segment_manager = sm_index;
 464   (*rx_fifo)->segment_manager = sm_index;
 465
 466   clib_spinlock_unlock (&sm->lockp);
 467
 468   if (added_a_segment)
 469     return application_add_segment_notify (sm->app_index,
 470                                            *fifo_segment_index);
 471
 472   return 0;
 473 }
 474
 475 void
 476 segment_manager_dealloc_fifos (u32 svm_segment_index, svm_fifo_t * rx_fifo,
 477                                svm_fifo_t * tx_fifo)
 478 {
 479   segment_manager_t *sm;
 480   svm_fifo_segment_private_t *fifo_segment;
 481   u32 i, segment_index = ~0;
 482   u8 is_first;
 483
 484   sm = segment_manager_get_if_valid (rx_fifo->segment_manager);
 485
 486   /* It's possible to have no segment manager if the session was removed
 487    * as result of a detach. */
 488   if (!sm)
 489     return;
 490
 491   fifo_segment = svm_fifo_segment_get_segment (svm_segment_index);
 492   svm_fifo_segment_free_fifo (fifo_segment, rx_fifo,
 493                               FIFO_SEGMENT_RX_FREELIST);
 494   svm_fifo_segment_free_fifo (fifo_segment, tx_fifo,
 495                               FIFO_SEGMENT_TX_FREELIST);
 496
 497   /*
 498    * Try to remove svm segment if it has no fifos. This can be done only if
 499    * the segment is not the first in the segment manager or if it is first
 500    * and it is not protected. Moreover, if the segment is first and the app
 501    * has detached from the segment manager, remove the segment manager.
 502    */
 503   if (!svm_fifo_segment_has_fifos (fifo_segment))
 504     {
 505       is_first = sm->segment_indices[0] == svm_segment_index;
 506
 507       /* Remove segment if it holds no fifos or first but not protected */
 508       if (!is_first || !sm->first_is_protected)
 509         {
 510           /* Find the segment manager segment index */
 511           for (i = 0; i < vec_len (sm->segment_indices); i++)
 512             if (sm->segment_indices[i] == svm_segment_index)
 513               {
 514                 segment_index = i;
 515                 break;
 516               }
 517           ASSERT (segment_index != (u32) ~ 0);
 518           segment_manager_del_segment (sm, segment_index);
 519         }
 520
 521       /* Remove segment manager if no sessions and detached from app */
 522       if (segment_manager_app_detached (sm)
 523           && !segment_manager_has_fifos (sm))
 524         segment_manager_del (sm);
 525     }
 526 }
 527
 528 /**
 529  * Allocates shm queue in the first segment
 530  */
 531 svm_queue_t *
 532 segment_manager_alloc_queue (segment_manager_t * sm, u32 queue_size)
 533 {
 534   ssvm_shared_header_t *sh;
 535   svm_fifo_segment_private_t *segment;
 536   svm_queue_t *q;
 537   void *oldheap;
 538
 539   ASSERT (sm->segment_indices != 0);
 540
 541   segment = svm_fifo_segment_get_segment (sm->segment_indices[0]);
 542   sh = segment->ssvm.sh;
 543
 544   oldheap = ssvm_push_heap (sh);
 545   q = svm_queue_init (queue_size,
 546                       sizeof (session_fifo_event_t), 0 /* consumer pid */ ,
 547                       0 /* signal when queue non-empty */ );
 548   ssvm_pop_heap (oldheap);
 549   return q;
 550 }
 551
 552 /**
 553  * Frees shm queue allocated in the first segment
 554  */
 555 void
 556 segment_manager_dealloc_queue (segment_manager_t * sm, svm_queue_t * q)
 557 {
 558   ssvm_shared_header_t *sh;
 559   svm_fifo_segment_private_t *segment;
 560   void *oldheap;
 561
 562   ASSERT (sm->segment_indices != 0);
 563
 564   segment = svm_fifo_segment_get_segment (sm->segment_indices[0]);
 565   sh = segment->ssvm.sh;
 566
 567   oldheap = ssvm_push_heap (sh);
 568   svm_queue_free (q);
 569   ssvm_pop_heap (oldheap);
 570 }
 571
 572 static clib_error_t *
 573 segment_manager_show_fn (vlib_main_t * vm, unformat_input_t * input,
 574                          vlib_cli_command_t * cmd)
 575 {
 576   svm_fifo_segment_private_t *segments, *seg;
 577   segment_manager_t *sm;
 578   u8 show_segments = 0, verbose = 0;
 579   uword address;
 580   u64 size;
 581   u32 active_fifos;
 582   u32 free_fifos;
 583
 584   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
 585     {
 586       if (unformat (input, "segments"))
 587         show_segments = 1;
 588       else if (unformat (input, "verbose"))
 589         verbose = 1;
 590       else
 591         return clib_error_return (0, "unknown input `%U'",
 592                                   format_unformat_error, input);
 593     }
 594   vlib_cli_output (vm, "%d segment managers allocated",
 595                    pool_elts (segment_managers));
 596   if (verbose && pool_elts (segment_managers))
 597     {
 598       vlib_cli_output (vm, "%-10s%=15s%=12s", "Index", "App Index",
 599                        "Segments");
 600
 601       /* *INDENT-OFF* */
 602       pool_foreach (sm, segment_managers, ({
 603         vlib_cli_output (vm, "%-10d%=15d%=12d", segment_manager_index(sm),
 604                            sm->app_index, vec_len (sm->segment_indices));
 605       }));
 606       /* *INDENT-ON* */
 607
 608     }
 609   if (show_segments)
 610     {
 611       segments = svm_fifo_segment_segments_pool ();
 612       vlib_cli_output (vm, "%d svm fifo segments allocated",
 613                        pool_elts (segments));
 614       vlib_cli_output (vm, "%-15s%10s%15s%15s%15s%15s", "Name", "Type",
 615                        "HeapSize (M)", "ActiveFifos", "FreeFifos", "Address");
 616
 617       /* *INDENT-OFF* */
 618       pool_foreach (seg, segments, ({
 619         svm_fifo_segment_info (seg, &address, &size);
 620         active_fifos = svm_fifo_segment_num_fifos (seg);
 621         free_fifos = svm_fifo_segment_num_free_fifos (seg, ~0 /* size */);
 622         vlib_cli_output (vm, "%-15v%10U%15llu%15u%15u%15llx",
 623                          ssvm_name (&seg->ssvm), format_svm_fifo_segment_type,
 624                          seg, size >> 20ULL, active_fifos, free_fifos,
 625                          address);
 626         if (verbose)
 627           vlib_cli_output (vm, "%U", format_svm_fifo_segment, seg, verbose);
 628       }));
 629       /* *INDENT-ON* */
 630
 631     }
 632   return 0;
 633 }
 634
 635 /* *INDENT-OFF* */
 636 VLIB_CLI_COMMAND (segment_manager_show_command, static) =
 637 {
 638   .path = "show segment-manager",
 639   .short_help = "show segment-manager [segments][verbose]",
 640   .function = segment_manager_show_fn,
 641 };
 642 /* *INDENT-ON* */
 643
 644 /*
 645  * fd.io coding-style-patch-verification: ON
 646  *
 647  * Local Variables:
 648  * eval: (c-set-style "gnu")
 649  * End:
 650  */