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             stream_session_disconnect (session);
 310           fifo = fifo->next;
 311         }
 312
 313       /* Instead of removing the segment, test when cleaning up disconnected
 314        * sessions if the segment can be removed.
 315        */
 316     }
 317 }
 318
 319 /**
 320  * Removes segment manager.
 321  *
 322  * Since the fifos allocated in the segment keep backpointers to the sessions
 323  * prior to removing the segment, we call session disconnect. This
 324  * subsequently propagates into transport.
 325  */
 326 void
 327 segment_manager_del (segment_manager_t * sm)
 328 {
 329   int i;
 330
 331   ASSERT (!segment_manager_has_fifos (sm)
 332           && segment_manager_app_detached (sm));
 333
 334   /* If we have empty preallocated segments that haven't been removed, remove
 335    * them now. Apart from that, the first segment in the first segment manager
 336    * is not removed when all fifos are removed. It can only be removed when
 337    * the manager is explicitly deleted/detached by the app. */
 338   for (i = vec_len (sm->segment_indices) - 1; i >= 0; i--)
 339     {
 340       if (CLIB_DEBUG)
 341         {
 342           svm_fifo_segment_private_t *segment;
 343           segment = svm_fifo_segment_get_segment (sm->segment_indices[i]);
 344           ASSERT (!svm_fifo_segment_has_fifos (segment));
 345         }
 346       segment_manager_del_segment (sm, i);
 347     }
 348   clib_spinlock_free (&sm->lockp);
 349   if (CLIB_DEBUG)
 350     memset (sm, 0xfe, sizeof (*sm));
 351   pool_put (segment_managers, sm);
 352 }
 353
 354 void
 355 segment_manager_init_del (segment_manager_t * sm)
 356 {
 357   segment_manager_app_detach (sm);
 358   if (segment_manager_has_fifos (sm))
 359     segment_manager_del_sessions (sm);
 360   else
 361     {
 362       ASSERT (!sm->first_is_protected || segment_manager_app_detached (sm));
 363       segment_manager_del (sm);
 364     }
 365 }
 366
 367 int
 368 segment_manager_alloc_session_fifos (segment_manager_t * sm,
 369                                      svm_fifo_t ** rx_fifo,
 370                                      svm_fifo_t ** tx_fifo,
 371                                      u32 * fifo_segment_index)
 372 {
 373   svm_fifo_segment_private_t *fifo_segment;
 374   segment_manager_properties_t *props;
 375   u32 fifo_size, sm_index;
 376   u8 added_a_segment = 0;
 377   int i;
 378
 379   ASSERT (vec_len (sm->segment_indices));
 380
 381   /* Make sure we don't have multiple threads trying to allocate segments
 382    * at the same time. */
 383   clib_spinlock_lock (&sm->lockp);
 384
 385   /* Allocate svm fifos */
 386   props = segment_manager_properties_get (sm->properties_index);
 387 again:
 388   for (i = 0; i < vec_len (sm->segment_indices); i++)
 389     {
 390       *fifo_segment_index = vec_elt (sm->segment_indices, i);
 391       fifo_segment = svm_fifo_segment_get_segment (*fifo_segment_index);
 392
 393       fifo_size = props->rx_fifo_size;
 394       fifo_size = (fifo_size == 0) ? default_fifo_size : fifo_size;
 395       *rx_fifo = svm_fifo_segment_alloc_fifo (fifo_segment, fifo_size,
 396                                               FIFO_SEGMENT_RX_FREELIST);
 397
 398       fifo_size = props->tx_fifo_size;
 399       fifo_size = (fifo_size == 0) ? default_fifo_size : fifo_size;
 400       *tx_fifo = svm_fifo_segment_alloc_fifo (fifo_segment, fifo_size,
 401                                               FIFO_SEGMENT_TX_FREELIST);
 402
 403       if (*rx_fifo == 0)
 404         {
 405           /* This would be very odd, but handle it... */
 406           if (*tx_fifo != 0)
 407             {
 408               svm_fifo_segment_free_fifo (fifo_segment, *tx_fifo,
 409                                           FIFO_SEGMENT_TX_FREELIST);
 410               *tx_fifo = 0;
 411             }
 412           continue;
 413         }
 414       if (*tx_fifo == 0)
 415         {
 416           if (*rx_fifo != 0)
 417             {
 418               svm_fifo_segment_free_fifo (fifo_segment, *rx_fifo,
 419                                           FIFO_SEGMENT_RX_FREELIST);
 420               *rx_fifo = 0;
 421             }
 422           continue;
 423         }
 424       break;
 425     }
 426
 427   /* See if we're supposed to create another segment */
 428   if (*rx_fifo == 0)
 429     {
 430       if (props->add_segment && !props->segment_type)
 431         {
 432           if (added_a_segment)
 433             {
 434               clib_warning ("added a segment, still can't allocate a fifo");
 435               clib_spinlock_unlock (&sm->lockp);
 436               return SESSION_ERROR_NEW_SEG_NO_SPACE;
 437             }
 438
 439           if (segment_manager_add_segment (sm))
 440             {
 441               clib_spinlock_unlock (&sm->lockp);
 442               return VNET_API_ERROR_URI_FIFO_CREATE_FAILED;
 443             }
 444
 445           added_a_segment = 1;
 446           goto again;
 447         }
 448       else
 449         {
 450           clib_warning ("No space to allocate fifos!");
 451           clib_spinlock_unlock (&sm->lockp);
 452           return SESSION_ERROR_NO_SPACE;
 453         }
 454     }
 455
 456   /* Backpointers to segment manager */
 457   sm_index = segment_manager_index (sm);
 458   (*tx_fifo)->segment_manager = sm_index;
 459   (*rx_fifo)->segment_manager = sm_index;
 460
 461   clib_spinlock_unlock (&sm->lockp);
 462
 463   if (added_a_segment)
 464     return application_add_segment_notify (sm->app_index,
 465                                            *fifo_segment_index);
 466
 467   return 0;
 468 }
 469
 470 void
 471 segment_manager_dealloc_fifos (u32 svm_segment_index, svm_fifo_t * rx_fifo,
 472                                svm_fifo_t * tx_fifo)
 473 {
 474   segment_manager_t *sm;
 475   svm_fifo_segment_private_t *fifo_segment;
 476   u32 i, segment_index = ~0;
 477   u8 is_first;
 478
 479   sm = segment_manager_get_if_valid (rx_fifo->segment_manager);
 480
 481   /* It's possible to have no segment manager if the session was removed
 482    * as result of a detach. */
 483   if (!sm)
 484     return;
 485
 486   fifo_segment = svm_fifo_segment_get_segment (svm_segment_index);
 487   svm_fifo_segment_free_fifo (fifo_segment, rx_fifo,
 488                               FIFO_SEGMENT_RX_FREELIST);
 489   svm_fifo_segment_free_fifo (fifo_segment, tx_fifo,
 490                               FIFO_SEGMENT_TX_FREELIST);
 491
 492   /*
 493    * Try to remove svm segment if it has no fifos. This can be done only if
 494    * the segment is not the first in the segment manager or if it is first
 495    * and it is not protected. Moreover, if the segment is first and the app
 496    * has detached from the segment manager, remove the segment manager.
 497    */
 498   if (!svm_fifo_segment_has_fifos (fifo_segment))
 499     {
 500       is_first = sm->segment_indices[0] == svm_segment_index;
 501
 502       /* Remove segment if it holds no fifos or first but not protected */
 503       if (!is_first || !sm->first_is_protected)
 504         {
 505           /* Find the segment manager segment index */
 506           for (i = 0; i < vec_len (sm->segment_indices); i++)
 507             if (sm->segment_indices[i] == svm_segment_index)
 508               {
 509                 segment_index = i;
 510                 break;
 511               }
 512           ASSERT (segment_index != (u32) ~ 0);
 513           segment_manager_del_segment (sm, segment_index);
 514         }
 515
 516       /* Remove segment manager if no sessions and detached from app */
 517       if (segment_manager_app_detached (sm)
 518           && !segment_manager_has_fifos (sm))
 519         segment_manager_del (sm);
 520     }
 521 }
 522
 523 /**
 524  * Allocates shm queue in the first segment
 525  */
 526 svm_queue_t *
 527 segment_manager_alloc_queue (segment_manager_t * sm, u32 queue_size)
 528 {
 529   ssvm_shared_header_t *sh;
 530   svm_fifo_segment_private_t *segment;
 531   svm_queue_t *q;
 532   void *oldheap;
 533
 534   ASSERT (sm->segment_indices != 0);
 535
 536   segment = svm_fifo_segment_get_segment (sm->segment_indices[0]);
 537   sh = segment->ssvm.sh;
 538
 539   oldheap = ssvm_push_heap (sh);
 540   q = svm_queue_init (queue_size,
 541                       sizeof (session_fifo_event_t), 0 /* consumer pid */ ,
 542                       0 /* signal when queue non-empty */ );
 543   ssvm_pop_heap (oldheap);
 544   return q;
 545 }
 546
 547 /**
 548  * Frees shm queue allocated in the first segment
 549  */
 550 void
 551 segment_manager_dealloc_queue (segment_manager_t * sm, svm_queue_t * q)
 552 {
 553   ssvm_shared_header_t *sh;
 554   svm_fifo_segment_private_t *segment;
 555   void *oldheap;
 556
 557   ASSERT (sm->segment_indices != 0);
 558
 559   segment = svm_fifo_segment_get_segment (sm->segment_indices[0]);
 560   sh = segment->ssvm.sh;
 561
 562   oldheap = ssvm_push_heap (sh);
 563   svm_queue_free (q);
 564   ssvm_pop_heap (oldheap);
 565 }
 566
 567 static clib_error_t *
 568 segment_manager_show_fn (vlib_main_t * vm, unformat_input_t * input,
 569                          vlib_cli_command_t * cmd)
 570 {
 571   svm_fifo_segment_private_t *segments, *seg;
 572   segment_manager_t *sm;
 573   u8 show_segments = 0, verbose = 0;
 574   uword address;
 575   u64 size;
 576   u32 active_fifos;
 577   u32 free_fifos;
 578
 579   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
 580     {
 581       if (unformat (input, "segments"))
 582         show_segments = 1;
 583       else if (unformat (input, "verbose"))
 584         verbose = 1;
 585       else
 586         return clib_error_return (0, "unknown input `%U'",
 587                                   format_unformat_error, input);
 588     }
 589   vlib_cli_output (vm, "%d segment managers allocated",
 590                    pool_elts (segment_managers));
 591   if (verbose && pool_elts (segment_managers))
 592     {
 593       vlib_cli_output (vm, "%-10s%=15s%=12s", "Index", "App Index",
 594                        "Segments");
 595
 596       /* *INDENT-OFF* */
 597       pool_foreach (sm, segment_managers, ({
 598         vlib_cli_output (vm, "%-10d%=15d%=12d", segment_manager_index(sm),
 599                            sm->app_index, vec_len (sm->segment_indices));
 600       }));
 601       /* *INDENT-ON* */
 602
 603     }
 604   if (show_segments)
 605     {
 606       segments = svm_fifo_segment_segments_pool ();
 607       vlib_cli_output (vm, "%d svm fifo segments allocated",
 608                        pool_elts (segments));
 609       vlib_cli_output (vm, "%-15s%15s%15s%15s%15s%15s", "Name", "Type",
 610                        "HeapSize (M)", "ActiveFifos", "FreeFifos", "Address");
 611
 612       /* *INDENT-OFF* */
 613       pool_foreach (seg, segments, ({
 614         svm_fifo_segment_info (seg, &address, &size);
 615         active_fifos = svm_fifo_segment_num_fifos (seg);
 616         free_fifos = svm_fifo_segment_num_free_fifos (seg, ~0 /* size */);
 617         vlib_cli_output (vm, "%-15v%15U%15llu%15u%15u%15llx",
 618                          ssvm_name (&seg->ssvm), format_svm_fifo_segment_type,
 619                          seg, size >> 20ULL, active_fifos, free_fifos,
 620                          address);
 621         if (verbose)
 622           vlib_cli_output (vm, "%U", format_svm_fifo_segment, seg, verbose);
 623       }));
 624       /* *INDENT-ON* */
 625
 626     }
 627   return 0;
 628 }
 629
 630 /* *INDENT-OFF* */
 631 VLIB_CLI_COMMAND (segment_manager_show_command, static) =
 632 {
 633   .path = "show segment-manager",
 634   .short_help = "show segment-manager [segments][verbose]",
 635   .function = segment_manager_show_fn,
 636 };
 637 /* *INDENT-ON* */
 638
 639 /*
 640  * fd.io coding-style-patch-verification: ON
 641  *
 642  * Local Variables:
 643  * eval: (c-set-style "gnu")
 644  * End:
 645  */