src/surf/vm_workstation.c

   1 /* Copyright (c) 2004, 2005, 2006, 2007, 2008, 2009, 2010. The SimGrid Team.
   2  * All rights reserved.                                                     */
   3
   4 /* This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the license (GNU LGPL) which comes with this package. */
   6
   7 #include "xbt/ex.h"
   8 #include "xbt/dict.h"
   9 #include "portable.h"
  10 #include "surf_private.h"
  11 #include "surf/surf_resource.h"
  12 #include "simgrid/sg_config.h"
  13 #include "vm_workstation_private.h"
  14 #include "cpu_cas01_private.h"
  15 #include "maxmin_private.h"
  16
  17 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(surf_vm_workstation, surf,
  18                                 "Logging specific to the SURF VM workstation module");
  19
  20
  21 surf_model_t surf_vm_workstation_model = NULL;
  22
  23 /* ind means ''indirect'' that this is a reference on the whole dict_elm
  24  * structure (i.e not on the surf_resource_private infos) */
  25
  26 static void vm_ws_create(const char *name, void *ind_phys_workstation)
  27 {
  28   workstation_CLM03_t sub_ws = surf_workstation_resource_priv(ind_phys_workstation);
  29   const char *sub_ws_name = sub_ws->generic_resource.name;
  30
  31   /* The workstation_VM2013 struct inherits the workstation_CLM03 struct. We
  32    * create a physical workstation resource, but specifying the size of
  33    * s_workstation_VM2013_t and the vm workstation model object. */
  34   workstation_CLM03_t ws = (workstation_CLM03_t) surf_resource_new(sizeof(s_workstation_VM2013_t),
  35       surf_vm_workstation_model, name, NULL);
  36
  37   /* Currently, we assume a VM has no storage. */
  38   ws->storage = NULL;
  39
  40   /* Currently, a VM uses the network resource of its physical host. In
  41    * host_lib, this network resource object is refered from two different keys.
  42    * When deregistering the reference that points the network resource object
  43    * from the VM name, we have to make sure that the system does not call the
  44    * free callback for the network resource object. The network resource object
  45    * is still used by the physical machine. */
  46   ws->net_elm = xbt_lib_get_or_null(host_lib, sub_ws_name, ROUTING_HOST_LEVEL);
  47   xbt_lib_set(host_lib, name, ROUTING_HOST_LEVEL, ws->net_elm);
  48
  49   /* The SURF_WKS_LEVEL at host_lib saves workstation_CLM03 objects. Please
  50    * note workstation_VM2013 objects, inheriting the workstation_CLM03
  51    * structure, are also saved there.
  52    *
  53    * If you want to get a workstation_VM2013 object from host_lib, see
  54    * ws->generic_resouce.model->type first. If it is
  55    * SURF_MODEL_TYPE_VM_WORKSTATION, you can cast ws to vm_ws. */
  56   XBT_INFO("Create VM(%s)@PM(%s) with %ld mounted disks", name, sub_ws_name, xbt_dynar_length(ws->storage));
  57   xbt_lib_set(host_lib, name, SURF_WKS_LEVEL, ws);
  58
  59
  60   /* We initialize the VM-specific members. */
  61   workstation_VM2013_t vm_ws = (workstation_VM2013_t) ws;
  62   vm_ws->sub_ws = sub_ws;
  63   vm_ws->current_state = SURF_VM_STATE_CREATED;
  64
  65
  66
  67   // //// CPU  RELATED STUFF ////
  68   // Roughly, create a vcpu resource by using the values of the sub_cpu one.
  69   cpu_Cas01_t sub_cpu = surf_cpu_resource_priv(ind_phys_workstation);
  70
  71   /* We can assume one core and cas01 cpu for the first step.
  72    * Do xbt_lib_set(host_lib, name, SURF_CPU_LEVEL, cpu) if you get the resource. */
  73   cpu_cas01_create_resource(name, // name
  74       sub_cpu->power_peak,        // host->power_peak,
  75       1,                          // host->power_scale,
  76       NULL,                       // host->power_trace,
  77       1,                          // host->core_amount,
  78       SURF_RESOURCE_ON,           // host->initial_state,
  79       NULL,                       // host->state_trace,
  80       NULL,                       // host->properties,
  81       surf_cpu_model_vm);
  82
  83
  84
  85   /* We create cpu_action corresponding to a VM process on the host operating system. */
  86   /* FIXME: TODO: we have to peridocally input GUESTOS_NOISE to the system? how ? */
  87   // vm_ws->cpu_action = surf_cpu_model_pm->extension.cpu.execute(ind_phys_workstation, GUESTOS_NOISE);
  88   vm_ws->cpu_action = surf_cpu_model_pm->extension.cpu.execute(ind_phys_workstation, 0);
  89
  90
  91   /* TODO:
  92    * - check how network requests are scheduled between distinct processes competing for the same card.
  93    */
  94 }
  95
  96 /*
  97  * Update the physical host of the given VM
  98  */
  99 static void vm_ws_migrate(void *ind_vm, void *ind_dst_pm)
 100 {
 101    /* ind_phys_workstation equals to smx_host_t */
 102    workstation_VM2013_t ws_vm2013 = surf_workstation_resource_priv(ind_vm);
 103    workstation_CLM03_t ws_clm03_dst = surf_workstation_resource_priv(ind_dst_pm);
 104    const char *vm_name = ws_vm2013->ws.generic_resource.name;
 105    const char *pm_name_src = ws_vm2013->sub_ws->generic_resource.name;
 106    const char *pm_name_dst = ws_clm03_dst->generic_resource.name;
 107
 108    xbt_assert(ws_vm2013);
 109    xbt_assert(ws_clm03_dst);
 110
 111    /* do something */
 112
 113    /* update net_elm with that of the destination physical host */
 114    void *old_net_elm = ws_vm2013->ws.net_elm;
 115    void *new_net_elm = xbt_lib_get_or_null(host_lib, pm_name_dst, ROUTING_HOST_LEVEL);
 116    xbt_assert(new_net_elm);
 117
 118    /* Unregister the current net_elm from host_lib. Do not call the free callback. */
 119    xbt_lib_unset(host_lib, vm_name, ROUTING_HOST_LEVEL, 0);
 120
 121    /* Then, resister the new one. */
 122    ws_vm2013->ws.net_elm = new_net_elm;
 123    xbt_lib_set(host_lib, vm_name, ROUTING_HOST_LEVEL, ws_vm2013->ws.net_elm);
 124
 125    ws_vm2013->sub_ws = ws_clm03_dst;
 126
 127    /* Update vcpu's action for the new pm */
 128    {
 129 #if 0
 130      XBT_INFO("cpu_action->remains %g", ws_vm2013->cpu_action->remains);
 131      XBT_INFO("cost %f remains %f start %f finish %f", ws_vm2013->cpu_action->cost,
 132          ws_vm2013->cpu_action->remains,
 133          ws_vm2013->cpu_action->start,
 134          ws_vm2013->cpu_action->finish
 135          );
 136      XBT_INFO("cpu_action state %d", surf_action_state_get(ws_vm2013->cpu_action));
 137 #endif
 138
 139      /* create a cpu action bound to the pm model at the destination. */
 140      surf_action_t new_cpu_action = surf_cpu_model_pm->extension.cpu.execute(ind_dst_pm, 0);
 141
 142      e_surf_action_state_t state = surf_action_state_get(ws_vm2013->cpu_action);
 143      if (state != SURF_ACTION_DONE)
 144        XBT_CRITICAL("FIXME: may need a proper handling, %d", state);
 145      if (ws_vm2013->cpu_action->remains > 0)
 146        XBT_CRITICAL("FIXME: need copy the state(?), %f", ws_vm2013->cpu_action->remains);
 147
 148      int ret = surf_cpu_model_pm->action_unref(ws_vm2013->cpu_action);
 149      xbt_assert(ret == 1, "Bug: some resource still remains");
 150
 151      ws_vm2013->cpu_action = new_cpu_action;
 152    }
 153
 154    XBT_DEBUG("migrate VM(%s): change net_elm (%p to %p)", vm_name, old_net_elm, new_net_elm);
 155    XBT_DEBUG("migrate VM(%s): change PM (%s to %s)", vm_name, pm_name_src, pm_name_dst);
 156 }
 157
 158 /*
 159  * A physical host does not disapper in the current SimGrid code, but a VM may
 160  * disapper during a simulation.
 161  */
 162 static void vm_ws_destroy(void *ind_vm_workstation)
 163 {
 164         /* ind_phys_workstation equals to smx_host_t */
 165
 166   /* Before clearing the entries in host_lib, we have to pick up resources. */
 167         workstation_VM2013_t vm_ws = surf_workstation_resource_priv(ind_vm_workstation);
 168   cpu_Cas01_t cpu = surf_cpu_resource_priv(ind_vm_workstation);
 169         const char *name = vm_ws->ws.generic_resource.name;
 170
 171         xbt_assert(vm_ws);
 172         xbt_assert(vm_ws->ws.generic_resource.model == surf_vm_workstation_model);
 173
 174
 175   /* We deregister objects from host_lib, without invoking the freeing callback
 176    * of each level.
 177    *
 178    * Do not call xbt_lib_remove() here. It deletes all levels of the key,
 179    * including MSG_HOST_LEVEL and others. We should unregister only what we know.
 180    */
 181   xbt_lib_unset(host_lib, name, SURF_CPU_LEVEL, 0);
 182   xbt_lib_unset(host_lib, name, ROUTING_HOST_LEVEL, 0);
 183   xbt_lib_unset(host_lib, name, SURF_WKS_LEVEL, 0);
 184
 185   /* TODO: comment out when VM stroage is implemented. */
 186   // xbt_lib_unset(host_lib, name, SURF_STORAGE_LEVEL, 0);
 187
 188
 189   /* Free the cpu_action of the VM. */
 190   int ret = surf_cpu_model_pm->action_unref(vm_ws->cpu_action);
 191   xbt_assert(ret == 1, "Bug: some resource still remains");
 192
 193   /* Free the cpu resource of the VM. If using power_trace, we will have to
 194    * free other objects than lmm_constraint. */
 195   surf_model_t cpu_model = cpu->generic_resource.model;
 196   lmm_constraint_free(cpu_model->model_private->maxmin_system, cpu->constraint);
 197   surf_resource_free(cpu);
 198
 199   /* Free the network resource of the VM. */
 200         // Nothing has to be done, because net_elmts is just a pointer on the physical one
 201
 202   /* Free the storage resource of the VM. */
 203   // Not relevant yet
 204
 205         /* Free the workstation resource of the VM. */
 206   surf_resource_free(vm_ws);
 207 }
 208
 209 static int vm_ws_get_state(void *ind_vm_ws)
 210 {
 211         return ((workstation_VM2013_t) surf_workstation_resource_priv(ind_vm_ws))->current_state;
 212 }
 213
 214 static void vm_ws_set_state(void *ind_vm_ws, int state)
 215 {
 216          ((workstation_VM2013_t) surf_workstation_resource_priv(ind_vm_ws))->current_state = state;
 217 }
 218
 219 static void vm_ws_suspend(void *ind_vm_ws)
 220 {
 221   workstation_VM2013_t vm_ws = surf_workstation_resource_priv(ind_vm_ws);
 222
 223   surf_action_suspend(vm_ws->cpu_action);
 224
 225   vm_ws->current_state = SURF_VM_STATE_SUSPENDED;
 226 }
 227
 228 static void vm_ws_resume(void *ind_vm_ws)
 229 {
 230   workstation_VM2013_t vm_ws = surf_workstation_resource_priv(ind_vm_ws);
 231
 232   surf_action_resume(vm_ws->cpu_action);
 233
 234   vm_ws->current_state = SURF_VM_STATE_RUNNING;
 235 }
 236
 237 static void vm_ws_save(void *ind_vm_ws)
 238 {
 239   workstation_VM2013_t vm_ws = surf_workstation_resource_priv(ind_vm_ws);
 240
 241   vm_ws->current_state = SURF_VM_STATE_SAVING;
 242
 243   /* FIXME: do something here */
 244   surf_action_suspend(vm_ws->cpu_action);
 245
 246   vm_ws->current_state = SURF_VM_STATE_SAVED;
 247 }
 248
 249 static void vm_ws_restore(void *ind_vm_ws)
 250 {
 251   workstation_VM2013_t vm_ws = surf_workstation_resource_priv(ind_vm_ws);
 252
 253   vm_ws->current_state = SURF_VM_STATE_RESTORING;
 254
 255   /* FIXME: do something here */
 256   surf_action_resume(vm_ws->cpu_action);
 257
 258   vm_ws->current_state = SURF_VM_STATE_RUNNING;
 259 }
 260
 261 static double get_solved_value(surf_action_t cpu_action)
 262 {
 263   lmm_variable_t var = ((surf_action_lmm_t) cpu_action)->variable;
 264
 265   return var->value;
 266 }
 267
 268 /* In the real world, processes on the guest operating system will be somewhat
 269  * degraded due to virtualization overhead. The total CPU share that these
 270  * processes get is smaller than that of the VM process gets on a host
 271  * operating system. */
 272 // const double virt_overhead = 0.95;
 273 const double virt_overhead = 1;
 274
 275 static double vm_ws_share_resources(surf_model_t workstation_model, double now)
 276 {
 277   /* TODO: udpate action's cost with the total cost of processes on the VM. */
 278
 279
 280   /* 0. Make sure that we already calculated the resource share at the physical
 281    * machine layer. */
 282   {
 283     unsigned int index_of_pm_ws_model = xbt_dynar_search(model_list_invoke, &surf_workstation_model);
 284     unsigned int index_of_vm_ws_model = xbt_dynar_search(model_list_invoke, &surf_vm_workstation_model);
 285     xbt_assert((index_of_pm_ws_model < index_of_vm_ws_model), "Cannot assume surf_workstation_model comes before");
 286
 287     /* Another option is that we call sub_ws->share_resource() here. The
 288      * share_resource() function has no side-effect. We can call it here to
 289      * ensure that. */
 290   }
 291
 292
 293   /* 1. Now we know how many resource should be assigned to each virtual
 294    * machine. We update constraints of the virtual machine layer.
 295    *
 296    *
 297    * If we have two virtual machine (VM1 and VM2) on a physical machine (PM1).
 298    *     X1 + X2 = C       (Equation 1)
 299    * where
 300    *    the resource share of VM1: X1
 301    *    the resource share of VM2: X2
 302    *    the capacity of PM1: C
 303    *
 304    * Then, if we have two process (P1 and P2) on VM1.
 305    *     X1_1 + X1_2 = X1  (Equation 2)
 306    * where
 307    *    the resource share of P1: X1_1
 308    *    the resource share of P2: X1_2
 309    *    the capacity of VM1: X1
 310    *
 311    * Equation 1 was solved in the physical machine layer.
 312    * Equation 2 is solved in the virtual machine layer (here).
 313    * X1 must be passed to the virtual machine laye as a constraint value.
 314    *
 315    **/
 316
 317   /* iterate for all hosts including virtual machines */
 318   xbt_lib_cursor_t cursor;
 319   char *key;
 320   void **ind_host;
 321   xbt_lib_foreach(host_lib, cursor, key, ind_host) {
 322     workstation_CLM03_t ws_clm03 = ind_host[SURF_WKS_LEVEL];
 323     cpu_Cas01_t cpu_cas01 = ind_host[SURF_CPU_LEVEL];
 324
 325     if (!ws_clm03)
 326       continue;
 327     /* skip if it is not a virtual machine */
 328     if (ws_clm03->generic_resource.model != surf_vm_workstation_model)
 329       continue;
 330     xbt_assert(cpu_cas01, "cpu-less workstation");
 331
 332     /* It is a virtual machine, so we can cast it to workstation_VM2013_t */
 333     workstation_VM2013_t ws_vm2013 = (workstation_VM2013_t) ws_clm03;
 334
 335     double solved_value = get_solved_value(ws_vm2013->cpu_action);
 336     XBT_DEBUG("assign %f to vm %s @ pm %s", solved_value,
 337         ws_clm03->generic_resource.name, ws_vm2013->sub_ws->generic_resource.name);
 338
 339     // TODO: check lmm_update_constraint_bound() works fine instead of the below manual substitution.
 340     // cpu_cas01->constraint->bound = solved_value;
 341     surf_model_t cpu_model = cpu_cas01->generic_resource.model;
 342     xbt_assert(cpu_model == surf_cpu_model_vm);
 343     lmm_system_t vcpu_system = cpu_model->model_private->maxmin_system;
 344     lmm_update_constraint_bound(vcpu_system, cpu_cas01->constraint, virt_overhead * solved_value);
 345   }
 346
 347
 348   /* 2. Calculate resource share at the virtual machine layer. */
 349   double ret = ws_share_resources(workstation_model, now);
 350
 351
 352   /* FIXME: 3. do we have to re-initialize our cpu_action object? */
 353 #if 0
 354   /* iterate for all hosts including virtual machines */
 355   xbt_lib_foreach(host_lib, cursor, key, ind_host) {
 356     workstation_CLM03_t ws_clm03 = ind_host[SURF_WKS_LEVEL];
 357
 358     /* skip if it is not a virtual machine */
 359     if (!ws_clm03)
 360       continue;
 361     if (ws_clm03->generic_resource.model != surf_vm_workstation_model)
 362       continue;
 363
 364     /* It is a virtual machine, so we can cast it to workstation_VM2013_t */
 365     {
 366 #if 0
 367       workstation_VM2013_t ws_vm2013 = (workstation_VM2013_t) ws_clm03;
 368       XBT_INFO("cost %f remains %f start %f finish %f", ws_vm2013->cpu_action->cost,
 369           ws_vm2013->cpu_action->remains,
 370           ws_vm2013->cpu_action->start,
 371           ws_vm2013->cpu_action->finish
 372           );
 373 #endif
 374 #if 0
 375       void *ind_sub_host = xbt_lib_get_elm_or_null(host_lib, ws_vm2013->sub_ws->generic_resource.name);
 376       surf_cpu_model_pm->action_unref(ws_vm2013->cpu_action);
 377       /* FIXME: this means busy loop? */
 378       // ws_vm2013->cpu_action = surf_cpu_model_pm->extension.cpu.execute(ind_sub_host, GUESTOS_NOISE);
 379       ws_vm2013->cpu_action = surf_cpu_model_pm->extension.cpu.execute(ind_sub_host, 0);
 380 #endif
 381
 382     }
 383   }
 384 #endif
 385
 386
 387   return ret;
 388 }
 389
 390
 391 /*
 392  * A surf level object will be useless in the upper layer. Returing the
 393  * dict_elm of the host.
 394  **/
 395 static void *vm_ws_get_pm(void *ind_vm_ws)
 396 {
 397         workstation_VM2013_t vm_ws = surf_workstation_resource_priv(ind_vm_ws);
 398   const char *sub_ws_name = vm_ws->sub_ws->generic_resource.name;
 399
 400   return xbt_lib_get_elm_or_null(host_lib, sub_ws_name);
 401 }
 402
 403
 404 /* Adding a task to a VM updates the VCPU task on its physical machine. */
 405 static surf_action_t vm_ws_execute(void *workstation, double size)
 406 {
 407   surf_resource_t ws = ((surf_resource_t) surf_workstation_resource_priv(workstation));
 408
 409   xbt_assert(ws->model->type == SURF_MODEL_TYPE_VM_WORKSTATION);
 410   workstation_VM2013_t vm_ws = (workstation_VM2013_t) ws;
 411
 412   double old_cost = vm_ws->cpu_action->cost;
 413   double new_cost = old_cost + size;
 414
 415   XBT_DEBUG("VM(%s)@PM(%s): update dummy action's cost (%f -> %f)",
 416       ws->name, vm_ws->sub_ws->generic_resource.name,
 417       old_cost, new_cost);
 418
 419   vm_ws->cpu_action->cost = new_cost;
 420
 421   return ws_execute(workstation, size);
 422 }
 423
 424 static void vm_ws_action_cancel(surf_action_t action)
 425 {
 426   XBT_CRITICAL("FIXME: Not yet implemented. Reduce dummy action's cost by %f", action->cost);
 427
 428   ws_action_cancel(action);
 429 }
 430
 431
 432 /* Now we can set bound for each task by using MSG_task_set_bound. But, it does
 433  * not work for the dummy CPU action of a VM. Here, we add the set_bound
 434  * function for the dummy CPU action. */
 435 static void vm_ws_set_vm_bound(void *workstation, double bound)
 436 {
 437   surf_resource_t ws = ((surf_resource_t) surf_workstation_resource_priv(workstation));
 438   xbt_assert(ws->model->type == SURF_MODEL_TYPE_VM_WORKSTATION);
 439   workstation_VM2013_t vm_ws = (workstation_VM2013_t) ws;
 440
 441   surf_action_set_bound(vm_ws->cpu_action, bound);
 442 }
 443
 444
 445 static void surf_vm_workstation_model_init_internal(void)
 446 {
 447   surf_model_t model = surf_model_init();
 448
 449   model->name = "Virtual Workstation";
 450   model->type = SURF_MODEL_TYPE_VM_WORKSTATION;
 451
 452   model->action_unref     = ws_action_unref;
 453   model->action_cancel    = vm_ws_action_cancel;
 454   // model->action_state_set = ws_action_state_set;
 455
 456
 457   model->model_private->share_resources       = vm_ws_share_resources;
 458   model->model_private->resource_used         = ws_resource_used;
 459   model->model_private->update_actions_state  = ws_update_actions_state;
 460   model->model_private->update_resource_state = ws_update_resource_state;
 461   model->model_private->finalize              = ws_finalize;
 462
 463
 464   /* operation for an action, not for VM it self */
 465   model->suspend          = ws_action_suspend;
 466   model->resume           = ws_action_resume;
 467 //   model->is_suspended     = ws_action_is_suspended;
 468 //   model->set_max_duration = ws_action_set_max_duration;
 469   model->set_priority     = ws_action_set_priority;
 470   model->set_bound        = ws_action_set_bound;
 471 // #ifdef HAVE_TRACING
 472 //   model->set_category     = ws_action_set_category;
 473 // #endif
 474   model->get_remains      = ws_action_get_remains;
 475 // #ifdef HAVE_LATENCY_BOUND_TRACKING
 476 //   model->get_latency_limited = ws_get_latency_limited;
 477 // #endif
 478
 479
 480
 481
 482
 483
 484
 485   xbt_assert(surf_cpu_model_vm);
 486   model->extension.workstation.cpu_model = surf_cpu_model_vm;
 487
 488   model->extension.workstation.execute   = vm_ws_execute;
 489   model->extension.workstation.sleep     = ws_action_sleep;
 490   model->extension.workstation.get_state = ws_get_state;
 491   model->extension.workstation.get_speed = ws_get_speed;
 492   // model->extension.workstation.get_available_speed = ws_get_available_speed;
 493
 494   // model->extension.workstation.communicate           = ws_communicate;
 495   // model->extension.workstation.get_route             = ws_get_route;
 496   // model->extension.workstation.execute_parallel_task = ws_execute_parallel_task;
 497   // model->extension.workstation.get_link_bandwidth    = ws_get_link_bandwidth;
 498   // model->extension.workstation.get_link_latency      = ws_get_link_latency;
 499   // model->extension.workstation.link_shared           = ws_link_shared;
 500   // model->extension.workstation.get_properties        = ws_get_properties;
 501
 502   // model->extension.workstation.open   = ws_action_open;
 503   // model->extension.workstation.close  = ws_action_close;
 504   // model->extension.workstation.read   = ws_action_read;
 505   // model->extension.workstation.write  = ws_action_write;
 506   // model->extension.workstation.stat   = ws_action_stat;
 507   // model->extension.workstation.unlink = ws_action_unlink;
 508   // model->extension.workstation.ls     = ws_action_ls;
 509
 510
 511   model->extension.vm_workstation.create        = vm_ws_create;
 512   model->extension.vm_workstation.set_state     = vm_ws_set_state;
 513   model->extension.vm_workstation.get_state     = vm_ws_get_state;
 514   model->extension.vm_workstation.migrate       = vm_ws_migrate;
 515   model->extension.vm_workstation.destroy       = vm_ws_destroy;
 516   model->extension.vm_workstation.suspend       = vm_ws_suspend;
 517   model->extension.vm_workstation.resume        = vm_ws_resume;
 518   model->extension.vm_workstation.save          = vm_ws_save;
 519   model->extension.vm_workstation.restore       = vm_ws_restore;
 520   model->extension.vm_workstation.get_pm        = vm_ws_get_pm;
 521   model->extension.vm_workstation.set_vm_bound  = vm_ws_set_vm_bound;
 522
 523   model->extension.workstation.set_params    = ws_set_params;
 524   model->extension.workstation.get_params    = ws_get_params;
 525
 526   surf_vm_workstation_model = model;
 527 }
 528
 529 void surf_vm_workstation_model_init(void)
 530 {
 531   surf_vm_workstation_model_init_internal();
 532   xbt_dynar_push(model_list, &surf_vm_workstation_model);
 533   xbt_dynar_push(model_list_invoke, &surf_vm_workstation_model);
 534 }