X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/4cd446e94a6b7c4c7d15cb0b645124942223fb73..4e5def63badcab36ae4c7b58645aa0a65ce4e0d0:/src/simix/smx_vm.c

diff --git a/src/simix/smx_vm.c b/src/simix/smx_vm.c
index ff765eb511..213c1651f5 100644
--- a/src/simix/smx_vm.c
+++ b/src/simix/smx_vm.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2007-2012. The SimGrid Team.
+/* Copyright (c) 2007-2014. The SimGrid Team.
  * All rights reserved.                                                     */
 
 /* This program is free software; you can redistribute it and/or modify it
@@ -10,8 +10,9 @@
 #include "xbt/dict.h"
 #include "mc/mc.h"
 
-XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_vm, simix,
-                                "Logging specific to SIMIX (vms)");
+//If you need to log some stuffs, just uncomment these two lines and uses XBT_DEBUG for instance
+XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_vm, simix, "Logging specific to SIMIX (vms)");
+
 /* **** create a VM **** */
 
 /**
@@ -19,550 +20,355 @@ XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_vm, simix,
  * \param name name of the host to create
  * \param data some user data (may be NULL)
  */
-smx_host_t SIMIX_vm_create(const char *name, smx_host_t phys_host)
+smx_host_t SIMIX_vm_create(const char *name, smx_host_t ind_phys_host)
 {
+  /* Create surf associated resource */
+  surf_vm_workstation_model_create(name, ind_phys_host);
 
-  smx_host_priv_t smx_host = xbt_new0(s_smx_host_priv_t, 1);
-  s_smx_process_t proc;
+  smx_host_t smx_host = SIMIX_host_create(name, ind_phys_host, NULL);
 
-  // TODO check why we do not have any VM here and why we have the host_proc_hookup  ?
+  /* We will be able to register the VM to its physical host, so that we can promptly
+   * retrieve the list VMs on the physical host. */
 
-  /* Host structure */
-  smx_host->data = NULL;
-  smx_host->process_list =
-      xbt_swag_new(xbt_swag_offset(proc, host_proc_hookup));
+  return smx_host;
+}
 
-  /* Update global variables */
-  xbt_lib_set(host_lib,name,SIMIX_HOST_LEVEL,smx_host);
 
-  /* Create surf associated resource */
-  // TODO change phys_host into the right workstation surf model
-  surf_vm_workstation_model->extension.vm_workstation.create(name, phys_host);
+/* works for VMs and PMs */
+static long host_get_ramsize(smx_host_t vm, int *overcommit)
+{
+  s_ws_params_t params;
+  surf_workstation_get_params(vm, &params);
 
-  return xbt_lib_get_elm_or_null(host_lib, name);
+  if (overcommit)
+    *overcommit = params.overcommit;
+
+  return params.ramsize;
 }
 
+/* **** start a VM **** */
+static int __can_be_started(smx_host_t vm)
+{
+  smx_host_t pm = surf_vm_workstation_get_pm(vm);
 
-smx_host_t SIMIX_pre_vm_create(smx_simcall_t simcall, const char *name, smx_host_t phys_host){
-   return SIMIX_vm_create(name, phys_host);
-}
+  int pm_overcommit = 0;
+  long pm_ramsize = host_get_ramsize(pm, &pm_overcommit);
+  long vm_ramsize = host_get_ramsize(vm, NULL);
 
+  if (!pm_ramsize) {
+    /* We assume users do not want to care about ramsize. */
+    return 1;
+  }
 
-/* **** start a VM **** */
-int __can_be_started(smx_host_t vm){
-	// TODO add checking code related to overcommitment or not.
+  if (pm_overcommit) {
+    XBT_INFO("%s allows memory overcommit.", pm->key);
+    return 1;
+  }
+
+  long total_ramsize_of_vms = 0;
+  xbt_dynar_t dyn_vms = surf_workstation_get_vms(pm);
+  {
+    unsigned int cursor = 0;
+    smx_host_t another_vm;
+    xbt_dynar_foreach(dyn_vms, cursor, another_vm) {
+      long another_vm_ramsize = host_get_ramsize(vm, NULL);
+      total_ramsize_of_vms += another_vm_ramsize;
+    }
+  }
+
+  if (vm_ramsize > pm_ramsize - total_ramsize_of_vms) {
+    XBT_WARN("cannnot start %s@%s due to memory shortage: vm_ramsize %ld, free %ld, pm_ramsize %ld (bytes).",
+        vm->key, pm->key, vm_ramsize, pm_ramsize - total_ramsize_of_vms, pm_ramsize);
+    xbt_dynar_free(&dyn_vms);
+    return 0;
+  }
+
+  xbt_dynar_free(&dyn_vms);
 	return 1;
 }
-void SIMIX_vm_start(smx_host_t vm){
 
-  //TODO only start the VM if you can
-  if (can_be_started(vm))
-	  SIMIX_set_vm_state(vm, msg_vm_state_running);
+void SIMIX_vm_start(smx_host_t ind_vm)
+{
+  if (__can_be_started(ind_vm))
+    surf_resource_set_state(surf_workstation_resource_priv(ind_vm),
+                            (int)SURF_VM_STATE_RUNNING);
   else
-	  THROWF(vm_error, 0, "The VM %s cannot be started", SIMIX_host_get_name(vm));
+    THROWF(vm_error, 0, "The VM %s cannot be started", SIMIX_host_get_name(ind_vm));
 }
 
-void SIMIX_pre_vm_start(smx_simcall_t simcall, smx_host_t vm){
-   SIMIX_vm_start(vm);
-}
-
-/* ***** set/get state of a VM ***** */
-void SIMIX_set_vm_state(smx_host_t vm, int state){
-
-}
-void SIMIX_prev_set_vm_state(smx_host_t vm, int state){
-	SIMIX_set_vm_state(vm, state);
-}
 
-int SIMIX_get_vm_state(smx_host_t vm){
- return surf_vm_workstation_model->extension.vm_workstation.get_state(vm);
-}
-int SIMIX_pre_vm_state(smx_host_t vm){
-	return SIMIX_get_vm_state(vm);
+int SIMIX_vm_get_state(smx_host_t ind_vm)
+{
+  return surf_resource_get_state(surf_workstation_resource_priv(ind_vm));
 }
 
 /**
- * \brief Function to destroy a SIMIX VM host.
+ * \brief Function to migrate a SIMIX VM host.
  *
- * \param host the vm host to destroy (a smx_host_t)
+ * \param host the vm host to migrate (a smx_host_t)
  */
-void SIMIX_vm_destroy(smx_host_t host)
+void SIMIX_vm_migrate(smx_host_t ind_vm, smx_host_t ind_dst_pm)
 {
-  /* this code basically performs a similar thing like SIMIX_host_destroy() */
+  /* precopy migration makes the VM temporally paused */
+  xbt_assert(SIMIX_vm_get_state(ind_vm) == SURF_VM_STATE_SUSPENDED);
 
-  xbt_assert((host != NULL), "Invalid parameters");
-  char *hostname = host->key;
-
-  smx_host_priv_t host_priv = SIMIX_host_priv(host);
-
-  /* this will call the registered callback function, i.e., SIMIX_host_destroy().  */
-  xbt_lib_unset(host_lib, hostname, SIMIX_HOST_LEVEL)
-
-  /* jump to vm_ws_destroy(). The surf level resource will be freed. */
-  surf_vm_workstation_model->extension.vm_workstation.destroy(host);
+  /* jump to vm_ws_xigrate(). this will update the vm location. */
+  surf_vm_workstation_migrate(ind_vm, ind_dst_pm);
 }
 
-void SIMIX_pre_vm_destroy(smx_simcall_t simcall, smx_host_t vm){
-   SIMIX_vm_start(vm);
-}
-
-smx_host_t SIMIX_host_get_by_name(const char *name){
-  xbt_assert(((simix_global != NULL)
-               && (host_lib != NULL)),
-              "Environment not set yet");
+/**
+ * \brief Encompassing simcall to prevent the removal of the src or the dst node at the end of a VM migration
+ *  The simcall actually invokes the following calls: 
+ *     simcall_vm_set_affinity(vm, src_pm, 0); 
+ *     simcall_vm_migrate(vm, dst_pm); 
+ *     simcall_vm_resume(vm);
+ *
+ * It is called at the end of the migration_rx_fun function from msg/msg_vm.c
+ *
+ * \param vm VM to migrate
+ * \param src_pm  Source physical host
+ * \param dst_pmt Destination physical host
+ */
+void SIMIX_vm_migratefrom_resumeto(smx_host_t vm, smx_host_t src_pm, smx_host_t dst_pm)
+{
+  /* deinstall the current affinity setting for the CPU */
+  SIMIX_vm_set_affinity(vm, src_pm, 0);
 
-  return xbt_lib_get_elm_or_null(host_lib, name);
-}
+  /* Update the vm location */
+  SIMIX_vm_migrate(vm, dst_pm);
+ 
+  /* Resume the VM */
+  smx_process_t self = SIMIX_process_self(); 
+  SIMIX_vm_resume(vm, self->simcall.issuer);
+} 
 
-smx_host_t SIMIX_host_self(void)
+/**
+ * \brief Function to get the physical host of the given SIMIX VM host.
+ *
+ * \param host the vm host to get_phys_host (a smx_host_t)
+ */
+void *SIMIX_vm_get_pm(smx_host_t ind_vm)
 {
-  smx_process_t process = SIMIX_process_self();
-  return (process == NULL) ? NULL : SIMIX_process_get_host(process);
+  /* jump to vm_ws_get_pm(). this will return the vm name. */
+  return surf_vm_workstation_get_pm(ind_vm);
 }
 
-const char* SIMIX_pre_host_self_get_name(smx_simcall_t simcall){
-   return SIMIX_host_self_get_name();
-}
-/* needs to be public and without simcall because it is called
-   by exceptions and logging events */
-const char* SIMIX_host_self_get_name(void)
+/**
+ * \brief Function to set the CPU bound of the given SIMIX VM host.
+ *
+ * \param host the vm host (a smx_host_t)
+ * \param bound bound (a double)
+ */
+void SIMIX_vm_set_bound(smx_host_t ind_vm, double bound)
 {
-  smx_host_t host = SIMIX_host_self();
-  if (host == NULL || SIMIX_process_self() == simix_global->maestro_process)
-    return "";
-
-  return SIMIX_host_get_name(host);
+  /* jump to vm_ws_set_vm_bound(). */
+  surf_vm_workstation_set_bound(ind_vm, bound);
 }
 
-const char* SIMIX_pre_host_get_name(smx_simcall_t simcall, smx_host_t host){
-   return SIMIX_host_get_name(host);
-}
-const char* SIMIX_host_get_name(smx_host_t host){
-  xbt_assert((host != NULL), "Invalid parameters");
-
-  return sg_host_name(host);
-}
+/**
+ * \brief Function to set the CPU affinity of the given SIMIX VM host.
+ *
+ * \param host the vm host (a smx_host_t)
+ * \param host the pm host (a smx_host_t)
+ * \param mask affinity mask (a unsigned long)
+ */
+void SIMIX_vm_set_affinity(smx_host_t ind_vm, smx_host_t ind_pm, unsigned long mask)
+{
+  /* make sure this at the MSG layer. */
+  xbt_assert(SIMIX_vm_get_pm(ind_vm) == ind_pm);
 
-xbt_dict_t SIMIX_pre_host_get_properties(smx_simcall_t simcall, smx_host_t host){
-  return SIMIX_host_get_properties(host);
+  /* jump to vm_ws_set_vm_affinity(). */
+  surf_vm_workstation_set_affinity(ind_vm, ind_pm, mask);
 }
-xbt_dict_t SIMIX_host_get_properties(smx_host_t host){
-  xbt_assert((host != NULL), "Invalid parameters (simix host is NULL)");
 
-  return surf_workstation_model->extension.workstation.get_properties(host);
-}
 
-double SIMIX_pre_host_get_speed(smx_simcall_t simcall, smx_host_t host){
-  return SIMIX_host_get_speed(host);
-}
-double SIMIX_host_get_speed(smx_host_t host){
-  xbt_assert((host != NULL), "Invalid parameters (simix host is NULL)");
+/**
+ * \brief Function to suspend a SIMIX VM host. This function stops the execution of the
+ * VM. All the processes on this VM will pause. The state of the VM is
+ * preserved on memory. We can later resume it again.
+ *
+ * \param host the vm host to suspend (a smx_host_t)
+ */
+void SIMIX_vm_suspend(smx_host_t ind_vm, smx_process_t issuer)
+{
+  const char *name = SIMIX_host_get_name(ind_vm);
 
-  return surf_workstation_model->extension.workstation.
-      get_speed(host, 1.0);
-}
+  if (SIMIX_vm_get_state(ind_vm) != SURF_VM_STATE_RUNNING)
+    THROWF(vm_error, 0, "VM(%s) is not running", name);
 
-double SIMIX_pre_host_get_available_speed(smx_simcall_t simcall, smx_host_t host){
-  return SIMIX_host_get_available_speed(host);
-}
-double SIMIX_host_get_available_speed(smx_host_t host){
-  xbt_assert((host != NULL), "Invalid parameters (simix host is NULL)");
+  XBT_DEBUG("suspend VM(%s), where %d processes exist", name, xbt_swag_size(SIMIX_host_priv(ind_vm)->process_list));
 
-  return surf_workstation_model->extension.workstation.
-      get_available_speed(host);
-}
+  /* jump to vm_ws_suspend. The state will be set. */
+  surf_vm_workstation_suspend(ind_vm);
 
-int SIMIX_pre_host_get_state(smx_simcall_t simcall, smx_host_t host){
-  return SIMIX_host_get_state(host);
-}
-int SIMIX_host_get_state(smx_host_t host){
-  xbt_assert((host != NULL), "Invalid parameters (simix host is NULL)");
+  smx_process_t smx_process, smx_process_safe;
+  xbt_swag_foreach_safe(smx_process, smx_process_safe, SIMIX_host_priv(ind_vm)->process_list) {
+    XBT_DEBUG("suspend %s", smx_process->name);
+    SIMIX_process_suspend(smx_process, issuer);
+  }
 
-  return surf_workstation_model->extension.workstation.
-      get_state(host);
+  XBT_DEBUG("suspend all processes on the VM done done");
 }
 
-void* SIMIX_pre_host_self_get_data(smx_simcall_t simcall){
-  return SIMIX_host_self_get_data();
-}
-void* SIMIX_host_self_get_data(void)
+void simcall_HANDLER_vm_suspend(smx_simcall_t simcall, smx_host_t ind_vm)
 {
-  smx_host_t self = SIMIX_host_self();
-  return SIMIX_host_get_data(self);
-}
+  if (simcall->issuer->smx_host == ind_vm) {
+    XBT_ERROR("cannot suspend the VM where I run");
+    DIE_IMPOSSIBLE;
+  }
 
-void SIMIX_host_self_set_data(void *data)
-{
-  smx_host_t self = SIMIX_host_self();
-  SIMIX_host_set_data(self, data);
-}
+  SIMIX_vm_suspend(ind_vm, simcall->issuer);
 
-void* SIMIX_pre_host_get_data(smx_simcall_t simcall,smx_host_t host){
-  return SIMIX_host_get_data(host);
+  XBT_DEBUG("simcall_HANDLER_vm_suspend done");
 }
-void* SIMIX_host_get_data(smx_host_t host){
-  xbt_assert((host != NULL), "Invalid parameters (simix host is NULL)");
 
-  return SIMIX_host_priv(host)->data;
-}
-void _SIMIX_host_free_process_arg(void *);
-void _SIMIX_host_free_process_arg(void *data)
-{
-  smx_process_arg_t arg = *(void**)data;
-  xbt_free(arg->name);
-  xbt_free(arg);
-}
+
 /**
- * \brief Add a process to the list of the processes that the host will restart when it comes back
- * This function add a process to the list of the processes that will be restarted when the host comes
- * back. It is expected that this function is called when the host is down.
- * The processes will only be restarted once, meaning that you will have to register the process
- * again to restart the process again.
+ * \brief Function to resume a SIMIX VM host. This function restart the execution of the
+ * VM. All the processes on this VM will run again.
+ *
+ * \param host the vm host to resume (a smx_host_t)
  */
-void SIMIX_host_add_auto_restart_process(smx_host_t host,
-                                         const char *name,
-                                         xbt_main_func_t code,
-                                         void *data,
-                                         const char *hostname,
-                                         double kill_time,
-                                         int argc, char **argv,
-                                         xbt_dict_t properties,
-                                         int auto_restart)
+void SIMIX_vm_resume(smx_host_t ind_vm, smx_process_t issuer)
 {
-  if (!SIMIX_host_priv(host)->auto_restart_processes) {
-    SIMIX_host_priv(host)->auto_restart_processes = xbt_dynar_new(sizeof(smx_process_arg_t),_SIMIX_host_free_process_arg);
-  }
-  smx_process_arg_t arg = xbt_new(s_smx_process_arg_t,1);
-  arg->name = xbt_strdup(name);
-  arg->code = code;
-  arg->data = data;
-  arg->hostname = hostname;
-  arg->kill_time = kill_time;
-  arg->argc = argc;
-
-  arg->argv = xbt_new(char*,argc + 1);
-
-  int i;
-  for (i = 0; i < argc; i++) {
-    arg->argv[i] = xbt_strdup(argv[i]);
-  }
-  arg->argv[argc] = NULL;
+  const char *name = SIMIX_host_get_name(ind_vm);
 
-  arg->properties = properties;
-  arg->auto_restart = auto_restart;
+  if (SIMIX_vm_get_state(ind_vm) != SURF_VM_STATE_SUSPENDED)
+    THROWF(vm_error, 0, "VM(%s) was not suspended", name);
 
-  if( SIMIX_host_get_state(host) == SURF_RESOURCE_OFF
-      && !xbt_dict_get_or_null(watched_hosts_lib,sg_host_name(host))){
-    xbt_dict_set(watched_hosts_lib,sg_host_name(host),host,NULL);
-    XBT_DEBUG("Have push host %s to watched_hosts_lib because state == SURF_RESOURCE_OFF",sg_host_name(host));
-  }
-  xbt_dynar_push_as(SIMIX_host_priv(host)->auto_restart_processes,smx_process_arg_t,arg);
-}
-/**
- * \brief Restart the list of processes that have been registered to the host
- */
-void SIMIX_host_restart_processes(smx_host_t host)
-{
-  unsigned int cpt;
-  smx_process_arg_t arg;
-  xbt_dynar_foreach(SIMIX_host_priv(host)->auto_restart_processes,cpt,arg) {
-
-    smx_process_t process;
-
-    XBT_DEBUG("Restarting Process %s(%s) right now", arg->argv[0], arg->hostname);
-    if (simix_global->create_process_function) {
-      simix_global->create_process_function(&process,
-                                            arg->argv[0],
-                                            arg->code,
-                                            NULL,
-                                            arg->hostname,
-                                            arg->kill_time,
-                                            arg->argc,
-                                            arg->argv,
-                                            arg->properties,
-                                            arg->auto_restart);
-    }
-    else {
-      simcall_process_create(&process,
-                                            arg->argv[0],
-                                            arg->code,
-                                            NULL,
-                                            arg->hostname,
-                                            arg->kill_time,
-                                            arg->argc,
-                                            arg->argv,
-                                            arg->properties,
-                                            arg->auto_restart);
+  XBT_DEBUG("resume VM(%s), where %d processes exist", name, xbt_swag_size(SIMIX_host_priv(ind_vm)->process_list));
 
-    }
+  /* jump to vm_ws_resume() */
+  surf_vm_workstation_resume(ind_vm);
+
+  smx_process_t smx_process, smx_process_safe;
+  xbt_swag_foreach_safe(smx_process, smx_process_safe, SIMIX_host_priv(ind_vm)->process_list) {
+    XBT_DEBUG("resume %s", smx_process->name);
+    SIMIX_process_resume(smx_process, issuer);
   }
-  xbt_dynar_reset(SIMIX_host_priv(host)->auto_restart_processes);
 }
 
-void SIMIX_host_autorestart(smx_host_t host)
+void simcall_HANDLER_vm_resume(smx_simcall_t simcall, smx_host_t ind_vm)
 {
-  if(simix_global->autorestart)
-    simix_global->autorestart(host);
-  else
-    xbt_die("No function for simix_global->autorestart");
-}
-
-void SIMIX_pre_host_set_data(smx_simcall_t simcall, smx_host_t host, void *data) {
-  SIMIX_host_set_data(host, data);
+  SIMIX_vm_resume(ind_vm, simcall->issuer);
 }
-void SIMIX_host_set_data(smx_host_t host, void *data){
-  xbt_assert((host != NULL), "Invalid parameters");
-  xbt_assert((SIMIX_host_priv(host)->data == NULL), "Data already set");
 
-  SIMIX_host_priv(host)->data = data;
-}
-
-smx_action_t SIMIX_pre_host_execute(smx_simcall_t simcall,const char *name,
-    smx_host_t host, double computation_amount, double priority){
-  return SIMIX_host_execute(name, host, computation_amount, priority);
-}
-smx_action_t SIMIX_host_execute(const char *name,
-    smx_host_t host, double computation_amount, double priority){
-
-  /* alloc structures and initialize */
-  smx_action_t action = xbt_mallocator_get(simix_global->action_mallocator);
-  action->type = SIMIX_ACTION_EXECUTE;
-  action->name = xbt_strdup(name);
-  action->state = SIMIX_RUNNING;
-  action->execution.host = host;
-
-#ifdef HAVE_TRACING
-  action->category = NULL;
-#endif
-
-  /* set surf's action */
-  if (!MC_is_active()) {
-    action->execution.surf_exec =
-      surf_workstation_model->extension.workstation.execute(host,
-    computation_amount);
-    surf_workstation_model->action_data_set(action->execution.surf_exec, action);
-    surf_workstation_model->set_priority(action->execution.surf_exec, priority);
-  }
 
-  XBT_DEBUG("Create execute action %p", action);
+/**
+ * \brief Function to save a SIMIX VM host.
+ * This function is the same as vm_suspend, but the state of the VM is saved to the disk, and not preserved on memory.
+ * We can later restore it again.
+ *
+ * \param host the vm host to save (a smx_host_t)
+ */
+void SIMIX_vm_save(smx_host_t ind_vm, smx_process_t issuer)
+{
+  const char *name = SIMIX_host_get_name(ind_vm);
 
-  return action;
-}
+  if (SIMIX_vm_get_state(ind_vm) != SURF_VM_STATE_RUNNING)
+    THROWF(vm_error, 0, "VM(%s) is not running", name);
 
-smx_action_t SIMIX_pre_host_parallel_execute(smx_simcall_t simcall, const char *name,
-    int host_nb, smx_host_t *host_list,
-    double *computation_amount, double *communication_amount,
-    double amount, double rate){
-  return SIMIX_host_parallel_execute(name, host_nb, host_list, computation_amount,
-		                     communication_amount, amount, rate);
-}
-smx_action_t SIMIX_host_parallel_execute(const char *name,
-    int host_nb, smx_host_t *host_list,
-    double *computation_amount, double *communication_amount,
-    double amount, double rate){
-
-  void **workstation_list = NULL;
-  int i;
-
-  /* alloc structures and initialize */
-  smx_action_t action = xbt_mallocator_get(simix_global->action_mallocator);
-  action->type = SIMIX_ACTION_PARALLEL_EXECUTE;
-  action->name = xbt_strdup(name);
-  action->state = SIMIX_RUNNING;
-  action->execution.host = NULL; /* FIXME: do we need the list of hosts? */
-
-#ifdef HAVE_TRACING
-  action->category = NULL;
-#endif
-
-  /* set surf's action */
-  workstation_list = xbt_new0(void *, host_nb);
-  for (i = 0; i < host_nb; i++)
-    workstation_list[i] = host_list[i];
-
-  /* set surf's action */
-  if (!MC_is_active()) {
-    action->execution.surf_exec =
-      surf_workstation_model->extension.workstation.
-      execute_parallel_task(host_nb, workstation_list, computation_amount,
-                      communication_amount, rate);
-
-    surf_workstation_model->action_data_set(action->execution.surf_exec, action);
-  }
-  XBT_DEBUG("Create parallel execute action %p", action);
 
-  return action;
-}
+  XBT_DEBUG("save VM(%s), where %d processes exist", name, xbt_swag_size(SIMIX_host_priv(ind_vm)->process_list));
 
-void SIMIX_pre_host_execution_destroy(smx_simcall_t simcall, smx_action_t action){
-  SIMIX_host_execution_destroy(action);
-}
-void SIMIX_host_execution_destroy(smx_action_t action){
-  XBT_DEBUG("Destroy action %p", action);
+  /* jump to vm_ws_save() */
+  surf_vm_workstation_save(ind_vm);
 
-  if (action->execution.surf_exec) {
-    surf_workstation_model->action_unref(action->execution.surf_exec);
-    action->execution.surf_exec = NULL;
+  smx_process_t smx_process, smx_process_safe;
+  xbt_swag_foreach_safe(smx_process, smx_process_safe, SIMIX_host_priv(ind_vm)->process_list) {
+    XBT_DEBUG("suspend %s", smx_process->name);
+    SIMIX_process_suspend(smx_process, issuer);
   }
-  xbt_free(action->name);
-  xbt_mallocator_release(simix_global->action_mallocator, action);
 }
 
-void SIMIX_pre_host_execution_cancel(smx_simcall_t simcall, smx_action_t action){
-  SIMIX_host_execution_cancel(action);
-}
-void SIMIX_host_execution_cancel(smx_action_t action){
-  XBT_DEBUG("Cancel action %p", action);
-
-  if (action->execution.surf_exec)
-    surf_workstation_model->action_cancel(action->execution.surf_exec);
-}
-
-double SIMIX_pre_host_execution_get_remains(smx_simcall_t simcall, smx_action_t action){
-  return SIMIX_host_execution_get_remains(action);
-}
-double SIMIX_host_execution_get_remains(smx_action_t action){
-  double result = 0.0;
-
-  if (action->state == SIMIX_RUNNING)
-    result = surf_workstation_model->get_remains(action->execution.surf_exec);
-
-  return result;
+void simcall_HANDLER_vm_save(smx_simcall_t simcall, smx_host_t ind_vm)
+{
+  SIMIX_vm_save(ind_vm, simcall->issuer);
 }
 
-e_smx_state_t SIMIX_pre_host_execution_get_state(smx_simcall_t simcall, smx_action_t action){
-  return SIMIX_host_execution_get_state(action);
-}
-e_smx_state_t SIMIX_host_execution_get_state(smx_action_t action){
-  return action->state;
-}
 
-void SIMIX_pre_host_execution_set_priority(smx_simcall_t simcall, smx_action_t action,
-		                        double priority){
-  return SIMIX_host_execution_set_priority(action, priority);
-}
-void SIMIX_host_execution_set_priority(smx_action_t action, double priority){
-  if(action->execution.surf_exec)
-    surf_workstation_model->set_priority(action->execution.surf_exec, priority);
-}
+/**
+ * \brief Function to restore a SIMIX VM host. This function restart the execution of the
+ * VM. All the processes on this VM will run again.
+ *
+ * \param host the vm host to restore (a smx_host_t)
+ */
+void SIMIX_vm_restore(smx_host_t ind_vm, smx_process_t issuer)
+{
+  const char *name = SIMIX_host_get_name(ind_vm);
 
-void SIMIX_pre_host_execution_wait(smx_simcall_t simcall, smx_action_t action){
+  if (SIMIX_vm_get_state(ind_vm) != SURF_VM_STATE_SAVED)
+    THROWF(vm_error, 0, "VM(%s) was not saved", name);
 
-  XBT_DEBUG("Wait for execution of action %p, state %d", action, (int)action->state);
+  XBT_DEBUG("restore VM(%s), where %d processes exist", name, xbt_swag_size(SIMIX_host_priv(ind_vm)->process_list));
 
-  /* Associate this simcall to the action */
-  xbt_fifo_push(action->simcalls, simcall);
-  simcall->issuer->waiting_action = action;
+  /* jump to vm_ws_restore() */
+  surf_vm_workstation_resume(ind_vm);
 
-  /* set surf's action */
-  if (MC_is_active()) {
-    action->state = SIMIX_DONE;
-    SIMIX_execution_finish(action);
-    return;
+  smx_process_t smx_process, smx_process_safe;
+  xbt_swag_foreach_safe(smx_process, smx_process_safe, SIMIX_host_priv(ind_vm)->process_list) {
+    XBT_DEBUG("resume %s", smx_process->name);
+    SIMIX_process_resume(smx_process, issuer);
   }
-
-  /* If the action is already finished then perform the error handling */
-  if (action->state != SIMIX_RUNNING)
-    SIMIX_execution_finish(action);
 }
 
-void SIMIX_host_execution_suspend(smx_action_t action)
+void simcall_HANDLER_vm_restore(smx_simcall_t simcall, smx_host_t ind_vm)
 {
-  if(action->execution.surf_exec)
-    surf_workstation_model->suspend(action->execution.surf_exec);
+  SIMIX_vm_restore(ind_vm, simcall->issuer);
 }
 
-void SIMIX_host_execution_resume(smx_action_t action)
-{
-  if(action->execution.surf_exec)
-    surf_workstation_model->resume(action->execution.surf_exec);
-}
 
-void SIMIX_execution_finish(smx_action_t action)
+/**
+ * \brief Function to shutdown a SIMIX VM host. This function powers off the
+ * VM. All the processes on this VM will be killed. But, the state of the VM is
+ * preserved on memory. We can later start it again.
+ *
+ * \param host the vm host to shutdown (a smx_host_t)
+ */
+void SIMIX_vm_shutdown(smx_host_t ind_vm, smx_process_t issuer)
 {
-  xbt_fifo_item_t item;
-  smx_simcall_t simcall;
-
-  xbt_fifo_foreach(action->simcalls, item, simcall, smx_simcall_t) {
-
-    switch (action->state) {
-
-      case SIMIX_DONE:
-        /* do nothing, action done */
-  XBT_DEBUG("SIMIX_execution_finished: execution successful");
-        break;
+  const char *name = SIMIX_host_get_name(ind_vm);
 
-      case SIMIX_FAILED:
-        XBT_DEBUG("SIMIX_execution_finished: host '%s' failed", sg_host_name(simcall->issuer->smx_host));
-        simcall->issuer->context->iwannadie = 1;
-        //SMX_EXCEPTION(simcall->issuer, host_error, 0, "Host failed");
-        break;
+  if (SIMIX_vm_get_state(ind_vm) != SURF_VM_STATE_RUNNING)
+    THROWF(vm_error, 0, "VM(%s) is not running", name);
 
-      case SIMIX_CANCELED:
-        XBT_DEBUG("SIMIX_execution_finished: execution canceled");
-        SMX_EXCEPTION(simcall->issuer, cancel_error, 0, "Canceled");
-        break;
+  XBT_DEBUG("shutdown %s", name);
+  XBT_DEBUG("%d processes in the VM", xbt_swag_size(SIMIX_host_priv(ind_vm)->process_list));
 
-      default:
-        xbt_die("Internal error in SIMIX_execution_finish: unexpected action state %d",
-            (int)action->state);
-    }
-    /* check if the host is down */
-    if (surf_workstation_model->extension.
-        workstation.get_state(simcall->issuer->smx_host) != SURF_RESOURCE_ON) {
-      simcall->issuer->context->iwannadie = 1;
-    }
-
-    simcall->issuer->waiting_action =    NULL;
-    simcall_host_execution_wait__set__result(simcall, action->state);
-    SIMIX_simcall_answer(simcall);
+  smx_process_t smx_process, smx_process_safe;
+  xbt_swag_foreach_safe(smx_process, smx_process_safe, SIMIX_host_priv(ind_vm)->process_list) {
+    XBT_DEBUG("kill %s", smx_process->name);
+    SIMIX_process_kill(smx_process, issuer);
   }
 
-  /* We no longer need it */
-  SIMIX_host_execution_destroy(action);
+  /* FIXME: we may have to do something at the surf layer, e.g., vcpu action */
+  surf_resource_set_state(surf_workstation_resource_priv(ind_vm),
+                          (int)SURF_VM_STATE_CREATED);
 }
 
-void SIMIX_post_host_execute(smx_action_t action)
+void simcall_HANDLER_vm_shutdown(smx_simcall_t simcall, smx_host_t ind_vm)
 {
-  if (action->type == SIMIX_ACTION_EXECUTE && /* FIMXE: handle resource failure
-                                               * for parallel tasks too */
-      surf_workstation_model->extension.workstation.get_state(action->execution.host) == SURF_RESOURCE_OFF) {
-    /* If the host running the action failed, notice it so that the asking
-     * process can be killed if it runs on that host itself */
-    action->state = SIMIX_FAILED;
-  } else if (surf_workstation_model->action_state_get(action->execution.surf_exec) == SURF_ACTION_FAILED) {
-    /* If the host running the action didn't fail, then the action was
-     * canceled */
-    action->state = SIMIX_CANCELED;
-  } else {
-    action->state = SIMIX_DONE;
-  }
-
-  if (action->execution.surf_exec) {
-    surf_workstation_model->action_unref(action->execution.surf_exec);
-    action->execution.surf_exec = NULL;
-  }
-
-  /* If there are simcalls associated with the action, then answer them */
-  if (xbt_fifo_size(action->simcalls)) {
-    SIMIX_execution_finish(action);
-  }
+  SIMIX_vm_shutdown(ind_vm, simcall->issuer);
 }
 
 
-#ifdef HAVE_TRACING
-void SIMIX_pre_set_category(smx_simcall_t simcall, smx_action_t action,
-		            const char *category){
-  SIMIX_set_category(action, category);
-}
-void SIMIX_set_category(smx_action_t action, const char *category)
+/**
+ * \brief Function to destroy a SIMIX VM host.
+ *
+ * \param host the vm host to destroy (a smx_host_t)
+ */
+void SIMIX_vm_destroy(smx_host_t ind_vm)
 {
-  if (action->state != SIMIX_RUNNING) return;
-  if (action->type == SIMIX_ACTION_EXECUTE){
-    surf_workstation_model->set_category(action->execution.surf_exec, category);
-  }else if (action->type == SIMIX_ACTION_COMMUNICATE){
-    surf_workstation_model->set_category(action->comm.surf_comm, category);
-  }
-}
-#endif
+  /* this code basically performs a similar thing like SIMIX_host_destroy() */
+
+  xbt_assert((ind_vm != NULL), "Invalid parameters");
+  const char *hostname = SIMIX_host_get_name(ind_vm);
+
+  XBT_DEBUG("destroy %s", hostname);
 
+  /* this will call the registered callback function, i.e., SIMIX_host_destroy().  */
+  xbt_lib_unset(host_lib, hostname, SIMIX_HOST_LEVEL, 1);
+
+  /* jump to vm_ws_destroy(). The surf level resource will be freed. */
+  surf_vm_workstation_destroy(ind_vm);
+}