palacios/src/palacios/vmm_scheduler.c

   1 /*
   2  * This file is part of the Palacios Virtual Machine Monitor developed
   3  * by the V3VEE Project with funding from the United States National
   4  * Science Foundation and the Department of Energy.
   5  *
   6  * The V3VEE Project is a joint project between Northwestern University
   7  * and the University of New Mexico.  You can find out more at
   8  * http://www.v3vee.org
   9  *
  10  * Copyright (c) 2013, Oscar Mondragon <omondrag@cs.unm.edu>
  11  * Copyright (c) 2013, Patrick G. Bridges <bridges@cs.unm.edu>
  12  * Copyright (c) 2013, The V3VEE Project <http://www.v3vee.org>
  13  * All rights reserved.
  14  *
  15  * Author: Oscar Mondragon <omondrag@cs.unm.edu>
  16  *         Patrick G. Bridges <bridges@cs.unm.edu>
  17  *
  18  * This is free software.  You are permitted to use,
  19  * redistribute, and modify it as specified in the file "V3VEE_LICENSE".
  20  */
  21
  22 #include <palacios/vmm.h>
  23 #include <palacios/vm_guest.h>
  24 #include <palacios/vmm_scheduler.h>
  25 #include <palacios/vmm_hashtable.h>
  26
  27 #ifndef V3_CONFIG_DEBUG_SCHEDULER
  28 #undef PrintDebug
  29 #define PrintDebug(fmt, args...)
  30 #endif
  31
  32 static char default_strategy[] = "host";
  33 static struct hashtable * master_scheduler_table = NULL;
  34 static int create_host_scheduler();
  35 static int destroy_host_scheduler();
  36
  37 static struct vm_scheduler_impl *scheduler = NULL;
  38
  39 static uint_t scheduler_hash_fn(addr_t key) {
  40     char * name = (char *)key;
  41     return v3_hash_buffer((uint8_t *)name, strlen(name));
  42 }
  43
  44 static int scheduler_eq_fn(addr_t key1, addr_t key2) {
  45     char * name1 = (char *)key1;
  46     char * name2 = (char *)key2;
  47
  48     return (strcmp(name1, name2) == 0);
  49 }
  50
  51 int V3_init_scheduling() {
  52
  53      PrintDebug(VM_NONE, VCORE_NONE,"Initializing scheduler");
  54
  55     master_scheduler_table = v3_create_htable(0, scheduler_hash_fn, scheduler_eq_fn);
  56     return create_host_scheduler();
  57 }
  58
  59 int V3_deinit_scheduling()
  60 {
  61     destroy_host_scheduler();
  62     v3_free_htable(master_scheduler_table,1,1);
  63     return 0;
  64 }
  65
  66
  67 int v3_register_scheduler(struct vm_scheduler_impl *s) {
  68
  69     PrintDebug(VM_NONE, VCORE_NONE,"Registering Scheduler (%s)\n", s->name);
  70
  71     if (v3_htable_search(master_scheduler_table, (addr_t)(s->name))) {
  72         PrintError(VM_NONE, VCORE_NONE, "Multiple instances of scheduler (%s)\n", s->name);
  73         return -1;
  74     }
  75
  76     if (v3_htable_insert(master_scheduler_table,
  77                          (addr_t)(s->name),
  78                          (addr_t)(s)) == 0) {
  79         PrintError(VM_NONE, VCORE_NONE, "Could not register scheduler (%s)\n", s->name);
  80         return -1;
  81     }
  82
  83     return 0;
  84 }
  85
  86
  87 struct vm_scheduler_impl *v3_unregister_scheduler(char *name) {
  88
  89     PrintDebug(VM_NONE, VCORE_NONE,"Unregistering Scheduler (%s)\n",name);
  90
  91     struct vm_scheduler_impl *f = (struct vm_scheduler_impl *) v3_htable_remove(master_scheduler_table,(addr_t)(name),0);
  92
  93     if (!f) {
  94        PrintError(VM_NONE,VCORE_NONE,"Could not find Scheduler (%s)\n",name);
  95        return NULL;
  96     } else {
  97        return f;
  98     }
  99 }
 100
 101
 102
 103
 104 struct vm_scheduler_impl *v3_scheduler_lookup(char *name)
 105 {
 106     return (struct vm_scheduler_impl *)v3_htable_search(master_scheduler_table, (addr_t)(name));
 107 }
 108
 109 int V3_enable_scheduler() {
 110     char *sched_name;
 111
 112     scheduler = NULL;
 113     sched_name = v3_lookup_option("scheduler");
 114
 115     if (sched_name) {
 116         scheduler = v3_scheduler_lookup(sched_name);
 117     }
 118
 119     if (!scheduler) {
 120         scheduler = v3_scheduler_lookup(default_strategy);
 121     }
 122
 123     if (!scheduler) {
 124         PrintError(VM_NONE, VCORE_NONE,"Specified Palacios scheduler \"%s\" not found.\n", default_strategy);
 125         return -1;
 126     }
 127
 128     PrintDebug(VM_NONE, VCORE_NONE,"Scheduler %s found",scheduler->name);
 129
 130     if (scheduler->init) {
 131         return scheduler->init();
 132     } else {
 133         return 0;
 134     }
 135 }
 136
 137 int V3_disable_scheduler()
 138 {
 139     if (scheduler->deinit) {
 140        return scheduler->deinit();
 141     } else {
 142        return 0;
 143     }
 144 }
 145
 146 int v3_scheduler_register_vm(struct v3_vm_info *vm) {
 147     if (scheduler->vm_init) {
 148         return scheduler->vm_init(vm);
 149     } else {
 150         return 0;
 151     }
 152 }
 153 int v3_scheduler_register_core(struct guest_info *core) {
 154     if (scheduler->core_init) {
 155         return scheduler->core_init(core);
 156     } else {
 157         return 0;
 158     }
 159 }
 160 int v3_scheduler_admit_vm(struct v3_vm_info *vm) {
 161     if (scheduler->admit) {
 162         return scheduler->admit(vm);
 163     } else {
 164         return 0;
 165     }
 166 }
 167 int v3_scheduler_notify_remap(struct v3_vm_info *vm) {
 168     if (scheduler->remap) {
 169         return scheduler->remap(vm);
 170     } else {
 171         return 0;
 172     }
 173 }
 174 int v3_scheduler_notify_dvfs(struct v3_vm_info *vm) {
 175     if (scheduler->dvfs) {
 176         return scheduler->dvfs(vm);
 177     } else {
 178         return 0;
 179     }
 180 }
 181 void v3_schedule(struct guest_info *core) {
 182     if (scheduler->schedule) {
 183         scheduler->schedule(core);
 184     }
 185     return;
 186 }
 187 void v3_yield(struct guest_info *core, int usec) {
 188     if (scheduler->yield) {
 189         scheduler->yield(core, usec);
 190     }
 191     return;
 192 }
 193
 194 int host_sched_vm_init(struct v3_vm_info *vm)
 195 {
 196
 197     PrintDebug(vm, VCORE_NONE,"Sched. host_sched_init\n");
 198
 199     char * schedule_hz_str = v3_cfg_val(vm->cfg_data->cfg, "schedule_hz");
 200     uint32_t sched_hz = 100;
 201
 202
 203     if (schedule_hz_str) {
 204         sched_hz = atoi(schedule_hz_str);
 205     }
 206
 207     PrintDebug(vm, VCORE_NONE,"CPU_KHZ = %d, schedule_freq=%p\n", V3_CPU_KHZ(),
 208                (void *)(addr_t)sched_hz);
 209
 210     uint64_t yield_cycle_period = (V3_CPU_KHZ() * 1000) / sched_hz;
 211     vm->sched_priv_data = (void *)yield_cycle_period;
 212
 213     return 0;
 214 }
 215
 216 int host_sched_core_init(struct guest_info *core)
 217 {
 218     PrintDebug(core->vm_info, core,"Sched. host_sched_core_init\n");
 219
 220     uint64_t t = v3_get_host_time(&core->time_state);
 221     core->sched_priv_data = (void *)t;
 222
 223     return 0;
 224 }
 225
 226 int host_sched_core_stop(struct guest_info *core){
 227
 228     v3_yield(NULL,-1);
 229     return 0;
 230 }
 231
 232
 233 void host_sched_schedule(struct guest_info *core)
 234 {
 235     uint64_t cur_cycle;
 236     cur_cycle = v3_get_host_time(&core->time_state);
 237
 238     if (cur_cycle > ( (uint64_t)core->sched_priv_data + (uint64_t)core->vm_info->sched_priv_data)) {
 239
 240         V3_Yield();
 241
 242 #if 0
 243         uint64_t yield_start_cycle = (uint64_t) core->sched_priv_data;
 244         yield_start_cycle +=  (uint64_t)core->vm_info->sched_priv_data;
 245         core->sched_priv_data = (void *)yield_start_cycle;
 246 #else
 247         core->sched_priv_data = (void*)v3_get_host_time(&(core->time_state));
 248 #endif
 249
 250     }
 251 }
 252
 253 /*
 254  * unconditional cpu yield
 255  * if the yielding thread is a guest context, the guest quantum is reset on resumption
 256  * Non guest context threads should call this function with a NULL argument
 257  *
 258  * usec <0  => the non-timed yield is used
 259  * usec >=0 => the timed yield is used, which also usually implies interruptible
 260  */
 261 void host_sched_yield(struct guest_info * core, int usec) {
 262     if (usec < 0) {
 263         V3_Yield();
 264     } else {
 265         V3_Sleep(usec);
 266     }
 267     if (core){
 268 #if 0
 269     uint64_t yield_start_cycle;
 270          yield_start_cycle = (uint64_t) core->sched_priv_data
 271                              + (uint64_t)core->vm_info->sched_priv_data;
 272          core->sched_priv_data = (void *)yield_start_cycle;
 273 #else
 274         core->sched_priv_data = (void*)v3_get_host_time(&(core->time_state));
 275 #endif
 276     }
 277 }
 278
 279
 280 int host_sched_admit(struct v3_vm_info *vm){
 281     return 0;
 282 }
 283
 284 int v3_scheduler_free_vm(struct v3_vm_info *vm) {
 285     if (scheduler->vm_deinit) {
 286         return scheduler->vm_deinit(vm);
 287     } else {
 288         return 0;
 289     }
 290 }
 291
 292 int v3_scheduler_free_core(struct guest_info *core) {
 293     if (scheduler->core_deinit) {
 294         return scheduler->core_deinit(core);
 295     } else {
 296         return 0;
 297     }
 298 }
 299
 300
 301 int v3_scheduler_stop_core(struct guest_info *core){
 302     if (scheduler->core_stop) {
 303         return scheduler->core_stop(core);
 304     } else {
 305         return 0;
 306     }
 307 }
 308
 309 static struct vm_scheduler_impl host_sched_impl = {
 310     .name = "host",
 311     .init = NULL,
 312     .deinit = NULL,
 313     .vm_init = host_sched_vm_init,
 314     .vm_deinit = NULL,
 315     .core_init = host_sched_core_init,
 316     .core_stop = host_sched_core_stop,
 317     .core_deinit = NULL,
 318     .schedule = host_sched_schedule,
 319     .yield = host_sched_yield,
 320     .admit = host_sched_admit,
 321     .remap = NULL,
 322     .dvfs=NULL
 323 };
 324
 325 static int create_host_scheduler()
 326 {
 327         v3_register_scheduler(&host_sched_impl);
 328         return 0;
 329 }
 330
 331 static int destroy_host_scheduler()
 332 {
 333        v3_unregister_scheduler(host_sched_impl.name);
 334        return 0;
 335 }