block/qapi-sysemu.c

   1 /*
   2  * QMP command handlers specific to the system emulators
   3  *
   4  * Copyright (c) 2003-2008 Fabrice Bellard
   5  *
   6  * This work is licensed under the terms of the GNU GPL, version 2 or
   7  * later.  See the COPYING file in the top-level directory.
   8  *
   9  * This file incorporates work covered by the following copyright and
  10  * permission notice:
  11  *
  12  * Copyright (c) 2003-2008 Fabrice Bellard
  13  *
  14  * Permission is hereby granted, free of charge, to any person obtaining a copy
  15  * of this software and associated documentation files (the "Software"), to deal
  16  * in the Software without restriction, including without limitation the rights
  17  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  18  * copies of the Software, and to permit persons to whom the Software is
  19  * furnished to do so, subject to the following conditions:
  20  *
  21  * The above copyright notice and this permission notice shall be included in
  22  * all copies or substantial portions of the Software.
  23  *
  24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  25  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  26  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  27  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  28  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  29  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  30  * THE SOFTWARE.
  31  */
  32
  33 #include "qemu/osdep.h"
  34
  35 #include "qapi/error.h"
  36 #include "qapi/qapi-commands-block.h"
  37 #include "qapi/qmp/qdict.h"
  38 #include "sysemu/block-backend.h"
  39 #include "sysemu/blockdev.h"
  40
  41 static BlockBackend *qmp_get_blk(const char *blk_name, const char *qdev_id,
  42                                  Error **errp)
  43 {
  44     BlockBackend *blk;
  45
  46     if (!blk_name == !qdev_id) {
  47         error_setg(errp, "Need exactly one of 'device' and 'id'");
  48         return NULL;
  49     }
  50
  51     if (qdev_id) {
  52         blk = blk_by_qdev_id(qdev_id, errp);
  53     } else {
  54         blk = blk_by_name(blk_name);
  55         if (blk == NULL) {
  56             error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
  57                       "Device '%s' not found", blk_name);
  58         }
  59     }
  60
  61     return blk;
  62 }
  63
  64 /*
  65  * Attempt to open the tray of @device.
  66  * If @force, ignore its tray lock.
  67  * Else, if the tray is locked, don't open it, but ask the guest to open it.
  68  * On error, store an error through @errp and return -errno.
  69  * If @device does not exist, return -ENODEV.
  70  * If it has no removable media, return -ENOTSUP.
  71  * If it has no tray, return -ENOSYS.
  72  * If the guest was asked to open the tray, return -EINPROGRESS.
  73  * Else, return 0.
  74  */
  75 static int do_open_tray(const char *blk_name, const char *qdev_id,
  76                         bool force, Error **errp)
  77 {
  78     BlockBackend *blk;
  79     const char *device = qdev_id ?: blk_name;
  80     bool locked;
  81
  82     blk = qmp_get_blk(blk_name, qdev_id, errp);
  83     if (!blk) {
  84         return -ENODEV;
  85     }
  86
  87     if (!blk_dev_has_removable_media(blk)) {
  88         error_setg(errp, "Device '%s' is not removable", device);
  89         return -ENOTSUP;
  90     }
  91
  92     if (!blk_dev_has_tray(blk)) {
  93         error_setg(errp, "Device '%s' does not have a tray", device);
  94         return -ENOSYS;
  95     }
  96
  97     if (blk_dev_is_tray_open(blk)) {
  98         return 0;
  99     }
 100
 101     locked = blk_dev_is_medium_locked(blk);
 102     if (locked) {
 103         blk_dev_eject_request(blk, force);
 104     }
 105
 106     if (!locked || force) {
 107         blk_dev_change_media_cb(blk, false, &error_abort);
 108     }
 109
 110     if (locked && !force) {
 111         error_setg(errp, "Device '%s' is locked and force was not specified, "
 112                    "wait for tray to open and try again", device);
 113         return -EINPROGRESS;
 114     }
 115
 116     return 0;
 117 }
 118
 119 void qmp_blockdev_open_tray(bool has_device, const char *device,
 120                             bool has_id, const char *id,
 121                             bool has_force, bool force,
 122                             Error **errp)
 123 {
 124     Error *local_err = NULL;
 125     int rc;
 126
 127     if (!has_force) {
 128         force = false;
 129     }
 130     rc = do_open_tray(has_device ? device : NULL,
 131                       has_id ? id : NULL,
 132                       force, &local_err);
 133     if (rc && rc != -ENOSYS && rc != -EINPROGRESS) {
 134         error_propagate(errp, local_err);
 135         return;
 136     }
 137     error_free(local_err);
 138 }
 139
 140 void qmp_blockdev_close_tray(bool has_device, const char *device,
 141                              bool has_id, const char *id,
 142                              Error **errp)
 143 {
 144     BlockBackend *blk;
 145     Error *local_err = NULL;
 146
 147     device = has_device ? device : NULL;
 148     id = has_id ? id : NULL;
 149
 150     blk = qmp_get_blk(device, id, errp);
 151     if (!blk) {
 152         return;
 153     }
 154
 155     if (!blk_dev_has_removable_media(blk)) {
 156         error_setg(errp, "Device '%s' is not removable", device ?: id);
 157         return;
 158     }
 159
 160     if (!blk_dev_has_tray(blk)) {
 161         /* Ignore this command on tray-less devices */
 162         return;
 163     }
 164
 165     if (!blk_dev_is_tray_open(blk)) {
 166         return;
 167     }
 168
 169     blk_dev_change_media_cb(blk, true, &local_err);
 170     if (local_err) {
 171         error_propagate(errp, local_err);
 172         return;
 173     }
 174 }
 175
 176 static void blockdev_remove_medium(bool has_device, const char *device,
 177                                    bool has_id, const char *id, Error **errp)
 178 {
 179     BlockBackend *blk;
 180     BlockDriverState *bs;
 181     AioContext *aio_context;
 182     bool has_attached_device;
 183
 184     device = has_device ? device : NULL;
 185     id = has_id ? id : NULL;
 186
 187     blk = qmp_get_blk(device, id, errp);
 188     if (!blk) {
 189         return;
 190     }
 191
 192     /* For BBs without a device, we can exchange the BDS tree at will */
 193     has_attached_device = blk_get_attached_dev(blk);
 194
 195     if (has_attached_device && !blk_dev_has_removable_media(blk)) {
 196         error_setg(errp, "Device '%s' is not removable", device ?: id);
 197         return;
 198     }
 199
 200     if (has_attached_device && blk_dev_has_tray(blk) &&
 201         !blk_dev_is_tray_open(blk))
 202     {
 203         error_setg(errp, "Tray of device '%s' is not open", device ?: id);
 204         return;
 205     }
 206
 207     bs = blk_bs(blk);
 208     if (!bs) {
 209         return;
 210     }
 211
 212     aio_context = bdrv_get_aio_context(bs);
 213     aio_context_acquire(aio_context);
 214
 215     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_EJECT, errp)) {
 216         goto out;
 217     }
 218
 219     blk_remove_bs(blk);
 220
 221     if (!blk_dev_has_tray(blk)) {
 222         /* For tray-less devices, blockdev-open-tray is a no-op (or may not be
 223          * called at all); therefore, the medium needs to be ejected here.
 224          * Do it after blk_remove_bs() so blk_is_inserted(blk) returns the @load
 225          * value passed here (i.e. false). */
 226         blk_dev_change_media_cb(blk, false, &error_abort);
 227     }
 228
 229 out:
 230     aio_context_release(aio_context);
 231 }
 232
 233 void qmp_blockdev_remove_medium(const char *id, Error **errp)
 234 {
 235     blockdev_remove_medium(false, NULL, true, id, errp);
 236 }
 237
 238 static void qmp_blockdev_insert_anon_medium(BlockBackend *blk,
 239                                             BlockDriverState *bs, Error **errp)
 240 {
 241     Error *local_err = NULL;
 242     bool has_device;
 243     int ret;
 244
 245     /* For BBs without a device, we can exchange the BDS tree at will */
 246     has_device = blk_get_attached_dev(blk);
 247
 248     if (has_device && !blk_dev_has_removable_media(blk)) {
 249         error_setg(errp, "Device is not removable");
 250         return;
 251     }
 252
 253     if (has_device && blk_dev_has_tray(blk) && !blk_dev_is_tray_open(blk)) {
 254         error_setg(errp, "Tray of the device is not open");
 255         return;
 256     }
 257
 258     if (blk_bs(blk)) {
 259         error_setg(errp, "There already is a medium in the device");
 260         return;
 261     }
 262
 263     ret = blk_insert_bs(blk, bs, errp);
 264     if (ret < 0) {
 265         return;
 266     }
 267
 268     if (!blk_dev_has_tray(blk)) {
 269         /* For tray-less devices, blockdev-close-tray is a no-op (or may not be
 270          * called at all); therefore, the medium needs to be pushed into the
 271          * slot here.
 272          * Do it after blk_insert_bs() so blk_is_inserted(blk) returns the @load
 273          * value passed here (i.e. true). */
 274         blk_dev_change_media_cb(blk, true, &local_err);
 275         if (local_err) {
 276             error_propagate(errp, local_err);
 277             blk_remove_bs(blk);
 278             return;
 279         }
 280     }
 281 }
 282
 283 static void blockdev_insert_medium(bool has_device, const char *device,
 284                                    bool has_id, const char *id,
 285                                    const char *node_name, Error **errp)
 286 {
 287     BlockBackend *blk;
 288     BlockDriverState *bs;
 289
 290     blk = qmp_get_blk(has_device ? device : NULL,
 291                       has_id ? id : NULL,
 292                       errp);
 293     if (!blk) {
 294         return;
 295     }
 296
 297     bs = bdrv_find_node(node_name);
 298     if (!bs) {
 299         error_setg(errp, "Node '%s' not found", node_name);
 300         return;
 301     }
 302
 303     if (bdrv_has_blk(bs)) {
 304         error_setg(errp, "Node '%s' is already in use", node_name);
 305         return;
 306     }
 307
 308     qmp_blockdev_insert_anon_medium(blk, bs, errp);
 309 }
 310
 311 void qmp_blockdev_insert_medium(const char *id, const char *node_name,
 312                                 Error **errp)
 313 {
 314     blockdev_insert_medium(false, NULL, true, id, node_name, errp);
 315 }
 316
 317 void qmp_blockdev_change_medium(bool has_device, const char *device,
 318                                 bool has_id, const char *id,
 319                                 const char *filename,
 320                                 bool has_format, const char *format,
 321                                 bool has_read_only,
 322                                 BlockdevChangeReadOnlyMode read_only,
 323                                 Error **errp)
 324 {
 325     BlockBackend *blk;
 326     BlockDriverState *medium_bs = NULL;
 327     int bdrv_flags;
 328     bool detect_zeroes;
 329     int rc;
 330     QDict *options = NULL;
 331     Error *err = NULL;
 332
 333     blk = qmp_get_blk(has_device ? device : NULL,
 334                       has_id ? id : NULL,
 335                       errp);
 336     if (!blk) {
 337         goto fail;
 338     }
 339
 340     if (blk_bs(blk)) {
 341         blk_update_root_state(blk);
 342     }
 343
 344     bdrv_flags = blk_get_open_flags_from_root_state(blk);
 345     bdrv_flags &= ~(BDRV_O_TEMPORARY | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING |
 346         BDRV_O_PROTOCOL | BDRV_O_AUTO_RDONLY);
 347
 348     if (!has_read_only) {
 349         read_only = BLOCKDEV_CHANGE_READ_ONLY_MODE_RETAIN;
 350     }
 351
 352     switch (read_only) {
 353     case BLOCKDEV_CHANGE_READ_ONLY_MODE_RETAIN:
 354         break;
 355
 356     case BLOCKDEV_CHANGE_READ_ONLY_MODE_READ_ONLY:
 357         bdrv_flags &= ~BDRV_O_RDWR;
 358         break;
 359
 360     case BLOCKDEV_CHANGE_READ_ONLY_MODE_READ_WRITE:
 361         bdrv_flags |= BDRV_O_RDWR;
 362         break;
 363
 364     default:
 365         abort();
 366     }
 367
 368     options = qdict_new();
 369     detect_zeroes = blk_get_detect_zeroes_from_root_state(blk);
 370     qdict_put_str(options, "detect-zeroes", detect_zeroes ? "on" : "off");
 371
 372     if (has_format) {
 373         qdict_put_str(options, "driver", format);
 374     }
 375
 376     medium_bs = bdrv_open(filename, NULL, options, bdrv_flags, errp);
 377     if (!medium_bs) {
 378         goto fail;
 379     }
 380
 381     rc = do_open_tray(has_device ? device : NULL,
 382                       has_id ? id : NULL,
 383                       false, &err);
 384     if (rc && rc != -ENOSYS) {
 385         error_propagate(errp, err);
 386         goto fail;
 387     }
 388     error_free(err);
 389     err = NULL;
 390
 391     blockdev_remove_medium(has_device, device, has_id, id, &err);
 392     if (err) {
 393         error_propagate(errp, err);
 394         goto fail;
 395     }
 396
 397     qmp_blockdev_insert_anon_medium(blk, medium_bs, &err);
 398     if (err) {
 399         error_propagate(errp, err);
 400         goto fail;
 401     }
 402
 403     qmp_blockdev_close_tray(has_device, device, has_id, id, errp);
 404
 405 fail:
 406     /* If the medium has been inserted, the device has its own reference, so
 407      * ours must be relinquished; and if it has not been inserted successfully,
 408      * the reference must be relinquished anyway */
 409     bdrv_unref(medium_bs);
 410 }
 411
 412 void qmp_eject(bool has_device, const char *device,
 413                bool has_id, const char *id,
 414                bool has_force, bool force, Error **errp)
 415 {
 416     Error *local_err = NULL;
 417     int rc;
 418
 419     if (!has_force) {
 420         force = false;
 421     }
 422
 423     rc = do_open_tray(has_device ? device : NULL,
 424                       has_id ? id : NULL,
 425                       force, &local_err);
 426     if (rc && rc != -ENOSYS) {
 427         error_propagate(errp, local_err);
 428         return;
 429     }
 430     error_free(local_err);
 431
 432     blockdev_remove_medium(has_device, device, has_id, id, errp);
 433 }
 434
 435 /* throttling disk I/O limits */
 436 void qmp_block_set_io_throttle(BlockIOThrottle *arg, Error **errp)
 437 {
 438     ThrottleConfig cfg;
 439     BlockDriverState *bs;
 440     BlockBackend *blk;
 441     AioContext *aio_context;
 442
 443     blk = qmp_get_blk(arg->has_device ? arg->device : NULL,
 444                       arg->has_id ? arg->id : NULL,
 445                       errp);
 446     if (!blk) {
 447         return;
 448     }
 449
 450     aio_context = blk_get_aio_context(blk);
 451     aio_context_acquire(aio_context);
 452
 453     bs = blk_bs(blk);
 454     if (!bs) {
 455         error_setg(errp, "Device has no medium");
 456         goto out;
 457     }
 458
 459     throttle_config_init(&cfg);
 460     cfg.buckets[THROTTLE_BPS_TOTAL].avg = arg->bps;
 461     cfg.buckets[THROTTLE_BPS_READ].avg  = arg->bps_rd;
 462     cfg.buckets[THROTTLE_BPS_WRITE].avg = arg->bps_wr;
 463
 464     cfg.buckets[THROTTLE_OPS_TOTAL].avg = arg->iops;
 465     cfg.buckets[THROTTLE_OPS_READ].avg  = arg->iops_rd;
 466     cfg.buckets[THROTTLE_OPS_WRITE].avg = arg->iops_wr;
 467
 468     if (arg->has_bps_max) {
 469         cfg.buckets[THROTTLE_BPS_TOTAL].max = arg->bps_max;
 470     }
 471     if (arg->has_bps_rd_max) {
 472         cfg.buckets[THROTTLE_BPS_READ].max = arg->bps_rd_max;
 473     }
 474     if (arg->has_bps_wr_max) {
 475         cfg.buckets[THROTTLE_BPS_WRITE].max = arg->bps_wr_max;
 476     }
 477     if (arg->has_iops_max) {
 478         cfg.buckets[THROTTLE_OPS_TOTAL].max = arg->iops_max;
 479     }
 480     if (arg->has_iops_rd_max) {
 481         cfg.buckets[THROTTLE_OPS_READ].max = arg->iops_rd_max;
 482     }
 483     if (arg->has_iops_wr_max) {
 484         cfg.buckets[THROTTLE_OPS_WRITE].max = arg->iops_wr_max;
 485     }
 486
 487     if (arg->has_bps_max_length) {
 488         cfg.buckets[THROTTLE_BPS_TOTAL].burst_length = arg->bps_max_length;
 489     }
 490     if (arg->has_bps_rd_max_length) {
 491         cfg.buckets[THROTTLE_BPS_READ].burst_length = arg->bps_rd_max_length;
 492     }
 493     if (arg->has_bps_wr_max_length) {
 494         cfg.buckets[THROTTLE_BPS_WRITE].burst_length = arg->bps_wr_max_length;
 495     }
 496     if (arg->has_iops_max_length) {
 497         cfg.buckets[THROTTLE_OPS_TOTAL].burst_length = arg->iops_max_length;
 498     }
 499     if (arg->has_iops_rd_max_length) {
 500         cfg.buckets[THROTTLE_OPS_READ].burst_length = arg->iops_rd_max_length;
 501     }
 502     if (arg->has_iops_wr_max_length) {
 503         cfg.buckets[THROTTLE_OPS_WRITE].burst_length = arg->iops_wr_max_length;
 504     }
 505
 506     if (arg->has_iops_size) {
 507         cfg.op_size = arg->iops_size;
 508     }
 509
 510     if (!throttle_is_valid(&cfg, errp)) {
 511         goto out;
 512     }
 513
 514     if (throttle_enabled(&cfg)) {
 515         /* Enable I/O limits if they're not enabled yet, otherwise
 516          * just update the throttling group. */
 517         if (!blk_get_public(blk)->throttle_group_member.throttle_state) {
 518             blk_io_limits_enable(blk,
 519                                  arg->has_group ? arg->group :
 520                                  arg->has_device ? arg->device :
 521                                  arg->id);
 522         } else if (arg->has_group) {
 523             blk_io_limits_update_group(blk, arg->group);
 524         }
 525         /* Set the new throttling configuration */
 526         blk_set_io_limits(blk, &cfg);
 527     } else if (blk_get_public(blk)->throttle_group_member.throttle_state) {
 528         /* If all throttling settings are set to 0, disable I/O limits */
 529         blk_io_limits_disable(blk);
 530     }
 531
 532 out:
 533     aio_context_release(aio_context);
 534 }
 535
 536 void qmp_block_latency_histogram_set(
 537     const char *id,
 538     bool has_boundaries, uint64List *boundaries,
 539     bool has_boundaries_read, uint64List *boundaries_read,
 540     bool has_boundaries_write, uint64List *boundaries_write,
 541     bool has_boundaries_flush, uint64List *boundaries_flush,
 542     Error **errp)
 543 {
 544     BlockBackend *blk = qmp_get_blk(NULL, id, errp);
 545     BlockAcctStats *stats;
 546     int ret;
 547
 548     if (!blk) {
 549         return;
 550     }
 551
 552     stats = blk_get_stats(blk);
 553
 554     if (!has_boundaries && !has_boundaries_read && !has_boundaries_write &&
 555         !has_boundaries_flush)
 556     {
 557         block_latency_histograms_clear(stats);
 558         return;
 559     }
 560
 561     if (has_boundaries || has_boundaries_read) {
 562         ret = block_latency_histogram_set(
 563             stats, BLOCK_ACCT_READ,
 564             has_boundaries_read ? boundaries_read : boundaries);
 565         if (ret) {
 566             error_setg(errp, "Device '%s' set read boundaries fail", id);
 567             return;
 568         }
 569     }
 570
 571     if (has_boundaries || has_boundaries_write) {
 572         ret = block_latency_histogram_set(
 573             stats, BLOCK_ACCT_WRITE,
 574             has_boundaries_write ? boundaries_write : boundaries);
 575         if (ret) {
 576             error_setg(errp, "Device '%s' set write boundaries fail", id);
 577             return;
 578         }
 579     }
 580
 581     if (has_boundaries || has_boundaries_flush) {
 582         ret = block_latency_histogram_set(
 583             stats, BLOCK_ACCT_FLUSH,
 584             has_boundaries_flush ? boundaries_flush : boundaries);
 585         if (ret) {
 586             error_setg(errp, "Device '%s' set flush boundaries fail", id);
 587             return;
 588         }
 589     }
 590 }