examples/vhost_scsi/vhost_scsi.c

   1 /*-
   2  *   BSD LICENSE
   3  *
   4  *   Copyright(c) 2010-2017 Intel Corporation. All rights reserved.
   5  *   All rights reserved.
   6  *
   7  *   Redistribution and use in source and binary forms, with or without
   8  *   modification, are permitted provided that the following conditions
   9  *   are met:
  10  *
  11  *     * Redistributions of source code must retain the above copyright
  12  *       notice, this list of conditions and the following disclaimer.
  13  *     * Redistributions in binary form must reproduce the above copyright
  14  *       notice, this list of conditions and the following disclaimer in
  15  *       the documentation and/or other materials provided with the
  16  *       distribution.
  17  *     * Neither the name of Intel Corporation nor the names of its
  18  *       contributors may be used to endorse or promote products derived
  19  *       from this software without specific prior written permission.
  20  *
  21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 #include <stdint.h>
  35 #include <unistd.h>
  36 #include <stdbool.h>
  37 #include <signal.h>
  38 #include <assert.h>
  39 #include <semaphore.h>
  40 #include <linux/virtio_scsi.h>
  41 #include <linux/virtio_ring.h>
  42
  43 #include <rte_atomic.h>
  44 #include <rte_cycles.h>
  45 #include <rte_log.h>
  46 #include <rte_malloc.h>
  47 #include <rte_vhost.h>
  48
  49 #include "vhost_scsi.h"
  50 #include "scsi_spec.h"
  51
  52 #define VIRTIO_SCSI_FEATURES ((1 << VIRTIO_F_NOTIFY_ON_EMPTY) |\
  53                               (1 << VIRTIO_RING_F_EVENT_IDX) |\
  54                               (1 << VIRTIO_SCSI_F_INOUT) |\
  55                               (1 << VIRTIO_SCSI_F_CHANGE))
  56
  57 /* Path to folder where character device will be created. Can be set by user. */
  58 static char dev_pathname[PATH_MAX] = "";
  59
  60 static struct vhost_scsi_ctrlr *g_vhost_ctrlr;
  61 static int g_should_stop;
  62 static sem_t exit_sem;
  63
  64 static struct vhost_scsi_ctrlr *
  65 vhost_scsi_ctrlr_find(__rte_unused const char *ctrlr_name)
  66 {
  67         /* currently we only support 1 socket file fd */
  68         return g_vhost_ctrlr;
  69 }
  70
  71 static uint64_t gpa_to_vva(int vid, uint64_t gpa, uint64_t *len)
  72 {
  73         char path[PATH_MAX];
  74         struct vhost_scsi_ctrlr *ctrlr;
  75         int ret = 0;
  76
  77         ret = rte_vhost_get_ifname(vid, path, PATH_MAX);
  78         if (ret) {
  79                 fprintf(stderr, "Cannot get socket name\n");
  80                 assert(ret != 0);
  81         }
  82
  83         ctrlr = vhost_scsi_ctrlr_find(path);
  84         if (!ctrlr) {
  85                 fprintf(stderr, "Controller is not ready\n");
  86                 assert(ctrlr != NULL);
  87         }
  88
  89         assert(ctrlr->mem != NULL);
  90
  91         return rte_vhost_va_from_guest_pa(ctrlr->mem, gpa, len);
  92 }
  93
  94 static struct vring_desc *
  95 descriptor_get_next(struct vring_desc *vq_desc, struct vring_desc *cur_desc)
  96 {
  97         return &vq_desc[cur_desc->next];
  98 }
  99
 100 static bool
 101 descriptor_has_next(struct vring_desc *cur_desc)
 102 {
 103         return !!(cur_desc->flags & VRING_DESC_F_NEXT);
 104 }
 105
 106 static bool
 107 descriptor_is_wr(struct vring_desc *cur_desc)
 108 {
 109         return !!(cur_desc->flags & VRING_DESC_F_WRITE);
 110 }
 111
 112 static void
 113 submit_completion(struct vhost_scsi_task *task)
 114 {
 115         struct rte_vhost_vring *vq;
 116         struct vring_used *used;
 117
 118         vq = task->vq;
 119         used = vq->used;
 120         /* Fill out the next entry in the "used" ring.  id = the
 121          * index of the descriptor that contained the SCSI request.
 122          * len = the total amount of data transferred for the SCSI
 123          * request. We must report the correct len, for variable
 124          * length SCSI CDBs, where we may return less data than
 125          * allocated by the guest VM.
 126          */
 127         used->ring[used->idx & (vq->size - 1)].id = task->req_idx;
 128         used->ring[used->idx & (vq->size - 1)].len = task->data_len;
 129         used->idx++;
 130
 131         /* Send an interrupt back to the guest VM so that it knows
 132          * a completion is ready to be processed.
 133          */
 134         eventfd_write(vq->callfd, (eventfd_t)1);
 135 }
 136
 137 static void
 138 vhost_process_read_payload_chain(struct vhost_scsi_task *task)
 139 {
 140         void *data;
 141         uint64_t chunck_len;
 142
 143         task->iovs_cnt = 0;
 144         chunck_len = task->desc->len;
 145         task->resp = (void *)(uintptr_t)gpa_to_vva(task->bdev->vid,
 146                                                    task->desc->addr,
 147                                                    &chunck_len);
 148         if (!task->resp || chunck_len != task->desc->len) {
 149                 fprintf(stderr, "failed to translate desc address.\n");
 150                 return;
 151         }
 152
 153         while (descriptor_has_next(task->desc)) {
 154                 task->desc = descriptor_get_next(task->vq->desc, task->desc);
 155                 chunck_len = task->desc->len;
 156                 data = (void *)(uintptr_t)gpa_to_vva(task->bdev->vid,
 157                                                      task->desc->addr,
 158                                                          &chunck_len);
 159                 if (!data || chunck_len != task->desc->len) {
 160                         fprintf(stderr, "failed to translate desc address.\n");
 161                         return;
 162                 }
 163
 164                 task->iovs[task->iovs_cnt].iov_base = data;
 165                 task->iovs[task->iovs_cnt].iov_len = task->desc->len;
 166                 task->data_len += task->desc->len;
 167                 task->iovs_cnt++;
 168         }
 169 }
 170
 171 static void
 172 vhost_process_write_payload_chain(struct vhost_scsi_task *task)
 173 {
 174         void *data;
 175         uint64_t chunck_len;
 176
 177         task->iovs_cnt = 0;
 178
 179         do {
 180                 chunck_len = task->desc->len;
 181                 data = (void *)(uintptr_t)gpa_to_vva(task->bdev->vid,
 182                                                      task->desc->addr,
 183                                                          &chunck_len);
 184                 if (!data || chunck_len != task->desc->len) {
 185                         fprintf(stderr, "failed to translate desc address.\n");
 186                         return;
 187                 }
 188
 189                 task->iovs[task->iovs_cnt].iov_base = data;
 190                 task->iovs[task->iovs_cnt].iov_len = task->desc->len;
 191                 task->data_len += task->desc->len;
 192                 task->iovs_cnt++;
 193                 task->desc = descriptor_get_next(task->vq->desc, task->desc);
 194         } while (descriptor_has_next(task->desc));
 195
 196         chunck_len = task->desc->len;
 197         task->resp = (void *)(uintptr_t)gpa_to_vva(task->bdev->vid,
 198                                                    task->desc->addr,
 199                                                    &chunck_len);
 200         if (!task->resp || chunck_len != task->desc->len)
 201                 fprintf(stderr, "failed to translate desc address.\n");
 202 }
 203
 204 static struct vhost_block_dev *
 205 vhost_scsi_bdev_construct(const char *bdev_name, const char *bdev_serial,
 206                           uint32_t blk_size, uint64_t blk_cnt,
 207                           bool wce_enable)
 208 {
 209         struct vhost_block_dev *bdev;
 210
 211         bdev = rte_zmalloc(NULL, sizeof(*bdev), RTE_CACHE_LINE_SIZE);
 212         if (!bdev)
 213                 return NULL;
 214
 215         strncpy(bdev->name, bdev_name, sizeof(bdev->name));
 216         strncpy(bdev->product_name, bdev_serial, sizeof(bdev->product_name));
 217         bdev->blocklen = blk_size;
 218         bdev->blockcnt = blk_cnt;
 219         bdev->write_cache = wce_enable;
 220
 221         /* use memory as disk storage space */
 222         bdev->data = rte_zmalloc(NULL, blk_cnt * blk_size, 0);
 223         if (!bdev->data) {
 224                 fprintf(stderr, "no enough reseverd huge memory for disk\n");
 225                 return NULL;
 226         }
 227
 228         return bdev;
 229 }
 230
 231 static void
 232 process_requestq(struct vhost_scsi_ctrlr *ctrlr, uint32_t q_idx)
 233 {
 234         int ret;
 235         struct vhost_scsi_queue *scsi_vq;
 236         struct rte_vhost_vring *vq;
 237
 238         scsi_vq = &ctrlr->bdev->queues[q_idx];
 239         vq = &scsi_vq->vq;
 240         ret = rte_vhost_get_vhost_vring(ctrlr->bdev->vid, q_idx, vq);
 241         assert(ret == 0);
 242
 243         while (vq->avail->idx != scsi_vq->last_used_idx) {
 244                 int req_idx;
 245                 uint16_t last_idx;
 246                 struct vhost_scsi_task *task;
 247                 uint64_t chunck_len;
 248
 249                 last_idx = scsi_vq->last_used_idx & (vq->size - 1);
 250                 req_idx = vq->avail->ring[last_idx];
 251
 252                 task = rte_zmalloc(NULL, sizeof(*task), 0);
 253                 assert(task != NULL);
 254
 255                 task->ctrlr = ctrlr;
 256                 task->bdev = ctrlr->bdev;
 257                 task->vq = vq;
 258                 task->req_idx = req_idx;
 259                 task->desc = &task->vq->desc[task->req_idx];
 260
 261                 /* does not support indirect descriptors */
 262                 assert((task->desc->flags & VRING_DESC_F_INDIRECT) == 0);
 263                 scsi_vq->last_used_idx++;
 264
 265                 chunck_len = task->desc->len;
 266                 task->req = (void *)(uintptr_t)gpa_to_vva(task->bdev->vid,
 267                                                           task->desc->addr,
 268                                                           &chunck_len);
 269                 if (!task->req || chunck_len != task->desc->len) {
 270                         fprintf(stderr, "failed to translate desc address.\n");
 271                         return;
 272                 }
 273
 274                 task->desc = descriptor_get_next(task->vq->desc, task->desc);
 275                 if (!descriptor_has_next(task->desc)) {
 276                         task->dxfer_dir = SCSI_DIR_NONE;
 277                         chunck_len = task->desc->len;
 278                         task->resp = (void *)(uintptr_t)
 279                                               gpa_to_vva(task->bdev->vid,
 280                                                          task->desc->addr,
 281                                                          &chunck_len);
 282                         if (!task->resp || chunck_len != task->desc->len) {
 283                                 fprintf(stderr, "failed to translate desc address.\n");
 284                                 return;
 285                         }
 286                 } else if (!descriptor_is_wr(task->desc)) {
 287                         task->dxfer_dir = SCSI_DIR_TO_DEV;
 288                         vhost_process_write_payload_chain(task);
 289                 } else {
 290                         task->dxfer_dir = SCSI_DIR_FROM_DEV;
 291                         vhost_process_read_payload_chain(task);
 292                 }
 293
 294                 ret = vhost_bdev_process_scsi_commands(ctrlr->bdev, task);
 295                 if (ret) {
 296                         /* invalid response */
 297                         task->resp->response = VIRTIO_SCSI_S_BAD_TARGET;
 298                 } else {
 299                         /* successfully */
 300                         task->resp->response = VIRTIO_SCSI_S_OK;
 301                         task->resp->status = 0;
 302                         task->resp->resid = 0;
 303                 }
 304                 submit_completion(task);
 305                 rte_free(task);
 306         }
 307 }
 308
 309 /* Main framework for processing IOs */
 310 static void *
 311 ctrlr_worker(void *arg)
 312 {
 313         uint32_t idx, num;
 314         struct vhost_scsi_ctrlr *ctrlr = (struct vhost_scsi_ctrlr *)arg;
 315         cpu_set_t cpuset;
 316         pthread_t thread;
 317
 318         thread = pthread_self();
 319         CPU_ZERO(&cpuset);
 320         CPU_SET(0, &cpuset);
 321         pthread_setaffinity_np(thread, sizeof(cpu_set_t), &cpuset);
 322
 323         num =  rte_vhost_get_vring_num(ctrlr->bdev->vid);
 324         fprintf(stdout, "Ctrlr Worker Thread Started with %u Vring\n", num);
 325
 326         if (num != NUM_OF_SCSI_QUEUES) {
 327                 fprintf(stderr, "Only 1 IO queue are supported\n");
 328                 exit(0);
 329         }
 330
 331         while (!g_should_stop && ctrlr->bdev != NULL) {
 332                 /* At least 3 vrings, currently only can support 1 IO queue
 333                  * Queue 2 for IO queue, does not support TMF and hotplug
 334                  * for the example application now
 335                  */
 336                 for (idx = 2; idx < num; idx++)
 337                         process_requestq(ctrlr, idx);
 338         }
 339
 340         fprintf(stdout, "Ctrlr Worker Thread Exiting\n");
 341         sem_post(&exit_sem);
 342         return NULL;
 343 }
 344
 345 static int
 346 new_device(int vid)
 347 {
 348         char path[PATH_MAX];
 349         struct vhost_scsi_ctrlr *ctrlr;
 350         struct vhost_scsi_queue *scsi_vq;
 351         struct rte_vhost_vring *vq;
 352         pthread_t tid;
 353         int i, ret;
 354
 355         ret = rte_vhost_get_ifname(vid, path, PATH_MAX);
 356         if (ret) {
 357                 fprintf(stderr, "Cannot get socket name\n");
 358                 return -1;
 359         }
 360
 361         ctrlr = vhost_scsi_ctrlr_find(path);
 362         if (!ctrlr) {
 363                 fprintf(stderr, "Controller is not ready\n");
 364                 return -1;
 365         }
 366
 367         ret = rte_vhost_get_mem_table(vid, &ctrlr->mem);
 368         if (ret) {
 369                 fprintf(stderr, "Get Controller memory region failed\n");
 370                 return -1;
 371         }
 372         assert(ctrlr->mem != NULL);
 373
 374         /* hardcoded block device information with 128MiB */
 375         ctrlr->bdev = vhost_scsi_bdev_construct("malloc0", "vhost_scsi_malloc0",
 376                                                 4096, 32768, 0);
 377         if (!ctrlr->bdev)
 378                 return -1;
 379
 380         ctrlr->bdev->vid = vid;
 381
 382         /* Disable Notifications */
 383         for (i = 0; i < NUM_OF_SCSI_QUEUES; i++) {
 384                 rte_vhost_enable_guest_notification(vid, i, 0);
 385                 /* restore used index */
 386                 scsi_vq = &ctrlr->bdev->queues[i];
 387                 vq = &scsi_vq->vq;
 388                 ret = rte_vhost_get_vhost_vring(ctrlr->bdev->vid, i, vq);
 389                 assert(ret == 0);
 390                 scsi_vq->last_used_idx = vq->used->idx;
 391                 scsi_vq->last_avail_idx = vq->used->idx;
 392         }
 393
 394         g_should_stop = 0;
 395         fprintf(stdout, "New Device %s, Device ID %d\n", path, vid);
 396         if (pthread_create(&tid, NULL, &ctrlr_worker, ctrlr) < 0) {
 397                 fprintf(stderr, "Worker Thread Started Failed\n");
 398                 return -1;
 399         }
 400         pthread_detach(tid);
 401         return 0;
 402 }
 403
 404 static void
 405 destroy_device(int vid)
 406 {
 407         char path[PATH_MAX];
 408         struct vhost_scsi_ctrlr *ctrlr;
 409
 410         rte_vhost_get_ifname(vid, path, PATH_MAX);
 411         fprintf(stdout, "Destroy %s Device ID %d\n", path, vid);
 412         ctrlr = vhost_scsi_ctrlr_find(path);
 413         if (!ctrlr) {
 414                 fprintf(stderr, "Destroy Ctrlr Failed\n");
 415                 return;
 416         }
 417         ctrlr->bdev = NULL;
 418         g_should_stop = 1;
 419
 420         sem_wait(&exit_sem);
 421 }
 422
 423 static const struct vhost_device_ops vhost_scsi_device_ops = {
 424         .new_device =  new_device,
 425         .destroy_device = destroy_device,
 426 };
 427
 428 static struct vhost_scsi_ctrlr *
 429 vhost_scsi_ctrlr_construct(const char *ctrlr_name)
 430 {
 431         int ret;
 432         struct vhost_scsi_ctrlr *ctrlr;
 433         char *path;
 434         char cwd[PATH_MAX];
 435
 436         /* always use current directory */
 437         path = getcwd(cwd, PATH_MAX);
 438         if (!path) {
 439                 fprintf(stderr, "Cannot get current working directory\n");
 440                 return NULL;
 441         }
 442         snprintf(dev_pathname, sizeof(dev_pathname), "%s/%s", path, ctrlr_name);
 443
 444         if (access(dev_pathname, F_OK) != -1) {
 445                 if (unlink(dev_pathname) != 0)
 446                         rte_exit(EXIT_FAILURE, "Cannot remove %s.\n",
 447                                  dev_pathname);
 448         }
 449
 450         if (rte_vhost_driver_register(dev_pathname, 0) != 0) {
 451                 fprintf(stderr, "socket %s already exists\n", dev_pathname);
 452                 return NULL;
 453         }
 454
 455         fprintf(stdout, "socket file: %s created\n", dev_pathname);
 456
 457         ret = rte_vhost_driver_set_features(dev_pathname, VIRTIO_SCSI_FEATURES);
 458         if (ret != 0) {
 459                 fprintf(stderr, "Set vhost driver features failed\n");
 460                 return NULL;
 461         }
 462
 463         ctrlr = rte_zmalloc(NULL, sizeof(*ctrlr), RTE_CACHE_LINE_SIZE);
 464         if (!ctrlr)
 465                 return NULL;
 466
 467         rte_vhost_driver_callback_register(dev_pathname,
 468                                            &vhost_scsi_device_ops);
 469
 470         return ctrlr;
 471 }
 472
 473 static void
 474 signal_handler(__rte_unused int signum)
 475 {
 476
 477         if (access(dev_pathname, F_OK) == 0)
 478                 unlink(dev_pathname);
 479         exit(0);
 480 }
 481
 482 int main(int argc, char *argv[])
 483 {
 484         int ret;
 485
 486         signal(SIGINT, signal_handler);
 487
 488         /* init EAL */
 489         ret = rte_eal_init(argc, argv);
 490         if (ret < 0)
 491                 rte_exit(EXIT_FAILURE, "Error with EAL initialization\n");
 492
 493         g_vhost_ctrlr = vhost_scsi_ctrlr_construct("vhost.socket");
 494         if (g_vhost_ctrlr == NULL) {
 495                 fprintf(stderr, "Construct vhost scsi controller failed\n");
 496                 return 0;
 497         }
 498
 499         if (sem_init(&exit_sem, 0, 0) < 0) {
 500                 fprintf(stderr, "Error init exit_sem\n");
 501                 return -1;
 502         }
 503
 504         rte_vhost_driver_start(dev_pathname);
 505
 506         /* loop for exit the application */
 507         while (1)
 508                 sleep(1);
 509
 510         return 0;
 511 }
 512