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)
  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_gpa_to_vva(ctrlr->mem, gpa);
  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
 142         task->iovs_cnt = 0;
 143         task->resp = (void *)(uintptr_t)gpa_to_vva(task->bdev->vid,
 144                                                    task->desc->addr);
 145
 146         while (descriptor_has_next(task->desc)) {
 147                 task->desc = descriptor_get_next(task->vq->desc, task->desc);
 148                 data = (void *)(uintptr_t)gpa_to_vva(task->bdev->vid,
 149                                                      task->desc->addr);
 150                 task->iovs[task->iovs_cnt].iov_base = data;
 151                 task->iovs[task->iovs_cnt].iov_len = task->desc->len;
 152                 task->data_len += task->desc->len;
 153                 task->iovs_cnt++;
 154         }
 155 }
 156
 157 static void
 158 vhost_process_write_payload_chain(struct vhost_scsi_task *task)
 159 {
 160         void *data;
 161
 162         task->iovs_cnt = 0;
 163
 164         do {
 165                 data = (void *)(uintptr_t)gpa_to_vva(task->bdev->vid,
 166                                                      task->desc->addr);
 167                 task->iovs[task->iovs_cnt].iov_base = data;
 168                 task->iovs[task->iovs_cnt].iov_len = task->desc->len;
 169                 task->data_len += task->desc->len;
 170                 task->iovs_cnt++;
 171                 task->desc = descriptor_get_next(task->vq->desc, task->desc);
 172         } while (descriptor_has_next(task->desc));
 173
 174         task->resp = (void *)(uintptr_t)gpa_to_vva(task->bdev->vid,
 175                                                    task->desc->addr);
 176 }
 177
 178 static struct vhost_block_dev *
 179 vhost_scsi_bdev_construct(const char *bdev_name, const char *bdev_serial,
 180                           uint32_t blk_size, uint64_t blk_cnt,
 181                           bool wce_enable)
 182 {
 183         struct vhost_block_dev *bdev;
 184
 185         bdev = rte_zmalloc(NULL, sizeof(*bdev), RTE_CACHE_LINE_SIZE);
 186         if (!bdev)
 187                 return NULL;
 188
 189         strncpy(bdev->name, bdev_name, sizeof(bdev->name));
 190         strncpy(bdev->product_name, bdev_serial, sizeof(bdev->product_name));
 191         bdev->blocklen = blk_size;
 192         bdev->blockcnt = blk_cnt;
 193         bdev->write_cache = wce_enable;
 194
 195         /* use memory as disk storage space */
 196         bdev->data = rte_zmalloc(NULL, blk_cnt * blk_size, 0);
 197         if (!bdev->data) {
 198                 fprintf(stderr, "no enough reseverd huge memory for disk\n");
 199                 return NULL;
 200         }
 201
 202         return bdev;
 203 }
 204
 205 static void
 206 process_requestq(struct vhost_scsi_ctrlr *ctrlr, uint32_t q_idx)
 207 {
 208         int ret;
 209         struct vhost_scsi_queue *scsi_vq;
 210         struct rte_vhost_vring *vq;
 211
 212         scsi_vq = &ctrlr->bdev->queues[q_idx];
 213         vq = &scsi_vq->vq;
 214         ret = rte_vhost_get_vhost_vring(ctrlr->bdev->vid, q_idx, vq);
 215         assert(ret == 0);
 216
 217         while (vq->avail->idx != scsi_vq->last_used_idx) {
 218                 int req_idx;
 219                 uint16_t last_idx;
 220                 struct vhost_scsi_task *task;
 221
 222                 last_idx = scsi_vq->last_used_idx & (vq->size - 1);
 223                 req_idx = vq->avail->ring[last_idx];
 224
 225                 task = rte_zmalloc(NULL, sizeof(*task), 0);
 226                 assert(task != NULL);
 227
 228                 task->ctrlr = ctrlr;
 229                 task->bdev = ctrlr->bdev;
 230                 task->vq = vq;
 231                 task->req_idx = req_idx;
 232                 task->desc = &task->vq->desc[task->req_idx];
 233
 234                 /* does not support indirect descriptors */
 235                 assert((task->desc->flags & VRING_DESC_F_INDIRECT) == 0);
 236                 scsi_vq->last_used_idx++;
 237
 238                 task->req = (void *)(uintptr_t)gpa_to_vva(task->bdev->vid,
 239                                                           task->desc->addr);
 240
 241                 task->desc = descriptor_get_next(task->vq->desc, task->desc);
 242                 if (!descriptor_has_next(task->desc)) {
 243                         task->dxfer_dir = SCSI_DIR_NONE;
 244                         task->resp = (void *)(uintptr_t)
 245                                               gpa_to_vva(task->bdev->vid,
 246                                                          task->desc->addr);
 247
 248                 } else if (!descriptor_is_wr(task->desc)) {
 249                         task->dxfer_dir = SCSI_DIR_TO_DEV;
 250                         vhost_process_write_payload_chain(task);
 251                 } else {
 252                         task->dxfer_dir = SCSI_DIR_FROM_DEV;
 253                         vhost_process_read_payload_chain(task);
 254                 }
 255
 256                 ret = vhost_bdev_process_scsi_commands(ctrlr->bdev, task);
 257                 if (ret) {
 258                         /* invalid response */
 259                         task->resp->response = VIRTIO_SCSI_S_BAD_TARGET;
 260                 } else {
 261                         /* successfully */
 262                         task->resp->response = VIRTIO_SCSI_S_OK;
 263                         task->resp->status = 0;
 264                         task->resp->resid = 0;
 265                 }
 266                 submit_completion(task);
 267                 rte_free(task);
 268         }
 269 }
 270
 271 /* Main framework for processing IOs */
 272 static void *
 273 ctrlr_worker(void *arg)
 274 {
 275         uint32_t idx, num;
 276         struct vhost_scsi_ctrlr *ctrlr = (struct vhost_scsi_ctrlr *)arg;
 277         cpu_set_t cpuset;
 278         pthread_t thread;
 279
 280         thread = pthread_self();
 281         CPU_ZERO(&cpuset);
 282         CPU_SET(0, &cpuset);
 283         pthread_setaffinity_np(thread, sizeof(cpu_set_t), &cpuset);
 284
 285         num =  rte_vhost_get_vring_num(ctrlr->bdev->vid);
 286         fprintf(stdout, "Ctrlr Worker Thread Started with %u Vring\n", num);
 287
 288         if (num != NUM_OF_SCSI_QUEUES) {
 289                 fprintf(stderr, "Only 1 IO queue are supported\n");
 290                 exit(0);
 291         }
 292
 293         while (!g_should_stop && ctrlr->bdev != NULL) {
 294                 /* At least 3 vrings, currently only can support 1 IO queue
 295                  * Queue 2 for IO queue, does not support TMF and hotplug
 296                  * for the example application now
 297                  */
 298                 for (idx = 2; idx < num; idx++)
 299                         process_requestq(ctrlr, idx);
 300         }
 301
 302         fprintf(stdout, "Ctrlr Worker Thread Exiting\n");
 303         sem_post(&exit_sem);
 304         return NULL;
 305 }
 306
 307 static int
 308 new_device(int vid)
 309 {
 310         char path[PATH_MAX];
 311         struct vhost_scsi_ctrlr *ctrlr;
 312         struct vhost_scsi_queue *scsi_vq;
 313         struct rte_vhost_vring *vq;
 314         pthread_t tid;
 315         int i, ret;
 316
 317         ret = rte_vhost_get_ifname(vid, path, PATH_MAX);
 318         if (ret) {
 319                 fprintf(stderr, "Cannot get socket name\n");
 320                 return -1;
 321         }
 322
 323         ctrlr = vhost_scsi_ctrlr_find(path);
 324         if (!ctrlr) {
 325                 fprintf(stderr, "Controller is not ready\n");
 326                 return -1;
 327         }
 328
 329         ret = rte_vhost_get_mem_table(vid, &ctrlr->mem);
 330         if (ret) {
 331                 fprintf(stderr, "Get Controller memory region failed\n");
 332                 return -1;
 333         }
 334         assert(ctrlr->mem != NULL);
 335
 336         /* hardcoded block device information with 128MiB */
 337         ctrlr->bdev = vhost_scsi_bdev_construct("malloc0", "vhost_scsi_malloc0",
 338                                                 4096, 32768, 0);
 339         if (!ctrlr->bdev)
 340                 return -1;
 341
 342         ctrlr->bdev->vid = vid;
 343
 344         /* Disable Notifications */
 345         for (i = 0; i < NUM_OF_SCSI_QUEUES; i++) {
 346                 rte_vhost_enable_guest_notification(vid, i, 0);
 347                 /* restore used index */
 348                 scsi_vq = &ctrlr->bdev->queues[i];
 349                 vq = &scsi_vq->vq;
 350                 ret = rte_vhost_get_vhost_vring(ctrlr->bdev->vid, i, vq);
 351                 assert(ret == 0);
 352                 scsi_vq->last_used_idx = vq->used->idx;
 353                 scsi_vq->last_avail_idx = vq->used->idx;
 354         }
 355
 356         g_should_stop = 0;
 357         fprintf(stdout, "New Device %s, Device ID %d\n", path, vid);
 358         if (pthread_create(&tid, NULL, &ctrlr_worker, ctrlr) < 0) {
 359                 fprintf(stderr, "Worker Thread Started Failed\n");
 360                 return -1;
 361         }
 362         pthread_detach(tid);
 363         return 0;
 364 }
 365
 366 static void
 367 destroy_device(int vid)
 368 {
 369         char path[PATH_MAX];
 370         struct vhost_scsi_ctrlr *ctrlr;
 371
 372         rte_vhost_get_ifname(vid, path, PATH_MAX);
 373         fprintf(stdout, "Destroy %s Device ID %d\n", path, vid);
 374         ctrlr = vhost_scsi_ctrlr_find(path);
 375         if (!ctrlr) {
 376                 fprintf(stderr, "Destroy Ctrlr Failed\n");
 377                 return;
 378         }
 379         ctrlr->bdev = NULL;
 380         g_should_stop = 1;
 381
 382         sem_wait(&exit_sem);
 383 }
 384
 385 static const struct vhost_device_ops vhost_scsi_device_ops = {
 386         .new_device =  new_device,
 387         .destroy_device = destroy_device,
 388 };
 389
 390 static struct vhost_scsi_ctrlr *
 391 vhost_scsi_ctrlr_construct(const char *ctrlr_name)
 392 {
 393         int ret;
 394         struct vhost_scsi_ctrlr *ctrlr;
 395         char *path;
 396         char cwd[PATH_MAX];
 397
 398         /* always use current directory */
 399         path = getcwd(cwd, PATH_MAX);
 400         if (!path) {
 401                 fprintf(stderr, "Cannot get current working directory\n");
 402                 return NULL;
 403         }
 404         snprintf(dev_pathname, sizeof(dev_pathname), "%s/%s", path, ctrlr_name);
 405
 406         if (access(dev_pathname, F_OK) != -1) {
 407                 if (unlink(dev_pathname) != 0)
 408                         rte_exit(EXIT_FAILURE, "Cannot remove %s.\n",
 409                                  dev_pathname);
 410         }
 411
 412         if (rte_vhost_driver_register(dev_pathname, 0) != 0) {
 413                 fprintf(stderr, "socket %s already exists\n", dev_pathname);
 414                 return NULL;
 415         }
 416
 417         fprintf(stdout, "socket file: %s created\n", dev_pathname);
 418
 419         ret = rte_vhost_driver_set_features(dev_pathname, VIRTIO_SCSI_FEATURES);
 420         if (ret != 0) {
 421                 fprintf(stderr, "Set vhost driver features failed\n");
 422                 return NULL;
 423         }
 424
 425         ctrlr = rte_zmalloc(NULL, sizeof(*ctrlr), RTE_CACHE_LINE_SIZE);
 426         if (!ctrlr)
 427                 return NULL;
 428
 429         rte_vhost_driver_callback_register(dev_pathname,
 430                                            &vhost_scsi_device_ops);
 431
 432         return ctrlr;
 433 }
 434
 435 static void
 436 signal_handler(__rte_unused int signum)
 437 {
 438
 439         if (access(dev_pathname, F_OK) == 0)
 440                 unlink(dev_pathname);
 441         exit(0);
 442 }
 443
 444 int main(int argc, char *argv[])
 445 {
 446         int ret;
 447
 448         signal(SIGINT, signal_handler);
 449
 450         /* init EAL */
 451         ret = rte_eal_init(argc, argv);
 452         if (ret < 0)
 453                 rte_exit(EXIT_FAILURE, "Error with EAL initialization\n");
 454
 455         g_vhost_ctrlr = vhost_scsi_ctrlr_construct("vhost.socket");
 456         if (g_vhost_ctrlr == NULL) {
 457                 fprintf(stderr, "Construct vhost scsi controller failed\n");
 458                 return 0;
 459         }
 460
 461         if (sem_init(&exit_sem, 0, 0) < 0) {
 462                 fprintf(stderr, "Error init exit_sem\n");
 463                 return -1;
 464         }
 465
 466         rte_vhost_driver_start(dev_pathname);
 467
 468         /* loop for exit the application */
 469         while (1)
 470                 sleep(1);
 471
 472         return 0;
 473 }
 474