examples/vhost_scsi/vhost_scsi.c

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