drivers/net/virtio/virtio_user/virtio_user_dev.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2010-2016 Intel Corporation
   3  */
   4
   5 #include <stdint.h>
   6 #include <stdio.h>
   7 #include <fcntl.h>
   8 #include <string.h>
   9 #include <errno.h>
  10 #include <sys/mman.h>
  11 #include <unistd.h>
  12 #include <sys/eventfd.h>
  13 #include <sys/types.h>
  14 #include <sys/stat.h>
  15
  16 #include <rte_string_fns.h>
  17 #include <rte_eal_memconfig.h>
  18
  19 #include "vhost.h"
  20 #include "virtio_user_dev.h"
  21 #include "../virtio_ethdev.h"
  22
  23 #define VIRTIO_USER_MEM_EVENT_CLB_NAME "virtio_user_mem_event_clb"
  24
  25 static int
  26 virtio_user_create_queue(struct virtio_user_dev *dev, uint32_t queue_sel)
  27 {
  28         /* Of all per virtqueue MSGs, make sure VHOST_SET_VRING_CALL come
  29          * firstly because vhost depends on this msg to allocate virtqueue
  30          * pair.
  31          */
  32         struct vhost_vring_file file;
  33
  34         file.index = queue_sel;
  35         file.fd = dev->callfds[queue_sel];
  36         dev->ops->send_request(dev, VHOST_USER_SET_VRING_CALL, &file);
  37
  38         return 0;
  39 }
  40
  41 static int
  42 virtio_user_kick_queue(struct virtio_user_dev *dev, uint32_t queue_sel)
  43 {
  44         struct vhost_vring_file file;
  45         struct vhost_vring_state state;
  46         struct vring *vring = &dev->vrings[queue_sel];
  47         struct vring_packed *pq_vring = &dev->packed_vrings[queue_sel];
  48         struct vhost_vring_addr addr = {
  49                 .index = queue_sel,
  50                 .log_guest_addr = 0,
  51                 .flags = 0, /* disable log */
  52         };
  53
  54         if (dev->features & (1ULL << VIRTIO_F_RING_PACKED)) {
  55                 addr.desc_user_addr =
  56                         (uint64_t)(uintptr_t)pq_vring->desc;
  57                 addr.avail_user_addr =
  58                         (uint64_t)(uintptr_t)pq_vring->driver;
  59                 addr.used_user_addr =
  60                         (uint64_t)(uintptr_t)pq_vring->device;
  61         } else {
  62                 addr.desc_user_addr = (uint64_t)(uintptr_t)vring->desc;
  63                 addr.avail_user_addr = (uint64_t)(uintptr_t)vring->avail;
  64                 addr.used_user_addr = (uint64_t)(uintptr_t)vring->used;
  65         }
  66
  67         state.index = queue_sel;
  68         state.num = vring->num;
  69         dev->ops->send_request(dev, VHOST_USER_SET_VRING_NUM, &state);
  70
  71         state.index = queue_sel;
  72         state.num = 0; /* no reservation */
  73         if (dev->features & (1ULL << VIRTIO_F_RING_PACKED))
  74                 state.num |= (1 << 15);
  75         dev->ops->send_request(dev, VHOST_USER_SET_VRING_BASE, &state);
  76
  77         dev->ops->send_request(dev, VHOST_USER_SET_VRING_ADDR, &addr);
  78
  79         /* Of all per virtqueue MSGs, make sure VHOST_USER_SET_VRING_KICK comes
  80          * lastly because vhost depends on this msg to judge if
  81          * virtio is ready.
  82          */
  83         file.index = queue_sel;
  84         file.fd = dev->kickfds[queue_sel];
  85         dev->ops->send_request(dev, VHOST_USER_SET_VRING_KICK, &file);
  86
  87         return 0;
  88 }
  89
  90 static int
  91 virtio_user_queue_setup(struct virtio_user_dev *dev,
  92                         int (*fn)(struct virtio_user_dev *, uint32_t))
  93 {
  94         uint32_t i, queue_sel;
  95
  96         for (i = 0; i < dev->max_queue_pairs; ++i) {
  97                 queue_sel = 2 * i + VTNET_SQ_RQ_QUEUE_IDX;
  98                 if (fn(dev, queue_sel) < 0) {
  99                         PMD_DRV_LOG(INFO, "setup rx vq fails: %u", i);
 100                         return -1;
 101                 }
 102         }
 103         for (i = 0; i < dev->max_queue_pairs; ++i) {
 104                 queue_sel = 2 * i + VTNET_SQ_TQ_QUEUE_IDX;
 105                 if (fn(dev, queue_sel) < 0) {
 106                         PMD_DRV_LOG(INFO, "setup tx vq fails: %u", i);
 107                         return -1;
 108                 }
 109         }
 110
 111         return 0;
 112 }
 113
 114 int
 115 is_vhost_user_by_type(const char *path)
 116 {
 117         struct stat sb;
 118
 119         if (stat(path, &sb) == -1)
 120                 return 0;
 121
 122         return S_ISSOCK(sb.st_mode);
 123 }
 124
 125 int
 126 virtio_user_start_device(struct virtio_user_dev *dev)
 127 {
 128         uint64_t features;
 129         int ret;
 130
 131         /*
 132          * XXX workaround!
 133          *
 134          * We need to make sure that the locks will be
 135          * taken in the correct order to avoid deadlocks.
 136          *
 137          * Before releasing this lock, this thread should
 138          * not trigger any memory hotplug events.
 139          *
 140          * This is a temporary workaround, and should be
 141          * replaced when we get proper supports from the
 142          * memory subsystem in the future.
 143          */
 144         rte_mcfg_mem_read_lock();
 145         pthread_mutex_lock(&dev->mutex);
 146
 147         if (is_vhost_user_by_type(dev->path) && dev->vhostfd < 0)
 148                 goto error;
 149
 150         /* Step 0: tell vhost to create queues */
 151         if (virtio_user_queue_setup(dev, virtio_user_create_queue) < 0)
 152                 goto error;
 153
 154         /* Step 1: negotiate protocol features & set features */
 155         features = dev->features;
 156
 157
 158         /* Strip VIRTIO_NET_F_MAC, as MAC address is handled in vdev init */
 159         features &= ~(1ull << VIRTIO_NET_F_MAC);
 160         /* Strip VIRTIO_NET_F_CTRL_VQ, as devices do not really need to know */
 161         features &= ~(1ull << VIRTIO_NET_F_CTRL_VQ);
 162         features &= ~(1ull << VIRTIO_NET_F_STATUS);
 163         ret = dev->ops->send_request(dev, VHOST_USER_SET_FEATURES, &features);
 164         if (ret < 0)
 165                 goto error;
 166         PMD_DRV_LOG(INFO, "set features: %" PRIx64, features);
 167
 168         /* Step 2: share memory regions */
 169         ret = dev->ops->send_request(dev, VHOST_USER_SET_MEM_TABLE, NULL);
 170         if (ret < 0)
 171                 goto error;
 172
 173         /* Step 3: kick queues */
 174         if (virtio_user_queue_setup(dev, virtio_user_kick_queue) < 0)
 175                 goto error;
 176
 177         /* Step 4: enable queues
 178          * we enable the 1st queue pair by default.
 179          */
 180         dev->ops->enable_qp(dev, 0, 1);
 181
 182         dev->started = true;
 183         pthread_mutex_unlock(&dev->mutex);
 184         rte_mcfg_mem_read_unlock();
 185
 186         return 0;
 187 error:
 188         pthread_mutex_unlock(&dev->mutex);
 189         rte_mcfg_mem_read_unlock();
 190         /* TODO: free resource here or caller to check */
 191         return -1;
 192 }
 193
 194 int virtio_user_stop_device(struct virtio_user_dev *dev)
 195 {
 196         struct vhost_vring_state state;
 197         uint32_t i;
 198         int error = 0;
 199
 200         pthread_mutex_lock(&dev->mutex);
 201         if (!dev->started)
 202                 goto out;
 203
 204         for (i = 0; i < dev->max_queue_pairs; ++i)
 205                 dev->ops->enable_qp(dev, i, 0);
 206
 207         /* Stop the backend. */
 208         for (i = 0; i < dev->max_queue_pairs * 2; ++i) {
 209                 state.index = i;
 210                 if (dev->ops->send_request(dev, VHOST_USER_GET_VRING_BASE,
 211                                            &state) < 0) {
 212                         PMD_DRV_LOG(ERR, "get_vring_base failed, index=%u\n",
 213                                     i);
 214                         error = -1;
 215                         goto out;
 216                 }
 217         }
 218
 219         dev->started = false;
 220 out:
 221         pthread_mutex_unlock(&dev->mutex);
 222
 223         return error;
 224 }
 225
 226 static inline void
 227 parse_mac(struct virtio_user_dev *dev, const char *mac)
 228 {
 229         struct rte_ether_addr tmp;
 230
 231         if (!mac)
 232                 return;
 233
 234         if (rte_ether_unformat_addr(mac, &tmp) == 0) {
 235                 memcpy(dev->mac_addr, &tmp, RTE_ETHER_ADDR_LEN);
 236                 dev->mac_specified = 1;
 237         } else {
 238                 /* ignore the wrong mac, use random mac */
 239                 PMD_DRV_LOG(ERR, "wrong format of mac: %s", mac);
 240         }
 241 }
 242
 243 static int
 244 virtio_user_dev_init_notify(struct virtio_user_dev *dev)
 245 {
 246         uint32_t i, j;
 247         int callfd;
 248         int kickfd;
 249
 250         for (i = 0; i < VIRTIO_MAX_VIRTQUEUES; ++i) {
 251                 if (i >= dev->max_queue_pairs * 2) {
 252                         dev->kickfds[i] = -1;
 253                         dev->callfds[i] = -1;
 254                         continue;
 255                 }
 256
 257                 /* May use invalid flag, but some backend uses kickfd and
 258                  * callfd as criteria to judge if dev is alive. so finally we
 259                  * use real event_fd.
 260                  */
 261                 callfd = eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK);
 262                 if (callfd < 0) {
 263                         PMD_DRV_LOG(ERR, "callfd error, %s", strerror(errno));
 264                         break;
 265                 }
 266                 kickfd = eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK);
 267                 if (kickfd < 0) {
 268                         PMD_DRV_LOG(ERR, "kickfd error, %s", strerror(errno));
 269                         break;
 270                 }
 271                 dev->callfds[i] = callfd;
 272                 dev->kickfds[i] = kickfd;
 273         }
 274
 275         if (i < VIRTIO_MAX_VIRTQUEUES) {
 276                 for (j = 0; j <= i; ++j) {
 277                         close(dev->callfds[j]);
 278                         close(dev->kickfds[j]);
 279                 }
 280
 281                 return -1;
 282         }
 283
 284         return 0;
 285 }
 286
 287 static int
 288 virtio_user_fill_intr_handle(struct virtio_user_dev *dev)
 289 {
 290         uint32_t i;
 291         struct rte_eth_dev *eth_dev = &rte_eth_devices[dev->port_id];
 292
 293         if (!eth_dev->intr_handle) {
 294                 eth_dev->intr_handle = malloc(sizeof(*eth_dev->intr_handle));
 295                 if (!eth_dev->intr_handle) {
 296                         PMD_DRV_LOG(ERR, "fail to allocate intr_handle");
 297                         return -1;
 298                 }
 299                 memset(eth_dev->intr_handle, 0, sizeof(*eth_dev->intr_handle));
 300         }
 301
 302         for (i = 0; i < dev->max_queue_pairs; ++i)
 303                 eth_dev->intr_handle->efds[i] = dev->callfds[i];
 304         eth_dev->intr_handle->nb_efd = dev->max_queue_pairs;
 305         eth_dev->intr_handle->max_intr = dev->max_queue_pairs + 1;
 306         eth_dev->intr_handle->type = RTE_INTR_HANDLE_VDEV;
 307         /* For virtio vdev, no need to read counter for clean */
 308         eth_dev->intr_handle->efd_counter_size = 0;
 309         eth_dev->intr_handle->fd = -1;
 310         if (dev->vhostfd >= 0)
 311                 eth_dev->intr_handle->fd = dev->vhostfd;
 312         else if (dev->is_server)
 313                 eth_dev->intr_handle->fd = dev->listenfd;
 314
 315         return 0;
 316 }
 317
 318 static void
 319 virtio_user_mem_event_cb(enum rte_mem_event type __rte_unused,
 320                          const void *addr,
 321                          size_t len __rte_unused,
 322                          void *arg)
 323 {
 324         struct virtio_user_dev *dev = arg;
 325         struct rte_memseg_list *msl;
 326         uint16_t i;
 327
 328         /* ignore externally allocated memory */
 329         msl = rte_mem_virt2memseg_list(addr);
 330         if (msl->external)
 331                 return;
 332
 333         pthread_mutex_lock(&dev->mutex);
 334
 335         if (dev->started == false)
 336                 goto exit;
 337
 338         /* Step 1: pause the active queues */
 339         for (i = 0; i < dev->queue_pairs; i++)
 340                 dev->ops->enable_qp(dev, i, 0);
 341
 342         /* Step 2: update memory regions */
 343         dev->ops->send_request(dev, VHOST_USER_SET_MEM_TABLE, NULL);
 344
 345         /* Step 3: resume the active queues */
 346         for (i = 0; i < dev->queue_pairs; i++)
 347                 dev->ops->enable_qp(dev, i, 1);
 348
 349 exit:
 350         pthread_mutex_unlock(&dev->mutex);
 351 }
 352
 353 static int
 354 virtio_user_dev_setup(struct virtio_user_dev *dev)
 355 {
 356         uint32_t q;
 357
 358         dev->vhostfd = -1;
 359         dev->vhostfds = NULL;
 360         dev->tapfds = NULL;
 361
 362         if (dev->is_server) {
 363                 if (access(dev->path, F_OK) == 0 &&
 364                     !is_vhost_user_by_type(dev->path)) {
 365                         PMD_DRV_LOG(ERR, "Server mode doesn't support vhost-kernel!");
 366                         return -1;
 367                 }
 368                 dev->ops = &virtio_ops_user;
 369         } else {
 370                 if (is_vhost_user_by_type(dev->path)) {
 371                         dev->ops = &virtio_ops_user;
 372                 } else {
 373                         dev->ops = &virtio_ops_kernel;
 374
 375                         dev->vhostfds = malloc(dev->max_queue_pairs *
 376                                                sizeof(int));
 377                         dev->tapfds = malloc(dev->max_queue_pairs *
 378                                              sizeof(int));
 379                         if (!dev->vhostfds || !dev->tapfds) {
 380                                 PMD_INIT_LOG(ERR, "Failed to malloc");
 381                                 return -1;
 382                         }
 383
 384                         for (q = 0; q < dev->max_queue_pairs; ++q) {
 385                                 dev->vhostfds[q] = -1;
 386                                 dev->tapfds[q] = -1;
 387                         }
 388                 }
 389         }
 390
 391         if (dev->ops->setup(dev) < 0)
 392                 return -1;
 393
 394         if (virtio_user_dev_init_notify(dev) < 0)
 395                 return -1;
 396
 397         if (virtio_user_fill_intr_handle(dev) < 0)
 398                 return -1;
 399
 400         return 0;
 401 }
 402
 403 /* Use below macro to filter features from vhost backend */
 404 #define VIRTIO_USER_SUPPORTED_FEATURES                  \
 405         (1ULL << VIRTIO_NET_F_MAC               |       \
 406          1ULL << VIRTIO_NET_F_STATUS            |       \
 407          1ULL << VIRTIO_NET_F_MQ                |       \
 408          1ULL << VIRTIO_NET_F_CTRL_MAC_ADDR     |       \
 409          1ULL << VIRTIO_NET_F_CTRL_VQ           |       \
 410          1ULL << VIRTIO_NET_F_CTRL_RX           |       \
 411          1ULL << VIRTIO_NET_F_CTRL_VLAN         |       \
 412          1ULL << VIRTIO_NET_F_CSUM              |       \
 413          1ULL << VIRTIO_NET_F_HOST_TSO4         |       \
 414          1ULL << VIRTIO_NET_F_HOST_TSO6         |       \
 415          1ULL << VIRTIO_NET_F_MRG_RXBUF         |       \
 416          1ULL << VIRTIO_RING_F_INDIRECT_DESC    |       \
 417          1ULL << VIRTIO_NET_F_GUEST_CSUM        |       \
 418          1ULL << VIRTIO_NET_F_GUEST_TSO4        |       \
 419          1ULL << VIRTIO_NET_F_GUEST_TSO6        |       \
 420          1ULL << VIRTIO_F_IN_ORDER              |       \
 421          1ULL << VIRTIO_F_VERSION_1             |       \
 422          1ULL << VIRTIO_F_RING_PACKED           |       \
 423          1ULL << VHOST_USER_F_PROTOCOL_FEATURES)
 424
 425 #define VIRTIO_USER_SUPPORTED_PROTOCOL_FEATURES         \
 426         (1ULL << VHOST_USER_PROTOCOL_F_MQ)
 427
 428 int
 429 virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
 430                      int cq, int queue_size, const char *mac, char **ifname,
 431                      int server, int mrg_rxbuf, int in_order, int packed_vq)
 432 {
 433         uint64_t protocol_features = 0;
 434
 435         pthread_mutex_init(&dev->mutex, NULL);
 436         strlcpy(dev->path, path, PATH_MAX);
 437         dev->started = 0;
 438         dev->max_queue_pairs = queues;
 439         dev->queue_pairs = 1; /* mq disabled by default */
 440         dev->queue_size = queue_size;
 441         dev->is_server = server;
 442         dev->mac_specified = 0;
 443         dev->frontend_features = 0;
 444         dev->unsupported_features = ~VIRTIO_USER_SUPPORTED_FEATURES;
 445         dev->protocol_features = VIRTIO_USER_SUPPORTED_PROTOCOL_FEATURES;
 446         parse_mac(dev, mac);
 447
 448         if (*ifname) {
 449                 dev->ifname = *ifname;
 450                 *ifname = NULL;
 451         }
 452
 453         if (virtio_user_dev_setup(dev) < 0) {
 454                 PMD_INIT_LOG(ERR, "backend set up fails");
 455                 return -1;
 456         }
 457
 458         if (!is_vhost_user_by_type(dev->path))
 459                 dev->unsupported_features |=
 460                         (1ULL << VHOST_USER_F_PROTOCOL_FEATURES);
 461
 462         if (!dev->is_server) {
 463                 if (dev->ops->send_request(dev, VHOST_USER_SET_OWNER,
 464                                            NULL) < 0) {
 465                         PMD_INIT_LOG(ERR, "set_owner fails: %s",
 466                                      strerror(errno));
 467                         return -1;
 468                 }
 469
 470                 if (dev->ops->send_request(dev, VHOST_USER_GET_FEATURES,
 471                                            &dev->device_features) < 0) {
 472                         PMD_INIT_LOG(ERR, "get_features failed: %s",
 473                                      strerror(errno));
 474                         return -1;
 475                 }
 476
 477
 478                 if (dev->device_features &
 479                                 (1ULL << VHOST_USER_F_PROTOCOL_FEATURES)) {
 480                         if (dev->ops->send_request(dev,
 481                                         VHOST_USER_GET_PROTOCOL_FEATURES,
 482                                         &protocol_features))
 483                                 return -1;
 484
 485                         dev->protocol_features &= protocol_features;
 486
 487                         if (dev->ops->send_request(dev,
 488                                         VHOST_USER_SET_PROTOCOL_FEATURES,
 489                                         &dev->protocol_features))
 490                                 return -1;
 491
 492                         if (!(dev->protocol_features &
 493                                         (1ULL << VHOST_USER_PROTOCOL_F_MQ)))
 494                                 dev->unsupported_features |=
 495                                         (1ull << VIRTIO_NET_F_MQ);
 496                 }
 497         } else {
 498                 /* We just pretend vhost-user can support all these features.
 499                  * Note that this could be problematic that if some feature is
 500                  * negotiated but not supported by the vhost-user which comes
 501                  * later.
 502                  */
 503                 dev->device_features = VIRTIO_USER_SUPPORTED_FEATURES;
 504         }
 505
 506
 507
 508         if (!mrg_rxbuf)
 509                 dev->unsupported_features |= (1ull << VIRTIO_NET_F_MRG_RXBUF);
 510
 511         if (!in_order)
 512                 dev->unsupported_features |= (1ull << VIRTIO_F_IN_ORDER);
 513
 514         if (!packed_vq)
 515                 dev->unsupported_features |= (1ull << VIRTIO_F_RING_PACKED);
 516
 517         if (dev->mac_specified)
 518                 dev->frontend_features |= (1ull << VIRTIO_NET_F_MAC);
 519         else
 520                 dev->unsupported_features |= (1ull << VIRTIO_NET_F_MAC);
 521
 522         if (cq) {
 523                 /* device does not really need to know anything about CQ,
 524                  * so if necessary, we just claim to support CQ
 525                  */
 526                 dev->frontend_features |= (1ull << VIRTIO_NET_F_CTRL_VQ);
 527         } else {
 528                 dev->unsupported_features |= (1ull << VIRTIO_NET_F_CTRL_VQ);
 529                 /* Also disable features that depend on VIRTIO_NET_F_CTRL_VQ */
 530                 dev->unsupported_features |= (1ull << VIRTIO_NET_F_CTRL_RX);
 531                 dev->unsupported_features |= (1ull << VIRTIO_NET_F_CTRL_VLAN);
 532                 dev->unsupported_features |=
 533                         (1ull << VIRTIO_NET_F_GUEST_ANNOUNCE);
 534                 dev->unsupported_features |= (1ull << VIRTIO_NET_F_MQ);
 535                 dev->unsupported_features |=
 536                         (1ull << VIRTIO_NET_F_CTRL_MAC_ADDR);
 537         }
 538
 539         /* The backend will not report this feature, we add it explicitly */
 540         if (is_vhost_user_by_type(dev->path))
 541                 dev->frontend_features |= (1ull << VIRTIO_NET_F_STATUS);
 542
 543         /*
 544          * Device features =
 545          *     (frontend_features | backend_features) & ~unsupported_features;
 546          */
 547         dev->device_features |= dev->frontend_features;
 548         dev->device_features &= ~dev->unsupported_features;
 549
 550         if (rte_mem_event_callback_register(VIRTIO_USER_MEM_EVENT_CLB_NAME,
 551                                 virtio_user_mem_event_cb, dev)) {
 552                 if (rte_errno != ENOTSUP) {
 553                         PMD_INIT_LOG(ERR, "Failed to register mem event"
 554                                         " callback\n");
 555                         return -1;
 556                 }
 557         }
 558
 559         return 0;
 560 }
 561
 562 void
 563 virtio_user_dev_uninit(struct virtio_user_dev *dev)
 564 {
 565         uint32_t i;
 566
 567         virtio_user_stop_device(dev);
 568
 569         rte_mem_event_callback_unregister(VIRTIO_USER_MEM_EVENT_CLB_NAME, dev);
 570
 571         for (i = 0; i < dev->max_queue_pairs * 2; ++i) {
 572                 close(dev->callfds[i]);
 573                 close(dev->kickfds[i]);
 574         }
 575
 576         if (dev->vhostfd >= 0)
 577                 close(dev->vhostfd);
 578
 579         if (dev->is_server && dev->listenfd >= 0) {
 580                 close(dev->listenfd);
 581                 dev->listenfd = -1;
 582         }
 583
 584         if (dev->vhostfds) {
 585                 for (i = 0; i < dev->max_queue_pairs; ++i) {
 586                         close(dev->vhostfds[i]);
 587                         if (dev->tapfds[i] >= 0)
 588                                 close(dev->tapfds[i]);
 589                 }
 590                 free(dev->vhostfds);
 591                 free(dev->tapfds);
 592         }
 593
 594         free(dev->ifname);
 595
 596         if (dev->is_server)
 597                 unlink(dev->path);
 598 }
 599
 600 uint8_t
 601 virtio_user_handle_mq(struct virtio_user_dev *dev, uint16_t q_pairs)
 602 {
 603         uint16_t i;
 604         uint8_t ret = 0;
 605
 606         if (q_pairs > dev->max_queue_pairs) {
 607                 PMD_INIT_LOG(ERR, "multi-q config %u, but only %u supported",
 608                              q_pairs, dev->max_queue_pairs);
 609                 return -1;
 610         }
 611
 612         /* Server mode can't enable queue pairs if vhostfd is invalid,
 613          * always return 0 in this case.
 614          */
 615         if (!dev->is_server || dev->vhostfd >= 0) {
 616                 for (i = 0; i < q_pairs; ++i)
 617                         ret |= dev->ops->enable_qp(dev, i, 1);
 618                 for (i = q_pairs; i < dev->max_queue_pairs; ++i)
 619                         ret |= dev->ops->enable_qp(dev, i, 0);
 620         }
 621         dev->queue_pairs = q_pairs;
 622
 623         return ret;
 624 }
 625
 626 static uint32_t
 627 virtio_user_handle_ctrl_msg(struct virtio_user_dev *dev, struct vring *vring,
 628                             uint16_t idx_hdr)
 629 {
 630         struct virtio_net_ctrl_hdr *hdr;
 631         virtio_net_ctrl_ack status = ~0;
 632         uint16_t i, idx_data, idx_status;
 633         uint32_t n_descs = 0;
 634
 635         /* locate desc for header, data, and status */
 636         idx_data = vring->desc[idx_hdr].next;
 637         n_descs++;
 638
 639         i = idx_data;
 640         while (vring->desc[i].flags == VRING_DESC_F_NEXT) {
 641                 i = vring->desc[i].next;
 642                 n_descs++;
 643         }
 644
 645         /* locate desc for status */
 646         idx_status = i;
 647         n_descs++;
 648
 649         hdr = (void *)(uintptr_t)vring->desc[idx_hdr].addr;
 650         if (hdr->class == VIRTIO_NET_CTRL_MQ &&
 651             hdr->cmd == VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET) {
 652                 uint16_t queues;
 653
 654                 queues = *(uint16_t *)(uintptr_t)vring->desc[idx_data].addr;
 655                 status = virtio_user_handle_mq(dev, queues);
 656         } else if (hdr->class == VIRTIO_NET_CTRL_RX  ||
 657                    hdr->class == VIRTIO_NET_CTRL_MAC ||
 658                    hdr->class == VIRTIO_NET_CTRL_VLAN) {
 659                 status = 0;
 660         }
 661
 662         /* Update status */
 663         *(virtio_net_ctrl_ack *)(uintptr_t)vring->desc[idx_status].addr = status;
 664
 665         return n_descs;
 666 }
 667
 668 static inline int
 669 desc_is_avail(struct vring_packed_desc *desc, bool wrap_counter)
 670 {
 671         uint16_t flags = __atomic_load_n(&desc->flags, __ATOMIC_ACQUIRE);
 672
 673         return wrap_counter == !!(flags & VRING_PACKED_DESC_F_AVAIL) &&
 674                 wrap_counter != !!(flags & VRING_PACKED_DESC_F_USED);
 675 }
 676
 677 static uint32_t
 678 virtio_user_handle_ctrl_msg_packed(struct virtio_user_dev *dev,
 679                                    struct vring_packed *vring,
 680                                    uint16_t idx_hdr)
 681 {
 682         struct virtio_net_ctrl_hdr *hdr;
 683         virtio_net_ctrl_ack status = ~0;
 684         uint16_t idx_data, idx_status;
 685         /* initialize to one, header is first */
 686         uint32_t n_descs = 1;
 687
 688         /* locate desc for header, data, and status */
 689         idx_data = idx_hdr + 1;
 690         if (idx_data >= dev->queue_size)
 691                 idx_data -= dev->queue_size;
 692
 693         n_descs++;
 694
 695         idx_status = idx_data;
 696         while (vring->desc[idx_status].flags & VRING_DESC_F_NEXT) {
 697                 idx_status++;
 698                 if (idx_status >= dev->queue_size)
 699                         idx_status -= dev->queue_size;
 700                 n_descs++;
 701         }
 702
 703         hdr = (void *)(uintptr_t)vring->desc[idx_hdr].addr;
 704         if (hdr->class == VIRTIO_NET_CTRL_MQ &&
 705             hdr->cmd == VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET) {
 706                 uint16_t queues;
 707
 708                 queues = *(uint16_t *)(uintptr_t)
 709                                 vring->desc[idx_data].addr;
 710                 status = virtio_user_handle_mq(dev, queues);
 711         } else if (hdr->class == VIRTIO_NET_CTRL_RX  ||
 712                    hdr->class == VIRTIO_NET_CTRL_MAC ||
 713                    hdr->class == VIRTIO_NET_CTRL_VLAN) {
 714                 status = 0;
 715         }
 716
 717         /* Update status */
 718         *(virtio_net_ctrl_ack *)(uintptr_t)
 719                 vring->desc[idx_status].addr = status;
 720
 721         /* Update used descriptor */
 722         vring->desc[idx_hdr].id = vring->desc[idx_status].id;
 723         vring->desc[idx_hdr].len = sizeof(status);
 724
 725         return n_descs;
 726 }
 727
 728 void
 729 virtio_user_handle_cq_packed(struct virtio_user_dev *dev, uint16_t queue_idx)
 730 {
 731         struct virtio_user_queue *vq = &dev->packed_queues[queue_idx];
 732         struct vring_packed *vring = &dev->packed_vrings[queue_idx];
 733         uint16_t n_descs, flags;
 734
 735         /* Perform a load-acquire barrier in desc_is_avail to
 736          * enforce the ordering between desc flags and desc
 737          * content.
 738          */
 739         while (desc_is_avail(&vring->desc[vq->used_idx],
 740                              vq->used_wrap_counter)) {
 741
 742                 n_descs = virtio_user_handle_ctrl_msg_packed(dev, vring,
 743                                 vq->used_idx);
 744
 745                 flags = VRING_DESC_F_WRITE;
 746                 if (vq->used_wrap_counter)
 747                         flags |= VRING_PACKED_DESC_F_AVAIL_USED;
 748
 749                 __atomic_store_n(&vring->desc[vq->used_idx].flags, flags,
 750                                  __ATOMIC_RELEASE);
 751
 752                 vq->used_idx += n_descs;
 753                 if (vq->used_idx >= dev->queue_size) {
 754                         vq->used_idx -= dev->queue_size;
 755                         vq->used_wrap_counter ^= 1;
 756                 }
 757         }
 758 }
 759
 760 void
 761 virtio_user_handle_cq(struct virtio_user_dev *dev, uint16_t queue_idx)
 762 {
 763         uint16_t avail_idx, desc_idx;
 764         struct vring_used_elem *uep;
 765         uint32_t n_descs;
 766         struct vring *vring = &dev->vrings[queue_idx];
 767
 768         /* Consume avail ring, using used ring idx as first one */
 769         while (__atomic_load_n(&vring->used->idx, __ATOMIC_RELAXED)
 770                != vring->avail->idx) {
 771                 avail_idx = __atomic_load_n(&vring->used->idx, __ATOMIC_RELAXED)
 772                             & (vring->num - 1);
 773                 desc_idx = vring->avail->ring[avail_idx];
 774
 775                 n_descs = virtio_user_handle_ctrl_msg(dev, vring, desc_idx);
 776
 777                 /* Update used ring */
 778                 uep = &vring->used->ring[avail_idx];
 779                 uep->id = desc_idx;
 780                 uep->len = n_descs;
 781
 782                 __atomic_add_fetch(&vring->used->idx, 1, __ATOMIC_RELAXED);
 783         }
 784 }