drivers/net/virtio/virtio_user/vhost_kernel.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2016 Intel Corporation
   3  */
   4
   5 #include <sys/types.h>
   6 #include <sys/stat.h>
   7 #include <fcntl.h>
   8 #include <unistd.h>
   9 #include <errno.h>
  10
  11 #include <rte_memory.h>
  12
  13 #include "vhost.h"
  14 #include "virtio_user_dev.h"
  15 #include "vhost_kernel_tap.h"
  16
  17 struct vhost_kernel_data {
  18         int *vhostfds;
  19         int *tapfds;
  20 };
  21
  22 struct vhost_memory_kernel {
  23         uint32_t nregions;
  24         uint32_t padding;
  25         struct vhost_memory_region regions[0];
  26 };
  27
  28 /* vhost kernel ioctls */
  29 #define VHOST_VIRTIO 0xAF
  30 #define VHOST_GET_FEATURES _IOR(VHOST_VIRTIO, 0x00, __u64)
  31 #define VHOST_SET_FEATURES _IOW(VHOST_VIRTIO, 0x00, __u64)
  32 #define VHOST_SET_OWNER _IO(VHOST_VIRTIO, 0x01)
  33 #define VHOST_RESET_OWNER _IO(VHOST_VIRTIO, 0x02)
  34 #define VHOST_SET_MEM_TABLE _IOW(VHOST_VIRTIO, 0x03, struct vhost_memory_kernel)
  35 #define VHOST_SET_LOG_BASE _IOW(VHOST_VIRTIO, 0x04, __u64)
  36 #define VHOST_SET_LOG_FD _IOW(VHOST_VIRTIO, 0x07, int)
  37 #define VHOST_SET_VRING_NUM _IOW(VHOST_VIRTIO, 0x10, struct vhost_vring_state)
  38 #define VHOST_SET_VRING_ADDR _IOW(VHOST_VIRTIO, 0x11, struct vhost_vring_addr)
  39 #define VHOST_SET_VRING_BASE _IOW(VHOST_VIRTIO, 0x12, struct vhost_vring_state)
  40 #define VHOST_GET_VRING_BASE _IOWR(VHOST_VIRTIO, 0x12, struct vhost_vring_state)
  41 #define VHOST_SET_VRING_KICK _IOW(VHOST_VIRTIO, 0x20, struct vhost_vring_file)
  42 #define VHOST_SET_VRING_CALL _IOW(VHOST_VIRTIO, 0x21, struct vhost_vring_file)
  43 #define VHOST_SET_VRING_ERR _IOW(VHOST_VIRTIO, 0x22, struct vhost_vring_file)
  44 #define VHOST_NET_SET_BACKEND _IOW(VHOST_VIRTIO, 0x30, struct vhost_vring_file)
  45
  46 /* with below features, vhost kernel does not need to do the checksum and TSO,
  47  * these info will be passed to virtio_user through virtio net header.
  48  */
  49 #define VHOST_KERNEL_GUEST_OFFLOADS_MASK        \
  50         ((1ULL << VIRTIO_NET_F_GUEST_CSUM) |    \
  51          (1ULL << VIRTIO_NET_F_GUEST_TSO4) |    \
  52          (1ULL << VIRTIO_NET_F_GUEST_TSO6) |    \
  53          (1ULL << VIRTIO_NET_F_GUEST_ECN)  |    \
  54          (1ULL << VIRTIO_NET_F_GUEST_UFO))
  55
  56 /* with below features, when flows from virtio_user to vhost kernel
  57  * (1) if flows goes up through the kernel networking stack, it does not need
  58  * to verify checksum, which can save CPU cycles;
  59  * (2) if flows goes through a Linux bridge and outside from an interface
  60  * (kernel driver), checksum and TSO will be done by GSO in kernel or even
  61  * offloaded into real physical device.
  62  */
  63 #define VHOST_KERNEL_HOST_OFFLOADS_MASK         \
  64         ((1ULL << VIRTIO_NET_F_HOST_TSO4) |     \
  65          (1ULL << VIRTIO_NET_F_HOST_TSO6) |     \
  66          (1ULL << VIRTIO_NET_F_CSUM))
  67
  68 static uint64_t max_regions = 64;
  69
  70 static void
  71 get_vhost_kernel_max_regions(void)
  72 {
  73         int fd;
  74         char buf[20] = {'\0'};
  75
  76         fd = open("/sys/module/vhost/parameters/max_mem_regions", O_RDONLY);
  77         if (fd < 0)
  78                 return;
  79
  80         if (read(fd, buf, sizeof(buf) - 1) > 0)
  81                 max_regions = strtoull(buf, NULL, 10);
  82
  83         close(fd);
  84 }
  85
  86 static int
  87 vhost_kernel_ioctl(int fd, uint64_t request, void *arg)
  88 {
  89         int ret;
  90
  91         ret = ioctl(fd, request, arg);
  92         if (ret) {
  93                 PMD_DRV_LOG(ERR, "Vhost-kernel ioctl %"PRIu64" failed (%s)",
  94                                 request, strerror(errno));
  95                 return -1;
  96         }
  97
  98         return 0;
  99 }
 100
 101 static int
 102 vhost_kernel_set_owner(struct virtio_user_dev *dev)
 103 {
 104         int ret;
 105         uint32_t i;
 106         struct vhost_kernel_data *data = dev->backend_data;
 107
 108         for (i = 0; i < dev->max_queue_pairs; ++i) {
 109                 if (data->vhostfds[i] < 0)
 110                         continue;
 111
 112                 ret = vhost_kernel_ioctl(data->vhostfds[i], VHOST_SET_OWNER, NULL);
 113                 if (ret < 0)
 114                         return ret;
 115         }
 116
 117         return 0;
 118 }
 119
 120 static int
 121 vhost_kernel_get_features(struct virtio_user_dev *dev, uint64_t *features)
 122 {
 123         struct vhost_kernel_data *data = dev->backend_data;
 124         unsigned int tap_flags;
 125         int ret;
 126
 127         ret = vhost_kernel_ioctl(data->vhostfds[0], VHOST_GET_FEATURES, features);
 128         if (ret < 0) {
 129                 PMD_DRV_LOG(ERR, "Failed to get features");
 130                 return -1;
 131         }
 132
 133         ret = tap_get_flags(data->tapfds[0], &tap_flags);
 134         if (ret < 0) {
 135                 PMD_DRV_LOG(ERR, "Failed to get TAP features");
 136                 return -1;
 137         }
 138
 139         /* with tap as the backend, all these features are supported
 140          * but not claimed by vhost-net, so we add them back when
 141          * reporting to upper layer.
 142          */
 143         if (tap_flags & IFF_VNET_HDR) {
 144                 *features |= VHOST_KERNEL_GUEST_OFFLOADS_MASK;
 145                 *features |= VHOST_KERNEL_HOST_OFFLOADS_MASK;
 146         }
 147
 148         /* vhost_kernel will not declare this feature, but it does
 149          * support multi-queue.
 150          */
 151         if (tap_flags & IFF_MULTI_QUEUE)
 152                 *features |= (1ull << VIRTIO_NET_F_MQ);
 153
 154         return 0;
 155 }
 156
 157 static int
 158 vhost_kernel_set_features(struct virtio_user_dev *dev, uint64_t features)
 159 {
 160         struct vhost_kernel_data *data = dev->backend_data;
 161         uint32_t i;
 162         int ret;
 163
 164         /* We don't need memory protection here */
 165         features &= ~(1ULL << VIRTIO_F_IOMMU_PLATFORM);
 166         /* VHOST kernel does not know about below flags */
 167         features &= ~VHOST_KERNEL_GUEST_OFFLOADS_MASK;
 168         features &= ~VHOST_KERNEL_HOST_OFFLOADS_MASK;
 169         features &= ~(1ULL << VIRTIO_NET_F_MQ);
 170
 171         for (i = 0; i < dev->max_queue_pairs; ++i) {
 172                 if (data->vhostfds[i] < 0)
 173                         continue;
 174
 175                 ret = vhost_kernel_ioctl(data->vhostfds[i], VHOST_SET_FEATURES, &features);
 176                 if (ret < 0)
 177                         return ret;
 178         }
 179
 180         return 0;
 181 }
 182
 183 static int
 184 add_memseg_list(const struct rte_memseg_list *msl, void *arg)
 185 {
 186         struct vhost_memory_kernel *vm = arg;
 187         struct vhost_memory_region *mr;
 188         void *start_addr;
 189         uint64_t len;
 190
 191         if (msl->external)
 192                 return 0;
 193
 194         if (vm->nregions >= max_regions)
 195                 return -1;
 196
 197         start_addr = msl->base_va;
 198         len = msl->page_sz * msl->memseg_arr.len;
 199
 200         mr = &vm->regions[vm->nregions++];
 201
 202         mr->guest_phys_addr = (uint64_t)(uintptr_t)start_addr;
 203         mr->userspace_addr = (uint64_t)(uintptr_t)start_addr;
 204         mr->memory_size = len;
 205         mr->mmap_offset = 0; /* flags_padding */
 206
 207         PMD_DRV_LOG(DEBUG, "index=%u addr=%p len=%" PRIu64,
 208                         vm->nregions - 1, start_addr, len);
 209
 210         return 0;
 211 }
 212
 213 /* By default, vhost kernel module allows 64 regions, but DPDK may
 214  * have much more memory regions. Below function will treat each
 215  * contiguous memory space reserved by DPDK as one region.
 216  */
 217 static int
 218 vhost_kernel_set_memory_table(struct virtio_user_dev *dev)
 219 {
 220         uint32_t i;
 221         struct vhost_kernel_data *data = dev->backend_data;
 222         struct vhost_memory_kernel *vm;
 223         int ret;
 224
 225         vm = malloc(sizeof(struct vhost_memory_kernel) +
 226                         max_regions *
 227                         sizeof(struct vhost_memory_region));
 228         if (!vm)
 229                 goto err;
 230
 231         vm->nregions = 0;
 232         vm->padding = 0;
 233
 234         /*
 235          * The memory lock has already been taken by memory subsystem
 236          * or virtio_user_start_device().
 237          */
 238         ret = rte_memseg_list_walk_thread_unsafe(add_memseg_list, vm);
 239         if (ret < 0)
 240                 goto err_free;
 241
 242         for (i = 0; i < dev->max_queue_pairs; ++i) {
 243                 if (data->vhostfds[i] < 0)
 244                         continue;
 245
 246                 ret = vhost_kernel_ioctl(data->vhostfds[i], VHOST_SET_MEM_TABLE, vm);
 247                 if (ret < 0)
 248                         goto err_free;
 249         }
 250
 251         free(vm);
 252
 253         return 0;
 254 err_free:
 255         free(vm);
 256 err:
 257         PMD_DRV_LOG(ERR, "Failed to set memory table");
 258         return -1;
 259 }
 260
 261 static int
 262 vhost_kernel_set_vring(struct virtio_user_dev *dev, uint64_t req, struct vhost_vring_state *state)
 263 {
 264         int ret, fd;
 265         unsigned int index = state->index;
 266         struct vhost_kernel_data *data = dev->backend_data;
 267
 268         /* Convert from queue index to queue-pair & offset */
 269         fd = data->vhostfds[state->index / 2];
 270         state->index %= 2;
 271
 272         ret = vhost_kernel_ioctl(fd, req, state);
 273         if (ret < 0) {
 274                 PMD_DRV_LOG(ERR, "Failed to set vring (request %" PRIu64 ")", req);
 275                 return -1;
 276         }
 277
 278         /* restore index back to queue index */
 279         state->index = index;
 280
 281         return 0;
 282 }
 283
 284 static int
 285 vhost_kernel_set_vring_num(struct virtio_user_dev *dev, struct vhost_vring_state *state)
 286 {
 287         return vhost_kernel_set_vring(dev, VHOST_SET_VRING_NUM, state);
 288 }
 289
 290 static int
 291 vhost_kernel_set_vring_base(struct virtio_user_dev *dev, struct vhost_vring_state *state)
 292 {
 293         return vhost_kernel_set_vring(dev, VHOST_SET_VRING_BASE, state);
 294 }
 295
 296 static int
 297 vhost_kernel_get_vring_base(struct virtio_user_dev *dev, struct vhost_vring_state *state)
 298 {
 299         return vhost_kernel_set_vring(dev, VHOST_GET_VRING_BASE, state);
 300 }
 301
 302 static int
 303 vhost_kernel_set_vring_file(struct virtio_user_dev *dev, uint64_t req,
 304                 struct vhost_vring_file *file)
 305 {
 306         int ret, fd;
 307         unsigned int index = file->index;
 308         struct vhost_kernel_data *data = dev->backend_data;
 309
 310         /* Convert from queue index to queue-pair & offset */
 311         fd = data->vhostfds[file->index / 2];
 312         file->index %= 2;
 313
 314         ret = vhost_kernel_ioctl(fd, req, file);
 315         if (ret < 0) {
 316                 PMD_DRV_LOG(ERR, "Failed to set vring file (request %" PRIu64 ")", req);
 317                 return -1;
 318         }
 319
 320         /* restore index back to queue index */
 321         file->index = index;
 322
 323         return 0;
 324 }
 325
 326 static int
 327 vhost_kernel_set_vring_kick(struct virtio_user_dev *dev, struct vhost_vring_file *file)
 328 {
 329         return vhost_kernel_set_vring_file(dev, VHOST_SET_VRING_KICK, file);
 330 }
 331
 332 static int
 333 vhost_kernel_set_vring_call(struct virtio_user_dev *dev, struct vhost_vring_file *file)
 334 {
 335         return vhost_kernel_set_vring_file(dev, VHOST_SET_VRING_CALL, file);
 336 }
 337
 338 static int
 339 vhost_kernel_set_vring_addr(struct virtio_user_dev *dev, struct vhost_vring_addr *addr)
 340 {
 341         int ret, fd;
 342         unsigned int index = addr->index;
 343         struct vhost_kernel_data *data = dev->backend_data;
 344
 345         /* Convert from queue index to queue-pair & offset */
 346         fd = data->vhostfds[addr->index / 2];
 347         addr->index %= 2;
 348
 349         ret = vhost_kernel_ioctl(fd, VHOST_SET_VRING_ADDR, addr);
 350         if (ret < 0) {
 351                 PMD_DRV_LOG(ERR, "Failed to set vring address");
 352                 return -1;
 353         }
 354
 355         /* restore index back to queue index */
 356         addr->index = index;
 357
 358         return 0;
 359 }
 360
 361 static int
 362 vhost_kernel_get_status(struct virtio_user_dev *dev __rte_unused, uint8_t *status __rte_unused)
 363 {
 364         return -ENOTSUP;
 365 }
 366
 367 static int
 368 vhost_kernel_set_status(struct virtio_user_dev *dev __rte_unused, uint8_t status __rte_unused)
 369 {
 370         return -ENOTSUP;
 371 }
 372
 373 /**
 374  * Set up environment to talk with a vhost kernel backend.
 375  *
 376  * @return
 377  *   - (-1) if fail to set up;
 378  *   - (>=0) if successful.
 379  */
 380 static int
 381 vhost_kernel_setup(struct virtio_user_dev *dev)
 382 {
 383         struct vhost_kernel_data *data;
 384         unsigned int tap_features;
 385         unsigned int tap_flags;
 386         const char *ifname;
 387         uint32_t q, i;
 388         int vhostfd;
 389
 390         if (tap_support_features(&tap_features) < 0)
 391                 return -1;
 392
 393         if ((tap_features & IFF_VNET_HDR) == 0) {
 394                 PMD_INIT_LOG(ERR, "TAP does not support IFF_VNET_HDR");
 395                 return -1;
 396         }
 397
 398         data = malloc(sizeof(*data));
 399         if (!data) {
 400                 PMD_INIT_LOG(ERR, "(%s) Failed to allocate Vhost-kernel data", dev->path);
 401                 return -1;
 402         }
 403
 404         data->vhostfds = malloc(dev->max_queue_pairs * sizeof(int));
 405         if (!data->vhostfds) {
 406                 PMD_INIT_LOG(ERR, "(%s) Failed to allocate Vhost FDs", dev->path);
 407                 goto err_data;
 408         }
 409         data->tapfds = malloc(dev->max_queue_pairs * sizeof(int));
 410         if (!data->tapfds) {
 411                 PMD_INIT_LOG(ERR, "(%s) Failed to allocate TAP FDs", dev->path);
 412                 goto err_vhostfds;
 413         }
 414
 415         for (q = 0; q < dev->max_queue_pairs; ++q) {
 416                 data->vhostfds[q] = -1;
 417                 data->tapfds[q] = -1;
 418         }
 419
 420         get_vhost_kernel_max_regions();
 421
 422         for (i = 0; i < dev->max_queue_pairs; ++i) {
 423                 vhostfd = open(dev->path, O_RDWR);
 424                 if (vhostfd < 0) {
 425                         PMD_DRV_LOG(ERR, "fail to open %s, %s", dev->path, strerror(errno));
 426                         goto err_tapfds;
 427                 }
 428                 data->vhostfds[i] = vhostfd;
 429         }
 430
 431         ifname = dev->ifname != NULL ? dev->ifname : "tap%d";
 432         data->tapfds[0] = tap_open(ifname, (tap_features & IFF_MULTI_QUEUE) != 0);
 433         if (data->tapfds[0] < 0)
 434                 goto err_tapfds;
 435         if (dev->ifname == NULL && tap_get_name(data->tapfds[0], &dev->ifname) < 0) {
 436                 PMD_DRV_LOG(ERR, "fail to get tap name (%d)", data->tapfds[0]);
 437                 goto err_tapfds;
 438         }
 439         if (tap_get_flags(data->tapfds[0], &tap_flags) < 0) {
 440                 PMD_DRV_LOG(ERR, "fail to get tap flags for tap %s", dev->ifname);
 441                 goto err_tapfds;
 442         }
 443         if ((tap_flags & IFF_MULTI_QUEUE) == 0 && dev->max_queue_pairs > 1) {
 444                 PMD_DRV_LOG(ERR, "tap %s does not support multi queue", dev->ifname);
 445                 goto err_tapfds;
 446         }
 447
 448         for (i = 1; i < dev->max_queue_pairs; i++) {
 449                 data->tapfds[i] = tap_open(dev->ifname, true);
 450                 if (data->tapfds[i] < 0)
 451                         goto err_tapfds;
 452         }
 453
 454         dev->backend_data = data;
 455
 456         return 0;
 457
 458 err_tapfds:
 459         for (i = 0; i < dev->max_queue_pairs; i++) {
 460                 if (data->vhostfds[i] >= 0)
 461                         close(data->vhostfds[i]);
 462                 if (data->tapfds[i] >= 0)
 463                         close(data->tapfds[i]);
 464         }
 465
 466         free(data->tapfds);
 467 err_vhostfds:
 468         free(data->vhostfds);
 469 err_data:
 470         free(data);
 471
 472         return -1;
 473 }
 474
 475 static int
 476 vhost_kernel_destroy(struct virtio_user_dev *dev)
 477 {
 478         struct vhost_kernel_data *data = dev->backend_data;
 479         uint32_t i;
 480
 481         if (!data)
 482                 return 0;
 483
 484         for (i = 0; i < dev->max_queue_pairs; ++i) {
 485                 if (data->vhostfds[i] >= 0)
 486                         close(data->vhostfds[i]);
 487                 if (data->tapfds[i] >= 0)
 488                         close(data->tapfds[i]);
 489         }
 490
 491         free(data->vhostfds);
 492         free(data->tapfds);
 493         free(data);
 494         dev->backend_data = NULL;
 495
 496         return 0;
 497 }
 498
 499 static int
 500 vhost_kernel_set_backend(int vhostfd, int tapfd)
 501 {
 502         struct vhost_vring_file f;
 503
 504         f.fd = tapfd;
 505         f.index = 0;
 506         if (ioctl(vhostfd, VHOST_NET_SET_BACKEND, &f) < 0) {
 507                 PMD_DRV_LOG(ERR, "VHOST_NET_SET_BACKEND fails, %s",
 508                                 strerror(errno));
 509                 return -1;
 510         }
 511
 512         f.index = 1;
 513         if (ioctl(vhostfd, VHOST_NET_SET_BACKEND, &f) < 0) {
 514                 PMD_DRV_LOG(ERR, "VHOST_NET_SET_BACKEND fails, %s",
 515                                 strerror(errno));
 516                 return -1;
 517         }
 518
 519         return 0;
 520 }
 521
 522 static int
 523 vhost_kernel_enable_queue_pair(struct virtio_user_dev *dev,
 524                                uint16_t pair_idx,
 525                                int enable)
 526 {
 527         struct vhost_kernel_data *data = dev->backend_data;
 528         int hdr_size;
 529         int vhostfd;
 530         int tapfd;
 531
 532         if (dev->qp_enabled[pair_idx] == enable)
 533                 return 0;
 534
 535         vhostfd = data->vhostfds[pair_idx];
 536         tapfd = data->tapfds[pair_idx];
 537
 538         if (!enable) {
 539                 if (vhost_kernel_set_backend(vhostfd, -1) < 0) {
 540                         PMD_DRV_LOG(ERR, "fail to set backend for vhost kernel");
 541                         return -1;
 542                 }
 543                 dev->qp_enabled[pair_idx] = false;
 544                 return 0;
 545         }
 546
 547         if ((dev->features & (1ULL << VIRTIO_NET_F_MRG_RXBUF)) ||
 548             (dev->features & (1ULL << VIRTIO_F_VERSION_1)))
 549                 hdr_size = sizeof(struct virtio_net_hdr_mrg_rxbuf);
 550         else
 551                 hdr_size = sizeof(struct virtio_net_hdr);
 552
 553         /* Set mac on tap only once when starting */
 554         if (!dev->started && pair_idx == 0 &&
 555                         tap_set_mac(data->tapfds[pair_idx], dev->mac_addr) < 0)
 556                 return -1;
 557
 558         if (vhost_kernel_tap_setup(tapfd, hdr_size, dev->features) < 0) {
 559                 PMD_DRV_LOG(ERR, "fail to setup tap for vhost kernel");
 560                 return -1;
 561         }
 562
 563         if (vhost_kernel_set_backend(vhostfd, tapfd) < 0) {
 564                 PMD_DRV_LOG(ERR, "fail to set backend for vhost kernel");
 565                 return -1;
 566         }
 567
 568         dev->qp_enabled[pair_idx] = true;
 569         return 0;
 570 }
 571
 572 static int
 573 vhost_kernel_get_backend_features(uint64_t *features)
 574 {
 575         *features = 0;
 576
 577         return 0;
 578 }
 579
 580 static int
 581 vhost_kernel_update_link_state(struct virtio_user_dev *dev __rte_unused)
 582 {
 583         /* Nothing to update (Maybe get TAP interface link state?) */
 584         return 0;
 585 }
 586
 587 static int
 588 vhost_kernel_get_intr_fd(struct virtio_user_dev *dev __rte_unused)
 589 {
 590         /* No link state interrupt with Vhost-kernel */
 591         return -1;
 592 }
 593
 594 struct virtio_user_backend_ops virtio_ops_kernel = {
 595         .setup = vhost_kernel_setup,
 596         .destroy = vhost_kernel_destroy,
 597         .get_backend_features = vhost_kernel_get_backend_features,
 598         .set_owner = vhost_kernel_set_owner,
 599         .get_features = vhost_kernel_get_features,
 600         .set_features = vhost_kernel_set_features,
 601         .set_memory_table = vhost_kernel_set_memory_table,
 602         .set_vring_num = vhost_kernel_set_vring_num,
 603         .set_vring_base = vhost_kernel_set_vring_base,
 604         .get_vring_base = vhost_kernel_get_vring_base,
 605         .set_vring_call = vhost_kernel_set_vring_call,
 606         .set_vring_kick = vhost_kernel_set_vring_kick,
 607         .set_vring_addr = vhost_kernel_set_vring_addr,
 608         .get_status = vhost_kernel_get_status,
 609         .set_status = vhost_kernel_set_status,
 610         .enable_qp = vhost_kernel_enable_queue_pair,
 611         .update_link_state = vhost_kernel_update_link_state,
 612         .get_intr_fd = vhost_kernel_get_intr_fd,
 613 };