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         int ret;
 124         unsigned int tap_features;
 125         struct vhost_kernel_data *data = dev->backend_data;
 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_support_features(&tap_features);
 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_features & 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_features & 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         int vhostfd;
 384         uint32_t q, i;
 385         struct vhost_kernel_data *data;
 386
 387         data = malloc(sizeof(*data));
 388         if (!data) {
 389                 PMD_INIT_LOG(ERR, "(%s) Failed to allocate Vhost-kernel data", dev->path);
 390                 return -1;
 391         }
 392
 393         data->vhostfds = malloc(dev->max_queue_pairs * sizeof(int));
 394         if (!data->vhostfds) {
 395                 PMD_INIT_LOG(ERR, "(%s) Failed to allocate Vhost FDs", dev->path);
 396                 goto err_data;
 397         }
 398         data->tapfds = malloc(dev->max_queue_pairs * sizeof(int));
 399         if (!data->tapfds) {
 400                 PMD_INIT_LOG(ERR, "(%s) Failed to allocate TAP FDs", dev->path);
 401                 goto err_vhostfds;
 402         }
 403
 404         for (q = 0; q < dev->max_queue_pairs; ++q) {
 405                 data->vhostfds[q] = -1;
 406                 data->tapfds[q] = -1;
 407         }
 408
 409         get_vhost_kernel_max_regions();
 410
 411         for (i = 0; i < dev->max_queue_pairs; ++i) {
 412                 vhostfd = open(dev->path, O_RDWR);
 413                 if (vhostfd < 0) {
 414                         PMD_DRV_LOG(ERR, "fail to open %s, %s", dev->path, strerror(errno));
 415                         goto err_tapfds;
 416                 }
 417
 418                 data->vhostfds[i] = vhostfd;
 419         }
 420
 421         dev->backend_data = data;
 422
 423         return 0;
 424
 425 err_tapfds:
 426         for (i = 0; i < dev->max_queue_pairs; i++)
 427                 if (data->vhostfds[i] >= 0)
 428                         close(data->vhostfds[i]);
 429
 430         free(data->tapfds);
 431 err_vhostfds:
 432         free(data->vhostfds);
 433 err_data:
 434         free(data);
 435
 436         return -1;
 437 }
 438
 439 static int
 440 vhost_kernel_destroy(struct virtio_user_dev *dev)
 441 {
 442         struct vhost_kernel_data *data = dev->backend_data;
 443         uint32_t i;
 444
 445         if (!data)
 446                 return 0;
 447
 448         for (i = 0; i < dev->max_queue_pairs; ++i) {
 449                 if (data->vhostfds[i] >= 0)
 450                         close(data->vhostfds[i]);
 451                 if (data->tapfds[i] >= 0)
 452                         close(data->tapfds[i]);
 453         }
 454
 455         free(data->vhostfds);
 456         free(data->tapfds);
 457         free(data);
 458         dev->backend_data = NULL;
 459
 460         return 0;
 461 }
 462
 463 static int
 464 vhost_kernel_set_backend(int vhostfd, int tapfd)
 465 {
 466         struct vhost_vring_file f;
 467
 468         f.fd = tapfd;
 469         f.index = 0;
 470         if (ioctl(vhostfd, VHOST_NET_SET_BACKEND, &f) < 0) {
 471                 PMD_DRV_LOG(ERR, "VHOST_NET_SET_BACKEND fails, %s",
 472                                 strerror(errno));
 473                 return -1;
 474         }
 475
 476         f.index = 1;
 477         if (ioctl(vhostfd, VHOST_NET_SET_BACKEND, &f) < 0) {
 478                 PMD_DRV_LOG(ERR, "VHOST_NET_SET_BACKEND fails, %s",
 479                                 strerror(errno));
 480                 return -1;
 481         }
 482
 483         return 0;
 484 }
 485
 486 static int
 487 vhost_kernel_enable_queue_pair(struct virtio_user_dev *dev,
 488                                uint16_t pair_idx,
 489                                int enable)
 490 {
 491         int hdr_size;
 492         int vhostfd;
 493         int tapfd;
 494         int req_mq = (dev->max_queue_pairs > 1);
 495         struct vhost_kernel_data *data = dev->backend_data;
 496
 497         vhostfd = data->vhostfds[pair_idx];
 498
 499         if (dev->qp_enabled[pair_idx] == enable)
 500                 return 0;
 501
 502         if (!enable) {
 503                 tapfd = data->tapfds[pair_idx];
 504                 if (vhost_kernel_set_backend(vhostfd, -1) < 0) {
 505                         PMD_DRV_LOG(ERR, "fail to set backend for vhost kernel");
 506                         return -1;
 507                 }
 508                 if (req_mq && vhost_kernel_tap_set_queue(tapfd, false) < 0) {
 509                         PMD_DRV_LOG(ERR, "fail to disable tap for vhost kernel");
 510                         return -1;
 511                 }
 512                 dev->qp_enabled[pair_idx] = false;
 513                 return 0;
 514         }
 515
 516         if (data->tapfds[pair_idx] >= 0) {
 517                 tapfd = data->tapfds[pair_idx];
 518                 if (vhost_kernel_tap_set_offload(tapfd, dev->features) == -1)
 519                         return -1;
 520                 if (req_mq && vhost_kernel_tap_set_queue(tapfd, true) < 0) {
 521                         PMD_DRV_LOG(ERR, "fail to enable tap for vhost kernel");
 522                         return -1;
 523                 }
 524                 goto set_backend;
 525         }
 526
 527         if ((dev->features & (1ULL << VIRTIO_NET_F_MRG_RXBUF)) ||
 528             (dev->features & (1ULL << VIRTIO_F_VERSION_1)))
 529                 hdr_size = sizeof(struct virtio_net_hdr_mrg_rxbuf);
 530         else
 531                 hdr_size = sizeof(struct virtio_net_hdr);
 532
 533         tapfd = vhost_kernel_open_tap(&dev->ifname, hdr_size, req_mq,
 534                          (char *)dev->mac_addr, dev->features);
 535         if (tapfd < 0) {
 536                 PMD_DRV_LOG(ERR, "fail to open tap for vhost kernel");
 537                 return -1;
 538         }
 539
 540         data->tapfds[pair_idx] = tapfd;
 541
 542 set_backend:
 543         if (vhost_kernel_set_backend(vhostfd, tapfd) < 0) {
 544                 PMD_DRV_LOG(ERR, "fail to set backend for vhost kernel");
 545                 return -1;
 546         }
 547
 548         dev->qp_enabled[pair_idx] = true;
 549         return 0;
 550 }
 551
 552 static int
 553 vhost_kernel_get_backend_features(uint64_t *features)
 554 {
 555         *features = 0;
 556
 557         return 0;
 558 }
 559
 560 static int
 561 vhost_kernel_update_link_state(struct virtio_user_dev *dev __rte_unused)
 562 {
 563         /* Nothing to update (Maybe get TAP interface link state?) */
 564         return 0;
 565 }
 566
 567 static int
 568 vhost_kernel_get_intr_fd(struct virtio_user_dev *dev __rte_unused)
 569 {
 570         /* No link state interrupt with Vhost-kernel */
 571         return -1;
 572 }
 573
 574 struct virtio_user_backend_ops virtio_ops_kernel = {
 575         .setup = vhost_kernel_setup,
 576         .destroy = vhost_kernel_destroy,
 577         .get_backend_features = vhost_kernel_get_backend_features,
 578         .set_owner = vhost_kernel_set_owner,
 579         .get_features = vhost_kernel_get_features,
 580         .set_features = vhost_kernel_set_features,
 581         .set_memory_table = vhost_kernel_set_memory_table,
 582         .set_vring_num = vhost_kernel_set_vring_num,
 583         .set_vring_base = vhost_kernel_set_vring_base,
 584         .get_vring_base = vhost_kernel_get_vring_base,
 585         .set_vring_call = vhost_kernel_set_vring_call,
 586         .set_vring_kick = vhost_kernel_set_vring_kick,
 587         .set_vring_addr = vhost_kernel_set_vring_addr,
 588         .get_status = vhost_kernel_get_status,
 589         .set_status = vhost_kernel_set_status,
 590         .enable_qp = vhost_kernel_enable_queue_pair,
 591         .update_link_state = vhost_kernel_update_link_state,
 592         .get_intr_fd = vhost_kernel_get_intr_fd,
 593 };