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
 162         /* We don't need memory protection here */
 163         features &= ~(1ULL << VIRTIO_F_IOMMU_PLATFORM);
 164         /* VHOST kernel does not know about below flags */
 165         features &= ~VHOST_KERNEL_GUEST_OFFLOADS_MASK;
 166         features &= ~VHOST_KERNEL_HOST_OFFLOADS_MASK;
 167         features &= ~(1ULL << VIRTIO_NET_F_MQ);
 168
 169         return vhost_kernel_ioctl(data->vhostfds[0], VHOST_SET_FEATURES, &features);
 170 }
 171
 172 static int
 173 add_memseg_list(const struct rte_memseg_list *msl, void *arg)
 174 {
 175         struct vhost_memory_kernel *vm = arg;
 176         struct vhost_memory_region *mr;
 177         void *start_addr;
 178         uint64_t len;
 179
 180         if (msl->external)
 181                 return 0;
 182
 183         if (vm->nregions >= max_regions)
 184                 return -1;
 185
 186         start_addr = msl->base_va;
 187         len = msl->page_sz * msl->memseg_arr.len;
 188
 189         mr = &vm->regions[vm->nregions++];
 190
 191         mr->guest_phys_addr = (uint64_t)(uintptr_t)start_addr;
 192         mr->userspace_addr = (uint64_t)(uintptr_t)start_addr;
 193         mr->memory_size = len;
 194         mr->mmap_offset = 0; /* flags_padding */
 195
 196         PMD_DRV_LOG(DEBUG, "index=%u addr=%p len=%" PRIu64,
 197                         vm->nregions - 1, start_addr, len);
 198
 199         return 0;
 200 }
 201
 202 /* By default, vhost kernel module allows 64 regions, but DPDK may
 203  * have much more memory regions. Below function will treat each
 204  * contiguous memory space reserved by DPDK as one region.
 205  */
 206 static int
 207 vhost_kernel_set_memory_table(struct virtio_user_dev *dev)
 208 {
 209         struct vhost_kernel_data *data = dev->backend_data;
 210         struct vhost_memory_kernel *vm;
 211         int ret;
 212
 213         vm = malloc(sizeof(struct vhost_memory_kernel) +
 214                         max_regions *
 215                         sizeof(struct vhost_memory_region));
 216         if (!vm)
 217                 goto err;
 218
 219         vm->nregions = 0;
 220         vm->padding = 0;
 221
 222         /*
 223          * The memory lock has already been taken by memory subsystem
 224          * or virtio_user_start_device().
 225          */
 226         ret = rte_memseg_list_walk_thread_unsafe(add_memseg_list, vm);
 227         if (ret < 0)
 228                 goto err_free;
 229
 230         ret = vhost_kernel_ioctl(data->vhostfds[0], VHOST_SET_MEM_TABLE, vm);
 231         if (ret < 0)
 232                 goto err_free;
 233
 234         free(vm);
 235
 236         return 0;
 237 err_free:
 238         free(vm);
 239 err:
 240         PMD_DRV_LOG(ERR, "Failed to set memory table");
 241         return -1;
 242 }
 243
 244 static int
 245 vhost_kernel_set_vring(struct virtio_user_dev *dev, uint64_t req, struct vhost_vring_state *state)
 246 {
 247         int ret, fd;
 248         unsigned int index = state->index;
 249         struct vhost_kernel_data *data = dev->backend_data;
 250
 251         /* Convert from queue index to queue-pair & offset */
 252         fd = data->vhostfds[state->index / 2];
 253         state->index %= 2;
 254
 255         ret = vhost_kernel_ioctl(fd, req, state);
 256         if (ret < 0) {
 257                 PMD_DRV_LOG(ERR, "Failed to set vring (request %" PRIu64 ")", req);
 258                 return -1;
 259         }
 260
 261         /* restore index back to queue index */
 262         state->index = index;
 263
 264         return 0;
 265 }
 266
 267 static int
 268 vhost_kernel_set_vring_num(struct virtio_user_dev *dev, struct vhost_vring_state *state)
 269 {
 270         return vhost_kernel_set_vring(dev, VHOST_SET_VRING_NUM, state);
 271 }
 272
 273 static int
 274 vhost_kernel_set_vring_base(struct virtio_user_dev *dev, struct vhost_vring_state *state)
 275 {
 276         return vhost_kernel_set_vring(dev, VHOST_SET_VRING_BASE, state);
 277 }
 278
 279 static int
 280 vhost_kernel_get_vring_base(struct virtio_user_dev *dev, struct vhost_vring_state *state)
 281 {
 282         return vhost_kernel_set_vring(dev, VHOST_GET_VRING_BASE, state);
 283 }
 284
 285 static int
 286 vhost_kernel_set_vring_file(struct virtio_user_dev *dev, uint64_t req,
 287                 struct vhost_vring_file *file)
 288 {
 289         int ret, fd;
 290         unsigned int index = file->index;
 291         struct vhost_kernel_data *data = dev->backend_data;
 292
 293         /* Convert from queue index to queue-pair & offset */
 294         fd = data->vhostfds[file->index / 2];
 295         file->index %= 2;
 296
 297         ret = vhost_kernel_ioctl(fd, req, file);
 298         if (ret < 0) {
 299                 PMD_DRV_LOG(ERR, "Failed to set vring file (request %" PRIu64 ")", req);
 300                 return -1;
 301         }
 302
 303         /* restore index back to queue index */
 304         file->index = index;
 305
 306         return 0;
 307 }
 308
 309 static int
 310 vhost_kernel_set_vring_kick(struct virtio_user_dev *dev, struct vhost_vring_file *file)
 311 {
 312         return vhost_kernel_set_vring_file(dev, VHOST_SET_VRING_KICK, file);
 313 }
 314
 315 static int
 316 vhost_kernel_set_vring_call(struct virtio_user_dev *dev, struct vhost_vring_file *file)
 317 {
 318         return vhost_kernel_set_vring_file(dev, VHOST_SET_VRING_CALL, file);
 319 }
 320
 321 static int
 322 vhost_kernel_set_vring_addr(struct virtio_user_dev *dev, struct vhost_vring_addr *addr)
 323 {
 324         int ret, fd;
 325         unsigned int index = addr->index;
 326         struct vhost_kernel_data *data = dev->backend_data;
 327
 328         /* Convert from queue index to queue-pair & offset */
 329         fd = data->vhostfds[addr->index / 2];
 330         addr->index %= 2;
 331
 332         ret = vhost_kernel_ioctl(fd, VHOST_SET_VRING_ADDR, addr);
 333         if (ret < 0) {
 334                 PMD_DRV_LOG(ERR, "Failed to set vring address");
 335                 return -1;
 336         }
 337
 338         /* restore index back to queue index */
 339         addr->index = index;
 340
 341         return 0;
 342 }
 343
 344 static int
 345 vhost_kernel_get_status(struct virtio_user_dev *dev __rte_unused, uint8_t *status __rte_unused)
 346 {
 347         return -ENOTSUP;
 348 }
 349
 350 static int
 351 vhost_kernel_set_status(struct virtio_user_dev *dev __rte_unused, uint8_t status __rte_unused)
 352 {
 353         return -ENOTSUP;
 354 }
 355
 356 /**
 357  * Set up environment to talk with a vhost kernel backend.
 358  *
 359  * @return
 360  *   - (-1) if fail to set up;
 361  *   - (>=0) if successful.
 362  */
 363 static int
 364 vhost_kernel_setup(struct virtio_user_dev *dev)
 365 {
 366         int vhostfd;
 367         uint32_t q, i;
 368         struct vhost_kernel_data *data;
 369
 370         data = malloc(sizeof(*data));
 371         if (!data) {
 372                 PMD_INIT_LOG(ERR, "(%s) Failed to allocate Vhost-kernel data", dev->path);
 373                 return -1;
 374         }
 375
 376         data->vhostfds = malloc(dev->max_queue_pairs * sizeof(int));
 377         if (!data->vhostfds) {
 378                 PMD_INIT_LOG(ERR, "(%s) Failed to allocate Vhost FDs", dev->path);
 379                 goto err_data;
 380         }
 381         data->tapfds = malloc(dev->max_queue_pairs * sizeof(int));
 382         if (!data->tapfds) {
 383                 PMD_INIT_LOG(ERR, "(%s) Failed to allocate TAP FDs", dev->path);
 384                 goto err_vhostfds;
 385         }
 386
 387         for (q = 0; q < dev->max_queue_pairs; ++q) {
 388                 data->vhostfds[q] = -1;
 389                 data->tapfds[q] = -1;
 390         }
 391
 392         get_vhost_kernel_max_regions();
 393
 394         for (i = 0; i < dev->max_queue_pairs; ++i) {
 395                 vhostfd = open(dev->path, O_RDWR);
 396                 if (vhostfd < 0) {
 397                         PMD_DRV_LOG(ERR, "fail to open %s, %s", dev->path, strerror(errno));
 398                         goto err_tapfds;
 399                 }
 400
 401                 data->vhostfds[i] = vhostfd;
 402         }
 403
 404         dev->backend_data = data;
 405
 406         return 0;
 407
 408 err_tapfds:
 409         for (i = 0; i < dev->max_queue_pairs; i++)
 410                 if (data->vhostfds[i] >= 0)
 411                         close(data->vhostfds[i]);
 412
 413         free(data->tapfds);
 414 err_vhostfds:
 415         free(data->vhostfds);
 416 err_data:
 417         free(data);
 418
 419         return -1;
 420 }
 421
 422 static int
 423 vhost_kernel_destroy(struct virtio_user_dev *dev)
 424 {
 425         struct vhost_kernel_data *data = dev->backend_data;
 426         uint32_t i;
 427
 428         if (!data)
 429                 return 0;
 430
 431         for (i = 0; i < dev->max_queue_pairs; ++i) {
 432                 if (data->vhostfds[i] >= 0)
 433                         close(data->vhostfds[i]);
 434                 if (data->tapfds[i] >= 0)
 435                         close(data->tapfds[i]);
 436         }
 437
 438         free(data->vhostfds);
 439         free(data->tapfds);
 440         free(data);
 441         dev->backend_data = NULL;
 442
 443         return 0;
 444 }
 445
 446 static int
 447 vhost_kernel_set_backend(int vhostfd, int tapfd)
 448 {
 449         struct vhost_vring_file f;
 450
 451         f.fd = tapfd;
 452         f.index = 0;
 453         if (ioctl(vhostfd, VHOST_NET_SET_BACKEND, &f) < 0) {
 454                 PMD_DRV_LOG(ERR, "VHOST_NET_SET_BACKEND fails, %s",
 455                                 strerror(errno));
 456                 return -1;
 457         }
 458
 459         f.index = 1;
 460         if (ioctl(vhostfd, VHOST_NET_SET_BACKEND, &f) < 0) {
 461                 PMD_DRV_LOG(ERR, "VHOST_NET_SET_BACKEND fails, %s",
 462                                 strerror(errno));
 463                 return -1;
 464         }
 465
 466         return 0;
 467 }
 468
 469 static int
 470 vhost_kernel_enable_queue_pair(struct virtio_user_dev *dev,
 471                                uint16_t pair_idx,
 472                                int enable)
 473 {
 474         int hdr_size;
 475         int vhostfd;
 476         int tapfd;
 477         int req_mq = (dev->max_queue_pairs > 1);
 478         struct vhost_kernel_data *data = dev->backend_data;
 479
 480         vhostfd = data->vhostfds[pair_idx];
 481
 482         if (dev->qp_enabled[pair_idx] == enable)
 483                 return 0;
 484
 485         if (!enable) {
 486                 tapfd = data->tapfds[pair_idx];
 487                 if (vhost_kernel_set_backend(vhostfd, -1) < 0) {
 488                         PMD_DRV_LOG(ERR, "fail to set backend for vhost kernel");
 489                         return -1;
 490                 }
 491                 if (req_mq && vhost_kernel_tap_set_queue(tapfd, false) < 0) {
 492                         PMD_DRV_LOG(ERR, "fail to disable tap for vhost kernel");
 493                         return -1;
 494                 }
 495                 dev->qp_enabled[pair_idx] = false;
 496                 return 0;
 497         }
 498
 499         if (data->tapfds[pair_idx] >= 0) {
 500                 tapfd = data->tapfds[pair_idx];
 501                 if (vhost_kernel_tap_set_offload(tapfd, dev->features) == -1)
 502                         return -1;
 503                 if (req_mq && vhost_kernel_tap_set_queue(tapfd, true) < 0) {
 504                         PMD_DRV_LOG(ERR, "fail to enable tap for vhost kernel");
 505                         return -1;
 506                 }
 507                 goto set_backend;
 508         }
 509
 510         if ((dev->features & (1ULL << VIRTIO_NET_F_MRG_RXBUF)) ||
 511             (dev->features & (1ULL << VIRTIO_F_VERSION_1)))
 512                 hdr_size = sizeof(struct virtio_net_hdr_mrg_rxbuf);
 513         else
 514                 hdr_size = sizeof(struct virtio_net_hdr);
 515
 516         tapfd = vhost_kernel_open_tap(&dev->ifname, hdr_size, req_mq,
 517                          (char *)dev->mac_addr, dev->features);
 518         if (tapfd < 0) {
 519                 PMD_DRV_LOG(ERR, "fail to open tap for vhost kernel");
 520                 return -1;
 521         }
 522
 523         data->tapfds[pair_idx] = tapfd;
 524
 525 set_backend:
 526         if (vhost_kernel_set_backend(vhostfd, tapfd) < 0) {
 527                 PMD_DRV_LOG(ERR, "fail to set backend for vhost kernel");
 528                 return -1;
 529         }
 530
 531         dev->qp_enabled[pair_idx] = true;
 532         return 0;
 533 }
 534
 535 static int
 536 vhost_kernel_get_backend_features(uint64_t *features)
 537 {
 538         *features = 0;
 539
 540         return 0;
 541 }
 542
 543 static int
 544 vhost_kernel_update_link_state(struct virtio_user_dev *dev __rte_unused)
 545 {
 546         /* Nothing to update (Maybe get TAP interface link state?) */
 547         return 0;
 548 }
 549
 550 static int
 551 vhost_kernel_get_intr_fd(struct virtio_user_dev *dev __rte_unused)
 552 {
 553         /* No link state interrupt with Vhost-kernel */
 554         return -1;
 555 }
 556
 557 struct virtio_user_backend_ops virtio_ops_kernel = {
 558         .setup = vhost_kernel_setup,
 559         .destroy = vhost_kernel_destroy,
 560         .get_backend_features = vhost_kernel_get_backend_features,
 561         .set_owner = vhost_kernel_set_owner,
 562         .get_features = vhost_kernel_get_features,
 563         .set_features = vhost_kernel_set_features,
 564         .set_memory_table = vhost_kernel_set_memory_table,
 565         .set_vring_num = vhost_kernel_set_vring_num,
 566         .set_vring_base = vhost_kernel_set_vring_base,
 567         .get_vring_base = vhost_kernel_get_vring_base,
 568         .set_vring_call = vhost_kernel_set_vring_call,
 569         .set_vring_kick = vhost_kernel_set_vring_kick,
 570         .set_vring_addr = vhost_kernel_set_vring_addr,
 571         .get_status = vhost_kernel_get_status,
 572         .set_status = vhost_kernel_set_status,
 573         .enable_qp = vhost_kernel_enable_queue_pair,
 574         .update_link_state = vhost_kernel_update_link_state,
 575         .get_intr_fd = vhost_kernel_get_intr_fd,
 576 };