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         uint32_t i;
 210         struct vhost_kernel_data *data = dev->backend_data;
 211         struct vhost_memory_kernel *vm;
 212         int ret;
 213
 214         vm = malloc(sizeof(struct vhost_memory_kernel) +
 215                         max_regions *
 216                         sizeof(struct vhost_memory_region));
 217         if (!vm)
 218                 goto err;
 219
 220         vm->nregions = 0;
 221         vm->padding = 0;
 222
 223         /*
 224          * The memory lock has already been taken by memory subsystem
 225          * or virtio_user_start_device().
 226          */
 227         ret = rte_memseg_list_walk_thread_unsafe(add_memseg_list, vm);
 228         if (ret < 0)
 229                 goto err_free;
 230
 231         for (i = 0; i < dev->max_queue_pairs; ++i) {
 232                 if (data->vhostfds[i] < 0)
 233                         continue;
 234
 235                 ret = vhost_kernel_ioctl(data->vhostfds[i], VHOST_SET_MEM_TABLE, vm);
 236                 if (ret < 0)
 237                         goto err_free;
 238         }
 239
 240         free(vm);
 241
 242         return 0;
 243 err_free:
 244         free(vm);
 245 err:
 246         PMD_DRV_LOG(ERR, "Failed to set memory table");
 247         return -1;
 248 }
 249
 250 static int
 251 vhost_kernel_set_vring(struct virtio_user_dev *dev, uint64_t req, struct vhost_vring_state *state)
 252 {
 253         int ret, fd;
 254         unsigned int index = state->index;
 255         struct vhost_kernel_data *data = dev->backend_data;
 256
 257         /* Convert from queue index to queue-pair & offset */
 258         fd = data->vhostfds[state->index / 2];
 259         state->index %= 2;
 260
 261         ret = vhost_kernel_ioctl(fd, req, state);
 262         if (ret < 0) {
 263                 PMD_DRV_LOG(ERR, "Failed to set vring (request %" PRIu64 ")", req);
 264                 return -1;
 265         }
 266
 267         /* restore index back to queue index */
 268         state->index = index;
 269
 270         return 0;
 271 }
 272
 273 static int
 274 vhost_kernel_set_vring_num(struct virtio_user_dev *dev, struct vhost_vring_state *state)
 275 {
 276         return vhost_kernel_set_vring(dev, VHOST_SET_VRING_NUM, state);
 277 }
 278
 279 static int
 280 vhost_kernel_set_vring_base(struct virtio_user_dev *dev, struct vhost_vring_state *state)
 281 {
 282         return vhost_kernel_set_vring(dev, VHOST_SET_VRING_BASE, state);
 283 }
 284
 285 static int
 286 vhost_kernel_get_vring_base(struct virtio_user_dev *dev, struct vhost_vring_state *state)
 287 {
 288         return vhost_kernel_set_vring(dev, VHOST_GET_VRING_BASE, state);
 289 }
 290
 291 static int
 292 vhost_kernel_set_vring_file(struct virtio_user_dev *dev, uint64_t req,
 293                 struct vhost_vring_file *file)
 294 {
 295         int ret, fd;
 296         unsigned int index = file->index;
 297         struct vhost_kernel_data *data = dev->backend_data;
 298
 299         /* Convert from queue index to queue-pair & offset */
 300         fd = data->vhostfds[file->index / 2];
 301         file->index %= 2;
 302
 303         ret = vhost_kernel_ioctl(fd, req, file);
 304         if (ret < 0) {
 305                 PMD_DRV_LOG(ERR, "Failed to set vring file (request %" PRIu64 ")", req);
 306                 return -1;
 307         }
 308
 309         /* restore index back to queue index */
 310         file->index = index;
 311
 312         return 0;
 313 }
 314
 315 static int
 316 vhost_kernel_set_vring_kick(struct virtio_user_dev *dev, struct vhost_vring_file *file)
 317 {
 318         return vhost_kernel_set_vring_file(dev, VHOST_SET_VRING_KICK, file);
 319 }
 320
 321 static int
 322 vhost_kernel_set_vring_call(struct virtio_user_dev *dev, struct vhost_vring_file *file)
 323 {
 324         return vhost_kernel_set_vring_file(dev, VHOST_SET_VRING_CALL, file);
 325 }
 326
 327 static int
 328 vhost_kernel_set_vring_addr(struct virtio_user_dev *dev, struct vhost_vring_addr *addr)
 329 {
 330         int ret, fd;
 331         unsigned int index = addr->index;
 332         struct vhost_kernel_data *data = dev->backend_data;
 333
 334         /* Convert from queue index to queue-pair & offset */
 335         fd = data->vhostfds[addr->index / 2];
 336         addr->index %= 2;
 337
 338         ret = vhost_kernel_ioctl(fd, VHOST_SET_VRING_ADDR, addr);
 339         if (ret < 0) {
 340                 PMD_DRV_LOG(ERR, "Failed to set vring address");
 341                 return -1;
 342         }
 343
 344         /* restore index back to queue index */
 345         addr->index = index;
 346
 347         return 0;
 348 }
 349
 350 static int
 351 vhost_kernel_get_status(struct virtio_user_dev *dev __rte_unused, uint8_t *status __rte_unused)
 352 {
 353         return -ENOTSUP;
 354 }
 355
 356 static int
 357 vhost_kernel_set_status(struct virtio_user_dev *dev __rte_unused, uint8_t status __rte_unused)
 358 {
 359         return -ENOTSUP;
 360 }
 361
 362 /**
 363  * Set up environment to talk with a vhost kernel backend.
 364  *
 365  * @return
 366  *   - (-1) if fail to set up;
 367  *   - (>=0) if successful.
 368  */
 369 static int
 370 vhost_kernel_setup(struct virtio_user_dev *dev)
 371 {
 372         int vhostfd;
 373         uint32_t q, i;
 374         struct vhost_kernel_data *data;
 375
 376         data = malloc(sizeof(*data));
 377         if (!data) {
 378                 PMD_INIT_LOG(ERR, "(%s) Failed to allocate Vhost-kernel data", dev->path);
 379                 return -1;
 380         }
 381
 382         data->vhostfds = malloc(dev->max_queue_pairs * sizeof(int));
 383         if (!data->vhostfds) {
 384                 PMD_INIT_LOG(ERR, "(%s) Failed to allocate Vhost FDs", dev->path);
 385                 goto err_data;
 386         }
 387         data->tapfds = malloc(dev->max_queue_pairs * sizeof(int));
 388         if (!data->tapfds) {
 389                 PMD_INIT_LOG(ERR, "(%s) Failed to allocate TAP FDs", dev->path);
 390                 goto err_vhostfds;
 391         }
 392
 393         for (q = 0; q < dev->max_queue_pairs; ++q) {
 394                 data->vhostfds[q] = -1;
 395                 data->tapfds[q] = -1;
 396         }
 397
 398         get_vhost_kernel_max_regions();
 399
 400         for (i = 0; i < dev->max_queue_pairs; ++i) {
 401                 vhostfd = open(dev->path, O_RDWR);
 402                 if (vhostfd < 0) {
 403                         PMD_DRV_LOG(ERR, "fail to open %s, %s", dev->path, strerror(errno));
 404                         goto err_tapfds;
 405                 }
 406
 407                 data->vhostfds[i] = vhostfd;
 408         }
 409
 410         dev->backend_data = data;
 411
 412         return 0;
 413
 414 err_tapfds:
 415         for (i = 0; i < dev->max_queue_pairs; i++)
 416                 if (data->vhostfds[i] >= 0)
 417                         close(data->vhostfds[i]);
 418
 419         free(data->tapfds);
 420 err_vhostfds:
 421         free(data->vhostfds);
 422 err_data:
 423         free(data);
 424
 425         return -1;
 426 }
 427
 428 static int
 429 vhost_kernel_destroy(struct virtio_user_dev *dev)
 430 {
 431         struct vhost_kernel_data *data = dev->backend_data;
 432         uint32_t i;
 433
 434         if (!data)
 435                 return 0;
 436
 437         for (i = 0; i < dev->max_queue_pairs; ++i) {
 438                 if (data->vhostfds[i] >= 0)
 439                         close(data->vhostfds[i]);
 440                 if (data->tapfds[i] >= 0)
 441                         close(data->tapfds[i]);
 442         }
 443
 444         free(data->vhostfds);
 445         free(data->tapfds);
 446         free(data);
 447         dev->backend_data = NULL;
 448
 449         return 0;
 450 }
 451
 452 static int
 453 vhost_kernel_set_backend(int vhostfd, int tapfd)
 454 {
 455         struct vhost_vring_file f;
 456
 457         f.fd = tapfd;
 458         f.index = 0;
 459         if (ioctl(vhostfd, VHOST_NET_SET_BACKEND, &f) < 0) {
 460                 PMD_DRV_LOG(ERR, "VHOST_NET_SET_BACKEND fails, %s",
 461                                 strerror(errno));
 462                 return -1;
 463         }
 464
 465         f.index = 1;
 466         if (ioctl(vhostfd, VHOST_NET_SET_BACKEND, &f) < 0) {
 467                 PMD_DRV_LOG(ERR, "VHOST_NET_SET_BACKEND fails, %s",
 468                                 strerror(errno));
 469                 return -1;
 470         }
 471
 472         return 0;
 473 }
 474
 475 static int
 476 vhost_kernel_enable_queue_pair(struct virtio_user_dev *dev,
 477                                uint16_t pair_idx,
 478                                int enable)
 479 {
 480         int hdr_size;
 481         int vhostfd;
 482         int tapfd;
 483         int req_mq = (dev->max_queue_pairs > 1);
 484         struct vhost_kernel_data *data = dev->backend_data;
 485
 486         vhostfd = data->vhostfds[pair_idx];
 487
 488         if (dev->qp_enabled[pair_idx] == enable)
 489                 return 0;
 490
 491         if (!enable) {
 492                 tapfd = data->tapfds[pair_idx];
 493                 if (vhost_kernel_set_backend(vhostfd, -1) < 0) {
 494                         PMD_DRV_LOG(ERR, "fail to set backend for vhost kernel");
 495                         return -1;
 496                 }
 497                 if (req_mq && vhost_kernel_tap_set_queue(tapfd, false) < 0) {
 498                         PMD_DRV_LOG(ERR, "fail to disable tap for vhost kernel");
 499                         return -1;
 500                 }
 501                 dev->qp_enabled[pair_idx] = false;
 502                 return 0;
 503         }
 504
 505         if (data->tapfds[pair_idx] >= 0) {
 506                 tapfd = data->tapfds[pair_idx];
 507                 if (vhost_kernel_tap_set_offload(tapfd, dev->features) == -1)
 508                         return -1;
 509                 if (req_mq && vhost_kernel_tap_set_queue(tapfd, true) < 0) {
 510                         PMD_DRV_LOG(ERR, "fail to enable tap for vhost kernel");
 511                         return -1;
 512                 }
 513                 goto set_backend;
 514         }
 515
 516         if ((dev->features & (1ULL << VIRTIO_NET_F_MRG_RXBUF)) ||
 517             (dev->features & (1ULL << VIRTIO_F_VERSION_1)))
 518                 hdr_size = sizeof(struct virtio_net_hdr_mrg_rxbuf);
 519         else
 520                 hdr_size = sizeof(struct virtio_net_hdr);
 521
 522         tapfd = vhost_kernel_open_tap(&dev->ifname, hdr_size, req_mq,
 523                          (char *)dev->mac_addr, dev->features);
 524         if (tapfd < 0) {
 525                 PMD_DRV_LOG(ERR, "fail to open tap for vhost kernel");
 526                 return -1;
 527         }
 528
 529         data->tapfds[pair_idx] = tapfd;
 530
 531 set_backend:
 532         if (vhost_kernel_set_backend(vhostfd, tapfd) < 0) {
 533                 PMD_DRV_LOG(ERR, "fail to set backend for vhost kernel");
 534                 return -1;
 535         }
 536
 537         dev->qp_enabled[pair_idx] = true;
 538         return 0;
 539 }
 540
 541 static int
 542 vhost_kernel_get_backend_features(uint64_t *features)
 543 {
 544         *features = 0;
 545
 546         return 0;
 547 }
 548
 549 static int
 550 vhost_kernel_update_link_state(struct virtio_user_dev *dev __rte_unused)
 551 {
 552         /* Nothing to update (Maybe get TAP interface link state?) */
 553         return 0;
 554 }
 555
 556 static int
 557 vhost_kernel_get_intr_fd(struct virtio_user_dev *dev __rte_unused)
 558 {
 559         /* No link state interrupt with Vhost-kernel */
 560         return -1;
 561 }
 562
 563 struct virtio_user_backend_ops virtio_ops_kernel = {
 564         .setup = vhost_kernel_setup,
 565         .destroy = vhost_kernel_destroy,
 566         .get_backend_features = vhost_kernel_get_backend_features,
 567         .set_owner = vhost_kernel_set_owner,
 568         .get_features = vhost_kernel_get_features,
 569         .set_features = vhost_kernel_set_features,
 570         .set_memory_table = vhost_kernel_set_memory_table,
 571         .set_vring_num = vhost_kernel_set_vring_num,
 572         .set_vring_base = vhost_kernel_set_vring_base,
 573         .get_vring_base = vhost_kernel_get_vring_base,
 574         .set_vring_call = vhost_kernel_set_vring_call,
 575         .set_vring_kick = vhost_kernel_set_vring_kick,
 576         .set_vring_addr = vhost_kernel_set_vring_addr,
 577         .get_status = vhost_kernel_get_status,
 578         .set_status = vhost_kernel_set_status,
 579         .enable_qp = vhost_kernel_enable_queue_pair,
 580         .update_link_state = vhost_kernel_update_link_state,
 581         .get_intr_fd = vhost_kernel_get_intr_fd,
 582 };