hw/virtio/vhost-user.c

   1 /*
   2  * vhost-user
   3  *
   4  * Copyright (c) 2013 Virtual Open Systems Sarl.
   5  *
   6  * This work is licensed under the terms of the GNU GPL, version 2 or later.
   7  * See the COPYING file in the top-level directory.
   8  *
   9  */
  10
  11 #include "qemu/osdep.h"
  12 #include "qapi/error.h"
  13 #include "hw/virtio/vhost.h"
  14 #include "hw/virtio/vhost-backend.h"
  15 #include "hw/virtio/virtio-net.h"
  16 #include "sysemu/char.h"
  17 #include "sysemu/kvm.h"
  18 #include "qemu/error-report.h"
  19 #include "qemu/sockets.h"
  20 #include "exec/ram_addr.h"
  21 #include "migration/migration.h"
  22
  23 #include <sys/ioctl.h>
  24 #include <sys/socket.h>
  25 #include <sys/un.h>
  26 #include <linux/vhost.h>
  27
  28 #define VHOST_MEMORY_MAX_NREGIONS    8
  29 #define VHOST_USER_F_PROTOCOL_FEATURES 30
  30
  31 enum VhostUserProtocolFeature {
  32     VHOST_USER_PROTOCOL_F_MQ = 0,
  33     VHOST_USER_PROTOCOL_F_LOG_SHMFD = 1,
  34     VHOST_USER_PROTOCOL_F_RARP = 2,
  35
  36     VHOST_USER_PROTOCOL_F_MAX
  37 };
  38
  39 #define VHOST_USER_PROTOCOL_FEATURE_MASK ((1 << VHOST_USER_PROTOCOL_F_MAX) - 1)
  40
  41 typedef enum VhostUserRequest {
  42     VHOST_USER_NONE = 0,
  43     VHOST_USER_GET_FEATURES = 1,
  44     VHOST_USER_SET_FEATURES = 2,
  45     VHOST_USER_SET_OWNER = 3,
  46     VHOST_USER_RESET_OWNER = 4,
  47     VHOST_USER_SET_MEM_TABLE = 5,
  48     VHOST_USER_SET_LOG_BASE = 6,
  49     VHOST_USER_SET_LOG_FD = 7,
  50     VHOST_USER_SET_VRING_NUM = 8,
  51     VHOST_USER_SET_VRING_ADDR = 9,
  52     VHOST_USER_SET_VRING_BASE = 10,
  53     VHOST_USER_GET_VRING_BASE = 11,
  54     VHOST_USER_SET_VRING_KICK = 12,
  55     VHOST_USER_SET_VRING_CALL = 13,
  56     VHOST_USER_SET_VRING_ERR = 14,
  57     VHOST_USER_GET_PROTOCOL_FEATURES = 15,
  58     VHOST_USER_SET_PROTOCOL_FEATURES = 16,
  59     VHOST_USER_GET_QUEUE_NUM = 17,
  60     VHOST_USER_SET_VRING_ENABLE = 18,
  61     VHOST_USER_SEND_RARP = 19,
  62     VHOST_USER_MAX
  63 } VhostUserRequest;
  64
  65 typedef struct VhostUserMemoryRegion {
  66     uint64_t guest_phys_addr;
  67     uint64_t memory_size;
  68     uint64_t userspace_addr;
  69     uint64_t mmap_offset;
  70 } VhostUserMemoryRegion;
  71
  72 typedef struct VhostUserMemory {
  73     uint32_t nregions;
  74     uint32_t padding;
  75     VhostUserMemoryRegion regions[VHOST_MEMORY_MAX_NREGIONS];
  76 } VhostUserMemory;
  77
  78 typedef struct VhostUserLog {
  79     uint64_t mmap_size;
  80     uint64_t mmap_offset;
  81 } VhostUserLog;
  82
  83 typedef struct VhostUserMsg {
  84     VhostUserRequest request;
  85
  86 #define VHOST_USER_VERSION_MASK     (0x3)
  87 #define VHOST_USER_REPLY_MASK       (0x1<<2)
  88     uint32_t flags;
  89     uint32_t size; /* the following payload size */
  90     union {
  91 #define VHOST_USER_VRING_IDX_MASK   (0xff)
  92 #define VHOST_USER_VRING_NOFD_MASK  (0x1<<8)
  93         uint64_t u64;
  94         struct vhost_vring_state state;
  95         struct vhost_vring_addr addr;
  96         VhostUserMemory memory;
  97         VhostUserLog log;
  98     } payload;
  99 } QEMU_PACKED VhostUserMsg;
 100
 101 static VhostUserMsg m __attribute__ ((unused));
 102 #define VHOST_USER_HDR_SIZE (sizeof(m.request) \
 103                             + sizeof(m.flags) \
 104                             + sizeof(m.size))
 105
 106 #define VHOST_USER_PAYLOAD_SIZE (sizeof(m) - VHOST_USER_HDR_SIZE)
 107
 108 /* The version of the protocol we support */
 109 #define VHOST_USER_VERSION    (0x1)
 110
 111 static bool ioeventfd_enabled(void)
 112 {
 113     return kvm_enabled() && kvm_eventfds_enabled();
 114 }
 115
 116 static int vhost_user_read(struct vhost_dev *dev, VhostUserMsg *msg)
 117 {
 118     CharDriverState *chr = dev->opaque;
 119     uint8_t *p = (uint8_t *) msg;
 120     int r, size = VHOST_USER_HDR_SIZE;
 121
 122     r = qemu_chr_fe_read_all(chr, p, size);
 123     if (r != size) {
 124         error_report("Failed to read msg header. Read %d instead of %d."
 125                      " Original request %d.", r, size, msg->request);
 126         goto fail;
 127     }
 128
 129     /* validate received flags */
 130     if (msg->flags != (VHOST_USER_REPLY_MASK | VHOST_USER_VERSION)) {
 131         error_report("Failed to read msg header."
 132                 " Flags 0x%x instead of 0x%x.", msg->flags,
 133                 VHOST_USER_REPLY_MASK | VHOST_USER_VERSION);
 134         goto fail;
 135     }
 136
 137     /* validate message size is sane */
 138     if (msg->size > VHOST_USER_PAYLOAD_SIZE) {
 139         error_report("Failed to read msg header."
 140                 " Size %d exceeds the maximum %zu.", msg->size,
 141                 VHOST_USER_PAYLOAD_SIZE);
 142         goto fail;
 143     }
 144
 145     if (msg->size) {
 146         p += VHOST_USER_HDR_SIZE;
 147         size = msg->size;
 148         r = qemu_chr_fe_read_all(chr, p, size);
 149         if (r != size) {
 150             error_report("Failed to read msg payload."
 151                          " Read %d instead of %d.", r, msg->size);
 152             goto fail;
 153         }
 154     }
 155
 156     return 0;
 157
 158 fail:
 159     return -1;
 160 }
 161
 162 static bool vhost_user_one_time_request(VhostUserRequest request)
 163 {
 164     switch (request) {
 165     case VHOST_USER_SET_OWNER:
 166     case VHOST_USER_RESET_OWNER:
 167     case VHOST_USER_SET_MEM_TABLE:
 168     case VHOST_USER_GET_QUEUE_NUM:
 169         return true;
 170     default:
 171         return false;
 172     }
 173 }
 174
 175 /* most non-init callers ignore the error */
 176 static int vhost_user_write(struct vhost_dev *dev, VhostUserMsg *msg,
 177                             int *fds, int fd_num)
 178 {
 179     CharDriverState *chr = dev->opaque;
 180     int size = VHOST_USER_HDR_SIZE + msg->size;
 181
 182     /*
 183      * For non-vring specific requests, like VHOST_USER_SET_MEM_TABLE,
 184      * we just need send it once in the first time. For later such
 185      * request, we just ignore it.
 186      */
 187     if (vhost_user_one_time_request(msg->request) && dev->vq_index != 0) {
 188         return 0;
 189     }
 190
 191     if (fd_num) {
 192         qemu_chr_fe_set_msgfds(chr, fds, fd_num);
 193     }
 194
 195     return qemu_chr_fe_write_all(chr, (const uint8_t *) msg, size) == size ?
 196             0 : -1;
 197 }
 198
 199 static int vhost_user_set_log_base(struct vhost_dev *dev, uint64_t base,
 200                                    struct vhost_log *log)
 201 {
 202     int fds[VHOST_MEMORY_MAX_NREGIONS];
 203     size_t fd_num = 0;
 204     bool shmfd = virtio_has_feature(dev->protocol_features,
 205                                     VHOST_USER_PROTOCOL_F_LOG_SHMFD);
 206     VhostUserMsg msg = {
 207         .request = VHOST_USER_SET_LOG_BASE,
 208         .flags = VHOST_USER_VERSION,
 209         .payload.log.mmap_size = log->size * sizeof(*(log->log)),
 210         .payload.log.mmap_offset = 0,
 211         .size = sizeof(msg.payload.log),
 212     };
 213
 214     if (shmfd && log->fd != -1) {
 215         fds[fd_num++] = log->fd;
 216     }
 217
 218     vhost_user_write(dev, &msg, fds, fd_num);
 219
 220     if (shmfd) {
 221         msg.size = 0;
 222         if (vhost_user_read(dev, &msg) < 0) {
 223             return 0;
 224         }
 225
 226         if (msg.request != VHOST_USER_SET_LOG_BASE) {
 227             error_report("Received unexpected msg type. "
 228                          "Expected %d received %d",
 229                          VHOST_USER_SET_LOG_BASE, msg.request);
 230             return -1;
 231         }
 232     }
 233
 234     return 0;
 235 }
 236
 237 static int vhost_user_set_mem_table(struct vhost_dev *dev,
 238                                     struct vhost_memory *mem)
 239 {
 240     int fds[VHOST_MEMORY_MAX_NREGIONS];
 241     int i, fd;
 242     size_t fd_num = 0;
 243     VhostUserMsg msg = {
 244         .request = VHOST_USER_SET_MEM_TABLE,
 245         .flags = VHOST_USER_VERSION,
 246     };
 247
 248     for (i = 0; i < dev->mem->nregions; ++i) {
 249         struct vhost_memory_region *reg = dev->mem->regions + i;
 250         ram_addr_t ram_addr;
 251         MemoryRegion *mr;
 252
 253         assert((uintptr_t)reg->userspace_addr == reg->userspace_addr);
 254         mr = qemu_ram_addr_from_host((void *)(uintptr_t)reg->userspace_addr,
 255                                      &ram_addr);
 256         fd = memory_region_get_fd(mr);
 257         if (fd > 0) {
 258             msg.payload.memory.regions[fd_num].userspace_addr = reg->userspace_addr;
 259             msg.payload.memory.regions[fd_num].memory_size  = reg->memory_size;
 260             msg.payload.memory.regions[fd_num].guest_phys_addr = reg->guest_phys_addr;
 261             msg.payload.memory.regions[fd_num].mmap_offset = reg->userspace_addr -
 262                 (uintptr_t) memory_region_get_ram_ptr(mr);
 263             assert(fd_num < VHOST_MEMORY_MAX_NREGIONS);
 264             fds[fd_num++] = fd;
 265         }
 266     }
 267
 268     msg.payload.memory.nregions = fd_num;
 269
 270     if (!fd_num) {
 271         error_report("Failed initializing vhost-user memory map, "
 272                      "consider using -object memory-backend-file share=on");
 273         return -1;
 274     }
 275
 276     msg.size = sizeof(msg.payload.memory.nregions);
 277     msg.size += sizeof(msg.payload.memory.padding);
 278     msg.size += fd_num * sizeof(VhostUserMemoryRegion);
 279
 280     vhost_user_write(dev, &msg, fds, fd_num);
 281
 282     return 0;
 283 }
 284
 285 static int vhost_user_set_vring_addr(struct vhost_dev *dev,
 286                                      struct vhost_vring_addr *addr)
 287 {
 288     VhostUserMsg msg = {
 289         .request = VHOST_USER_SET_VRING_ADDR,
 290         .flags = VHOST_USER_VERSION,
 291         .payload.addr = *addr,
 292         .size = sizeof(msg.payload.addr),
 293     };
 294
 295     vhost_user_write(dev, &msg, NULL, 0);
 296
 297     return 0;
 298 }
 299
 300 static int vhost_user_set_vring_endian(struct vhost_dev *dev,
 301                                        struct vhost_vring_state *ring)
 302 {
 303     error_report("vhost-user trying to send unhandled ioctl");
 304     return -1;
 305 }
 306
 307 static int vhost_set_vring(struct vhost_dev *dev,
 308                            unsigned long int request,
 309                            struct vhost_vring_state *ring)
 310 {
 311     VhostUserMsg msg = {
 312         .request = request,
 313         .flags = VHOST_USER_VERSION,
 314         .payload.state = *ring,
 315         .size = sizeof(msg.payload.state),
 316     };
 317
 318     vhost_user_write(dev, &msg, NULL, 0);
 319
 320     return 0;
 321 }
 322
 323 static int vhost_user_set_vring_num(struct vhost_dev *dev,
 324                                     struct vhost_vring_state *ring)
 325 {
 326     return vhost_set_vring(dev, VHOST_USER_SET_VRING_NUM, ring);
 327 }
 328
 329 static int vhost_user_set_vring_base(struct vhost_dev *dev,
 330                                      struct vhost_vring_state *ring)
 331 {
 332     return vhost_set_vring(dev, VHOST_USER_SET_VRING_BASE, ring);
 333 }
 334
 335 static int vhost_user_set_vring_enable(struct vhost_dev *dev, int enable)
 336 {
 337     int i;
 338
 339     if (!virtio_has_feature(dev->features, VHOST_USER_F_PROTOCOL_FEATURES)) {
 340         return -1;
 341     }
 342
 343     for (i = 0; i < dev->nvqs; ++i) {
 344         struct vhost_vring_state state = {
 345             .index = dev->vq_index + i,
 346             .num   = enable,
 347         };
 348
 349         vhost_set_vring(dev, VHOST_USER_SET_VRING_ENABLE, &state);
 350     }
 351
 352     return 0;
 353 }
 354
 355 static int vhost_user_get_vring_base(struct vhost_dev *dev,
 356                                      struct vhost_vring_state *ring)
 357 {
 358     VhostUserMsg msg = {
 359         .request = VHOST_USER_GET_VRING_BASE,
 360         .flags = VHOST_USER_VERSION,
 361         .payload.state = *ring,
 362         .size = sizeof(msg.payload.state),
 363     };
 364
 365     vhost_user_write(dev, &msg, NULL, 0);
 366
 367     if (vhost_user_read(dev, &msg) < 0) {
 368         return 0;
 369     }
 370
 371     if (msg.request != VHOST_USER_GET_VRING_BASE) {
 372         error_report("Received unexpected msg type. Expected %d received %d",
 373                      VHOST_USER_GET_VRING_BASE, msg.request);
 374         return -1;
 375     }
 376
 377     if (msg.size != sizeof(msg.payload.state)) {
 378         error_report("Received bad msg size.");
 379         return -1;
 380     }
 381
 382     *ring = msg.payload.state;
 383
 384     return 0;
 385 }
 386
 387 static int vhost_set_vring_file(struct vhost_dev *dev,
 388                                 VhostUserRequest request,
 389                                 struct vhost_vring_file *file)
 390 {
 391     int fds[VHOST_MEMORY_MAX_NREGIONS];
 392     size_t fd_num = 0;
 393     VhostUserMsg msg = {
 394         .request = request,
 395         .flags = VHOST_USER_VERSION,
 396         .payload.u64 = file->index & VHOST_USER_VRING_IDX_MASK,
 397         .size = sizeof(msg.payload.u64),
 398     };
 399
 400     if (ioeventfd_enabled() && file->fd > 0) {
 401         fds[fd_num++] = file->fd;
 402     } else {
 403         msg.payload.u64 |= VHOST_USER_VRING_NOFD_MASK;
 404     }
 405
 406     vhost_user_write(dev, &msg, fds, fd_num);
 407
 408     return 0;
 409 }
 410
 411 static int vhost_user_set_vring_kick(struct vhost_dev *dev,
 412                                      struct vhost_vring_file *file)
 413 {
 414     return vhost_set_vring_file(dev, VHOST_USER_SET_VRING_KICK, file);
 415 }
 416
 417 static int vhost_user_set_vring_call(struct vhost_dev *dev,
 418                                      struct vhost_vring_file *file)
 419 {
 420     return vhost_set_vring_file(dev, VHOST_USER_SET_VRING_CALL, file);
 421 }
 422
 423 static int vhost_user_set_u64(struct vhost_dev *dev, int request, uint64_t u64)
 424 {
 425     VhostUserMsg msg = {
 426         .request = request,
 427         .flags = VHOST_USER_VERSION,
 428         .payload.u64 = u64,
 429         .size = sizeof(msg.payload.u64),
 430     };
 431
 432     vhost_user_write(dev, &msg, NULL, 0);
 433
 434     return 0;
 435 }
 436
 437 static int vhost_user_set_features(struct vhost_dev *dev,
 438                                    uint64_t features)
 439 {
 440     return vhost_user_set_u64(dev, VHOST_USER_SET_FEATURES, features);
 441 }
 442
 443 static int vhost_user_set_protocol_features(struct vhost_dev *dev,
 444                                             uint64_t features)
 445 {
 446     return vhost_user_set_u64(dev, VHOST_USER_SET_PROTOCOL_FEATURES, features);
 447 }
 448
 449 static int vhost_user_get_u64(struct vhost_dev *dev, int request, uint64_t *u64)
 450 {
 451     VhostUserMsg msg = {
 452         .request = request,
 453         .flags = VHOST_USER_VERSION,
 454     };
 455
 456     if (vhost_user_one_time_request(request) && dev->vq_index != 0) {
 457         return 0;
 458     }
 459
 460     vhost_user_write(dev, &msg, NULL, 0);
 461
 462     if (vhost_user_read(dev, &msg) < 0) {
 463         return 0;
 464     }
 465
 466     if (msg.request != request) {
 467         error_report("Received unexpected msg type. Expected %d received %d",
 468                      request, msg.request);
 469         return -1;
 470     }
 471
 472     if (msg.size != sizeof(msg.payload.u64)) {
 473         error_report("Received bad msg size.");
 474         return -1;
 475     }
 476
 477     *u64 = msg.payload.u64;
 478
 479     return 0;
 480 }
 481
 482 static int vhost_user_get_features(struct vhost_dev *dev, uint64_t *features)
 483 {
 484     return vhost_user_get_u64(dev, VHOST_USER_GET_FEATURES, features);
 485 }
 486
 487 static int vhost_user_set_owner(struct vhost_dev *dev)
 488 {
 489     VhostUserMsg msg = {
 490         .request = VHOST_USER_SET_OWNER,
 491         .flags = VHOST_USER_VERSION,
 492     };
 493
 494     vhost_user_write(dev, &msg, NULL, 0);
 495
 496     return 0;
 497 }
 498
 499 static int vhost_user_reset_device(struct vhost_dev *dev)
 500 {
 501     VhostUserMsg msg = {
 502         .request = VHOST_USER_RESET_OWNER,
 503         .flags = VHOST_USER_VERSION,
 504     };
 505
 506     vhost_user_write(dev, &msg, NULL, 0);
 507
 508     return 0;
 509 }
 510
 511 static int vhost_user_init(struct vhost_dev *dev, void *opaque)
 512 {
 513     uint64_t features;
 514     int err;
 515
 516     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
 517
 518     dev->opaque = opaque;
 519
 520     err = vhost_user_get_features(dev, &features);
 521     if (err < 0) {
 522         return err;
 523     }
 524
 525     if (virtio_has_feature(features, VHOST_USER_F_PROTOCOL_FEATURES)) {
 526         dev->backend_features |= 1ULL << VHOST_USER_F_PROTOCOL_FEATURES;
 527
 528         err = vhost_user_get_u64(dev, VHOST_USER_GET_PROTOCOL_FEATURES,
 529                                  &features);
 530         if (err < 0) {
 531             return err;
 532         }
 533
 534         dev->protocol_features = features & VHOST_USER_PROTOCOL_FEATURE_MASK;
 535         err = vhost_user_set_protocol_features(dev, dev->protocol_features);
 536         if (err < 0) {
 537             return err;
 538         }
 539
 540         /* query the max queues we support if backend supports Multiple Queue */
 541         if (dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_MQ)) {
 542             err = vhost_user_get_u64(dev, VHOST_USER_GET_QUEUE_NUM,
 543                                      &dev->max_queues);
 544             if (err < 0) {
 545                 return err;
 546             }
 547         }
 548     }
 549
 550     if (dev->migration_blocker == NULL &&
 551         !virtio_has_feature(dev->protocol_features,
 552                             VHOST_USER_PROTOCOL_F_LOG_SHMFD)) {
 553         error_setg(&dev->migration_blocker,
 554                    "Migration disabled: vhost-user backend lacks "
 555                    "VHOST_USER_PROTOCOL_F_LOG_SHMFD feature.");
 556     }
 557
 558     return 0;
 559 }
 560
 561 static int vhost_user_cleanup(struct vhost_dev *dev)
 562 {
 563     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
 564
 565     dev->opaque = 0;
 566
 567     return 0;
 568 }
 569
 570 static int vhost_user_get_vq_index(struct vhost_dev *dev, int idx)
 571 {
 572     assert(idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs);
 573
 574     return idx;
 575 }
 576
 577 static int vhost_user_memslots_limit(struct vhost_dev *dev)
 578 {
 579     return VHOST_MEMORY_MAX_NREGIONS;
 580 }
 581
 582 static bool vhost_user_requires_shm_log(struct vhost_dev *dev)
 583 {
 584     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
 585
 586     return virtio_has_feature(dev->protocol_features,
 587                               VHOST_USER_PROTOCOL_F_LOG_SHMFD);
 588 }
 589
 590 static int vhost_user_migration_done(struct vhost_dev *dev, char* mac_addr)
 591 {
 592     VhostUserMsg msg = { 0 };
 593     int err;
 594
 595     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
 596
 597     /* If guest supports GUEST_ANNOUNCE do nothing */
 598     if (virtio_has_feature(dev->acked_features, VIRTIO_NET_F_GUEST_ANNOUNCE)) {
 599         return 0;
 600     }
 601
 602     /* if backend supports VHOST_USER_PROTOCOL_F_RARP ask it to send the RARP */
 603     if (virtio_has_feature(dev->protocol_features,
 604                            VHOST_USER_PROTOCOL_F_RARP)) {
 605         msg.request = VHOST_USER_SEND_RARP;
 606         msg.flags = VHOST_USER_VERSION;
 607         memcpy((char *)&msg.payload.u64, mac_addr, 6);
 608         msg.size = sizeof(msg.payload.u64);
 609
 610         err = vhost_user_write(dev, &msg, NULL, 0);
 611         return err;
 612     }
 613     return -1;
 614 }
 615
 616 static bool vhost_user_can_merge(struct vhost_dev *dev,
 617                                  uint64_t start1, uint64_t size1,
 618                                  uint64_t start2, uint64_t size2)
 619 {
 620     ram_addr_t ram_addr;
 621     int mfd, rfd;
 622     MemoryRegion *mr;
 623
 624     mr = qemu_ram_addr_from_host((void *)(uintptr_t)start1, &ram_addr);
 625     mfd = memory_region_get_fd(mr);
 626
 627     mr = qemu_ram_addr_from_host((void *)(uintptr_t)start2, &ram_addr);
 628     rfd = memory_region_get_fd(mr);
 629
 630     return mfd == rfd;
 631 }
 632
 633 const VhostOps user_ops = {
 634         .backend_type = VHOST_BACKEND_TYPE_USER,
 635         .vhost_backend_init = vhost_user_init,
 636         .vhost_backend_cleanup = vhost_user_cleanup,
 637         .vhost_backend_memslots_limit = vhost_user_memslots_limit,
 638         .vhost_set_log_base = vhost_user_set_log_base,
 639         .vhost_set_mem_table = vhost_user_set_mem_table,
 640         .vhost_set_vring_addr = vhost_user_set_vring_addr,
 641         .vhost_set_vring_endian = vhost_user_set_vring_endian,
 642         .vhost_set_vring_num = vhost_user_set_vring_num,
 643         .vhost_set_vring_base = vhost_user_set_vring_base,
 644         .vhost_get_vring_base = vhost_user_get_vring_base,
 645         .vhost_set_vring_kick = vhost_user_set_vring_kick,
 646         .vhost_set_vring_call = vhost_user_set_vring_call,
 647         .vhost_set_features = vhost_user_set_features,
 648         .vhost_get_features = vhost_user_get_features,
 649         .vhost_set_owner = vhost_user_set_owner,
 650         .vhost_reset_device = vhost_user_reset_device,
 651         .vhost_get_vq_index = vhost_user_get_vq_index,
 652         .vhost_set_vring_enable = vhost_user_set_vring_enable,
 653         .vhost_requires_shm_log = vhost_user_requires_shm_log,
 654         .vhost_migration_done = vhost_user_migration_done,
 655         .vhost_backend_can_merge = vhost_user_can_merge,
 656 };