hw/vhost.c

   1 /*
   2  * vhost support
   3  *
   4  * Copyright Red Hat, Inc. 2010
   5  *
   6  * Authors:
   7  *  Michael S. Tsirkin <mst@redhat.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2.  See
  10  * the COPYING file in the top-level directory.
  11  */
  12
  13 #include <sys/ioctl.h>
  14 #include "vhost.h"
  15 #include "hw/hw.h"
  16 #include "range.h"
  17 #include <linux/vhost.h>
  18
  19 static void vhost_dev_sync_region(struct vhost_dev *dev,
  20                                   uint64_t mfirst, uint64_t mlast,
  21                                   uint64_t rfirst, uint64_t rlast)
  22 {
  23     uint64_t start = MAX(mfirst, rfirst);
  24     uint64_t end = MIN(mlast, rlast);
  25     vhost_log_chunk_t *from = dev->log + start / VHOST_LOG_CHUNK;
  26     vhost_log_chunk_t *to = dev->log + end / VHOST_LOG_CHUNK + 1;
  27     uint64_t addr = (start / VHOST_LOG_CHUNK) * VHOST_LOG_CHUNK;
  28
  29     assert(end / VHOST_LOG_CHUNK < dev->log_size);
  30     assert(start / VHOST_LOG_CHUNK < dev->log_size);
  31     if (end < start) {
  32         return;
  33     }
  34     for (;from < to; ++from) {
  35         vhost_log_chunk_t log;
  36         int bit;
  37         /* We first check with non-atomic: much cheaper,
  38          * and we expect non-dirty to be the common case. */
  39         if (!*from) {
  40             continue;
  41         }
  42         /* Data must be read atomically. We don't really
  43          * need the barrier semantics of __sync
  44          * builtins, but it's easier to use them than
  45          * roll our own. */
  46         log = __sync_fetch_and_and(from, 0);
  47         while ((bit = sizeof(log) > sizeof(int) ?
  48                 ffsll(log) : ffs(log))) {
  49             bit -= 1;
  50             cpu_physical_memory_set_dirty(addr + bit * VHOST_LOG_PAGE);
  51             log &= ~(0x1ull << bit);
  52         }
  53         addr += VHOST_LOG_CHUNK;
  54     }
  55 }
  56
  57 static int vhost_client_sync_dirty_bitmap(CPUPhysMemoryClient *client,
  58                                           target_phys_addr_t start_addr,
  59                                           target_phys_addr_t end_addr)
  60 {
  61     struct vhost_dev *dev = container_of(client, struct vhost_dev, client);
  62     int i;
  63     if (!dev->log_enabled || !dev->started) {
  64         return 0;
  65     }
  66     for (i = 0; i < dev->mem->nregions; ++i) {
  67         struct vhost_memory_region *reg = dev->mem->regions + i;
  68         vhost_dev_sync_region(dev, start_addr, end_addr,
  69                               reg->guest_phys_addr,
  70                               range_get_last(reg->guest_phys_addr,
  71                                              reg->memory_size));
  72     }
  73     for (i = 0; i < dev->nvqs; ++i) {
  74         struct vhost_virtqueue *vq = dev->vqs + i;
  75         vhost_dev_sync_region(dev, start_addr, end_addr, vq->used_phys,
  76                               range_get_last(vq->used_phys, vq->used_size));
  77     }
  78     return 0;
  79 }
  80
  81 /* Assign/unassign. Keep an unsorted array of non-overlapping
  82  * memory regions in dev->mem. */
  83 static void vhost_dev_unassign_memory(struct vhost_dev *dev,
  84                                       uint64_t start_addr,
  85                                       uint64_t size)
  86 {
  87     int from, to, n = dev->mem->nregions;
  88     /* Track overlapping/split regions for sanity checking. */
  89     int overlap_start = 0, overlap_end = 0, overlap_middle = 0, split = 0;
  90
  91     for (from = 0, to = 0; from < n; ++from, ++to) {
  92         struct vhost_memory_region *reg = dev->mem->regions + to;
  93         uint64_t reglast;
  94         uint64_t memlast;
  95         uint64_t change;
  96
  97         /* clone old region */
  98         if (to != from) {
  99             memcpy(reg, dev->mem->regions + from, sizeof *reg);
 100         }
 101
 102         /* No overlap is simple */
 103         if (!ranges_overlap(reg->guest_phys_addr, reg->memory_size,
 104                             start_addr, size)) {
 105             continue;
 106         }
 107
 108         /* Split only happens if supplied region
 109          * is in the middle of an existing one. Thus it can not
 110          * overlap with any other existing region. */
 111         assert(!split);
 112
 113         reglast = range_get_last(reg->guest_phys_addr, reg->memory_size);
 114         memlast = range_get_last(start_addr, size);
 115
 116         /* Remove whole region */
 117         if (start_addr <= reg->guest_phys_addr && memlast >= reglast) {
 118             --dev->mem->nregions;
 119             --to;
 120             assert(to >= 0);
 121             ++overlap_middle;
 122             continue;
 123         }
 124
 125         /* Shrink region */
 126         if (memlast >= reglast) {
 127             reg->memory_size = start_addr - reg->guest_phys_addr;
 128             assert(reg->memory_size);
 129             assert(!overlap_end);
 130             ++overlap_end;
 131             continue;
 132         }
 133
 134         /* Shift region */
 135         if (start_addr <= reg->guest_phys_addr) {
 136             change = memlast + 1 - reg->guest_phys_addr;
 137             reg->memory_size -= change;
 138             reg->guest_phys_addr += change;
 139             reg->userspace_addr += change;
 140             assert(reg->memory_size);
 141             assert(!overlap_start);
 142             ++overlap_start;
 143             continue;
 144         }
 145
 146         /* This only happens if supplied region
 147          * is in the middle of an existing one. Thus it can not
 148          * overlap with any other existing region. */
 149         assert(!overlap_start);
 150         assert(!overlap_end);
 151         assert(!overlap_middle);
 152         /* Split region: shrink first part, shift second part. */
 153         memcpy(dev->mem->regions + n, reg, sizeof *reg);
 154         reg->memory_size = start_addr - reg->guest_phys_addr;
 155         assert(reg->memory_size);
 156         change = memlast + 1 - reg->guest_phys_addr;
 157         reg = dev->mem->regions + n;
 158         reg->memory_size -= change;
 159         assert(reg->memory_size);
 160         reg->guest_phys_addr += change;
 161         reg->userspace_addr += change;
 162         /* Never add more than 1 region */
 163         assert(dev->mem->nregions == n);
 164         ++dev->mem->nregions;
 165         ++split;
 166     }
 167 }
 168
 169 /* Called after unassign, so no regions overlap the given range. */
 170 static void vhost_dev_assign_memory(struct vhost_dev *dev,
 171                                     uint64_t start_addr,
 172                                     uint64_t size,
 173                                     uint64_t uaddr)
 174 {
 175     int from, to;
 176     struct vhost_memory_region *merged = NULL;
 177     for (from = 0, to = 0; from < dev->mem->nregions; ++from, ++to) {
 178         struct vhost_memory_region *reg = dev->mem->regions + to;
 179         uint64_t prlast, urlast;
 180         uint64_t pmlast, umlast;
 181         uint64_t s, e, u;
 182
 183         /* clone old region */
 184         if (to != from) {
 185             memcpy(reg, dev->mem->regions + from, sizeof *reg);
 186         }
 187         prlast = range_get_last(reg->guest_phys_addr, reg->memory_size);
 188         pmlast = range_get_last(start_addr, size);
 189         urlast = range_get_last(reg->userspace_addr, reg->memory_size);
 190         umlast = range_get_last(uaddr, size);
 191
 192         /* check for overlapping regions: should never happen. */
 193         assert(prlast < start_addr || pmlast < reg->guest_phys_addr);
 194         /* Not an adjacent or overlapping region - do not merge. */
 195         if ((prlast + 1 != start_addr || urlast + 1 != uaddr) &&
 196             (pmlast + 1 != reg->guest_phys_addr ||
 197              umlast + 1 != reg->userspace_addr)) {
 198             continue;
 199         }
 200
 201         if (merged) {
 202             --to;
 203             assert(to >= 0);
 204         } else {
 205             merged = reg;
 206         }
 207         u = MIN(uaddr, reg->userspace_addr);
 208         s = MIN(start_addr, reg->guest_phys_addr);
 209         e = MAX(pmlast, prlast);
 210         uaddr = merged->userspace_addr = u;
 211         start_addr = merged->guest_phys_addr = s;
 212         size = merged->memory_size = e - s + 1;
 213         assert(merged->memory_size);
 214     }
 215
 216     if (!merged) {
 217         struct vhost_memory_region *reg = dev->mem->regions + to;
 218         memset(reg, 0, sizeof *reg);
 219         reg->memory_size = size;
 220         assert(reg->memory_size);
 221         reg->guest_phys_addr = start_addr;
 222         reg->userspace_addr = uaddr;
 223         ++to;
 224     }
 225     assert(to <= dev->mem->nregions + 1);
 226     dev->mem->nregions = to;
 227 }
 228
 229 static uint64_t vhost_get_log_size(struct vhost_dev *dev)
 230 {
 231     uint64_t log_size = 0;
 232     int i;
 233     for (i = 0; i < dev->mem->nregions; ++i) {
 234         struct vhost_memory_region *reg = dev->mem->regions + i;
 235         uint64_t last = range_get_last(reg->guest_phys_addr,
 236                                        reg->memory_size);
 237         log_size = MAX(log_size, last / VHOST_LOG_CHUNK + 1);
 238     }
 239     for (i = 0; i < dev->nvqs; ++i) {
 240         struct vhost_virtqueue *vq = dev->vqs + i;
 241         uint64_t last = vq->used_phys + vq->used_size - 1;
 242         log_size = MAX(log_size, last / VHOST_LOG_CHUNK + 1);
 243     }
 244     return log_size;
 245 }
 246
 247 static inline void vhost_dev_log_resize(struct vhost_dev* dev, uint64_t size)
 248 {
 249     vhost_log_chunk_t *log;
 250     uint64_t log_base;
 251     int r;
 252     if (size) {
 253         log = qemu_mallocz(size * sizeof *log);
 254     } else {
 255         log = NULL;
 256     }
 257     log_base = (uint64_t)(unsigned long)log;
 258     r = ioctl(dev->control, VHOST_SET_LOG_BASE, &log_base);
 259     assert(r >= 0);
 260     vhost_client_sync_dirty_bitmap(&dev->client, 0,
 261                                    (target_phys_addr_t)~0x0ull);
 262     if (dev->log) {
 263         qemu_free(dev->log);
 264     }
 265     dev->log = log;
 266     dev->log_size = size;
 267 }
 268
 269 static int vhost_verify_ring_mappings(struct vhost_dev *dev,
 270                                       uint64_t start_addr,
 271                                       uint64_t size)
 272 {
 273     int i;
 274     for (i = 0; i < dev->nvqs; ++i) {
 275         struct vhost_virtqueue *vq = dev->vqs + i;
 276         target_phys_addr_t l;
 277         void *p;
 278
 279         if (!ranges_overlap(start_addr, size, vq->ring_phys, vq->ring_size)) {
 280             continue;
 281         }
 282         l = vq->ring_size;
 283         p = cpu_physical_memory_map(vq->ring_phys, &l, 1);
 284         if (!p || l != vq->ring_size) {
 285             fprintf(stderr, "Unable to map ring buffer for ring %d\n", i);
 286             return -ENOMEM;
 287         }
 288         if (p != vq->ring) {
 289             fprintf(stderr, "Ring buffer relocated for ring %d\n", i);
 290             return -EBUSY;
 291         }
 292         cpu_physical_memory_unmap(p, l, 0, 0);
 293     }
 294     return 0;
 295 }
 296
 297 static void vhost_client_set_memory(CPUPhysMemoryClient *client,
 298                                     target_phys_addr_t start_addr,
 299                                     ram_addr_t size,
 300                                     ram_addr_t phys_offset)
 301 {
 302     struct vhost_dev *dev = container_of(client, struct vhost_dev, client);
 303     ram_addr_t flags = phys_offset & ~TARGET_PAGE_MASK;
 304     int s = offsetof(struct vhost_memory, regions) +
 305         (dev->mem->nregions + 1) * sizeof dev->mem->regions[0];
 306     uint64_t log_size;
 307     int r;
 308     dev->mem = qemu_realloc(dev->mem, s);
 309
 310     assert(size);
 311
 312     vhost_dev_unassign_memory(dev, start_addr, size);
 313     if (flags == IO_MEM_RAM) {
 314         /* Add given mapping, merging adjacent regions if any */
 315         vhost_dev_assign_memory(dev, start_addr, size,
 316                                 (uintptr_t)qemu_get_ram_ptr(phys_offset));
 317     } else {
 318         /* Remove old mapping for this memory, if any. */
 319         vhost_dev_unassign_memory(dev, start_addr, size);
 320     }
 321
 322     if (!dev->started) {
 323         return;
 324     }
 325
 326     if (dev->started) {
 327         r = vhost_verify_ring_mappings(dev, start_addr, size);
 328         assert(r >= 0);
 329     }
 330
 331     if (!dev->log_enabled) {
 332         r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem);
 333         assert(r >= 0);
 334         return;
 335     }
 336     log_size = vhost_get_log_size(dev);
 337     /* We allocate an extra 4K bytes to log,
 338      * to reduce the * number of reallocations. */
 339 #define VHOST_LOG_BUFFER (0x1000 / sizeof *dev->log)
 340     /* To log more, must increase log size before table update. */
 341     if (dev->log_size < log_size) {
 342         vhost_dev_log_resize(dev, log_size + VHOST_LOG_BUFFER);
 343     }
 344     r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem);
 345     assert(r >= 0);
 346     /* To log less, can only decrease log size after table update. */
 347     if (dev->log_size > log_size + VHOST_LOG_BUFFER) {
 348         vhost_dev_log_resize(dev, log_size);
 349     }
 350 }
 351
 352 static int vhost_virtqueue_set_addr(struct vhost_dev *dev,
 353                                     struct vhost_virtqueue *vq,
 354                                     unsigned idx, bool enable_log)
 355 {
 356     struct vhost_vring_addr addr = {
 357         .index = idx,
 358         .desc_user_addr = (uint64_t)(unsigned long)vq->desc,
 359         .avail_user_addr = (uint64_t)(unsigned long)vq->avail,
 360         .used_user_addr = (uint64_t)(unsigned long)vq->used,
 361         .log_guest_addr = vq->used_phys,
 362         .flags = enable_log ? (1 << VHOST_VRING_F_LOG) : 0,
 363     };
 364     int r = ioctl(dev->control, VHOST_SET_VRING_ADDR, &addr);
 365     if (r < 0) {
 366         return -errno;
 367     }
 368     return 0;
 369 }
 370
 371 static int vhost_dev_set_features(struct vhost_dev *dev, bool enable_log)
 372 {
 373     uint64_t features = dev->acked_features;
 374     int r;
 375     if (enable_log) {
 376         features |= 0x1 << VHOST_F_LOG_ALL;
 377     }
 378     r = ioctl(dev->control, VHOST_SET_FEATURES, &features);
 379     return r < 0 ? -errno : 0;
 380 }
 381
 382 static int vhost_dev_set_log(struct vhost_dev *dev, bool enable_log)
 383 {
 384     int r, t, i;
 385     r = vhost_dev_set_features(dev, enable_log);
 386     if (r < 0) {
 387         goto err_features;
 388     }
 389     for (i = 0; i < dev->nvqs; ++i) {
 390         r = vhost_virtqueue_set_addr(dev, dev->vqs + i, i,
 391                                      enable_log);
 392         if (r < 0) {
 393             goto err_vq;
 394         }
 395     }
 396     return 0;
 397 err_vq:
 398     for (; i >= 0; --i) {
 399         t = vhost_virtqueue_set_addr(dev, dev->vqs + i, i,
 400                                      dev->log_enabled);
 401         assert(t >= 0);
 402     }
 403     t = vhost_dev_set_features(dev, dev->log_enabled);
 404     assert(t >= 0);
 405 err_features:
 406     return r;
 407 }
 408
 409 static int vhost_client_migration_log(CPUPhysMemoryClient *client,
 410                                       int enable)
 411 {
 412     struct vhost_dev *dev = container_of(client, struct vhost_dev, client);
 413     int r;
 414     if (!!enable == dev->log_enabled) {
 415         return 0;
 416     }
 417     if (!dev->started) {
 418         dev->log_enabled = enable;
 419         return 0;
 420     }
 421     if (!enable) {
 422         r = vhost_dev_set_log(dev, false);
 423         if (r < 0) {
 424             return r;
 425         }
 426         if (dev->log) {
 427             qemu_free(dev->log);
 428         }
 429         dev->log = NULL;
 430         dev->log_size = 0;
 431     } else {
 432         vhost_dev_log_resize(dev, vhost_get_log_size(dev));
 433         r = vhost_dev_set_log(dev, true);
 434         if (r < 0) {
 435             return r;
 436         }
 437     }
 438     dev->log_enabled = enable;
 439     return 0;
 440 }
 441
 442 static int vhost_virtqueue_init(struct vhost_dev *dev,
 443                                 struct VirtIODevice *vdev,
 444                                 struct vhost_virtqueue *vq,
 445                                 unsigned idx)
 446 {
 447     target_phys_addr_t s, l, a;
 448     int r;
 449     struct vhost_vring_file file = {
 450         .index = idx,
 451     };
 452     struct vhost_vring_state state = {
 453         .index = idx,
 454     };
 455     struct VirtQueue *vvq = virtio_get_queue(vdev, idx);
 456
 457     if (!vdev->binding->set_guest_notifier) {
 458         fprintf(stderr, "binding does not support guest notifiers\n");
 459         return -ENOSYS;
 460     }
 461
 462     if (!vdev->binding->set_host_notifier) {
 463         fprintf(stderr, "binding does not support host notifiers\n");
 464         return -ENOSYS;
 465     }
 466
 467     vq->num = state.num = virtio_queue_get_num(vdev, idx);
 468     r = ioctl(dev->control, VHOST_SET_VRING_NUM, &state);
 469     if (r) {
 470         return -errno;
 471     }
 472
 473     state.num = virtio_queue_get_last_avail_idx(vdev, idx);
 474     r = ioctl(dev->control, VHOST_SET_VRING_BASE, &state);
 475     if (r) {
 476         return -errno;
 477     }
 478
 479     s = l = virtio_queue_get_desc_size(vdev, idx);
 480     a = virtio_queue_get_desc_addr(vdev, idx);
 481     vq->desc = cpu_physical_memory_map(a, &l, 0);
 482     if (!vq->desc || l != s) {
 483         r = -ENOMEM;
 484         goto fail_alloc_desc;
 485     }
 486     s = l = virtio_queue_get_avail_size(vdev, idx);
 487     a = virtio_queue_get_avail_addr(vdev, idx);
 488     vq->avail = cpu_physical_memory_map(a, &l, 0);
 489     if (!vq->avail || l != s) {
 490         r = -ENOMEM;
 491         goto fail_alloc_avail;
 492     }
 493     vq->used_size = s = l = virtio_queue_get_used_size(vdev, idx);
 494     vq->used_phys = a = virtio_queue_get_used_addr(vdev, idx);
 495     vq->used = cpu_physical_memory_map(a, &l, 1);
 496     if (!vq->used || l != s) {
 497         r = -ENOMEM;
 498         goto fail_alloc_used;
 499     }
 500
 501     vq->ring_size = s = l = virtio_queue_get_ring_size(vdev, idx);
 502     vq->ring_phys = a = virtio_queue_get_ring_addr(vdev, idx);
 503     vq->ring = cpu_physical_memory_map(a, &l, 1);
 504     if (!vq->ring || l != s) {
 505         r = -ENOMEM;
 506         goto fail_alloc_ring;
 507     }
 508
 509     r = vhost_virtqueue_set_addr(dev, vq, idx, dev->log_enabled);
 510     if (r < 0) {
 511         r = -errno;
 512         goto fail_alloc;
 513     }
 514     r = vdev->binding->set_guest_notifier(vdev->binding_opaque, idx, true);
 515     if (r < 0) {
 516         fprintf(stderr, "Error binding guest notifier: %d\n", -r);
 517         goto fail_guest_notifier;
 518     }
 519
 520     r = vdev->binding->set_host_notifier(vdev->binding_opaque, idx, true);
 521     if (r < 0) {
 522         fprintf(stderr, "Error binding host notifier: %d\n", -r);
 523         goto fail_host_notifier;
 524     }
 525
 526     file.fd = event_notifier_get_fd(virtio_queue_get_host_notifier(vvq));
 527     r = ioctl(dev->control, VHOST_SET_VRING_KICK, &file);
 528     if (r) {
 529         goto fail_kick;
 530     }
 531
 532     file.fd = event_notifier_get_fd(virtio_queue_get_guest_notifier(vvq));
 533     r = ioctl(dev->control, VHOST_SET_VRING_CALL, &file);
 534     if (r) {
 535         goto fail_call;
 536     }
 537
 538     return 0;
 539
 540 fail_call:
 541 fail_kick:
 542     vdev->binding->set_host_notifier(vdev->binding_opaque, idx, false);
 543 fail_host_notifier:
 544     vdev->binding->set_guest_notifier(vdev->binding_opaque, idx, false);
 545 fail_guest_notifier:
 546 fail_alloc:
 547     cpu_physical_memory_unmap(vq->ring, virtio_queue_get_ring_size(vdev, idx),
 548                               0, 0);
 549 fail_alloc_ring:
 550     cpu_physical_memory_unmap(vq->used, virtio_queue_get_used_size(vdev, idx),
 551                               0, 0);
 552 fail_alloc_used:
 553     cpu_physical_memory_unmap(vq->avail, virtio_queue_get_avail_size(vdev, idx),
 554                               0, 0);
 555 fail_alloc_avail:
 556     cpu_physical_memory_unmap(vq->desc, virtio_queue_get_desc_size(vdev, idx),
 557                               0, 0);
 558 fail_alloc_desc:
 559     return r;
 560 }
 561
 562 static void vhost_virtqueue_cleanup(struct vhost_dev *dev,
 563                                     struct VirtIODevice *vdev,
 564                                     struct vhost_virtqueue *vq,
 565                                     unsigned idx)
 566 {
 567     struct vhost_vring_state state = {
 568         .index = idx,
 569     };
 570     int r;
 571     r = vdev->binding->set_guest_notifier(vdev->binding_opaque, idx, false);
 572     if (r < 0) {
 573         fprintf(stderr, "vhost VQ %d guest cleanup failed: %d\n", idx, r);
 574         fflush(stderr);
 575     }
 576     assert (r >= 0);
 577
 578     r = vdev->binding->set_host_notifier(vdev->binding_opaque, idx, false);
 579     if (r < 0) {
 580         fprintf(stderr, "vhost VQ %d host cleanup failed: %d\n", idx, r);
 581         fflush(stderr);
 582     }
 583     assert (r >= 0);
 584     r = ioctl(dev->control, VHOST_GET_VRING_BASE, &state);
 585     if (r < 0) {
 586         fprintf(stderr, "vhost VQ %d ring restore failed: %d\n", idx, r);
 587         fflush(stderr);
 588     }
 589     virtio_queue_set_last_avail_idx(vdev, idx, state.num);
 590     assert (r >= 0);
 591     cpu_physical_memory_unmap(vq->ring, virtio_queue_get_ring_size(vdev, idx),
 592                               0, virtio_queue_get_ring_size(vdev, idx));
 593     cpu_physical_memory_unmap(vq->used, virtio_queue_get_used_size(vdev, idx),
 594                               1, virtio_queue_get_used_size(vdev, idx));
 595     cpu_physical_memory_unmap(vq->avail, virtio_queue_get_avail_size(vdev, idx),
 596                               0, virtio_queue_get_avail_size(vdev, idx));
 597     cpu_physical_memory_unmap(vq->desc, virtio_queue_get_desc_size(vdev, idx),
 598                               0, virtio_queue_get_desc_size(vdev, idx));
 599 }
 600
 601 int vhost_dev_init(struct vhost_dev *hdev, int devfd)
 602 {
 603     uint64_t features;
 604     int r;
 605     if (devfd >= 0) {
 606         hdev->control = devfd;
 607     } else {
 608         hdev->control = open("/dev/vhost-net", O_RDWR);
 609         if (hdev->control < 0) {
 610             return -errno;
 611         }
 612     }
 613     r = ioctl(hdev->control, VHOST_SET_OWNER, NULL);
 614     if (r < 0) {
 615         goto fail;
 616     }
 617
 618     r = ioctl(hdev->control, VHOST_GET_FEATURES, &features);
 619     if (r < 0) {
 620         goto fail;
 621     }
 622     hdev->features = features;
 623
 624     hdev->client.set_memory = vhost_client_set_memory;
 625     hdev->client.sync_dirty_bitmap = vhost_client_sync_dirty_bitmap;
 626     hdev->client.migration_log = vhost_client_migration_log;
 627     hdev->mem = qemu_mallocz(offsetof(struct vhost_memory, regions));
 628     hdev->log = NULL;
 629     hdev->log_size = 0;
 630     hdev->log_enabled = false;
 631     hdev->started = false;
 632     cpu_register_phys_memory_client(&hdev->client);
 633     return 0;
 634 fail:
 635     r = -errno;
 636     close(hdev->control);
 637     return r;
 638 }
 639
 640 void vhost_dev_cleanup(struct vhost_dev *hdev)
 641 {
 642     cpu_unregister_phys_memory_client(&hdev->client);
 643     qemu_free(hdev->mem);
 644     close(hdev->control);
 645 }
 646
 647 int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev)
 648 {
 649     int i, r;
 650
 651     r = vhost_dev_set_features(hdev, hdev->log_enabled);
 652     if (r < 0) {
 653         goto fail;
 654     }
 655     r = ioctl(hdev->control, VHOST_SET_MEM_TABLE, hdev->mem);
 656     if (r < 0) {
 657         r = -errno;
 658         goto fail;
 659     }
 660     for (i = 0; i < hdev->nvqs; ++i) {
 661         r = vhost_virtqueue_init(hdev,
 662                                  vdev,
 663                                  hdev->vqs + i,
 664                                  i);
 665         if (r < 0) {
 666             goto fail_vq;
 667         }
 668     }
 669
 670     if (hdev->log_enabled) {
 671         hdev->log_size = vhost_get_log_size(hdev);
 672         hdev->log = hdev->log_size ?
 673             qemu_mallocz(hdev->log_size * sizeof *hdev->log) : NULL;
 674         r = ioctl(hdev->control, VHOST_SET_LOG_BASE,
 675                   (uint64_t)(unsigned long)hdev->log);
 676         if (r < 0) {
 677             r = -errno;
 678             goto fail_vq;
 679         }
 680     }
 681
 682     hdev->started = true;
 683
 684     return 0;
 685 fail_vq:
 686     while (--i >= 0) {
 687         vhost_virtqueue_cleanup(hdev,
 688                                 vdev,
 689                                 hdev->vqs + i,
 690                                 i);
 691     }
 692 fail:
 693     return r;
 694 }
 695
 696 void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
 697 {
 698     int i;
 699     for (i = 0; i < hdev->nvqs; ++i) {
 700         vhost_virtqueue_cleanup(hdev,
 701                                 vdev,
 702                                 hdev->vqs + i,
 703                                 i);
 704     }
 705     vhost_client_sync_dirty_bitmap(&hdev->client, 0,
 706                                    (target_phys_addr_t)~0x0ull);
 707     hdev->started = false;
 708     qemu_free(hdev->log);
 709     hdev->log_size = 0;
 710 }