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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
            addr += VHOST_LOG_CHUNK;
41
            continue;
42
        }
43
        /* Data must be read atomically. We don't really
44
         * need the barrier semantics of __sync
45
         * builtins, but it's easier to use them than
46
         * roll our own. */
47
        log = __sync_fetch_and_and(from, 0);
48
        while ((bit = sizeof(log) > sizeof(int) ?
49
                ffsll(log) : ffs(log))) {
50
            ram_addr_t ram_addr;
51
            bit -= 1;
52
            ram_addr = cpu_get_physical_page_desc(addr + bit * VHOST_LOG_PAGE);
53
            cpu_physical_memory_set_dirty(ram_addr);
54
            log &= ~(0x1ull << bit);
55
        }
56
        addr += VHOST_LOG_CHUNK;
57
    }
58
}
59

    
60
static int vhost_client_sync_dirty_bitmap(CPUPhysMemoryClient *client,
61
                                          target_phys_addr_t start_addr,
62
                                          target_phys_addr_t end_addr)
63
{
64
    struct vhost_dev *dev = container_of(client, struct vhost_dev, client);
65
    int i;
66
    if (!dev->log_enabled || !dev->started) {
67
        return 0;
68
    }
69
    for (i = 0; i < dev->mem->nregions; ++i) {
70
        struct vhost_memory_region *reg = dev->mem->regions + i;
71
        vhost_dev_sync_region(dev, start_addr, end_addr,
72
                              reg->guest_phys_addr,
73
                              range_get_last(reg->guest_phys_addr,
74
                                             reg->memory_size));
75
    }
76
    for (i = 0; i < dev->nvqs; ++i) {
77
        struct vhost_virtqueue *vq = dev->vqs + i;
78
        vhost_dev_sync_region(dev, start_addr, end_addr, vq->used_phys,
79
                              range_get_last(vq->used_phys, vq->used_size));
80
    }
81
    return 0;
82
}
83

    
84
/* Assign/unassign. Keep an unsorted array of non-overlapping
85
 * memory regions in dev->mem. */
86
static void vhost_dev_unassign_memory(struct vhost_dev *dev,
87
                                      uint64_t start_addr,
88
                                      uint64_t size)
89
{
90
    int from, to, n = dev->mem->nregions;
91
    /* Track overlapping/split regions for sanity checking. */
92
    int overlap_start = 0, overlap_end = 0, overlap_middle = 0, split = 0;
93

    
94
    for (from = 0, to = 0; from < n; ++from, ++to) {
95
        struct vhost_memory_region *reg = dev->mem->regions + to;
96
        uint64_t reglast;
97
        uint64_t memlast;
98
        uint64_t change;
99

    
100
        /* clone old region */
101
        if (to != from) {
102
            memcpy(reg, dev->mem->regions + from, sizeof *reg);
103
        }
104

    
105
        /* No overlap is simple */
106
        if (!ranges_overlap(reg->guest_phys_addr, reg->memory_size,
107
                            start_addr, size)) {
108
            continue;
109
        }
110

    
111
        /* Split only happens if supplied region
112
         * is in the middle of an existing one. Thus it can not
113
         * overlap with any other existing region. */
114
        assert(!split);
115

    
116
        reglast = range_get_last(reg->guest_phys_addr, reg->memory_size);
117
        memlast = range_get_last(start_addr, size);
118

    
119
        /* Remove whole region */
120
        if (start_addr <= reg->guest_phys_addr && memlast >= reglast) {
121
            --dev->mem->nregions;
122
            --to;
123
            assert(to >= 0);
124
            ++overlap_middle;
125
            continue;
126
        }
127

    
128
        /* Shrink region */
129
        if (memlast >= reglast) {
130
            reg->memory_size = start_addr - reg->guest_phys_addr;
131
            assert(reg->memory_size);
132
            assert(!overlap_end);
133
            ++overlap_end;
134
            continue;
135
        }
136

    
137
        /* Shift region */
138
        if (start_addr <= reg->guest_phys_addr) {
139
            change = memlast + 1 - reg->guest_phys_addr;
140
            reg->memory_size -= change;
141
            reg->guest_phys_addr += change;
142
            reg->userspace_addr += change;
143
            assert(reg->memory_size);
144
            assert(!overlap_start);
145
            ++overlap_start;
146
            continue;
147
        }
148

    
149
        /* This only happens if supplied region
150
         * is in the middle of an existing one. Thus it can not
151
         * overlap with any other existing region. */
152
        assert(!overlap_start);
153
        assert(!overlap_end);
154
        assert(!overlap_middle);
155
        /* Split region: shrink first part, shift second part. */
156
        memcpy(dev->mem->regions + n, reg, sizeof *reg);
157
        reg->memory_size = start_addr - reg->guest_phys_addr;
158
        assert(reg->memory_size);
159
        change = memlast + 1 - reg->guest_phys_addr;
160
        reg = dev->mem->regions + n;
161
        reg->memory_size -= change;
162
        assert(reg->memory_size);
163
        reg->guest_phys_addr += change;
164
        reg->userspace_addr += change;
165
        /* Never add more than 1 region */
166
        assert(dev->mem->nregions == n);
167
        ++dev->mem->nregions;
168
        ++split;
169
    }
170
}
171

    
172
/* Called after unassign, so no regions overlap the given range. */
173
static void vhost_dev_assign_memory(struct vhost_dev *dev,
174
                                    uint64_t start_addr,
175
                                    uint64_t size,
176
                                    uint64_t uaddr)
177
{
178
    int from, to;
179
    struct vhost_memory_region *merged = NULL;
180
    for (from = 0, to = 0; from < dev->mem->nregions; ++from, ++to) {
181
        struct vhost_memory_region *reg = dev->mem->regions + to;
182
        uint64_t prlast, urlast;
183
        uint64_t pmlast, umlast;
184
        uint64_t s, e, u;
185

    
186
        /* clone old region */
187
        if (to != from) {
188
            memcpy(reg, dev->mem->regions + from, sizeof *reg);
189
        }
190
        prlast = range_get_last(reg->guest_phys_addr, reg->memory_size);
191
        pmlast = range_get_last(start_addr, size);
192
        urlast = range_get_last(reg->userspace_addr, reg->memory_size);
193
        umlast = range_get_last(uaddr, size);
194

    
195
        /* check for overlapping regions: should never happen. */
196
        assert(prlast < start_addr || pmlast < reg->guest_phys_addr);
197
        /* Not an adjacent or overlapping region - do not merge. */
198
        if ((prlast + 1 != start_addr || urlast + 1 != uaddr) &&
199
            (pmlast + 1 != reg->guest_phys_addr ||
200
             umlast + 1 != reg->userspace_addr)) {
201
            continue;
202
        }
203

    
204
        if (merged) {
205
            --to;
206
            assert(to >= 0);
207
        } else {
208
            merged = reg;
209
        }
210
        u = MIN(uaddr, reg->userspace_addr);
211
        s = MIN(start_addr, reg->guest_phys_addr);
212
        e = MAX(pmlast, prlast);
213
        uaddr = merged->userspace_addr = u;
214
        start_addr = merged->guest_phys_addr = s;
215
        size = merged->memory_size = e - s + 1;
216
        assert(merged->memory_size);
217
    }
218

    
219
    if (!merged) {
220
        struct vhost_memory_region *reg = dev->mem->regions + to;
221
        memset(reg, 0, sizeof *reg);
222
        reg->memory_size = size;
223
        assert(reg->memory_size);
224
        reg->guest_phys_addr = start_addr;
225
        reg->userspace_addr = uaddr;
226
        ++to;
227
    }
228
    assert(to <= dev->mem->nregions + 1);
229
    dev->mem->nregions = to;
230
}
231

    
232
static uint64_t vhost_get_log_size(struct vhost_dev *dev)
233
{
234
    uint64_t log_size = 0;
235
    int i;
236
    for (i = 0; i < dev->mem->nregions; ++i) {
237
        struct vhost_memory_region *reg = dev->mem->regions + i;
238
        uint64_t last = range_get_last(reg->guest_phys_addr,
239
                                       reg->memory_size);
240
        log_size = MAX(log_size, last / VHOST_LOG_CHUNK + 1);
241
    }
242
    for (i = 0; i < dev->nvqs; ++i) {
243
        struct vhost_virtqueue *vq = dev->vqs + i;
244
        uint64_t last = vq->used_phys + vq->used_size - 1;
245
        log_size = MAX(log_size, last / VHOST_LOG_CHUNK + 1);
246
    }
247
    return log_size;
248
}
249

    
250
static inline void vhost_dev_log_resize(struct vhost_dev* dev, uint64_t size)
251
{
252
    vhost_log_chunk_t *log;
253
    uint64_t log_base;
254
    int r;
255
    if (size) {
256
        log = qemu_mallocz(size * sizeof *log);
257
    } else {
258
        log = NULL;
259
    }
260
    log_base = (uint64_t)(unsigned long)log;
261
    r = ioctl(dev->control, VHOST_SET_LOG_BASE, &log_base);
262
    assert(r >= 0);
263
    vhost_client_sync_dirty_bitmap(&dev->client, 0,
264
                                   (target_phys_addr_t)~0x0ull);
265
    if (dev->log) {
266
        qemu_free(dev->log);
267
    }
268
    dev->log = log;
269
    dev->log_size = size;
270
}
271

    
272
static int vhost_verify_ring_mappings(struct vhost_dev *dev,
273
                                      uint64_t start_addr,
274
                                      uint64_t size)
275
{
276
    int i;
277
    for (i = 0; i < dev->nvqs; ++i) {
278
        struct vhost_virtqueue *vq = dev->vqs + i;
279
        target_phys_addr_t l;
280
        void *p;
281

    
282
        if (!ranges_overlap(start_addr, size, vq->ring_phys, vq->ring_size)) {
283
            continue;
284
        }
285
        l = vq->ring_size;
286
        p = cpu_physical_memory_map(vq->ring_phys, &l, 1);
287
        if (!p || l != vq->ring_size) {
288
            fprintf(stderr, "Unable to map ring buffer for ring %d\n", i);
289
            return -ENOMEM;
290
        }
291
        if (p != vq->ring) {
292
            fprintf(stderr, "Ring buffer relocated for ring %d\n", i);
293
            return -EBUSY;
294
        }
295
        cpu_physical_memory_unmap(p, l, 0, 0);
296
    }
297
    return 0;
298
}
299

    
300
static struct vhost_memory_region *vhost_dev_find_reg(struct vhost_dev *dev,
301
                                                      uint64_t start_addr,
302
                                                      uint64_t size)
303
{
304
    int i, n = dev->mem->nregions;
305
    for (i = 0; i < n; ++i) {
306
        struct vhost_memory_region *reg = dev->mem->regions + i;
307
        if (ranges_overlap(reg->guest_phys_addr, reg->memory_size,
308
                           start_addr, size)) {
309
            return reg;
310
        }
311
    }
312
    return NULL;
313
}
314

    
315
static bool vhost_dev_cmp_memory(struct vhost_dev *dev,
316
                                 uint64_t start_addr,
317
                                 uint64_t size,
318
                                 uint64_t uaddr)
319
{
320
    struct vhost_memory_region *reg = vhost_dev_find_reg(dev, start_addr, size);
321
    uint64_t reglast;
322
    uint64_t memlast;
323

    
324
    if (!reg) {
325
        return true;
326
    }
327

    
328
    reglast = range_get_last(reg->guest_phys_addr, reg->memory_size);
329
    memlast = range_get_last(start_addr, size);
330

    
331
    /* Need to extend region? */
332
    if (start_addr < reg->guest_phys_addr || memlast > reglast) {
333
        return true;
334
    }
335
    /* userspace_addr changed? */
336
    return uaddr != reg->userspace_addr + start_addr - reg->guest_phys_addr;
337
}
338

    
339
static void vhost_client_set_memory(CPUPhysMemoryClient *client,
340
                                    target_phys_addr_t start_addr,
341
                                    ram_addr_t size,
342
                                    ram_addr_t phys_offset,
343
                                    bool log_dirty)
344
{
345
    struct vhost_dev *dev = container_of(client, struct vhost_dev, client);
346
    ram_addr_t flags = phys_offset & ~TARGET_PAGE_MASK;
347
    int s = offsetof(struct vhost_memory, regions) +
348
        (dev->mem->nregions + 1) * sizeof dev->mem->regions[0];
349
    uint64_t log_size;
350
    int r;
351

    
352
    dev->mem = qemu_realloc(dev->mem, s);
353

    
354
    if (log_dirty) {
355
        flags = IO_MEM_UNASSIGNED;
356
    }
357

    
358
    assert(size);
359

    
360
    /* Optimize no-change case. At least cirrus_vga does this a lot at this time. */
361
    if (flags == IO_MEM_RAM) {
362
        if (!vhost_dev_cmp_memory(dev, start_addr, size,
363
                                  (uintptr_t)qemu_get_ram_ptr(phys_offset))) {
364
            /* Region exists with same address. Nothing to do. */
365
            return;
366
        }
367
    } else {
368
        if (!vhost_dev_find_reg(dev, start_addr, size)) {
369
            /* Removing region that we don't access. Nothing to do. */
370
            return;
371
        }
372
    }
373

    
374
    vhost_dev_unassign_memory(dev, start_addr, size);
375
    if (flags == IO_MEM_RAM) {
376
        /* Add given mapping, merging adjacent regions if any */
377
        vhost_dev_assign_memory(dev, start_addr, size,
378
                                (uintptr_t)qemu_get_ram_ptr(phys_offset));
379
    } else {
380
        /* Remove old mapping for this memory, if any. */
381
        vhost_dev_unassign_memory(dev, start_addr, size);
382
    }
383

    
384
    if (!dev->started) {
385
        return;
386
    }
387

    
388
    if (dev->started) {
389
        r = vhost_verify_ring_mappings(dev, start_addr, size);
390
        assert(r >= 0);
391
    }
392

    
393
    if (!dev->log_enabled) {
394
        r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem);
395
        assert(r >= 0);
396
        return;
397
    }
398
    log_size = vhost_get_log_size(dev);
399
    /* We allocate an extra 4K bytes to log,
400
     * to reduce the * number of reallocations. */
401
#define VHOST_LOG_BUFFER (0x1000 / sizeof *dev->log)
402
    /* To log more, must increase log size before table update. */
403
    if (dev->log_size < log_size) {
404
        vhost_dev_log_resize(dev, log_size + VHOST_LOG_BUFFER);
405
    }
406
    r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem);
407
    assert(r >= 0);
408
    /* To log less, can only decrease log size after table update. */
409
    if (dev->log_size > log_size + VHOST_LOG_BUFFER) {
410
        vhost_dev_log_resize(dev, log_size);
411
    }
412
}
413

    
414
static int vhost_virtqueue_set_addr(struct vhost_dev *dev,
415
                                    struct vhost_virtqueue *vq,
416
                                    unsigned idx, bool enable_log)
417
{
418
    struct vhost_vring_addr addr = {
419
        .index = idx,
420
        .desc_user_addr = (uint64_t)(unsigned long)vq->desc,
421
        .avail_user_addr = (uint64_t)(unsigned long)vq->avail,
422
        .used_user_addr = (uint64_t)(unsigned long)vq->used,
423
        .log_guest_addr = vq->used_phys,
424
        .flags = enable_log ? (1 << VHOST_VRING_F_LOG) : 0,
425
    };
426
    int r = ioctl(dev->control, VHOST_SET_VRING_ADDR, &addr);
427
    if (r < 0) {
428
        return -errno;
429
    }
430
    return 0;
431
}
432

    
433
static int vhost_dev_set_features(struct vhost_dev *dev, bool enable_log)
434
{
435
    uint64_t features = dev->acked_features;
436
    int r;
437
    if (enable_log) {
438
        features |= 0x1 << VHOST_F_LOG_ALL;
439
    }
440
    r = ioctl(dev->control, VHOST_SET_FEATURES, &features);
441
    return r < 0 ? -errno : 0;
442
}
443

    
444
static int vhost_dev_set_log(struct vhost_dev *dev, bool enable_log)
445
{
446
    int r, t, i;
447
    r = vhost_dev_set_features(dev, enable_log);
448
    if (r < 0) {
449
        goto err_features;
450
    }
451
    for (i = 0; i < dev->nvqs; ++i) {
452
        r = vhost_virtqueue_set_addr(dev, dev->vqs + i, i,
453
                                     enable_log);
454
        if (r < 0) {
455
            goto err_vq;
456
        }
457
    }
458
    return 0;
459
err_vq:
460
    for (; i >= 0; --i) {
461
        t = vhost_virtqueue_set_addr(dev, dev->vqs + i, i,
462
                                     dev->log_enabled);
463
        assert(t >= 0);
464
    }
465
    t = vhost_dev_set_features(dev, dev->log_enabled);
466
    assert(t >= 0);
467
err_features:
468
    return r;
469
}
470

    
471
static int vhost_client_migration_log(CPUPhysMemoryClient *client,
472
                                      int enable)
473
{
474
    struct vhost_dev *dev = container_of(client, struct vhost_dev, client);
475
    int r;
476
    if (!!enable == dev->log_enabled) {
477
        return 0;
478
    }
479
    if (!dev->started) {
480
        dev->log_enabled = enable;
481
        return 0;
482
    }
483
    if (!enable) {
484
        r = vhost_dev_set_log(dev, false);
485
        if (r < 0) {
486
            return r;
487
        }
488
        if (dev->log) {
489
            qemu_free(dev->log);
490
        }
491
        dev->log = NULL;
492
        dev->log_size = 0;
493
    } else {
494
        vhost_dev_log_resize(dev, vhost_get_log_size(dev));
495
        r = vhost_dev_set_log(dev, true);
496
        if (r < 0) {
497
            return r;
498
        }
499
    }
500
    dev->log_enabled = enable;
501
    return 0;
502
}
503

    
504
static int vhost_virtqueue_init(struct vhost_dev *dev,
505
                                struct VirtIODevice *vdev,
506
                                struct vhost_virtqueue *vq,
507
                                unsigned idx)
508
{
509
    target_phys_addr_t s, l, a;
510
    int r;
511
    struct vhost_vring_file file = {
512
        .index = idx,
513
    };
514
    struct vhost_vring_state state = {
515
        .index = idx,
516
    };
517
    struct VirtQueue *vvq = virtio_get_queue(vdev, idx);
518

    
519
    if (!vdev->binding->set_host_notifier) {
520
        fprintf(stderr, "binding does not support host notifiers\n");
521
        return -ENOSYS;
522
    }
523

    
524
    vq->num = state.num = virtio_queue_get_num(vdev, idx);
525
    r = ioctl(dev->control, VHOST_SET_VRING_NUM, &state);
526
    if (r) {
527
        return -errno;
528
    }
529

    
530
    state.num = virtio_queue_get_last_avail_idx(vdev, idx);
531
    r = ioctl(dev->control, VHOST_SET_VRING_BASE, &state);
532
    if (r) {
533
        return -errno;
534
    }
535

    
536
    s = l = virtio_queue_get_desc_size(vdev, idx);
537
    a = virtio_queue_get_desc_addr(vdev, idx);
538
    vq->desc = cpu_physical_memory_map(a, &l, 0);
539
    if (!vq->desc || l != s) {
540
        r = -ENOMEM;
541
        goto fail_alloc_desc;
542
    }
543
    s = l = virtio_queue_get_avail_size(vdev, idx);
544
    a = virtio_queue_get_avail_addr(vdev, idx);
545
    vq->avail = cpu_physical_memory_map(a, &l, 0);
546
    if (!vq->avail || l != s) {
547
        r = -ENOMEM;
548
        goto fail_alloc_avail;
549
    }
550
    vq->used_size = s = l = virtio_queue_get_used_size(vdev, idx);
551
    vq->used_phys = a = virtio_queue_get_used_addr(vdev, idx);
552
    vq->used = cpu_physical_memory_map(a, &l, 1);
553
    if (!vq->used || l != s) {
554
        r = -ENOMEM;
555
        goto fail_alloc_used;
556
    }
557

    
558
    vq->ring_size = s = l = virtio_queue_get_ring_size(vdev, idx);
559
    vq->ring_phys = a = virtio_queue_get_ring_addr(vdev, idx);
560
    vq->ring = cpu_physical_memory_map(a, &l, 1);
561
    if (!vq->ring || l != s) {
562
        r = -ENOMEM;
563
        goto fail_alloc_ring;
564
    }
565

    
566
    r = vhost_virtqueue_set_addr(dev, vq, idx, dev->log_enabled);
567
    if (r < 0) {
568
        r = -errno;
569
        goto fail_alloc;
570
    }
571
    r = vdev->binding->set_host_notifier(vdev->binding_opaque, idx, true);
572
    if (r < 0) {
573
        fprintf(stderr, "Error binding host notifier: %d\n", -r);
574
        goto fail_host_notifier;
575
    }
576

    
577
    file.fd = event_notifier_get_fd(virtio_queue_get_host_notifier(vvq));
578
    r = ioctl(dev->control, VHOST_SET_VRING_KICK, &file);
579
    if (r) {
580
        r = -errno;
581
        goto fail_kick;
582
    }
583

    
584
    file.fd = event_notifier_get_fd(virtio_queue_get_guest_notifier(vvq));
585
    r = ioctl(dev->control, VHOST_SET_VRING_CALL, &file);
586
    if (r) {
587
        r = -errno;
588
        goto fail_call;
589
    }
590

    
591
    return 0;
592

    
593
fail_call:
594
fail_kick:
595
    vdev->binding->set_host_notifier(vdev->binding_opaque, idx, false);
596
fail_host_notifier:
597
fail_alloc:
598
    cpu_physical_memory_unmap(vq->ring, virtio_queue_get_ring_size(vdev, idx),
599
                              0, 0);
600
fail_alloc_ring:
601
    cpu_physical_memory_unmap(vq->used, virtio_queue_get_used_size(vdev, idx),
602
                              0, 0);
603
fail_alloc_used:
604
    cpu_physical_memory_unmap(vq->avail, virtio_queue_get_avail_size(vdev, idx),
605
                              0, 0);
606
fail_alloc_avail:
607
    cpu_physical_memory_unmap(vq->desc, virtio_queue_get_desc_size(vdev, idx),
608
                              0, 0);
609
fail_alloc_desc:
610
    return r;
611
}
612

    
613
static void vhost_virtqueue_cleanup(struct vhost_dev *dev,
614
                                    struct VirtIODevice *vdev,
615
                                    struct vhost_virtqueue *vq,
616
                                    unsigned idx)
617
{
618
    struct vhost_vring_state state = {
619
        .index = idx,
620
    };
621
    int r;
622
    r = vdev->binding->set_host_notifier(vdev->binding_opaque, idx, false);
623
    if (r < 0) {
624
        fprintf(stderr, "vhost VQ %d host cleanup failed: %d\n", idx, r);
625
        fflush(stderr);
626
    }
627
    assert (r >= 0);
628
    r = ioctl(dev->control, VHOST_GET_VRING_BASE, &state);
629
    if (r < 0) {
630
        fprintf(stderr, "vhost VQ %d ring restore failed: %d\n", idx, r);
631
        fflush(stderr);
632
    }
633
    virtio_queue_set_last_avail_idx(vdev, idx, state.num);
634
    assert (r >= 0);
635
    cpu_physical_memory_unmap(vq->ring, virtio_queue_get_ring_size(vdev, idx),
636
                              0, virtio_queue_get_ring_size(vdev, idx));
637
    cpu_physical_memory_unmap(vq->used, virtio_queue_get_used_size(vdev, idx),
638
                              1, virtio_queue_get_used_size(vdev, idx));
639
    cpu_physical_memory_unmap(vq->avail, virtio_queue_get_avail_size(vdev, idx),
640
                              0, virtio_queue_get_avail_size(vdev, idx));
641
    cpu_physical_memory_unmap(vq->desc, virtio_queue_get_desc_size(vdev, idx),
642
                              0, virtio_queue_get_desc_size(vdev, idx));
643
}
644

    
645
int vhost_dev_init(struct vhost_dev *hdev, int devfd, bool force)
646
{
647
    uint64_t features;
648
    int r;
649
    if (devfd >= 0) {
650
        hdev->control = devfd;
651
    } else {
652
        hdev->control = open("/dev/vhost-net", O_RDWR);
653
        if (hdev->control < 0) {
654
            return -errno;
655
        }
656
    }
657
    r = ioctl(hdev->control, VHOST_SET_OWNER, NULL);
658
    if (r < 0) {
659
        goto fail;
660
    }
661

    
662
    r = ioctl(hdev->control, VHOST_GET_FEATURES, &features);
663
    if (r < 0) {
664
        goto fail;
665
    }
666
    hdev->features = features;
667

    
668
    hdev->client.set_memory = vhost_client_set_memory;
669
    hdev->client.sync_dirty_bitmap = vhost_client_sync_dirty_bitmap;
670
    hdev->client.migration_log = vhost_client_migration_log;
671
    hdev->client.log_start = NULL;
672
    hdev->client.log_stop = NULL;
673
    hdev->mem = qemu_mallocz(offsetof(struct vhost_memory, regions));
674
    hdev->log = NULL;
675
    hdev->log_size = 0;
676
    hdev->log_enabled = false;
677
    hdev->started = false;
678
    cpu_register_phys_memory_client(&hdev->client);
679
    hdev->force = force;
680
    return 0;
681
fail:
682
    r = -errno;
683
    close(hdev->control);
684
    return r;
685
}
686

    
687
void vhost_dev_cleanup(struct vhost_dev *hdev)
688
{
689
    cpu_unregister_phys_memory_client(&hdev->client);
690
    qemu_free(hdev->mem);
691
    close(hdev->control);
692
}
693

    
694
bool vhost_dev_query(struct vhost_dev *hdev, VirtIODevice *vdev)
695
{
696
    return !vdev->binding->query_guest_notifiers ||
697
        vdev->binding->query_guest_notifiers(vdev->binding_opaque) ||
698
        hdev->force;
699
}
700

    
701
int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev)
702
{
703
    int i, r;
704
    if (!vdev->binding->set_guest_notifiers) {
705
        fprintf(stderr, "binding does not support guest notifiers\n");
706
        r = -ENOSYS;
707
        goto fail;
708
    }
709

    
710
    r = vdev->binding->set_guest_notifiers(vdev->binding_opaque, true);
711
    if (r < 0) {
712
        fprintf(stderr, "Error binding guest notifier: %d\n", -r);
713
        goto fail_notifiers;
714
    }
715

    
716
    r = vhost_dev_set_features(hdev, hdev->log_enabled);
717
    if (r < 0) {
718
        goto fail_features;
719
    }
720
    r = ioctl(hdev->control, VHOST_SET_MEM_TABLE, hdev->mem);
721
    if (r < 0) {
722
        r = -errno;
723
        goto fail_mem;
724
    }
725
    for (i = 0; i < hdev->nvqs; ++i) {
726
        r = vhost_virtqueue_init(hdev,
727
                                 vdev,
728
                                 hdev->vqs + i,
729
                                 i);
730
        if (r < 0) {
731
            goto fail_vq;
732
        }
733
    }
734

    
735
    if (hdev->log_enabled) {
736
        hdev->log_size = vhost_get_log_size(hdev);
737
        hdev->log = hdev->log_size ?
738
            qemu_mallocz(hdev->log_size * sizeof *hdev->log) : NULL;
739
        r = ioctl(hdev->control, VHOST_SET_LOG_BASE,
740
                  (uint64_t)(unsigned long)hdev->log);
741
        if (r < 0) {
742
            r = -errno;
743
            goto fail_log;
744
        }
745
    }
746

    
747
    hdev->started = true;
748

    
749
    return 0;
750
fail_log:
751
fail_vq:
752
    while (--i >= 0) {
753
        vhost_virtqueue_cleanup(hdev,
754
                                vdev,
755
                                hdev->vqs + i,
756
                                i);
757
    }
758
fail_mem:
759
fail_features:
760
    vdev->binding->set_guest_notifiers(vdev->binding_opaque, false);
761
fail_notifiers:
762
fail:
763
    return r;
764
}
765

    
766
void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
767
{
768
    int i, r;
769

    
770
    for (i = 0; i < hdev->nvqs; ++i) {
771
        vhost_virtqueue_cleanup(hdev,
772
                                vdev,
773
                                hdev->vqs + i,
774
                                i);
775
    }
776
    vhost_client_sync_dirty_bitmap(&hdev->client, 0,
777
                                   (target_phys_addr_t)~0x0ull);
778
    r = vdev->binding->set_guest_notifiers(vdev->binding_opaque, false);
779
    if (r < 0) {
780
        fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
781
        fflush(stderr);
782
    }
783
    assert (r >= 0);
784

    
785
    hdev->started = false;
786
    qemu_free(hdev->log);
787
    hdev->log = NULL;
788
    hdev->log_size = 0;
789
}