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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
 * Contributions after 2012-01-13 are licensed under the terms of the
13
 * GNU GPL, version 2 or (at your option) any later version.
14
 */
15

    
16
#include <sys/ioctl.h>
17
#include "vhost.h"
18
#include "hw/hw.h"
19
#include "range.h"
20
#include <linux/vhost.h>
21
#include "exec-memory.h"
22

    
23
static void vhost_dev_sync_region(struct vhost_dev *dev,
24
                                  MemoryRegionSection *section,
25
                                  uint64_t mfirst, uint64_t mlast,
26
                                  uint64_t rfirst, uint64_t rlast)
27
{
28
    uint64_t start = MAX(mfirst, rfirst);
29
    uint64_t end = MIN(mlast, rlast);
30
    vhost_log_chunk_t *from = dev->log + start / VHOST_LOG_CHUNK;
31
    vhost_log_chunk_t *to = dev->log + end / VHOST_LOG_CHUNK + 1;
32
    uint64_t addr = (start / VHOST_LOG_CHUNK) * VHOST_LOG_CHUNK;
33

    
34
    assert(end / VHOST_LOG_CHUNK < dev->log_size);
35
    assert(start / VHOST_LOG_CHUNK < dev->log_size);
36
    if (end < start) {
37
        return;
38
    }
39
    for (;from < to; ++from) {
40
        vhost_log_chunk_t log;
41
        int bit;
42
        /* We first check with non-atomic: much cheaper,
43
         * and we expect non-dirty to be the common case. */
44
        if (!*from) {
45
            addr += VHOST_LOG_CHUNK;
46
            continue;
47
        }
48
        /* Data must be read atomically. We don't really
49
         * need the barrier semantics of __sync
50
         * builtins, but it's easier to use them than
51
         * roll our own. */
52
        log = __sync_fetch_and_and(from, 0);
53
        while ((bit = sizeof(log) > sizeof(int) ?
54
                ffsll(log) : ffs(log))) {
55
            ram_addr_t ram_addr;
56
            bit -= 1;
57
            ram_addr = section->offset_within_region + bit * VHOST_LOG_PAGE;
58
            memory_region_set_dirty(section->mr, ram_addr);
59
            log &= ~(0x1ull << bit);
60
        }
61
        addr += VHOST_LOG_CHUNK;
62
    }
63
}
64

    
65
static int vhost_sync_dirty_bitmap(struct vhost_dev *dev,
66
                                   MemoryRegionSection *section,
67
                                   target_phys_addr_t start_addr,
68
                                   target_phys_addr_t end_addr)
69
{
70
    int i;
71

    
72
    if (!dev->log_enabled || !dev->started) {
73
        return 0;
74
    }
75
    for (i = 0; i < dev->mem->nregions; ++i) {
76
        struct vhost_memory_region *reg = dev->mem->regions + i;
77
        vhost_dev_sync_region(dev, section, start_addr, end_addr,
78
                              reg->guest_phys_addr,
79
                              range_get_last(reg->guest_phys_addr,
80
                                             reg->memory_size));
81
    }
82
    for (i = 0; i < dev->nvqs; ++i) {
83
        struct vhost_virtqueue *vq = dev->vqs + i;
84
        vhost_dev_sync_region(dev, section, start_addr, end_addr, vq->used_phys,
85
                              range_get_last(vq->used_phys, vq->used_size));
86
    }
87
    return 0;
88
}
89

    
90
static void vhost_log_sync(MemoryListener *listener,
91
                          MemoryRegionSection *section)
92
{
93
    struct vhost_dev *dev = container_of(listener, struct vhost_dev,
94
                                         memory_listener);
95
    target_phys_addr_t start_addr = section->offset_within_address_space;
96
    target_phys_addr_t end_addr = start_addr + section->size;
97

    
98
    vhost_sync_dirty_bitmap(dev, section, start_addr, end_addr);
99
}
100

    
101
/* Assign/unassign. Keep an unsorted array of non-overlapping
102
 * memory regions in dev->mem. */
103
static void vhost_dev_unassign_memory(struct vhost_dev *dev,
104
                                      uint64_t start_addr,
105
                                      uint64_t size)
106
{
107
    int from, to, n = dev->mem->nregions;
108
    /* Track overlapping/split regions for sanity checking. */
109
    int overlap_start = 0, overlap_end = 0, overlap_middle = 0, split = 0;
110

    
111
    for (from = 0, to = 0; from < n; ++from, ++to) {
112
        struct vhost_memory_region *reg = dev->mem->regions + to;
113
        uint64_t reglast;
114
        uint64_t memlast;
115
        uint64_t change;
116

    
117
        /* clone old region */
118
        if (to != from) {
119
            memcpy(reg, dev->mem->regions + from, sizeof *reg);
120
        }
121

    
122
        /* No overlap is simple */
123
        if (!ranges_overlap(reg->guest_phys_addr, reg->memory_size,
124
                            start_addr, size)) {
125
            continue;
126
        }
127

    
128
        /* Split only happens if supplied region
129
         * is in the middle of an existing one. Thus it can not
130
         * overlap with any other existing region. */
131
        assert(!split);
132

    
133
        reglast = range_get_last(reg->guest_phys_addr, reg->memory_size);
134
        memlast = range_get_last(start_addr, size);
135

    
136
        /* Remove whole region */
137
        if (start_addr <= reg->guest_phys_addr && memlast >= reglast) {
138
            --dev->mem->nregions;
139
            --to;
140
            ++overlap_middle;
141
            continue;
142
        }
143

    
144
        /* Shrink region */
145
        if (memlast >= reglast) {
146
            reg->memory_size = start_addr - reg->guest_phys_addr;
147
            assert(reg->memory_size);
148
            assert(!overlap_end);
149
            ++overlap_end;
150
            continue;
151
        }
152

    
153
        /* Shift region */
154
        if (start_addr <= reg->guest_phys_addr) {
155
            change = memlast + 1 - reg->guest_phys_addr;
156
            reg->memory_size -= change;
157
            reg->guest_phys_addr += change;
158
            reg->userspace_addr += change;
159
            assert(reg->memory_size);
160
            assert(!overlap_start);
161
            ++overlap_start;
162
            continue;
163
        }
164

    
165
        /* This only happens if supplied region
166
         * is in the middle of an existing one. Thus it can not
167
         * overlap with any other existing region. */
168
        assert(!overlap_start);
169
        assert(!overlap_end);
170
        assert(!overlap_middle);
171
        /* Split region: shrink first part, shift second part. */
172
        memcpy(dev->mem->regions + n, reg, sizeof *reg);
173
        reg->memory_size = start_addr - reg->guest_phys_addr;
174
        assert(reg->memory_size);
175
        change = memlast + 1 - reg->guest_phys_addr;
176
        reg = dev->mem->regions + n;
177
        reg->memory_size -= change;
178
        assert(reg->memory_size);
179
        reg->guest_phys_addr += change;
180
        reg->userspace_addr += change;
181
        /* Never add more than 1 region */
182
        assert(dev->mem->nregions == n);
183
        ++dev->mem->nregions;
184
        ++split;
185
    }
186
}
187

    
188
/* Called after unassign, so no regions overlap the given range. */
189
static void vhost_dev_assign_memory(struct vhost_dev *dev,
190
                                    uint64_t start_addr,
191
                                    uint64_t size,
192
                                    uint64_t uaddr)
193
{
194
    int from, to;
195
    struct vhost_memory_region *merged = NULL;
196
    for (from = 0, to = 0; from < dev->mem->nregions; ++from, ++to) {
197
        struct vhost_memory_region *reg = dev->mem->regions + to;
198
        uint64_t prlast, urlast;
199
        uint64_t pmlast, umlast;
200
        uint64_t s, e, u;
201

    
202
        /* clone old region */
203
        if (to != from) {
204
            memcpy(reg, dev->mem->regions + from, sizeof *reg);
205
        }
206
        prlast = range_get_last(reg->guest_phys_addr, reg->memory_size);
207
        pmlast = range_get_last(start_addr, size);
208
        urlast = range_get_last(reg->userspace_addr, reg->memory_size);
209
        umlast = range_get_last(uaddr, size);
210

    
211
        /* check for overlapping regions: should never happen. */
212
        assert(prlast < start_addr || pmlast < reg->guest_phys_addr);
213
        /* Not an adjacent or overlapping region - do not merge. */
214
        if ((prlast + 1 != start_addr || urlast + 1 != uaddr) &&
215
            (pmlast + 1 != reg->guest_phys_addr ||
216
             umlast + 1 != reg->userspace_addr)) {
217
            continue;
218
        }
219

    
220
        if (merged) {
221
            --to;
222
            assert(to >= 0);
223
        } else {
224
            merged = reg;
225
        }
226
        u = MIN(uaddr, reg->userspace_addr);
227
        s = MIN(start_addr, reg->guest_phys_addr);
228
        e = MAX(pmlast, prlast);
229
        uaddr = merged->userspace_addr = u;
230
        start_addr = merged->guest_phys_addr = s;
231
        size = merged->memory_size = e - s + 1;
232
        assert(merged->memory_size);
233
    }
234

    
235
    if (!merged) {
236
        struct vhost_memory_region *reg = dev->mem->regions + to;
237
        memset(reg, 0, sizeof *reg);
238
        reg->memory_size = size;
239
        assert(reg->memory_size);
240
        reg->guest_phys_addr = start_addr;
241
        reg->userspace_addr = uaddr;
242
        ++to;
243
    }
244
    assert(to <= dev->mem->nregions + 1);
245
    dev->mem->nregions = to;
246
}
247

    
248
static uint64_t vhost_get_log_size(struct vhost_dev *dev)
249
{
250
    uint64_t log_size = 0;
251
    int i;
252
    for (i = 0; i < dev->mem->nregions; ++i) {
253
        struct vhost_memory_region *reg = dev->mem->regions + i;
254
        uint64_t last = range_get_last(reg->guest_phys_addr,
255
                                       reg->memory_size);
256
        log_size = MAX(log_size, last / VHOST_LOG_CHUNK + 1);
257
    }
258
    for (i = 0; i < dev->nvqs; ++i) {
259
        struct vhost_virtqueue *vq = dev->vqs + i;
260
        uint64_t last = vq->used_phys + vq->used_size - 1;
261
        log_size = MAX(log_size, last / VHOST_LOG_CHUNK + 1);
262
    }
263
    return log_size;
264
}
265

    
266
static inline void vhost_dev_log_resize(struct vhost_dev* dev, uint64_t size)
267
{
268
    vhost_log_chunk_t *log;
269
    uint64_t log_base;
270
    int r, i;
271
    if (size) {
272
        log = g_malloc0(size * sizeof *log);
273
    } else {
274
        log = NULL;
275
    }
276
    log_base = (uint64_t)(unsigned long)log;
277
    r = ioctl(dev->control, VHOST_SET_LOG_BASE, &log_base);
278
    assert(r >= 0);
279
    for (i = 0; i < dev->n_mem_sections; ++i) {
280
        vhost_sync_dirty_bitmap(dev, &dev->mem_sections[i],
281
                                0, (target_phys_addr_t)~0x0ull);
282
    }
283
    if (dev->log) {
284
        g_free(dev->log);
285
    }
286
    dev->log = log;
287
    dev->log_size = size;
288
}
289

    
290
static int vhost_verify_ring_mappings(struct vhost_dev *dev,
291
                                      uint64_t start_addr,
292
                                      uint64_t size)
293
{
294
    int i;
295
    for (i = 0; i < dev->nvqs; ++i) {
296
        struct vhost_virtqueue *vq = dev->vqs + i;
297
        target_phys_addr_t l;
298
        void *p;
299

    
300
        if (!ranges_overlap(start_addr, size, vq->ring_phys, vq->ring_size)) {
301
            continue;
302
        }
303
        l = vq->ring_size;
304
        p = cpu_physical_memory_map(vq->ring_phys, &l, 1);
305
        if (!p || l != vq->ring_size) {
306
            fprintf(stderr, "Unable to map ring buffer for ring %d\n", i);
307
            return -ENOMEM;
308
        }
309
        if (p != vq->ring) {
310
            fprintf(stderr, "Ring buffer relocated for ring %d\n", i);
311
            return -EBUSY;
312
        }
313
        cpu_physical_memory_unmap(p, l, 0, 0);
314
    }
315
    return 0;
316
}
317

    
318
static struct vhost_memory_region *vhost_dev_find_reg(struct vhost_dev *dev,
319
                                                      uint64_t start_addr,
320
                                                      uint64_t size)
321
{
322
    int i, n = dev->mem->nregions;
323
    for (i = 0; i < n; ++i) {
324
        struct vhost_memory_region *reg = dev->mem->regions + i;
325
        if (ranges_overlap(reg->guest_phys_addr, reg->memory_size,
326
                           start_addr, size)) {
327
            return reg;
328
        }
329
    }
330
    return NULL;
331
}
332

    
333
static bool vhost_dev_cmp_memory(struct vhost_dev *dev,
334
                                 uint64_t start_addr,
335
                                 uint64_t size,
336
                                 uint64_t uaddr)
337
{
338
    struct vhost_memory_region *reg = vhost_dev_find_reg(dev, start_addr, size);
339
    uint64_t reglast;
340
    uint64_t memlast;
341

    
342
    if (!reg) {
343
        return true;
344
    }
345

    
346
    reglast = range_get_last(reg->guest_phys_addr, reg->memory_size);
347
    memlast = range_get_last(start_addr, size);
348

    
349
    /* Need to extend region? */
350
    if (start_addr < reg->guest_phys_addr || memlast > reglast) {
351
        return true;
352
    }
353
    /* userspace_addr changed? */
354
    return uaddr != reg->userspace_addr + start_addr - reg->guest_phys_addr;
355
}
356

    
357
static void vhost_set_memory(MemoryListener *listener,
358
                             MemoryRegionSection *section,
359
                             bool add)
360
{
361
    struct vhost_dev *dev = container_of(listener, struct vhost_dev,
362
                                         memory_listener);
363
    target_phys_addr_t start_addr = section->offset_within_address_space;
364
    ram_addr_t size = section->size;
365
    bool log_dirty = memory_region_is_logging(section->mr);
366
    int s = offsetof(struct vhost_memory, regions) +
367
        (dev->mem->nregions + 1) * sizeof dev->mem->regions[0];
368
    uint64_t log_size;
369
    int r;
370
    void *ram;
371

    
372
    dev->mem = g_realloc(dev->mem, s);
373

    
374
    if (log_dirty) {
375
        add = false;
376
    }
377

    
378
    assert(size);
379

    
380
    /* Optimize no-change case. At least cirrus_vga does this a lot at this time. */
381
    ram = memory_region_get_ram_ptr(section->mr) + section->offset_within_region;
382
    if (add) {
383
        if (!vhost_dev_cmp_memory(dev, start_addr, size, (uintptr_t)ram)) {
384
            /* Region exists with same address. Nothing to do. */
385
            return;
386
        }
387
    } else {
388
        if (!vhost_dev_find_reg(dev, start_addr, size)) {
389
            /* Removing region that we don't access. Nothing to do. */
390
            return;
391
        }
392
    }
393

    
394
    vhost_dev_unassign_memory(dev, start_addr, size);
395
    if (add) {
396
        /* Add given mapping, merging adjacent regions if any */
397
        vhost_dev_assign_memory(dev, start_addr, size, (uintptr_t)ram);
398
    } else {
399
        /* Remove old mapping for this memory, if any. */
400
        vhost_dev_unassign_memory(dev, start_addr, size);
401
    }
402

    
403
    if (!dev->started) {
404
        return;
405
    }
406

    
407
    if (dev->started) {
408
        r = vhost_verify_ring_mappings(dev, start_addr, size);
409
        assert(r >= 0);
410
    }
411

    
412
    if (!dev->log_enabled) {
413
        r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem);
414
        assert(r >= 0);
415
        return;
416
    }
417
    log_size = vhost_get_log_size(dev);
418
    /* We allocate an extra 4K bytes to log,
419
     * to reduce the * number of reallocations. */
420
#define VHOST_LOG_BUFFER (0x1000 / sizeof *dev->log)
421
    /* To log more, must increase log size before table update. */
422
    if (dev->log_size < log_size) {
423
        vhost_dev_log_resize(dev, log_size + VHOST_LOG_BUFFER);
424
    }
425
    r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem);
426
    assert(r >= 0);
427
    /* To log less, can only decrease log size after table update. */
428
    if (dev->log_size > log_size + VHOST_LOG_BUFFER) {
429
        vhost_dev_log_resize(dev, log_size);
430
    }
431
}
432

    
433
static bool vhost_section(MemoryRegionSection *section)
434
{
435
    return section->address_space == get_system_memory()
436
        && memory_region_is_ram(section->mr);
437
}
438

    
439
static void vhost_region_add(MemoryListener *listener,
440
                             MemoryRegionSection *section)
441
{
442
    struct vhost_dev *dev = container_of(listener, struct vhost_dev,
443
                                         memory_listener);
444

    
445
    if (!vhost_section(section)) {
446
        return;
447
    }
448

    
449
    ++dev->n_mem_sections;
450
    dev->mem_sections = g_renew(MemoryRegionSection, dev->mem_sections,
451
                                dev->n_mem_sections);
452
    dev->mem_sections[dev->n_mem_sections - 1] = *section;
453
    vhost_set_memory(listener, section, true);
454
}
455

    
456
static void vhost_region_del(MemoryListener *listener,
457
                             MemoryRegionSection *section)
458
{
459
    struct vhost_dev *dev = container_of(listener, struct vhost_dev,
460
                                         memory_listener);
461
    int i;
462

    
463
    if (!vhost_section(section)) {
464
        return;
465
    }
466

    
467
    vhost_set_memory(listener, section, false);
468
    for (i = 0; i < dev->n_mem_sections; ++i) {
469
        if (dev->mem_sections[i].offset_within_address_space
470
            == section->offset_within_address_space) {
471
            --dev->n_mem_sections;
472
            memmove(&dev->mem_sections[i], &dev->mem_sections[i+1],
473
                    (dev->n_mem_sections - i) * sizeof(*dev->mem_sections));
474
            break;
475
        }
476
    }
477
}
478

    
479
static int vhost_virtqueue_set_addr(struct vhost_dev *dev,
480
                                    struct vhost_virtqueue *vq,
481
                                    unsigned idx, bool enable_log)
482
{
483
    struct vhost_vring_addr addr = {
484
        .index = idx,
485
        .desc_user_addr = (uint64_t)(unsigned long)vq->desc,
486
        .avail_user_addr = (uint64_t)(unsigned long)vq->avail,
487
        .used_user_addr = (uint64_t)(unsigned long)vq->used,
488
        .log_guest_addr = vq->used_phys,
489
        .flags = enable_log ? (1 << VHOST_VRING_F_LOG) : 0,
490
    };
491
    int r = ioctl(dev->control, VHOST_SET_VRING_ADDR, &addr);
492
    if (r < 0) {
493
        return -errno;
494
    }
495
    return 0;
496
}
497

    
498
static int vhost_dev_set_features(struct vhost_dev *dev, bool enable_log)
499
{
500
    uint64_t features = dev->acked_features;
501
    int r;
502
    if (enable_log) {
503
        features |= 0x1 << VHOST_F_LOG_ALL;
504
    }
505
    r = ioctl(dev->control, VHOST_SET_FEATURES, &features);
506
    return r < 0 ? -errno : 0;
507
}
508

    
509
static int vhost_dev_set_log(struct vhost_dev *dev, bool enable_log)
510
{
511
    int r, t, i;
512
    r = vhost_dev_set_features(dev, enable_log);
513
    if (r < 0) {
514
        goto err_features;
515
    }
516
    for (i = 0; i < dev->nvqs; ++i) {
517
        r = vhost_virtqueue_set_addr(dev, dev->vqs + i, i,
518
                                     enable_log);
519
        if (r < 0) {
520
            goto err_vq;
521
        }
522
    }
523
    return 0;
524
err_vq:
525
    for (; i >= 0; --i) {
526
        t = vhost_virtqueue_set_addr(dev, dev->vqs + i, i,
527
                                     dev->log_enabled);
528
        assert(t >= 0);
529
    }
530
    t = vhost_dev_set_features(dev, dev->log_enabled);
531
    assert(t >= 0);
532
err_features:
533
    return r;
534
}
535

    
536
static int vhost_migration_log(MemoryListener *listener, int enable)
537
{
538
    struct vhost_dev *dev = container_of(listener, struct vhost_dev,
539
                                         memory_listener);
540
    int r;
541
    if (!!enable == dev->log_enabled) {
542
        return 0;
543
    }
544
    if (!dev->started) {
545
        dev->log_enabled = enable;
546
        return 0;
547
    }
548
    if (!enable) {
549
        r = vhost_dev_set_log(dev, false);
550
        if (r < 0) {
551
            return r;
552
        }
553
        if (dev->log) {
554
            g_free(dev->log);
555
        }
556
        dev->log = NULL;
557
        dev->log_size = 0;
558
    } else {
559
        vhost_dev_log_resize(dev, vhost_get_log_size(dev));
560
        r = vhost_dev_set_log(dev, true);
561
        if (r < 0) {
562
            return r;
563
        }
564
    }
565
    dev->log_enabled = enable;
566
    return 0;
567
}
568

    
569
static void vhost_log_global_start(MemoryListener *listener)
570
{
571
    int r;
572

    
573
    r = vhost_migration_log(listener, true);
574
    if (r < 0) {
575
        abort();
576
    }
577
}
578

    
579
static void vhost_log_global_stop(MemoryListener *listener)
580
{
581
    int r;
582

    
583
    r = vhost_migration_log(listener, false);
584
    if (r < 0) {
585
        abort();
586
    }
587
}
588

    
589
static void vhost_log_start(MemoryListener *listener,
590
                            MemoryRegionSection *section)
591
{
592
    /* FIXME: implement */
593
}
594

    
595
static void vhost_log_stop(MemoryListener *listener,
596
                           MemoryRegionSection *section)
597
{
598
    /* FIXME: implement */
599
}
600

    
601
static int vhost_virtqueue_init(struct vhost_dev *dev,
602
                                struct VirtIODevice *vdev,
603
                                struct vhost_virtqueue *vq,
604
                                unsigned idx)
605
{
606
    target_phys_addr_t s, l, a;
607
    int r;
608
    struct vhost_vring_file file = {
609
        .index = idx,
610
    };
611
    struct vhost_vring_state state = {
612
        .index = idx,
613
    };
614
    struct VirtQueue *vvq = virtio_get_queue(vdev, idx);
615

    
616
    vq->num = state.num = virtio_queue_get_num(vdev, idx);
617
    r = ioctl(dev->control, VHOST_SET_VRING_NUM, &state);
618
    if (r) {
619
        return -errno;
620
    }
621

    
622
    state.num = virtio_queue_get_last_avail_idx(vdev, idx);
623
    r = ioctl(dev->control, VHOST_SET_VRING_BASE, &state);
624
    if (r) {
625
        return -errno;
626
    }
627

    
628
    s = l = virtio_queue_get_desc_size(vdev, idx);
629
    a = virtio_queue_get_desc_addr(vdev, idx);
630
    vq->desc = cpu_physical_memory_map(a, &l, 0);
631
    if (!vq->desc || l != s) {
632
        r = -ENOMEM;
633
        goto fail_alloc_desc;
634
    }
635
    s = l = virtio_queue_get_avail_size(vdev, idx);
636
    a = virtio_queue_get_avail_addr(vdev, idx);
637
    vq->avail = cpu_physical_memory_map(a, &l, 0);
638
    if (!vq->avail || l != s) {
639
        r = -ENOMEM;
640
        goto fail_alloc_avail;
641
    }
642
    vq->used_size = s = l = virtio_queue_get_used_size(vdev, idx);
643
    vq->used_phys = a = virtio_queue_get_used_addr(vdev, idx);
644
    vq->used = cpu_physical_memory_map(a, &l, 1);
645
    if (!vq->used || l != s) {
646
        r = -ENOMEM;
647
        goto fail_alloc_used;
648
    }
649

    
650
    vq->ring_size = s = l = virtio_queue_get_ring_size(vdev, idx);
651
    vq->ring_phys = a = virtio_queue_get_ring_addr(vdev, idx);
652
    vq->ring = cpu_physical_memory_map(a, &l, 1);
653
    if (!vq->ring || l != s) {
654
        r = -ENOMEM;
655
        goto fail_alloc_ring;
656
    }
657

    
658
    r = vhost_virtqueue_set_addr(dev, vq, idx, dev->log_enabled);
659
    if (r < 0) {
660
        r = -errno;
661
        goto fail_alloc;
662
    }
663
    file.fd = event_notifier_get_fd(virtio_queue_get_host_notifier(vvq));
664
    r = ioctl(dev->control, VHOST_SET_VRING_KICK, &file);
665
    if (r) {
666
        r = -errno;
667
        goto fail_kick;
668
    }
669

    
670
    file.fd = event_notifier_get_fd(virtio_queue_get_guest_notifier(vvq));
671
    r = ioctl(dev->control, VHOST_SET_VRING_CALL, &file);
672
    if (r) {
673
        r = -errno;
674
        goto fail_call;
675
    }
676

    
677
    return 0;
678

    
679
fail_call:
680
fail_kick:
681
fail_alloc:
682
    cpu_physical_memory_unmap(vq->ring, virtio_queue_get_ring_size(vdev, idx),
683
                              0, 0);
684
fail_alloc_ring:
685
    cpu_physical_memory_unmap(vq->used, virtio_queue_get_used_size(vdev, idx),
686
                              0, 0);
687
fail_alloc_used:
688
    cpu_physical_memory_unmap(vq->avail, virtio_queue_get_avail_size(vdev, idx),
689
                              0, 0);
690
fail_alloc_avail:
691
    cpu_physical_memory_unmap(vq->desc, virtio_queue_get_desc_size(vdev, idx),
692
                              0, 0);
693
fail_alloc_desc:
694
    return r;
695
}
696

    
697
static void vhost_virtqueue_cleanup(struct vhost_dev *dev,
698
                                    struct VirtIODevice *vdev,
699
                                    struct vhost_virtqueue *vq,
700
                                    unsigned idx)
701
{
702
    struct vhost_vring_state state = {
703
        .index = idx,
704
    };
705
    int r;
706
    r = ioctl(dev->control, VHOST_GET_VRING_BASE, &state);
707
    if (r < 0) {
708
        fprintf(stderr, "vhost VQ %d ring restore failed: %d\n", idx, r);
709
        fflush(stderr);
710
    }
711
    virtio_queue_set_last_avail_idx(vdev, idx, state.num);
712
    assert (r >= 0);
713
    cpu_physical_memory_unmap(vq->ring, virtio_queue_get_ring_size(vdev, idx),
714
                              0, virtio_queue_get_ring_size(vdev, idx));
715
    cpu_physical_memory_unmap(vq->used, virtio_queue_get_used_size(vdev, idx),
716
                              1, virtio_queue_get_used_size(vdev, idx));
717
    cpu_physical_memory_unmap(vq->avail, virtio_queue_get_avail_size(vdev, idx),
718
                              0, virtio_queue_get_avail_size(vdev, idx));
719
    cpu_physical_memory_unmap(vq->desc, virtio_queue_get_desc_size(vdev, idx),
720
                              0, virtio_queue_get_desc_size(vdev, idx));
721
}
722

    
723
int vhost_dev_init(struct vhost_dev *hdev, int devfd, bool force)
724
{
725
    uint64_t features;
726
    int r;
727
    if (devfd >= 0) {
728
        hdev->control = devfd;
729
    } else {
730
        hdev->control = open("/dev/vhost-net", O_RDWR);
731
        if (hdev->control < 0) {
732
            return -errno;
733
        }
734
    }
735
    r = ioctl(hdev->control, VHOST_SET_OWNER, NULL);
736
    if (r < 0) {
737
        goto fail;
738
    }
739

    
740
    r = ioctl(hdev->control, VHOST_GET_FEATURES, &features);
741
    if (r < 0) {
742
        goto fail;
743
    }
744
    hdev->features = features;
745

    
746
    hdev->memory_listener = (MemoryListener) {
747
        .region_add = vhost_region_add,
748
        .region_del = vhost_region_del,
749
        .log_start = vhost_log_start,
750
        .log_stop = vhost_log_stop,
751
        .log_sync = vhost_log_sync,
752
        .log_global_start = vhost_log_global_start,
753
        .log_global_stop = vhost_log_global_stop,
754
    };
755
    hdev->mem = g_malloc0(offsetof(struct vhost_memory, regions));
756
    hdev->n_mem_sections = 0;
757
    hdev->mem_sections = NULL;
758
    hdev->log = NULL;
759
    hdev->log_size = 0;
760
    hdev->log_enabled = false;
761
    hdev->started = false;
762
    memory_listener_register(&hdev->memory_listener);
763
    hdev->force = force;
764
    return 0;
765
fail:
766
    r = -errno;
767
    close(hdev->control);
768
    return r;
769
}
770

    
771
void vhost_dev_cleanup(struct vhost_dev *hdev)
772
{
773
    memory_listener_unregister(&hdev->memory_listener);
774
    g_free(hdev->mem);
775
    g_free(hdev->mem_sections);
776
    close(hdev->control);
777
}
778

    
779
bool vhost_dev_query(struct vhost_dev *hdev, VirtIODevice *vdev)
780
{
781
    return !vdev->binding->query_guest_notifiers ||
782
        vdev->binding->query_guest_notifiers(vdev->binding_opaque) ||
783
        hdev->force;
784
}
785

    
786
/* Stop processing guest IO notifications in qemu.
787
 * Start processing them in vhost in kernel.
788
 */
789
int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev)
790
{
791
    int i, r;
792
    if (!vdev->binding->set_host_notifier) {
793
        fprintf(stderr, "binding does not support host notifiers\n");
794
        r = -ENOSYS;
795
        goto fail;
796
    }
797

    
798
    for (i = 0; i < hdev->nvqs; ++i) {
799
        r = vdev->binding->set_host_notifier(vdev->binding_opaque, i, true);
800
        if (r < 0) {
801
            fprintf(stderr, "vhost VQ %d notifier binding failed: %d\n", i, -r);
802
            goto fail_vq;
803
        }
804
    }
805

    
806
    return 0;
807
fail_vq:
808
    while (--i >= 0) {
809
        r = vdev->binding->set_host_notifier(vdev->binding_opaque, i, false);
810
        if (r < 0) {
811
            fprintf(stderr, "vhost VQ %d notifier cleanup error: %d\n", i, -r);
812
            fflush(stderr);
813
        }
814
        assert (r >= 0);
815
    }
816
fail:
817
    return r;
818
}
819

    
820
/* Stop processing guest IO notifications in vhost.
821
 * Start processing them in qemu.
822
 * This might actually run the qemu handlers right away,
823
 * so virtio in qemu must be completely setup when this is called.
824
 */
825
void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev)
826
{
827
    int i, r;
828

    
829
    for (i = 0; i < hdev->nvqs; ++i) {
830
        r = vdev->binding->set_host_notifier(vdev->binding_opaque, i, false);
831
        if (r < 0) {
832
            fprintf(stderr, "vhost VQ %d notifier cleanup failed: %d\n", i, -r);
833
            fflush(stderr);
834
        }
835
        assert (r >= 0);
836
    }
837
}
838

    
839
/* Host notifiers must be enabled at this point. */
840
int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev)
841
{
842
    int i, r;
843
    if (!vdev->binding->set_guest_notifiers) {
844
        fprintf(stderr, "binding does not support guest notifiers\n");
845
        r = -ENOSYS;
846
        goto fail;
847
    }
848

    
849
    r = vdev->binding->set_guest_notifiers(vdev->binding_opaque, true);
850
    if (r < 0) {
851
        fprintf(stderr, "Error binding guest notifier: %d\n", -r);
852
        goto fail_notifiers;
853
    }
854

    
855
    r = vhost_dev_set_features(hdev, hdev->log_enabled);
856
    if (r < 0) {
857
        goto fail_features;
858
    }
859
    r = ioctl(hdev->control, VHOST_SET_MEM_TABLE, hdev->mem);
860
    if (r < 0) {
861
        r = -errno;
862
        goto fail_mem;
863
    }
864
    for (i = 0; i < hdev->nvqs; ++i) {
865
        r = vhost_virtqueue_init(hdev,
866
                                 vdev,
867
                                 hdev->vqs + i,
868
                                 i);
869
        if (r < 0) {
870
            goto fail_vq;
871
        }
872
    }
873

    
874
    if (hdev->log_enabled) {
875
        hdev->log_size = vhost_get_log_size(hdev);
876
        hdev->log = hdev->log_size ?
877
            g_malloc0(hdev->log_size * sizeof *hdev->log) : NULL;
878
        r = ioctl(hdev->control, VHOST_SET_LOG_BASE,
879
                  (uint64_t)(unsigned long)hdev->log);
880
        if (r < 0) {
881
            r = -errno;
882
            goto fail_log;
883
        }
884
    }
885

    
886
    hdev->started = true;
887

    
888
    return 0;
889
fail_log:
890
fail_vq:
891
    while (--i >= 0) {
892
        vhost_virtqueue_cleanup(hdev,
893
                                vdev,
894
                                hdev->vqs + i,
895
                                i);
896
    }
897
fail_mem:
898
fail_features:
899
    vdev->binding->set_guest_notifiers(vdev->binding_opaque, false);
900
fail_notifiers:
901
fail:
902
    return r;
903
}
904

    
905
/* Host notifiers must be enabled at this point. */
906
void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
907
{
908
    int i, r;
909

    
910
    for (i = 0; i < hdev->nvqs; ++i) {
911
        vhost_virtqueue_cleanup(hdev,
912
                                vdev,
913
                                hdev->vqs + i,
914
                                i);
915
    }
916
    for (i = 0; i < hdev->n_mem_sections; ++i) {
917
        vhost_sync_dirty_bitmap(hdev, &hdev->mem_sections[i],
918
                                0, (target_phys_addr_t)~0x0ull);
919
    }
920
    r = vdev->binding->set_guest_notifiers(vdev->binding_opaque, false);
921
    if (r < 0) {
922
        fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
923
        fflush(stderr);
924
    }
925
    assert (r >= 0);
926

    
927
    hdev->started = false;
928
    g_free(hdev->log);
929
    hdev->log = NULL;
930
    hdev->log_size = 0;
931
}