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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, VHOST_LOG_PAGE);
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_begin(MemoryListener *listener)
440
{
441
}
442

    
443
static void vhost_commit(MemoryListener *listener)
444
{
445
}
446

    
447
static void vhost_region_add(MemoryListener *listener,
448
                             MemoryRegionSection *section)
449
{
450
    struct vhost_dev *dev = container_of(listener, struct vhost_dev,
451
                                         memory_listener);
452

    
453
    if (!vhost_section(section)) {
454
        return;
455
    }
456

    
457
    ++dev->n_mem_sections;
458
    dev->mem_sections = g_renew(MemoryRegionSection, dev->mem_sections,
459
                                dev->n_mem_sections);
460
    dev->mem_sections[dev->n_mem_sections - 1] = *section;
461
    vhost_set_memory(listener, section, true);
462
}
463

    
464
static void vhost_region_del(MemoryListener *listener,
465
                             MemoryRegionSection *section)
466
{
467
    struct vhost_dev *dev = container_of(listener, struct vhost_dev,
468
                                         memory_listener);
469
    int i;
470

    
471
    if (!vhost_section(section)) {
472
        return;
473
    }
474

    
475
    vhost_set_memory(listener, section, false);
476
    for (i = 0; i < dev->n_mem_sections; ++i) {
477
        if (dev->mem_sections[i].offset_within_address_space
478
            == section->offset_within_address_space) {
479
            --dev->n_mem_sections;
480
            memmove(&dev->mem_sections[i], &dev->mem_sections[i+1],
481
                    (dev->n_mem_sections - i) * sizeof(*dev->mem_sections));
482
            break;
483
        }
484
    }
485
}
486

    
487
static void vhost_region_nop(MemoryListener *listener,
488
                             MemoryRegionSection *section)
489
{
490
}
491

    
492
static int vhost_virtqueue_set_addr(struct vhost_dev *dev,
493
                                    struct vhost_virtqueue *vq,
494
                                    unsigned idx, bool enable_log)
495
{
496
    struct vhost_vring_addr addr = {
497
        .index = idx,
498
        .desc_user_addr = (uint64_t)(unsigned long)vq->desc,
499
        .avail_user_addr = (uint64_t)(unsigned long)vq->avail,
500
        .used_user_addr = (uint64_t)(unsigned long)vq->used,
501
        .log_guest_addr = vq->used_phys,
502
        .flags = enable_log ? (1 << VHOST_VRING_F_LOG) : 0,
503
    };
504
    int r = ioctl(dev->control, VHOST_SET_VRING_ADDR, &addr);
505
    if (r < 0) {
506
        return -errno;
507
    }
508
    return 0;
509
}
510

    
511
static int vhost_dev_set_features(struct vhost_dev *dev, bool enable_log)
512
{
513
    uint64_t features = dev->acked_features;
514
    int r;
515
    if (enable_log) {
516
        features |= 0x1 << VHOST_F_LOG_ALL;
517
    }
518
    r = ioctl(dev->control, VHOST_SET_FEATURES, &features);
519
    return r < 0 ? -errno : 0;
520
}
521

    
522
static int vhost_dev_set_log(struct vhost_dev *dev, bool enable_log)
523
{
524
    int r, t, i;
525
    r = vhost_dev_set_features(dev, enable_log);
526
    if (r < 0) {
527
        goto err_features;
528
    }
529
    for (i = 0; i < dev->nvqs; ++i) {
530
        r = vhost_virtqueue_set_addr(dev, dev->vqs + i, i,
531
                                     enable_log);
532
        if (r < 0) {
533
            goto err_vq;
534
        }
535
    }
536
    return 0;
537
err_vq:
538
    for (; i >= 0; --i) {
539
        t = vhost_virtqueue_set_addr(dev, dev->vqs + i, i,
540
                                     dev->log_enabled);
541
        assert(t >= 0);
542
    }
543
    t = vhost_dev_set_features(dev, dev->log_enabled);
544
    assert(t >= 0);
545
err_features:
546
    return r;
547
}
548

    
549
static int vhost_migration_log(MemoryListener *listener, int enable)
550
{
551
    struct vhost_dev *dev = container_of(listener, struct vhost_dev,
552
                                         memory_listener);
553
    int r;
554
    if (!!enable == dev->log_enabled) {
555
        return 0;
556
    }
557
    if (!dev->started) {
558
        dev->log_enabled = enable;
559
        return 0;
560
    }
561
    if (!enable) {
562
        r = vhost_dev_set_log(dev, false);
563
        if (r < 0) {
564
            return r;
565
        }
566
        if (dev->log) {
567
            g_free(dev->log);
568
        }
569
        dev->log = NULL;
570
        dev->log_size = 0;
571
    } else {
572
        vhost_dev_log_resize(dev, vhost_get_log_size(dev));
573
        r = vhost_dev_set_log(dev, true);
574
        if (r < 0) {
575
            return r;
576
        }
577
    }
578
    dev->log_enabled = enable;
579
    return 0;
580
}
581

    
582
static void vhost_log_global_start(MemoryListener *listener)
583
{
584
    int r;
585

    
586
    r = vhost_migration_log(listener, true);
587
    if (r < 0) {
588
        abort();
589
    }
590
}
591

    
592
static void vhost_log_global_stop(MemoryListener *listener)
593
{
594
    int r;
595

    
596
    r = vhost_migration_log(listener, false);
597
    if (r < 0) {
598
        abort();
599
    }
600
}
601

    
602
static void vhost_log_start(MemoryListener *listener,
603
                            MemoryRegionSection *section)
604
{
605
    /* FIXME: implement */
606
}
607

    
608
static void vhost_log_stop(MemoryListener *listener,
609
                           MemoryRegionSection *section)
610
{
611
    /* FIXME: implement */
612
}
613

    
614
static int vhost_virtqueue_init(struct vhost_dev *dev,
615
                                struct VirtIODevice *vdev,
616
                                struct vhost_virtqueue *vq,
617
                                unsigned idx)
618
{
619
    target_phys_addr_t s, l, a;
620
    int r;
621
    struct vhost_vring_file file = {
622
        .index = idx,
623
    };
624
    struct vhost_vring_state state = {
625
        .index = idx,
626
    };
627
    struct VirtQueue *vvq = virtio_get_queue(vdev, idx);
628

    
629
    vq->num = state.num = virtio_queue_get_num(vdev, idx);
630
    r = ioctl(dev->control, VHOST_SET_VRING_NUM, &state);
631
    if (r) {
632
        return -errno;
633
    }
634

    
635
    state.num = virtio_queue_get_last_avail_idx(vdev, idx);
636
    r = ioctl(dev->control, VHOST_SET_VRING_BASE, &state);
637
    if (r) {
638
        return -errno;
639
    }
640

    
641
    s = l = virtio_queue_get_desc_size(vdev, idx);
642
    a = virtio_queue_get_desc_addr(vdev, idx);
643
    vq->desc = cpu_physical_memory_map(a, &l, 0);
644
    if (!vq->desc || l != s) {
645
        r = -ENOMEM;
646
        goto fail_alloc_desc;
647
    }
648
    s = l = virtio_queue_get_avail_size(vdev, idx);
649
    a = virtio_queue_get_avail_addr(vdev, idx);
650
    vq->avail = cpu_physical_memory_map(a, &l, 0);
651
    if (!vq->avail || l != s) {
652
        r = -ENOMEM;
653
        goto fail_alloc_avail;
654
    }
655
    vq->used_size = s = l = virtio_queue_get_used_size(vdev, idx);
656
    vq->used_phys = a = virtio_queue_get_used_addr(vdev, idx);
657
    vq->used = cpu_physical_memory_map(a, &l, 1);
658
    if (!vq->used || l != s) {
659
        r = -ENOMEM;
660
        goto fail_alloc_used;
661
    }
662

    
663
    vq->ring_size = s = l = virtio_queue_get_ring_size(vdev, idx);
664
    vq->ring_phys = a = virtio_queue_get_ring_addr(vdev, idx);
665
    vq->ring = cpu_physical_memory_map(a, &l, 1);
666
    if (!vq->ring || l != s) {
667
        r = -ENOMEM;
668
        goto fail_alloc_ring;
669
    }
670

    
671
    r = vhost_virtqueue_set_addr(dev, vq, idx, dev->log_enabled);
672
    if (r < 0) {
673
        r = -errno;
674
        goto fail_alloc;
675
    }
676
    file.fd = event_notifier_get_fd(virtio_queue_get_host_notifier(vvq));
677
    r = ioctl(dev->control, VHOST_SET_VRING_KICK, &file);
678
    if (r) {
679
        r = -errno;
680
        goto fail_kick;
681
    }
682

    
683
    file.fd = event_notifier_get_fd(virtio_queue_get_guest_notifier(vvq));
684
    r = ioctl(dev->control, VHOST_SET_VRING_CALL, &file);
685
    if (r) {
686
        r = -errno;
687
        goto fail_call;
688
    }
689

    
690
    return 0;
691

    
692
fail_call:
693
fail_kick:
694
fail_alloc:
695
    cpu_physical_memory_unmap(vq->ring, virtio_queue_get_ring_size(vdev, idx),
696
                              0, 0);
697
fail_alloc_ring:
698
    cpu_physical_memory_unmap(vq->used, virtio_queue_get_used_size(vdev, idx),
699
                              0, 0);
700
fail_alloc_used:
701
    cpu_physical_memory_unmap(vq->avail, virtio_queue_get_avail_size(vdev, idx),
702
                              0, 0);
703
fail_alloc_avail:
704
    cpu_physical_memory_unmap(vq->desc, virtio_queue_get_desc_size(vdev, idx),
705
                              0, 0);
706
fail_alloc_desc:
707
    return r;
708
}
709

    
710
static void vhost_virtqueue_cleanup(struct vhost_dev *dev,
711
                                    struct VirtIODevice *vdev,
712
                                    struct vhost_virtqueue *vq,
713
                                    unsigned idx)
714
{
715
    struct vhost_vring_state state = {
716
        .index = idx,
717
    };
718
    int r;
719
    r = ioctl(dev->control, VHOST_GET_VRING_BASE, &state);
720
    if (r < 0) {
721
        fprintf(stderr, "vhost VQ %d ring restore failed: %d\n", idx, r);
722
        fflush(stderr);
723
    }
724
    virtio_queue_set_last_avail_idx(vdev, idx, state.num);
725
    assert (r >= 0);
726
    cpu_physical_memory_unmap(vq->ring, virtio_queue_get_ring_size(vdev, idx),
727
                              0, virtio_queue_get_ring_size(vdev, idx));
728
    cpu_physical_memory_unmap(vq->used, virtio_queue_get_used_size(vdev, idx),
729
                              1, virtio_queue_get_used_size(vdev, idx));
730
    cpu_physical_memory_unmap(vq->avail, virtio_queue_get_avail_size(vdev, idx),
731
                              0, virtio_queue_get_avail_size(vdev, idx));
732
    cpu_physical_memory_unmap(vq->desc, virtio_queue_get_desc_size(vdev, idx),
733
                              0, virtio_queue_get_desc_size(vdev, idx));
734
}
735

    
736
static void vhost_eventfd_add(MemoryListener *listener,
737
                              MemoryRegionSection *section,
738
                              bool match_data, uint64_t data, int fd)
739
{
740
}
741

    
742
static void vhost_eventfd_del(MemoryListener *listener,
743
                              MemoryRegionSection *section,
744
                              bool match_data, uint64_t data, int fd)
745
{
746
}
747

    
748
int vhost_dev_init(struct vhost_dev *hdev, int devfd, bool force)
749
{
750
    uint64_t features;
751
    int r;
752
    if (devfd >= 0) {
753
        hdev->control = devfd;
754
    } else {
755
        hdev->control = open("/dev/vhost-net", O_RDWR);
756
        if (hdev->control < 0) {
757
            return -errno;
758
        }
759
    }
760
    r = ioctl(hdev->control, VHOST_SET_OWNER, NULL);
761
    if (r < 0) {
762
        goto fail;
763
    }
764

    
765
    r = ioctl(hdev->control, VHOST_GET_FEATURES, &features);
766
    if (r < 0) {
767
        goto fail;
768
    }
769
    hdev->features = features;
770

    
771
    hdev->memory_listener = (MemoryListener) {
772
        .begin = vhost_begin,
773
        .commit = vhost_commit,
774
        .region_add = vhost_region_add,
775
        .region_del = vhost_region_del,
776
        .region_nop = vhost_region_nop,
777
        .log_start = vhost_log_start,
778
        .log_stop = vhost_log_stop,
779
        .log_sync = vhost_log_sync,
780
        .log_global_start = vhost_log_global_start,
781
        .log_global_stop = vhost_log_global_stop,
782
        .eventfd_add = vhost_eventfd_add,
783
        .eventfd_del = vhost_eventfd_del,
784
        .priority = 10
785
    };
786
    hdev->mem = g_malloc0(offsetof(struct vhost_memory, regions));
787
    hdev->n_mem_sections = 0;
788
    hdev->mem_sections = NULL;
789
    hdev->log = NULL;
790
    hdev->log_size = 0;
791
    hdev->log_enabled = false;
792
    hdev->started = false;
793
    memory_listener_register(&hdev->memory_listener, NULL);
794
    hdev->force = force;
795
    return 0;
796
fail:
797
    r = -errno;
798
    close(hdev->control);
799
    return r;
800
}
801

    
802
void vhost_dev_cleanup(struct vhost_dev *hdev)
803
{
804
    memory_listener_unregister(&hdev->memory_listener);
805
    g_free(hdev->mem);
806
    g_free(hdev->mem_sections);
807
    close(hdev->control);
808
}
809

    
810
bool vhost_dev_query(struct vhost_dev *hdev, VirtIODevice *vdev)
811
{
812
    return !vdev->binding->query_guest_notifiers ||
813
        vdev->binding->query_guest_notifiers(vdev->binding_opaque) ||
814
        hdev->force;
815
}
816

    
817
/* Stop processing guest IO notifications in qemu.
818
 * Start processing them in vhost in kernel.
819
 */
820
int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev)
821
{
822
    int i, r;
823
    if (!vdev->binding->set_host_notifier) {
824
        fprintf(stderr, "binding does not support host notifiers\n");
825
        r = -ENOSYS;
826
        goto fail;
827
    }
828

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

    
837
    return 0;
838
fail_vq:
839
    while (--i >= 0) {
840
        r = vdev->binding->set_host_notifier(vdev->binding_opaque, i, false);
841
        if (r < 0) {
842
            fprintf(stderr, "vhost VQ %d notifier cleanup error: %d\n", i, -r);
843
            fflush(stderr);
844
        }
845
        assert (r >= 0);
846
    }
847
fail:
848
    return r;
849
}
850

    
851
/* Stop processing guest IO notifications in vhost.
852
 * Start processing them in qemu.
853
 * This might actually run the qemu handlers right away,
854
 * so virtio in qemu must be completely setup when this is called.
855
 */
856
void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev)
857
{
858
    int i, r;
859

    
860
    for (i = 0; i < hdev->nvqs; ++i) {
861
        r = vdev->binding->set_host_notifier(vdev->binding_opaque, i, false);
862
        if (r < 0) {
863
            fprintf(stderr, "vhost VQ %d notifier cleanup failed: %d\n", i, -r);
864
            fflush(stderr);
865
        }
866
        assert (r >= 0);
867
    }
868
}
869

    
870
/* Host notifiers must be enabled at this point. */
871
int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev)
872
{
873
    int i, r;
874
    if (!vdev->binding->set_guest_notifiers) {
875
        fprintf(stderr, "binding does not support guest notifiers\n");
876
        r = -ENOSYS;
877
        goto fail;
878
    }
879

    
880
    r = vdev->binding->set_guest_notifiers(vdev->binding_opaque, true);
881
    if (r < 0) {
882
        fprintf(stderr, "Error binding guest notifier: %d\n", -r);
883
        goto fail_notifiers;
884
    }
885

    
886
    r = vhost_dev_set_features(hdev, hdev->log_enabled);
887
    if (r < 0) {
888
        goto fail_features;
889
    }
890
    r = ioctl(hdev->control, VHOST_SET_MEM_TABLE, hdev->mem);
891
    if (r < 0) {
892
        r = -errno;
893
        goto fail_mem;
894
    }
895
    for (i = 0; i < hdev->nvqs; ++i) {
896
        r = vhost_virtqueue_init(hdev,
897
                                 vdev,
898
                                 hdev->vqs + i,
899
                                 i);
900
        if (r < 0) {
901
            goto fail_vq;
902
        }
903
    }
904

    
905
    if (hdev->log_enabled) {
906
        hdev->log_size = vhost_get_log_size(hdev);
907
        hdev->log = hdev->log_size ?
908
            g_malloc0(hdev->log_size * sizeof *hdev->log) : NULL;
909
        r = ioctl(hdev->control, VHOST_SET_LOG_BASE,
910
                  (uint64_t)(unsigned long)hdev->log);
911
        if (r < 0) {
912
            r = -errno;
913
            goto fail_log;
914
        }
915
    }
916

    
917
    hdev->started = true;
918

    
919
    return 0;
920
fail_log:
921
fail_vq:
922
    while (--i >= 0) {
923
        vhost_virtqueue_cleanup(hdev,
924
                                vdev,
925
                                hdev->vqs + i,
926
                                i);
927
    }
928
fail_mem:
929
fail_features:
930
    vdev->binding->set_guest_notifiers(vdev->binding_opaque, false);
931
fail_notifiers:
932
fail:
933
    return r;
934
}
935

    
936
/* Host notifiers must be enabled at this point. */
937
void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
938
{
939
    int i, r;
940

    
941
    for (i = 0; i < hdev->nvqs; ++i) {
942
        vhost_virtqueue_cleanup(hdev,
943
                                vdev,
944
                                hdev->vqs + i,
945
                                i);
946
    }
947
    for (i = 0; i < hdev->n_mem_sections; ++i) {
948
        vhost_sync_dirty_bitmap(hdev, &hdev->mem_sections[i],
949
                                0, (target_phys_addr_t)~0x0ull);
950
    }
951
    r = vdev->binding->set_guest_notifiers(vdev->binding_opaque, false);
952
    if (r < 0) {
953
        fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
954
        fflush(stderr);
955
    }
956
    assert (r >= 0);
957

    
958
    hdev->started = false;
959
    g_free(hdev->log);
960
    hdev->log = NULL;
961
    hdev->log_size = 0;
962
}