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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 "qemu/range.h"
20
#include <linux/vhost.h>
21
#include "exec/address-spaces.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
    if (end < start) {
35
        return;
36
    }
37
    assert(end / VHOST_LOG_CHUNK < dev->log_size);
38
    assert(start / VHOST_LOG_CHUNK < dev->log_size);
39

    
40
    for (;from < to; ++from) {
41
        vhost_log_chunk_t log;
42
        int bit;
43
        /* We first check with non-atomic: much cheaper,
44
         * and we expect non-dirty to be the common case. */
45
        if (!*from) {
46
            addr += VHOST_LOG_CHUNK;
47
            continue;
48
        }
49
        /* Data must be read atomically. We don't really
50
         * need the barrier semantics of __sync
51
         * builtins, but it's easier to use them than
52
         * roll our own. */
53
        log = __sync_fetch_and_and(from, 0);
54
        while ((bit = sizeof(log) > sizeof(int) ?
55
                ffsll(log) : ffs(log))) {
56
            ram_addr_t ram_addr;
57
            bit -= 1;
58
            ram_addr = section->offset_within_region + bit * VHOST_LOG_PAGE;
59
            memory_region_set_dirty(section->mr, ram_addr, VHOST_LOG_PAGE);
60
            log &= ~(0x1ull << bit);
61
        }
62
        addr += VHOST_LOG_CHUNK;
63
    }
64
}
65

    
66
static int vhost_sync_dirty_bitmap(struct vhost_dev *dev,
67
                                   MemoryRegionSection *section,
68
                                   hwaddr start_addr,
69
                                   hwaddr end_addr)
70
{
71
    int i;
72

    
73
    if (!dev->log_enabled || !dev->started) {
74
        return 0;
75
    }
76
    for (i = 0; i < dev->mem->nregions; ++i) {
77
        struct vhost_memory_region *reg = dev->mem->regions + i;
78
        vhost_dev_sync_region(dev, section, start_addr, end_addr,
79
                              reg->guest_phys_addr,
80
                              range_get_last(reg->guest_phys_addr,
81
                                             reg->memory_size));
82
    }
83
    for (i = 0; i < dev->nvqs; ++i) {
84
        struct vhost_virtqueue *vq = dev->vqs + i;
85
        vhost_dev_sync_region(dev, section, start_addr, end_addr, vq->used_phys,
86
                              range_get_last(vq->used_phys, vq->used_size));
87
    }
88
    return 0;
89
}
90

    
91
static void vhost_log_sync(MemoryListener *listener,
92
                          MemoryRegionSection *section)
93
{
94
    struct vhost_dev *dev = container_of(listener, struct vhost_dev,
95
                                         memory_listener);
96
    hwaddr start_addr = section->offset_within_address_space;
97
    hwaddr end_addr = start_addr + section->size;
98

    
99
    vhost_sync_dirty_bitmap(dev, section, start_addr, end_addr);
100
}
101

    
102
/* Assign/unassign. Keep an unsorted array of non-overlapping
103
 * memory regions in dev->mem. */
104
static void vhost_dev_unassign_memory(struct vhost_dev *dev,
105
                                      uint64_t start_addr,
106
                                      uint64_t size)
107
{
108
    int from, to, n = dev->mem->nregions;
109
    /* Track overlapping/split regions for sanity checking. */
110
    int overlap_start = 0, overlap_end = 0, overlap_middle = 0, split = 0;
111

    
112
    for (from = 0, to = 0; from < n; ++from, ++to) {
113
        struct vhost_memory_region *reg = dev->mem->regions + to;
114
        uint64_t reglast;
115
        uint64_t memlast;
116
        uint64_t change;
117

    
118
        /* clone old region */
119
        if (to != from) {
120
            memcpy(reg, dev->mem->regions + from, sizeof *reg);
121
        }
122

    
123
        /* No overlap is simple */
124
        if (!ranges_overlap(reg->guest_phys_addr, reg->memory_size,
125
                            start_addr, size)) {
126
            continue;
127
        }
128

    
129
        /* Split only happens if supplied region
130
         * is in the middle of an existing one. Thus it can not
131
         * overlap with any other existing region. */
132
        assert(!split);
133

    
134
        reglast = range_get_last(reg->guest_phys_addr, reg->memory_size);
135
        memlast = range_get_last(start_addr, size);
136

    
137
        /* Remove whole region */
138
        if (start_addr <= reg->guest_phys_addr && memlast >= reglast) {
139
            --dev->mem->nregions;
140
            --to;
141
            ++overlap_middle;
142
            continue;
143
        }
144

    
145
        /* Shrink region */
146
        if (memlast >= reglast) {
147
            reg->memory_size = start_addr - reg->guest_phys_addr;
148
            assert(reg->memory_size);
149
            assert(!overlap_end);
150
            ++overlap_end;
151
            continue;
152
        }
153

    
154
        /* Shift region */
155
        if (start_addr <= reg->guest_phys_addr) {
156
            change = memlast + 1 - reg->guest_phys_addr;
157
            reg->memory_size -= change;
158
            reg->guest_phys_addr += change;
159
            reg->userspace_addr += change;
160
            assert(reg->memory_size);
161
            assert(!overlap_start);
162
            ++overlap_start;
163
            continue;
164
        }
165

    
166
        /* This only happens if supplied region
167
         * is in the middle of an existing one. Thus it can not
168
         * overlap with any other existing region. */
169
        assert(!overlap_start);
170
        assert(!overlap_end);
171
        assert(!overlap_middle);
172
        /* Split region: shrink first part, shift second part. */
173
        memcpy(dev->mem->regions + n, reg, sizeof *reg);
174
        reg->memory_size = start_addr - reg->guest_phys_addr;
175
        assert(reg->memory_size);
176
        change = memlast + 1 - reg->guest_phys_addr;
177
        reg = dev->mem->regions + n;
178
        reg->memory_size -= change;
179
        assert(reg->memory_size);
180
        reg->guest_phys_addr += change;
181
        reg->userspace_addr += change;
182
        /* Never add more than 1 region */
183
        assert(dev->mem->nregions == n);
184
        ++dev->mem->nregions;
185
        ++split;
186
    }
187
}
188

    
189
/* Called after unassign, so no regions overlap the given range. */
190
static void vhost_dev_assign_memory(struct vhost_dev *dev,
191
                                    uint64_t start_addr,
192
                                    uint64_t size,
193
                                    uint64_t uaddr)
194
{
195
    int from, to;
196
    struct vhost_memory_region *merged = NULL;
197
    for (from = 0, to = 0; from < dev->mem->nregions; ++from, ++to) {
198
        struct vhost_memory_region *reg = dev->mem->regions + to;
199
        uint64_t prlast, urlast;
200
        uint64_t pmlast, umlast;
201
        uint64_t s, e, u;
202

    
203
        /* clone old region */
204
        if (to != from) {
205
            memcpy(reg, dev->mem->regions + from, sizeof *reg);
206
        }
207
        prlast = range_get_last(reg->guest_phys_addr, reg->memory_size);
208
        pmlast = range_get_last(start_addr, size);
209
        urlast = range_get_last(reg->userspace_addr, reg->memory_size);
210
        umlast = range_get_last(uaddr, size);
211

    
212
        /* check for overlapping regions: should never happen. */
213
        assert(prlast < start_addr || pmlast < reg->guest_phys_addr);
214
        /* Not an adjacent or overlapping region - do not merge. */
215
        if ((prlast + 1 != start_addr || urlast + 1 != uaddr) &&
216
            (pmlast + 1 != reg->guest_phys_addr ||
217
             umlast + 1 != reg->userspace_addr)) {
218
            continue;
219
        }
220

    
221
        if (merged) {
222
            --to;
223
            assert(to >= 0);
224
        } else {
225
            merged = reg;
226
        }
227
        u = MIN(uaddr, reg->userspace_addr);
228
        s = MIN(start_addr, reg->guest_phys_addr);
229
        e = MAX(pmlast, prlast);
230
        uaddr = merged->userspace_addr = u;
231
        start_addr = merged->guest_phys_addr = s;
232
        size = merged->memory_size = e - s + 1;
233
        assert(merged->memory_size);
234
    }
235

    
236
    if (!merged) {
237
        struct vhost_memory_region *reg = dev->mem->regions + to;
238
        memset(reg, 0, sizeof *reg);
239
        reg->memory_size = size;
240
        assert(reg->memory_size);
241
        reg->guest_phys_addr = start_addr;
242
        reg->userspace_addr = uaddr;
243
        ++to;
244
    }
245
    assert(to <= dev->mem->nregions + 1);
246
    dev->mem->nregions = to;
247
}
248

    
249
static uint64_t vhost_get_log_size(struct vhost_dev *dev)
250
{
251
    uint64_t log_size = 0;
252
    int i;
253
    for (i = 0; i < dev->mem->nregions; ++i) {
254
        struct vhost_memory_region *reg = dev->mem->regions + i;
255
        uint64_t last = range_get_last(reg->guest_phys_addr,
256
                                       reg->memory_size);
257
        log_size = MAX(log_size, last / VHOST_LOG_CHUNK + 1);
258
    }
259
    for (i = 0; i < dev->nvqs; ++i) {
260
        struct vhost_virtqueue *vq = dev->vqs + i;
261
        uint64_t last = vq->used_phys + vq->used_size - 1;
262
        log_size = MAX(log_size, last / VHOST_LOG_CHUNK + 1);
263
    }
264
    return log_size;
265
}
266

    
267
static inline void vhost_dev_log_resize(struct vhost_dev* dev, uint64_t size)
268
{
269
    vhost_log_chunk_t *log;
270
    uint64_t log_base;
271
    int r, i;
272
    if (size) {
273
        log = g_malloc0(size * sizeof *log);
274
    } else {
275
        log = NULL;
276
    }
277
    log_base = (uint64_t)(unsigned long)log;
278
    r = ioctl(dev->control, VHOST_SET_LOG_BASE, &log_base);
279
    assert(r >= 0);
280
    for (i = 0; i < dev->n_mem_sections; ++i) {
281
        /* Sync only the range covered by the old log */
282
        vhost_sync_dirty_bitmap(dev, &dev->mem_sections[i], 0,
283
                                dev->log_size * VHOST_LOG_CHUNK - 1);
284
    }
285
    if (dev->log) {
286
        g_free(dev->log);
287
    }
288
    dev->log = log;
289
    dev->log_size = size;
290
}
291

    
292
static int vhost_verify_ring_mappings(struct vhost_dev *dev,
293
                                      uint64_t start_addr,
294
                                      uint64_t size)
295
{
296
    int i;
297
    for (i = 0; i < dev->nvqs; ++i) {
298
        struct vhost_virtqueue *vq = dev->vqs + i;
299
        hwaddr l;
300
        void *p;
301

    
302
        if (!ranges_overlap(start_addr, size, vq->ring_phys, vq->ring_size)) {
303
            continue;
304
        }
305
        l = vq->ring_size;
306
        p = cpu_physical_memory_map(vq->ring_phys, &l, 1);
307
        if (!p || l != vq->ring_size) {
308
            fprintf(stderr, "Unable to map ring buffer for ring %d\n", i);
309
            return -ENOMEM;
310
        }
311
        if (p != vq->ring) {
312
            fprintf(stderr, "Ring buffer relocated for ring %d\n", i);
313
            return -EBUSY;
314
        }
315
        cpu_physical_memory_unmap(p, l, 0, 0);
316
    }
317
    return 0;
318
}
319

    
320
static struct vhost_memory_region *vhost_dev_find_reg(struct vhost_dev *dev,
321
                                                      uint64_t start_addr,
322
                                                      uint64_t size)
323
{
324
    int i, n = dev->mem->nregions;
325
    for (i = 0; i < n; ++i) {
326
        struct vhost_memory_region *reg = dev->mem->regions + i;
327
        if (ranges_overlap(reg->guest_phys_addr, reg->memory_size,
328
                           start_addr, size)) {
329
            return reg;
330
        }
331
    }
332
    return NULL;
333
}
334

    
335
static bool vhost_dev_cmp_memory(struct vhost_dev *dev,
336
                                 uint64_t start_addr,
337
                                 uint64_t size,
338
                                 uint64_t uaddr)
339
{
340
    struct vhost_memory_region *reg = vhost_dev_find_reg(dev, start_addr, size);
341
    uint64_t reglast;
342
    uint64_t memlast;
343

    
344
    if (!reg) {
345
        return true;
346
    }
347

    
348
    reglast = range_get_last(reg->guest_phys_addr, reg->memory_size);
349
    memlast = range_get_last(start_addr, size);
350

    
351
    /* Need to extend region? */
352
    if (start_addr < reg->guest_phys_addr || memlast > reglast) {
353
        return true;
354
    }
355
    /* userspace_addr changed? */
356
    return uaddr != reg->userspace_addr + start_addr - reg->guest_phys_addr;
357
}
358

    
359
static void vhost_set_memory(MemoryListener *listener,
360
                             MemoryRegionSection *section,
361
                             bool add)
362
{
363
    struct vhost_dev *dev = container_of(listener, struct vhost_dev,
364
                                         memory_listener);
365
    hwaddr start_addr = section->offset_within_address_space;
366
    ram_addr_t size = section->size;
367
    bool log_dirty = memory_region_is_logging(section->mr);
368
    int s = offsetof(struct vhost_memory, regions) +
369
        (dev->mem->nregions + 1) * sizeof dev->mem->regions[0];
370
    uint64_t log_size;
371
    int r;
372
    void *ram;
373

    
374
    dev->mem = g_realloc(dev->mem, s);
375

    
376
    if (log_dirty) {
377
        add = false;
378
    }
379

    
380
    assert(size);
381

    
382
    /* Optimize no-change case. At least cirrus_vga does this a lot at this time. */
383
    ram = memory_region_get_ram_ptr(section->mr) + section->offset_within_region;
384
    if (add) {
385
        if (!vhost_dev_cmp_memory(dev, start_addr, size, (uintptr_t)ram)) {
386
            /* Region exists with same address. Nothing to do. */
387
            return;
388
        }
389
    } else {
390
        if (!vhost_dev_find_reg(dev, start_addr, size)) {
391
            /* Removing region that we don't access. Nothing to do. */
392
            return;
393
        }
394
    }
395

    
396
    vhost_dev_unassign_memory(dev, start_addr, size);
397
    if (add) {
398
        /* Add given mapping, merging adjacent regions if any */
399
        vhost_dev_assign_memory(dev, start_addr, size, (uintptr_t)ram);
400
    } else {
401
        /* Remove old mapping for this memory, if any. */
402
        vhost_dev_unassign_memory(dev, start_addr, size);
403
    }
404

    
405
    if (!dev->started) {
406
        return;
407
    }
408

    
409
    if (dev->started) {
410
        r = vhost_verify_ring_mappings(dev, start_addr, size);
411
        assert(r >= 0);
412
    }
413

    
414
    if (!dev->log_enabled) {
415
        r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem);
416
        assert(r >= 0);
417
        return;
418
    }
419
    log_size = vhost_get_log_size(dev);
420
    /* We allocate an extra 4K bytes to log,
421
     * to reduce the * number of reallocations. */
422
#define VHOST_LOG_BUFFER (0x1000 / sizeof *dev->log)
423
    /* To log more, must increase log size before table update. */
424
    if (dev->log_size < log_size) {
425
        vhost_dev_log_resize(dev, log_size + VHOST_LOG_BUFFER);
426
    }
427
    r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem);
428
    assert(r >= 0);
429
    /* To log less, can only decrease log size after table update. */
430
    if (dev->log_size > log_size + VHOST_LOG_BUFFER) {
431
        vhost_dev_log_resize(dev, log_size);
432
    }
433
}
434

    
435
static bool vhost_section(MemoryRegionSection *section)
436
{
437
    return memory_region_is_ram(section->mr);
438
}
439

    
440
static void vhost_begin(MemoryListener *listener)
441
{
442
}
443

    
444
static void vhost_commit(MemoryListener *listener)
445
{
446
}
447

    
448
static void vhost_region_add(MemoryListener *listener,
449
                             MemoryRegionSection *section)
450
{
451
    struct vhost_dev *dev = container_of(listener, struct vhost_dev,
452
                                         memory_listener);
453

    
454
    if (!vhost_section(section)) {
455
        return;
456
    }
457

    
458
    ++dev->n_mem_sections;
459
    dev->mem_sections = g_renew(MemoryRegionSection, dev->mem_sections,
460
                                dev->n_mem_sections);
461
    dev->mem_sections[dev->n_mem_sections - 1] = *section;
462
    vhost_set_memory(listener, section, true);
463
}
464

    
465
static void vhost_region_del(MemoryListener *listener,
466
                             MemoryRegionSection *section)
467
{
468
    struct vhost_dev *dev = container_of(listener, struct vhost_dev,
469
                                         memory_listener);
470
    int i;
471

    
472
    if (!vhost_section(section)) {
473
        return;
474
    }
475

    
476
    vhost_set_memory(listener, section, false);
477
    for (i = 0; i < dev->n_mem_sections; ++i) {
478
        if (dev->mem_sections[i].offset_within_address_space
479
            == section->offset_within_address_space) {
480
            --dev->n_mem_sections;
481
            memmove(&dev->mem_sections[i], &dev->mem_sections[i+1],
482
                    (dev->n_mem_sections - i) * sizeof(*dev->mem_sections));
483
            break;
484
        }
485
    }
486
}
487

    
488
static void vhost_region_nop(MemoryListener *listener,
489
                             MemoryRegionSection *section)
490
{
491
}
492

    
493
static int vhost_virtqueue_set_addr(struct vhost_dev *dev,
494
                                    struct vhost_virtqueue *vq,
495
                                    unsigned idx, bool enable_log)
496
{
497
    struct vhost_vring_addr addr = {
498
        .index = idx,
499
        .desc_user_addr = (uint64_t)(unsigned long)vq->desc,
500
        .avail_user_addr = (uint64_t)(unsigned long)vq->avail,
501
        .used_user_addr = (uint64_t)(unsigned long)vq->used,
502
        .log_guest_addr = vq->used_phys,
503
        .flags = enable_log ? (1 << VHOST_VRING_F_LOG) : 0,
504
    };
505
    int r = ioctl(dev->control, VHOST_SET_VRING_ADDR, &addr);
506
    if (r < 0) {
507
        return -errno;
508
    }
509
    return 0;
510
}
511

    
512
static int vhost_dev_set_features(struct vhost_dev *dev, bool enable_log)
513
{
514
    uint64_t features = dev->acked_features;
515
    int r;
516
    if (enable_log) {
517
        features |= 0x1 << VHOST_F_LOG_ALL;
518
    }
519
    r = ioctl(dev->control, VHOST_SET_FEATURES, &features);
520
    return r < 0 ? -errno : 0;
521
}
522

    
523
static int vhost_dev_set_log(struct vhost_dev *dev, bool enable_log)
524
{
525
    int r, t, i;
526
    r = vhost_dev_set_features(dev, enable_log);
527
    if (r < 0) {
528
        goto err_features;
529
    }
530
    for (i = 0; i < dev->nvqs; ++i) {
531
        r = vhost_virtqueue_set_addr(dev, dev->vqs + i, i,
532
                                     enable_log);
533
        if (r < 0) {
534
            goto err_vq;
535
        }
536
    }
537
    return 0;
538
err_vq:
539
    for (; i >= 0; --i) {
540
        t = vhost_virtqueue_set_addr(dev, dev->vqs + i, i,
541
                                     dev->log_enabled);
542
        assert(t >= 0);
543
    }
544
    t = vhost_dev_set_features(dev, dev->log_enabled);
545
    assert(t >= 0);
546
err_features:
547
    return r;
548
}
549

    
550
static int vhost_migration_log(MemoryListener *listener, int enable)
551
{
552
    struct vhost_dev *dev = container_of(listener, struct vhost_dev,
553
                                         memory_listener);
554
    int r;
555
    if (!!enable == dev->log_enabled) {
556
        return 0;
557
    }
558
    if (!dev->started) {
559
        dev->log_enabled = enable;
560
        return 0;
561
    }
562
    if (!enable) {
563
        r = vhost_dev_set_log(dev, false);
564
        if (r < 0) {
565
            return r;
566
        }
567
        if (dev->log) {
568
            g_free(dev->log);
569
        }
570
        dev->log = NULL;
571
        dev->log_size = 0;
572
    } else {
573
        vhost_dev_log_resize(dev, vhost_get_log_size(dev));
574
        r = vhost_dev_set_log(dev, true);
575
        if (r < 0) {
576
            return r;
577
        }
578
    }
579
    dev->log_enabled = enable;
580
    return 0;
581
}
582

    
583
static void vhost_log_global_start(MemoryListener *listener)
584
{
585
    int r;
586

    
587
    r = vhost_migration_log(listener, true);
588
    if (r < 0) {
589
        abort();
590
    }
591
}
592

    
593
static void vhost_log_global_stop(MemoryListener *listener)
594
{
595
    int r;
596

    
597
    r = vhost_migration_log(listener, false);
598
    if (r < 0) {
599
        abort();
600
    }
601
}
602

    
603
static void vhost_log_start(MemoryListener *listener,
604
                            MemoryRegionSection *section)
605
{
606
    /* FIXME: implement */
607
}
608

    
609
static void vhost_log_stop(MemoryListener *listener,
610
                           MemoryRegionSection *section)
611
{
612
    /* FIXME: implement */
613
}
614

    
615
static int vhost_virtqueue_init(struct vhost_dev *dev,
616
                                struct VirtIODevice *vdev,
617
                                struct vhost_virtqueue *vq,
618
                                unsigned idx)
619
{
620
    hwaddr s, l, a;
621
    int r;
622
    struct vhost_vring_file file = {
623
        .index = idx,
624
    };
625
    struct vhost_vring_state state = {
626
        .index = idx,
627
    };
628
    struct VirtQueue *vvq = virtio_get_queue(vdev, idx);
629

    
630
    vq->num = state.num = virtio_queue_get_num(vdev, idx);
631
    r = ioctl(dev->control, VHOST_SET_VRING_NUM, &state);
632
    if (r) {
633
        return -errno;
634
    }
635

    
636
    state.num = virtio_queue_get_last_avail_idx(vdev, idx);
637
    r = ioctl(dev->control, VHOST_SET_VRING_BASE, &state);
638
    if (r) {
639
        return -errno;
640
    }
641

    
642
    s = l = virtio_queue_get_desc_size(vdev, idx);
643
    a = virtio_queue_get_desc_addr(vdev, idx);
644
    vq->desc = cpu_physical_memory_map(a, &l, 0);
645
    if (!vq->desc || l != s) {
646
        r = -ENOMEM;
647
        goto fail_alloc_desc;
648
    }
649
    s = l = virtio_queue_get_avail_size(vdev, idx);
650
    a = virtio_queue_get_avail_addr(vdev, idx);
651
    vq->avail = cpu_physical_memory_map(a, &l, 0);
652
    if (!vq->avail || l != s) {
653
        r = -ENOMEM;
654
        goto fail_alloc_avail;
655
    }
656
    vq->used_size = s = l = virtio_queue_get_used_size(vdev, idx);
657
    vq->used_phys = a = virtio_queue_get_used_addr(vdev, idx);
658
    vq->used = cpu_physical_memory_map(a, &l, 1);
659
    if (!vq->used || l != s) {
660
        r = -ENOMEM;
661
        goto fail_alloc_used;
662
    }
663

    
664
    vq->ring_size = s = l = virtio_queue_get_ring_size(vdev, idx);
665
    vq->ring_phys = a = virtio_queue_get_ring_addr(vdev, idx);
666
    vq->ring = cpu_physical_memory_map(a, &l, 1);
667
    if (!vq->ring || l != s) {
668
        r = -ENOMEM;
669
        goto fail_alloc_ring;
670
    }
671

    
672
    r = vhost_virtqueue_set_addr(dev, vq, idx, dev->log_enabled);
673
    if (r < 0) {
674
        r = -errno;
675
        goto fail_alloc;
676
    }
677
    file.fd = event_notifier_get_fd(virtio_queue_get_host_notifier(vvq));
678
    r = ioctl(dev->control, VHOST_SET_VRING_KICK, &file);
679
    if (r) {
680
        r = -errno;
681
        goto fail_kick;
682
    }
683

    
684
    file.fd = event_notifier_get_fd(virtio_queue_get_guest_notifier(vvq));
685
    r = ioctl(dev->control, VHOST_SET_VRING_CALL, &file);
686
    if (r) {
687
        r = -errno;
688
        goto fail_call;
689
    }
690

    
691
    return 0;
692

    
693
fail_call:
694
fail_kick:
695
fail_alloc:
696
    cpu_physical_memory_unmap(vq->ring, virtio_queue_get_ring_size(vdev, idx),
697
                              0, 0);
698
fail_alloc_ring:
699
    cpu_physical_memory_unmap(vq->used, virtio_queue_get_used_size(vdev, idx),
700
                              0, 0);
701
fail_alloc_used:
702
    cpu_physical_memory_unmap(vq->avail, virtio_queue_get_avail_size(vdev, idx),
703
                              0, 0);
704
fail_alloc_avail:
705
    cpu_physical_memory_unmap(vq->desc, virtio_queue_get_desc_size(vdev, idx),
706
                              0, 0);
707
fail_alloc_desc:
708
    return r;
709
}
710

    
711
static void vhost_virtqueue_cleanup(struct vhost_dev *dev,
712
                                    struct VirtIODevice *vdev,
713
                                    struct vhost_virtqueue *vq,
714
                                    unsigned idx)
715
{
716
    struct vhost_vring_state state = {
717
        .index = idx,
718
    };
719
    int r;
720
    r = ioctl(dev->control, VHOST_GET_VRING_BASE, &state);
721
    if (r < 0) {
722
        fprintf(stderr, "vhost VQ %d ring restore failed: %d\n", idx, r);
723
        fflush(stderr);
724
    }
725
    virtio_queue_set_last_avail_idx(vdev, idx, state.num);
726
    assert (r >= 0);
727
    cpu_physical_memory_unmap(vq->ring, virtio_queue_get_ring_size(vdev, idx),
728
                              0, virtio_queue_get_ring_size(vdev, idx));
729
    cpu_physical_memory_unmap(vq->used, virtio_queue_get_used_size(vdev, idx),
730
                              1, virtio_queue_get_used_size(vdev, idx));
731
    cpu_physical_memory_unmap(vq->avail, virtio_queue_get_avail_size(vdev, idx),
732
                              0, virtio_queue_get_avail_size(vdev, idx));
733
    cpu_physical_memory_unmap(vq->desc, virtio_queue_get_desc_size(vdev, idx),
734
                              0, virtio_queue_get_desc_size(vdev, idx));
735
}
736

    
737
static void vhost_eventfd_add(MemoryListener *listener,
738
                              MemoryRegionSection *section,
739
                              bool match_data, uint64_t data, EventNotifier *e)
740
{
741
}
742

    
743
static void vhost_eventfd_del(MemoryListener *listener,
744
                              MemoryRegionSection *section,
745
                              bool match_data, uint64_t data, EventNotifier *e)
746
{
747
}
748

    
749
int vhost_dev_init(struct vhost_dev *hdev, int devfd, const char *devpath,
750
                   bool force)
751
{
752
    uint64_t features;
753
    int r;
754
    if (devfd >= 0) {
755
        hdev->control = devfd;
756
    } else {
757
        hdev->control = open(devpath, O_RDWR);
758
        if (hdev->control < 0) {
759
            return -errno;
760
        }
761
    }
762
    r = ioctl(hdev->control, VHOST_SET_OWNER, NULL);
763
    if (r < 0) {
764
        goto fail;
765
    }
766

    
767
    r = ioctl(hdev->control, VHOST_GET_FEATURES, &features);
768
    if (r < 0) {
769
        goto fail;
770
    }
771
    hdev->features = features;
772

    
773
    hdev->memory_listener = (MemoryListener) {
774
        .begin = vhost_begin,
775
        .commit = vhost_commit,
776
        .region_add = vhost_region_add,
777
        .region_del = vhost_region_del,
778
        .region_nop = vhost_region_nop,
779
        .log_start = vhost_log_start,
780
        .log_stop = vhost_log_stop,
781
        .log_sync = vhost_log_sync,
782
        .log_global_start = vhost_log_global_start,
783
        .log_global_stop = vhost_log_global_stop,
784
        .eventfd_add = vhost_eventfd_add,
785
        .eventfd_del = vhost_eventfd_del,
786
        .priority = 10
787
    };
788
    hdev->mem = g_malloc0(offsetof(struct vhost_memory, regions));
789
    hdev->n_mem_sections = 0;
790
    hdev->mem_sections = NULL;
791
    hdev->log = NULL;
792
    hdev->log_size = 0;
793
    hdev->log_enabled = false;
794
    hdev->started = false;
795
    memory_listener_register(&hdev->memory_listener, &address_space_memory);
796
    hdev->force = force;
797
    return 0;
798
fail:
799
    r = -errno;
800
    close(hdev->control);
801
    return r;
802
}
803

    
804
void vhost_dev_cleanup(struct vhost_dev *hdev)
805
{
806
    memory_listener_unregister(&hdev->memory_listener);
807
    g_free(hdev->mem);
808
    g_free(hdev->mem_sections);
809
    close(hdev->control);
810
}
811

    
812
bool vhost_dev_query(struct vhost_dev *hdev, VirtIODevice *vdev)
813
{
814
    return !vdev->binding->query_guest_notifiers ||
815
        vdev->binding->query_guest_notifiers(vdev->binding_opaque) ||
816
        hdev->force;
817
}
818

    
819
/* Stop processing guest IO notifications in qemu.
820
 * Start processing them in vhost in kernel.
821
 */
822
int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev)
823
{
824
    int i, r;
825
    if (!vdev->binding->set_host_notifier) {
826
        fprintf(stderr, "binding does not support host notifiers\n");
827
        r = -ENOSYS;
828
        goto fail;
829
    }
830

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

    
839
    return 0;
840
fail_vq:
841
    while (--i >= 0) {
842
        r = vdev->binding->set_host_notifier(vdev->binding_opaque, i, false);
843
        if (r < 0) {
844
            fprintf(stderr, "vhost VQ %d notifier cleanup error: %d\n", i, -r);
845
            fflush(stderr);
846
        }
847
        assert (r >= 0);
848
    }
849
fail:
850
    return r;
851
}
852

    
853
/* Stop processing guest IO notifications in vhost.
854
 * Start processing them in qemu.
855
 * This might actually run the qemu handlers right away,
856
 * so virtio in qemu must be completely setup when this is called.
857
 */
858
void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev)
859
{
860
    int i, r;
861

    
862
    for (i = 0; i < hdev->nvqs; ++i) {
863
        r = vdev->binding->set_host_notifier(vdev->binding_opaque, i, false);
864
        if (r < 0) {
865
            fprintf(stderr, "vhost VQ %d notifier cleanup failed: %d\n", i, -r);
866
            fflush(stderr);
867
        }
868
        assert (r >= 0);
869
    }
870
}
871

    
872
/* Host notifiers must be enabled at this point. */
873
int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev)
874
{
875
    int i, r;
876
    if (!vdev->binding->set_guest_notifiers) {
877
        fprintf(stderr, "binding does not support guest notifiers\n");
878
        r = -ENOSYS;
879
        goto fail;
880
    }
881

    
882
    r = vdev->binding->set_guest_notifiers(vdev->binding_opaque, true);
883
    if (r < 0) {
884
        fprintf(stderr, "Error binding guest notifier: %d\n", -r);
885
        goto fail_notifiers;
886
    }
887

    
888
    r = vhost_dev_set_features(hdev, hdev->log_enabled);
889
    if (r < 0) {
890
        goto fail_features;
891
    }
892
    r = ioctl(hdev->control, VHOST_SET_MEM_TABLE, hdev->mem);
893
    if (r < 0) {
894
        r = -errno;
895
        goto fail_mem;
896
    }
897
    for (i = 0; i < hdev->nvqs; ++i) {
898
        r = vhost_virtqueue_init(hdev,
899
                                 vdev,
900
                                 hdev->vqs + i,
901
                                 i);
902
        if (r < 0) {
903
            goto fail_vq;
904
        }
905
    }
906

    
907
    if (hdev->log_enabled) {
908
        hdev->log_size = vhost_get_log_size(hdev);
909
        hdev->log = hdev->log_size ?
910
            g_malloc0(hdev->log_size * sizeof *hdev->log) : NULL;
911
        r = ioctl(hdev->control, VHOST_SET_LOG_BASE,
912
                  (uint64_t)(unsigned long)hdev->log);
913
        if (r < 0) {
914
            r = -errno;
915
            goto fail_log;
916
        }
917
    }
918

    
919
    hdev->started = true;
920

    
921
    return 0;
922
fail_log:
923
fail_vq:
924
    while (--i >= 0) {
925
        vhost_virtqueue_cleanup(hdev,
926
                                vdev,
927
                                hdev->vqs + i,
928
                                i);
929
    }
930
fail_mem:
931
fail_features:
932
    vdev->binding->set_guest_notifiers(vdev->binding_opaque, false);
933
fail_notifiers:
934
fail:
935
    return r;
936
}
937

    
938
/* Host notifiers must be enabled at this point. */
939
void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
940
{
941
    int i, r;
942

    
943
    for (i = 0; i < hdev->nvqs; ++i) {
944
        vhost_virtqueue_cleanup(hdev,
945
                                vdev,
946
                                hdev->vqs + i,
947
                                i);
948
    }
949
    for (i = 0; i < hdev->n_mem_sections; ++i) {
950
        vhost_sync_dirty_bitmap(hdev, &hdev->mem_sections[i],
951
                                0, (hwaddr)~0x0ull);
952
    }
953
    r = vdev->binding->set_guest_notifiers(vdev->binding_opaque, false);
954
    if (r < 0) {
955
        fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
956
        fflush(stderr);
957
    }
958
    assert (r >= 0);
959

    
960
    hdev->started = false;
961
    g_free(hdev->log);
962
    hdev->log = NULL;
963
    hdev->log_size = 0;
964
}