summaryrefslogtreecommitdiff
blob: fe0774617b54c96417790f278e4d000bf1976a3a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
/*
 * Virtio Block Device
 *
 * Copyright IBM, Corp. 2007
 *
 * Authors:
 *  Anthony Liguori   <aliguori@us.ibm.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2.  See
 * the COPYING file in the top-level directory.
 *
 */

#include "qemu-common.h"
#include "qemu-error.h"
#include "trace.h"
#include "blockdev.h"
#include "virtio-blk.h"
#include "scsi-defs.h"
#ifdef __linux__
# include <scsi/sg.h>
#endif

typedef struct VirtIOBlock
{
    VirtIODevice vdev;
    BlockDriverState *bs;
    VirtQueue *vq;
    void *rq;
    QEMUBH *bh;
    BlockConf *conf;
    VirtIOBlkConf *blk;
    unsigned short sector_mask;
    DeviceState *qdev;
} VirtIOBlock;

static VirtIOBlock *to_virtio_blk(VirtIODevice *vdev)
{
    return (VirtIOBlock *)vdev;
}

typedef struct VirtIOBlockReq
{
    VirtIOBlock *dev;
    VirtQueueElement elem;
    struct virtio_blk_inhdr *in;
    struct virtio_blk_outhdr *out;
    struct virtio_scsi_inhdr *scsi;
    QEMUIOVector qiov;
    struct VirtIOBlockReq *next;
    BlockAcctCookie acct;
} VirtIOBlockReq;

static void virtio_blk_req_complete(VirtIOBlockReq *req, int status)
{
    VirtIOBlock *s = req->dev;

    trace_virtio_blk_req_complete(req, status);

    stb_p(&req->in->status, status);
    virtqueue_push(s->vq, &req->elem, req->qiov.size + sizeof(*req->in));
    virtio_notify(&s->vdev, s->vq);
}

static int virtio_blk_handle_rw_error(VirtIOBlockReq *req, int error,
    int is_read)
{
    BlockErrorAction action = bdrv_get_on_error(req->dev->bs, is_read);
    VirtIOBlock *s = req->dev;

    if (action == BLOCK_ERR_IGNORE) {
        bdrv_emit_qmp_error_event(s->bs, BDRV_ACTION_IGNORE, is_read);
        return 0;
    }

    if ((error == ENOSPC && action == BLOCK_ERR_STOP_ENOSPC)
            || action == BLOCK_ERR_STOP_ANY) {
        req->next = s->rq;
        s->rq = req;
        bdrv_emit_qmp_error_event(s->bs, BDRV_ACTION_STOP, is_read);
        vm_stop(RUN_STATE_IO_ERROR);
        bdrv_iostatus_set_err(s->bs, error);
    } else {
        virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
        bdrv_acct_done(s->bs, &req->acct);
        g_free(req);
        bdrv_emit_qmp_error_event(s->bs, BDRV_ACTION_REPORT, is_read);
    }

    return 1;
}

static void virtio_blk_rw_complete(void *opaque, int ret)
{
    VirtIOBlockReq *req = opaque;

    trace_virtio_blk_rw_complete(req, ret);

    if (ret) {
        int is_read = !(ldl_p(&req->out->type) & VIRTIO_BLK_T_OUT);
        if (virtio_blk_handle_rw_error(req, -ret, is_read))
            return;
    }

    virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
    bdrv_acct_done(req->dev->bs, &req->acct);
    g_free(req);
}

static void virtio_blk_flush_complete(void *opaque, int ret)
{
    VirtIOBlockReq *req = opaque;

    if (ret) {
        if (virtio_blk_handle_rw_error(req, -ret, 0)) {
            return;
        }
    }

    virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
    bdrv_acct_done(req->dev->bs, &req->acct);
    g_free(req);
}

static VirtIOBlockReq *virtio_blk_alloc_request(VirtIOBlock *s)
{
    VirtIOBlockReq *req = g_malloc(sizeof(*req));
    req->dev = s;
    req->qiov.size = 0;
    req->next = NULL;
    return req;
}

static VirtIOBlockReq *virtio_blk_get_request(VirtIOBlock *s)
{
    VirtIOBlockReq *req = virtio_blk_alloc_request(s);

    if (req != NULL) {
        if (!virtqueue_pop(s->vq, &req->elem)) {
            g_free(req);
            return NULL;
        }
    }

    return req;
}

static void virtio_blk_handle_scsi(VirtIOBlockReq *req)
{
#ifdef __linux__
    int ret;
    int i;
#endif
    int status = VIRTIO_BLK_S_OK;

    /*
     * We require at least one output segment each for the virtio_blk_outhdr
     * and the SCSI command block.
     *
     * We also at least require the virtio_blk_inhdr, the virtio_scsi_inhdr
     * and the sense buffer pointer in the input segments.
     */
    if (req->elem.out_num < 2 || req->elem.in_num < 3) {
        virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
        g_free(req);
        return;
    }

    /*
     * The scsi inhdr is placed in the second-to-last input segment, just
     * before the regular inhdr.
     */
    req->scsi = (void *)req->elem.in_sg[req->elem.in_num - 2].iov_base;

    if (!req->dev->blk->scsi) {
        status = VIRTIO_BLK_S_UNSUPP;
        goto fail;
    }

    /*
     * No support for bidirection commands yet.
     */
    if (req->elem.out_num > 2 && req->elem.in_num > 3) {
        status = VIRTIO_BLK_S_UNSUPP;
        goto fail;
    }

#ifdef __linux__
    struct sg_io_hdr hdr;
    memset(&hdr, 0, sizeof(struct sg_io_hdr));
    hdr.interface_id = 'S';
    hdr.cmd_len = req->elem.out_sg[1].iov_len;
    hdr.cmdp = req->elem.out_sg[1].iov_base;
    hdr.dxfer_len = 0;

    if (req->elem.out_num > 2) {
        /*
         * If there are more than the minimally required 2 output segments
         * there is write payload starting from the third iovec.
         */
        hdr.dxfer_direction = SG_DXFER_TO_DEV;
        hdr.iovec_count = req->elem.out_num - 2;

        for (i = 0; i < hdr.iovec_count; i++)
            hdr.dxfer_len += req->elem.out_sg[i + 2].iov_len;

        hdr.dxferp = req->elem.out_sg + 2;

    } else if (req->elem.in_num > 3) {
        /*
         * If we have more than 3 input segments the guest wants to actually
         * read data.
         */
        hdr.dxfer_direction = SG_DXFER_FROM_DEV;
        hdr.iovec_count = req->elem.in_num - 3;
        for (i = 0; i < hdr.iovec_count; i++)
            hdr.dxfer_len += req->elem.in_sg[i].iov_len;

        hdr.dxferp = req->elem.in_sg;
    } else {
        /*
         * Some SCSI commands don't actually transfer any data.
         */
        hdr.dxfer_direction = SG_DXFER_NONE;
    }

    hdr.sbp = req->elem.in_sg[req->elem.in_num - 3].iov_base;
    hdr.mx_sb_len = req->elem.in_sg[req->elem.in_num - 3].iov_len;

    ret = bdrv_ioctl(req->dev->bs, SG_IO, &hdr);
    if (ret) {
        status = VIRTIO_BLK_S_UNSUPP;
        goto fail;
    }

    /*
     * From SCSI-Generic-HOWTO: "Some lower level drivers (e.g. ide-scsi)
     * clear the masked_status field [hence status gets cleared too, see
     * block/scsi_ioctl.c] even when a CHECK_CONDITION or COMMAND_TERMINATED
     * status has occurred.  However they do set DRIVER_SENSE in driver_status
     * field. Also a (sb_len_wr > 0) indicates there is a sense buffer.
     */
    if (hdr.status == 0 && hdr.sb_len_wr > 0) {
        hdr.status = CHECK_CONDITION;
    }

    stl_p(&req->scsi->errors,
          hdr.status | (hdr.msg_status << 8) |
          (hdr.host_status << 16) | (hdr.driver_status << 24));
    stl_p(&req->scsi->residual, hdr.resid);
    stl_p(&req->scsi->sense_len, hdr.sb_len_wr);
    stl_p(&req->scsi->data_len, hdr.dxfer_len);

    virtio_blk_req_complete(req, status);
    g_free(req);
#else
    abort();
#endif

fail:
    /* Just put anything nonzero so that the ioctl fails in the guest.  */
    stl_p(&req->scsi->errors, 255);
    virtio_blk_req_complete(req, status);
    g_free(req);
}

typedef struct MultiReqBuffer {
    BlockRequest        blkreq[32];
    unsigned int        num_writes;
} MultiReqBuffer;

static void virtio_submit_multiwrite(BlockDriverState *bs, MultiReqBuffer *mrb)
{
    int i, ret;

    if (!mrb->num_writes) {
        return;
    }

    ret = bdrv_aio_multiwrite(bs, mrb->blkreq, mrb->num_writes);
    if (ret != 0) {
        for (i = 0; i < mrb->num_writes; i++) {
            if (mrb->blkreq[i].error) {
                virtio_blk_rw_complete(mrb->blkreq[i].opaque, -EIO);
            }
        }
    }

    mrb->num_writes = 0;
}

static void virtio_blk_handle_flush(VirtIOBlockReq *req, MultiReqBuffer *mrb)
{
    bdrv_acct_start(req->dev->bs, &req->acct, 0, BDRV_ACCT_FLUSH);

    /*
     * Make sure all outstanding writes are posted to the backing device.
     */
    virtio_submit_multiwrite(req->dev->bs, mrb);
    bdrv_aio_flush(req->dev->bs, virtio_blk_flush_complete, req);
}

static void virtio_blk_handle_write(VirtIOBlockReq *req, MultiReqBuffer *mrb)
{
    BlockRequest *blkreq;
    uint64_t sector;

    sector = ldq_p(&req->out->sector);

    bdrv_acct_start(req->dev->bs, &req->acct, req->qiov.size, BDRV_ACCT_WRITE);

    trace_virtio_blk_handle_write(req, sector, req->qiov.size / 512);

    if (sector & req->dev->sector_mask) {
        virtio_blk_rw_complete(req, -EIO);
        return;
    }
    if (req->qiov.size % req->dev->conf->logical_block_size) {
        virtio_blk_rw_complete(req, -EIO);
        return;
    }

    if (mrb->num_writes == 32) {
        virtio_submit_multiwrite(req->dev->bs, mrb);
    }

    blkreq = &mrb->blkreq[mrb->num_writes];
    blkreq->sector = sector;
    blkreq->nb_sectors = req->qiov.size / BDRV_SECTOR_SIZE;
    blkreq->qiov = &req->qiov;
    blkreq->cb = virtio_blk_rw_complete;
    blkreq->opaque = req;
    blkreq->error = 0;

    mrb->num_writes++;
}

static void virtio_blk_handle_read(VirtIOBlockReq *req)
{
    uint64_t sector;

    sector = ldq_p(&req->out->sector);

    bdrv_acct_start(req->dev->bs, &req->acct, req->qiov.size, BDRV_ACCT_READ);

    trace_virtio_blk_handle_read(req, sector, req->qiov.size / 512);

    if (sector & req->dev->sector_mask) {
        virtio_blk_rw_complete(req, -EIO);
        return;
    }
    if (req->qiov.size % req->dev->conf->logical_block_size) {
        virtio_blk_rw_complete(req, -EIO);
        return;
    }
    bdrv_aio_readv(req->dev->bs, sector, &req->qiov,
                   req->qiov.size / BDRV_SECTOR_SIZE,
                   virtio_blk_rw_complete, req);
}

static void virtio_blk_handle_request(VirtIOBlockReq *req,
    MultiReqBuffer *mrb)
{
    uint32_t type;

    if (req->elem.out_num < 1 || req->elem.in_num < 1) {
        error_report("virtio-blk missing headers");
        exit(1);
    }

    if (req->elem.out_sg[0].iov_len < sizeof(*req->out) ||
        req->elem.in_sg[req->elem.in_num - 1].iov_len < sizeof(*req->in)) {
        error_report("virtio-blk header not in correct element");
        exit(1);
    }

    req->out = (void *)req->elem.out_sg[0].iov_base;
    req->in = (void *)req->elem.in_sg[req->elem.in_num - 1].iov_base;

    type = ldl_p(&req->out->type);

    if (type & VIRTIO_BLK_T_FLUSH) {
        virtio_blk_handle_flush(req, mrb);
    } else if (type & VIRTIO_BLK_T_SCSI_CMD) {
        virtio_blk_handle_scsi(req);
    } else if (type & VIRTIO_BLK_T_GET_ID) {
        VirtIOBlock *s = req->dev;

        /*
         * NB: per existing s/n string convention the string is
         * terminated by '\0' only when shorter than buffer.
         */
        strncpy(req->elem.in_sg[0].iov_base,
                s->blk->serial ? s->blk->serial : "",
                MIN(req->elem.in_sg[0].iov_len, VIRTIO_BLK_ID_BYTES));
        virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
        g_free(req);
    } else if (type & VIRTIO_BLK_T_OUT) {
        qemu_iovec_init_external(&req->qiov, &req->elem.out_sg[1],
                                 req->elem.out_num - 1);
        virtio_blk_handle_write(req, mrb);
    } else {
        qemu_iovec_init_external(&req->qiov, &req->elem.in_sg[0],
                                 req->elem.in_num - 1);
        virtio_blk_handle_read(req);
    }
}

static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
{
    VirtIOBlock *s = to_virtio_blk(vdev);
    VirtIOBlockReq *req;
    MultiReqBuffer mrb = {
        .num_writes = 0,
    };

    while ((req = virtio_blk_get_request(s))) {
        virtio_blk_handle_request(req, &mrb);
    }

    virtio_submit_multiwrite(s->bs, &mrb);

    /*
     * FIXME: Want to check for completions before returning to guest mode,
     * so cached reads and writes are reported as quickly as possible. But
     * that should be done in the generic block layer.
     */
}

static void virtio_blk_dma_restart_bh(void *opaque)
{
    VirtIOBlock *s = opaque;
    VirtIOBlockReq *req = s->rq;
    MultiReqBuffer mrb = {
        .num_writes = 0,
    };

    qemu_bh_delete(s->bh);
    s->bh = NULL;

    s->rq = NULL;

    while (req) {
        virtio_blk_handle_request(req, &mrb);
        req = req->next;
    }

    virtio_submit_multiwrite(s->bs, &mrb);
}

static void virtio_blk_dma_restart_cb(void *opaque, int running,
                                      RunState state)
{
    VirtIOBlock *s = opaque;

    if (!running)
        return;

    if (!s->bh) {
        s->bh = qemu_bh_new(virtio_blk_dma_restart_bh, s);
        qemu_bh_schedule(s->bh);
    }
}

static void virtio_blk_reset(VirtIODevice *vdev)
{
    /*
     * This should cancel pending requests, but can't do nicely until there
     * are per-device request lists.
     */
    bdrv_drain_all();
}

/* coalesce internal state, copy to pci i/o region 0
 */
static void virtio_blk_update_config(VirtIODevice *vdev, uint8_t *config)
{
    VirtIOBlock *s = to_virtio_blk(vdev);
    struct virtio_blk_config blkcfg;
    uint64_t capacity;
    int cylinders, heads, secs;
    int blk_size = s->conf->logical_block_size;

    bdrv_get_geometry(s->bs, &capacity);
    bdrv_get_geometry_hint(s->bs, &cylinders, &heads, &secs);
    memset(&blkcfg, 0, sizeof(blkcfg));
    stq_raw(&blkcfg.capacity, capacity);
    stl_raw(&blkcfg.seg_max, 128 - 2);
    stw_raw(&blkcfg.cylinders, cylinders);
    stl_raw(&blkcfg.blk_size, blk_size);
    stw_raw(&blkcfg.min_io_size, s->conf->min_io_size / blk_size);
    stw_raw(&blkcfg.opt_io_size, s->conf->opt_io_size / blk_size);
    blkcfg.heads = heads;
    /*
     * We must ensure that the block device capacity is a multiple of
     * the logical block size. If that is not the case, lets use
     * sector_mask to adopt the geometry to have a correct picture.
     * For those devices where the capacity is ok for the given geometry
     * we dont touch the sector value of the geometry, since some devices
     * (like s390 dasd) need a specific value. Here the capacity is already
     * cyls*heads*secs*blk_size and the sector value is not block size
     * divided by 512 - instead it is the amount of blk_size blocks
     * per track (cylinder).
     */
    if (bdrv_getlength(s->bs) /  heads / secs % blk_size) {
        blkcfg.sectors = secs & ~s->sector_mask;
    } else {
        blkcfg.sectors = secs;
    }
    blkcfg.size_max = 0;
    blkcfg.physical_block_exp = get_physical_block_exp(s->conf);
    blkcfg.alignment_offset = 0;
    memcpy(config, &blkcfg, sizeof(struct virtio_blk_config));
}

static uint32_t virtio_blk_get_features(VirtIODevice *vdev, uint32_t features)
{
    VirtIOBlock *s = to_virtio_blk(vdev);

    features |= (1 << VIRTIO_BLK_F_SEG_MAX);
    features |= (1 << VIRTIO_BLK_F_GEOMETRY);
    features |= (1 << VIRTIO_BLK_F_TOPOLOGY);
    features |= (1 << VIRTIO_BLK_F_BLK_SIZE);
    features |= (1 << VIRTIO_BLK_F_SCSI);

    if (bdrv_enable_write_cache(s->bs))
        features |= (1 << VIRTIO_BLK_F_WCACHE);
    
    if (bdrv_is_read_only(s->bs))
        features |= 1 << VIRTIO_BLK_F_RO;

    return features;
}

static void virtio_blk_save(QEMUFile *f, void *opaque)
{
    VirtIOBlock *s = opaque;
    VirtIOBlockReq *req = s->rq;

    virtio_save(&s->vdev, f);
    
    while (req) {
        qemu_put_sbyte(f, 1);
        qemu_put_buffer(f, (unsigned char*)&req->elem, sizeof(req->elem));
        req = req->next;
    }
    qemu_put_sbyte(f, 0);
}

static int virtio_blk_load(QEMUFile *f, void *opaque, int version_id)
{
    VirtIOBlock *s = opaque;
    int ret;

    if (version_id != 2)
        return -EINVAL;

    ret = virtio_load(&s->vdev, f);
    if (ret) {
        return ret;
    }

    while (qemu_get_sbyte(f)) {
        VirtIOBlockReq *req = virtio_blk_alloc_request(s);
        qemu_get_buffer(f, (unsigned char*)&req->elem, sizeof(req->elem));
        req->next = s->rq;
        s->rq = req;

        virtqueue_map_sg(req->elem.in_sg, req->elem.in_addr,
            req->elem.in_num, 1);
        virtqueue_map_sg(req->elem.out_sg, req->elem.out_addr,
            req->elem.out_num, 0);
    }

    return 0;
}

static void virtio_blk_resize(void *opaque)
{
    VirtIOBlock *s = opaque;

    virtio_notify_config(&s->vdev);
}

static const BlockDevOps virtio_block_ops = {
    .resize_cb = virtio_blk_resize,
};

VirtIODevice *virtio_blk_init(DeviceState *dev, VirtIOBlkConf *blk)
{
    VirtIOBlock *s;
    int cylinders, heads, secs;
    static int virtio_blk_id;
    DriveInfo *dinfo;

    if (!blk->conf.bs) {
        error_report("drive property not set");
        return NULL;
    }
    if (!bdrv_is_inserted(blk->conf.bs)) {
        error_report("Device needs media, but drive is empty");
        return NULL;
    }

    if (!blk->serial) {
        /* try to fall back to value set with legacy -drive serial=... */
        dinfo = drive_get_by_blockdev(blk->conf.bs);
        if (*dinfo->serial) {
            blk->serial = strdup(dinfo->serial);
        }
    }

    s = (VirtIOBlock *)virtio_common_init("virtio-blk", VIRTIO_ID_BLOCK,
                                          sizeof(struct virtio_blk_config),
                                          sizeof(VirtIOBlock));

    s->vdev.get_config = virtio_blk_update_config;
    s->vdev.get_features = virtio_blk_get_features;
    s->vdev.reset = virtio_blk_reset;
    s->bs = blk->conf.bs;
    s->conf = &blk->conf;
    s->blk = blk;
    s->rq = NULL;
    s->sector_mask = (s->conf->logical_block_size / BDRV_SECTOR_SIZE) - 1;
    bdrv_guess_geometry(s->bs, &cylinders, &heads, &secs);

    s->vq = virtio_add_queue(&s->vdev, 128, virtio_blk_handle_output);

    qemu_add_vm_change_state_handler(virtio_blk_dma_restart_cb, s);
    s->qdev = dev;
    register_savevm(dev, "virtio-blk", virtio_blk_id++, 2,
                    virtio_blk_save, virtio_blk_load, s);
    bdrv_set_dev_ops(s->bs, &virtio_block_ops, s);
    bdrv_set_buffer_alignment(s->bs, s->conf->logical_block_size);

    bdrv_iostatus_enable(s->bs);
    add_boot_device_path(s->conf->bootindex, dev, "/disk@0,0");

    return &s->vdev;
}

void virtio_blk_exit(VirtIODevice *vdev)
{
    VirtIOBlock *s = to_virtio_blk(vdev);
    unregister_savevm(s->qdev, "virtio-blk", s);
    blockdev_mark_auto_del(s->bs);
    virtio_cleanup(vdev);
}