aboutsummaryrefslogtreecommitdiffstats
path: root/hw/scsi-generic.c
blob: d856d23b3bceb8ab5977cb53cd57cd13305dd402 (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
/*
 * Generic SCSI Device support
 *
 * Copyright (c) 2007 Bull S.A.S.
 * Based on code by Paul Brook
 * Based on code by Fabrice Bellard
 *
 * Written by Laurent Vivier <Laurent.Vivier@bull.net>
 *
 * This code is licensed under the LGPL.
 *
 */

#include "qemu-common.h"
#include "qemu-error.h"
#include "scsi.h"
#include "blockdev.h"

#ifdef __linux__

//#define DEBUG_SCSI

#ifdef DEBUG_SCSI
#define DPRINTF(fmt, ...) \
do { printf("scsi-generic: " fmt , ## __VA_ARGS__); } while (0)
#else
#define DPRINTF(fmt, ...) do {} while(0)
#endif

#define BADF(fmt, ...) \
do { fprintf(stderr, "scsi-generic: " fmt , ## __VA_ARGS__); } while (0)

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <scsi/sg.h>
#include "scsi-defs.h"

#define SCSI_SENSE_BUF_SIZE 96

#define SG_ERR_DRIVER_TIMEOUT  0x06
#define SG_ERR_DRIVER_SENSE    0x08

#define SG_ERR_DID_OK          0x00
#define SG_ERR_DID_NO_CONNECT  0x01
#define SG_ERR_DID_BUS_BUSY    0x02
#define SG_ERR_DID_TIME_OUT    0x03

#ifndef MAX_UINT
#define MAX_UINT ((unsigned int)-1)
#endif

typedef struct SCSIGenericReq {
    SCSIRequest req;
    uint8_t *buf;
    int buflen;
    int len;
    sg_io_hdr_t io_header;
} SCSIGenericReq;

static void scsi_generic_save_request(QEMUFile *f, SCSIRequest *req)
{
    SCSIGenericReq *r = DO_UPCAST(SCSIGenericReq, req, req);

    qemu_put_sbe32s(f, &r->buflen);
    if (r->buflen && r->req.cmd.mode == SCSI_XFER_TO_DEV) {
        assert(!r->req.sg);
        qemu_put_buffer(f, r->buf, r->req.cmd.xfer);
    }
}

static void scsi_generic_load_request(QEMUFile *f, SCSIRequest *req)
{
    SCSIGenericReq *r = DO_UPCAST(SCSIGenericReq, req, req);

    qemu_get_sbe32s(f, &r->buflen);
    if (r->buflen && r->req.cmd.mode == SCSI_XFER_TO_DEV) {
        assert(!r->req.sg);
        qemu_get_buffer(f, r->buf, r->req.cmd.xfer);
    }
}

static void scsi_free_request(SCSIRequest *req)
{
    SCSIGenericReq *r = DO_UPCAST(SCSIGenericReq, req, req);

    g_free(r->buf);
}

/* Helper function for command completion.  */
static void scsi_command_complete(void *opaque, int ret)
{
    int status;
    SCSIGenericReq *r = (SCSIGenericReq *)opaque;

    r->req.aiocb = NULL;
    if (r->io_header.driver_status & SG_ERR_DRIVER_SENSE) {
        r->req.sense_len = r->io_header.sb_len_wr;
    }

    if (ret != 0) {
        switch (ret) {
        case -EDOM:
            status = TASK_SET_FULL;
            break;
        case -ENOMEM:
            status = CHECK_CONDITION;
            scsi_req_build_sense(&r->req, SENSE_CODE(TARGET_FAILURE));
            break;
        default:
            status = CHECK_CONDITION;
            scsi_req_build_sense(&r->req, SENSE_CODE(IO_ERROR));
            break;
        }
    } else {
        if (r->io_header.host_status == SG_ERR_DID_NO_CONNECT ||
            r->io_header.host_status == SG_ERR_DID_BUS_BUSY ||
            r->io_header.host_status == SG_ERR_DID_TIME_OUT ||
            (r->io_header.driver_status & SG_ERR_DRIVER_TIMEOUT)) {
            status = BUSY;
            BADF("Driver Timeout\n");
        } else if (r->io_header.host_status) {
            status = CHECK_CONDITION;
            scsi_req_build_sense(&r->req, SENSE_CODE(I_T_NEXUS_LOSS));
        } else if (r->io_header.status) {
            status = r->io_header.status;
        } else if (r->io_header.driver_status & SG_ERR_DRIVER_SENSE) {
            status = CHECK_CONDITION;
        } else {
            status = GOOD;
        }
    }
    DPRINTF("Command complete 0x%p tag=0x%x status=%d\n",
            r, r->req.tag, status);

    scsi_req_complete(&r->req, status);
    if (!r->req.io_canceled) {
        scsi_req_unref(&r->req);
    }
}

/* Cancel a pending data transfer.  */
static void scsi_cancel_io(SCSIRequest *req)
{
    SCSIGenericReq *r = DO_UPCAST(SCSIGenericReq, req, req);

    DPRINTF("Cancel tag=0x%x\n", req->tag);
    if (r->req.aiocb) {
        bdrv_aio_cancel(r->req.aiocb);

        /* This reference was left in by scsi_*_data.  We take ownership of
         * it independent of whether bdrv_aio_cancel completes the request
         * or not.  */
        scsi_req_unref(&r->req);
    }
    r->req.aiocb = NULL;
}

static int execute_command(BlockDriverState *bdrv,
                           SCSIGenericReq *r, int direction,
			   BlockDriverCompletionFunc *complete)
{
    r->io_header.interface_id = 'S';
    r->io_header.dxfer_direction = direction;
    r->io_header.dxferp = r->buf;
    r->io_header.dxfer_len = r->buflen;
    r->io_header.cmdp = r->req.cmd.buf;
    r->io_header.cmd_len = r->req.cmd.len;
    r->io_header.mx_sb_len = sizeof(r->req.sense);
    r->io_header.sbp = r->req.sense;
    r->io_header.timeout = MAX_UINT;
    r->io_header.usr_ptr = r;
    r->io_header.flags |= SG_FLAG_DIRECT_IO;

    r->req.aiocb = bdrv_aio_ioctl(bdrv, SG_IO, &r->io_header, complete, r);

    return 0;
}

static void scsi_read_complete(void * opaque, int ret)
{
    SCSIGenericReq *r = (SCSIGenericReq *)opaque;
    SCSIDevice *s = r->req.dev;
    int len;

    r->req.aiocb = NULL;
    if (ret) {
        DPRINTF("IO error ret %d\n", ret);
        scsi_command_complete(r, ret);
        return;
    }
    len = r->io_header.dxfer_len - r->io_header.resid;
    DPRINTF("Data ready tag=0x%x len=%d\n", r->req.tag, len);

    r->len = -1;
    if (len == 0) {
        scsi_command_complete(r, 0);
    } else {
        /* Snoop READ CAPACITY output to set the blocksize.  */
        if (r->req.cmd.buf[0] == READ_CAPACITY_10) {
            s->blocksize = ldl_be_p(&r->buf[4]);
            s->max_lba = ldl_be_p(&r->buf[0]);
        } else if (r->req.cmd.buf[0] == SERVICE_ACTION_IN_16 &&
                   (r->req.cmd.buf[1] & 31) == SAI_READ_CAPACITY_16) {
            s->blocksize = ldl_be_p(&r->buf[8]);
            s->max_lba = ldq_be_p(&r->buf[0]);
        }
        bdrv_set_buffer_alignment(s->conf.bs, s->blocksize);

        scsi_req_data(&r->req, len);
        if (!r->req.io_canceled) {
            scsi_req_unref(&r->req);
        }
    }
}

/* Read more data from scsi device into buffer.  */
static void scsi_read_data(SCSIRequest *req)
{
    SCSIGenericReq *r = DO_UPCAST(SCSIGenericReq, req, req);
    SCSIDevice *s = r->req.dev;
    int ret;

    DPRINTF("scsi_read_data 0x%x\n", req->tag);

    /* The request is used as the AIO opaque value, so add a ref.  */
    scsi_req_ref(&r->req);
    if (r->len == -1) {
        scsi_command_complete(r, 0);
        return;
    }

    ret = execute_command(s->conf.bs, r, SG_DXFER_FROM_DEV, scsi_read_complete);
    if (ret < 0) {
        scsi_command_complete(r, ret);
    }
}

static void scsi_write_complete(void * opaque, int ret)
{
    SCSIGenericReq *r = (SCSIGenericReq *)opaque;
    SCSIDevice *s = r->req.dev;

    DPRINTF("scsi_write_complete() ret = %d\n", ret);
    r->req.aiocb = NULL;
    if (ret) {
        DPRINTF("IO error\n");
        scsi_command_complete(r, ret);
        return;
    }

    if (r->req.cmd.buf[0] == MODE_SELECT && r->req.cmd.buf[4] == 12 &&
        s->type == TYPE_TAPE) {
        s->blocksize = (r->buf[9] << 16) | (r->buf[10] << 8) | r->buf[11];
        DPRINTF("block size %d\n", s->blocksize);
    }

    scsi_command_complete(r, ret);
}

/* Write data to a scsi device.  Returns nonzero on failure.
   The transfer may complete asynchronously.  */
static void scsi_write_data(SCSIRequest *req)
{
    SCSIGenericReq *r = DO_UPCAST(SCSIGenericReq, req, req);
    SCSIDevice *s = r->req.dev;
    int ret;

    DPRINTF("scsi_write_data 0x%x\n", req->tag);
    if (r->len == 0) {
        r->len = r->buflen;
        scsi_req_data(&r->req, r->len);
        return;
    }

    /* The request is used as the AIO opaque value, so add a ref.  */
    scsi_req_ref(&r->req);
    ret = execute_command(s->conf.bs, r, SG_DXFER_TO_DEV, scsi_write_complete);
    if (ret < 0) {
        scsi_command_complete(r, ret);
    }
}

/* Return a pointer to the data buffer.  */
static uint8_t *scsi_get_buf(SCSIRequest *req)
{
    SCSIGenericReq *r = DO_UPCAST(SCSIGenericReq, req, req);

    return r->buf;
}

/* Execute a scsi command.  Returns the length of the data expected by the
   command.  This will be Positive for data transfers from the device
   (eg. disk reads), negative for transfers to the device (eg. disk writes),
   and zero if the command does not transfer any data.  */

static int32_t scsi_send_command(SCSIRequest *req, uint8_t *cmd)
{
    SCSIGenericReq *r = DO_UPCAST(SCSIGenericReq, req, req);
    SCSIDevice *s = r->req.dev;
    int ret;

    DPRINTF("Command: lun=%d tag=0x%x len %zd data=0x%02x", lun, tag,
            r->req.cmd.xfer, cmd[0]);

#ifdef DEBUG_SCSI
    {
        int i;
        for (i = 1; i < r->req.cmd.len; i++) {
            printf(" 0x%02x", cmd[i]);
        }
        printf("\n");
    }
#endif

    if (r->req.cmd.xfer == 0) {
        if (r->buf != NULL)
            g_free(r->buf);
        r->buflen = 0;
        r->buf = NULL;
        /* The request is used as the AIO opaque value, so add a ref.  */
        scsi_req_ref(&r->req);
        ret = execute_command(s->conf.bs, r, SG_DXFER_NONE, scsi_command_complete);
        if (ret < 0) {
            scsi_command_complete(r, ret);
            return 0;
        }
        return 0;
    }

    if (r->buflen != r->req.cmd.xfer) {
        if (r->buf != NULL)
            g_free(r->buf);
        r->buf = g_malloc(r->req.cmd.xfer);
        r->buflen = r->req.cmd.xfer;
    }

    memset(r->buf, 0, r->buflen);
    r->len = r->req.cmd.xfer;
    if (r->req.cmd.mode == SCSI_XFER_TO_DEV) {
        r->len = 0;
        return -r->req.cmd.xfer;
    } else {
        return r->req.cmd.xfer;
    }
}

static int get_stream_blocksize(BlockDriverState *bdrv)
{
    uint8_t cmd[6];
    uint8_t buf[12];
    uint8_t sensebuf[8];
    sg_io_hdr_t io_header;
    int ret;

    memset(cmd, 0, sizeof(cmd));
    memset(buf, 0, sizeof(buf));
    cmd[0] = MODE_SENSE;
    cmd[4] = sizeof(buf);

    memset(&io_header, 0, sizeof(io_header));
    io_header.interface_id = 'S';
    io_header.dxfer_direction = SG_DXFER_FROM_DEV;
    io_header.dxfer_len = sizeof(buf);
    io_header.dxferp = buf;
    io_header.cmdp = cmd;
    io_header.cmd_len = sizeof(cmd);
    io_header.mx_sb_len = sizeof(sensebuf);
    io_header.sbp = sensebuf;
    io_header.timeout = 6000; /* XXX */

    ret = bdrv_ioctl(bdrv, SG_IO, &io_header);
    if (ret < 0 || io_header.driver_status || io_header.host_status) {
        return -1;
    }
    return (buf[9] << 16) | (buf[10] << 8) | buf[11];
}

static void scsi_generic_reset(DeviceState *dev)
{
    SCSIDevice *s = SCSI_DEVICE(dev);

    scsi_device_purge_requests(s, SENSE_CODE(RESET));
}

static void scsi_destroy(SCSIDevice *s)
{
    scsi_device_purge_requests(s, SENSE_CODE(NO_SENSE));
    blockdev_mark_auto_del(s->conf.bs);
}

static int scsi_generic_initfn(SCSIDevice *s)
{
    int sg_version;
    struct sg_scsi_id scsiid;

    if (!s->conf.bs) {
        error_report("drive property not set");
        return -1;
    }

    /* check we are really using a /dev/sg* file */
    if (!bdrv_is_sg(s->conf.bs)) {
        error_report("not /dev/sg*");
        return -1;
    }

    if (bdrv_get_on_error(s->conf.bs, 0) != BLOCK_ERR_STOP_ENOSPC) {
        error_report("Device doesn't support drive option werror");
        return -1;
    }
    if (bdrv_get_on_error(s->conf.bs, 1) != BLOCK_ERR_REPORT) {
        error_report("Device doesn't support drive option rerror");
        return -1;
    }

    /* check we are using a driver managing SG_IO (version 3 and after */
    if (bdrv_ioctl(s->conf.bs, SG_GET_VERSION_NUM, &sg_version) < 0 ||
        sg_version < 30000) {
        error_report("scsi generic interface too old");
        return -1;
    }

    /* get LUN of the /dev/sg? */
    if (bdrv_ioctl(s->conf.bs, SG_GET_SCSI_ID, &scsiid)) {
        error_report("SG_GET_SCSI_ID ioctl failed");
        return -1;
    }

    /* define device state */
    s->type = scsiid.scsi_type;
    DPRINTF("device type %d\n", s->type);
    if (s->type == TYPE_DISK || s->type == TYPE_ROM) {
        add_boot_device_path(s->conf.bootindex, &s->qdev, NULL);
    }

    switch (s->type) {
    case TYPE_TAPE:
        s->blocksize = get_stream_blocksize(s->conf.bs);
        if (s->blocksize == -1) {
            s->blocksize = 0;
        }
        break;

        /* Make a guess for block devices, we'll fix it when the guest sends.
         * READ CAPACITY.  If they don't, they likely would assume these sizes
         * anyway. (TODO: they could also send MODE SENSE).
         */
    case TYPE_ROM:
    case TYPE_WORM:
        s->blocksize = 2048;
        break;
    default:
        s->blocksize = 512;
        break;
    }

    DPRINTF("block size %d\n", s->blocksize);
    return 0;
}

const SCSIReqOps scsi_generic_req_ops = {
    .size         = sizeof(SCSIGenericReq),
    .free_req     = scsi_free_request,
    .send_command = scsi_send_command,
    .read_data    = scsi_read_data,
    .write_data   = scsi_write_data,
    .cancel_io    = scsi_cancel_io,
    .get_buf      = scsi_get_buf,
    .load_request = scsi_generic_load_request,
    .save_request = scsi_generic_save_request,
};

static SCSIRequest *scsi_new_request(SCSIDevice *d, uint32_t tag, uint32_t lun,
                                     uint8_t *buf, void *hba_private)
{
    SCSIRequest *req;

    req = scsi_req_alloc(&scsi_generic_req_ops, d, tag, lun, hba_private);
    return req;
}

static Property scsi_generic_properties[] = {
    DEFINE_BLOCK_PROPERTIES(SCSIDevice, conf),
    DEFINE_PROP_END_OF_LIST(),
};

static void scsi_generic_class_initfn(ObjectClass *klass, void *data)
{
    DeviceClass *dc = DEVICE_CLASS(klass);
    SCSIDeviceClass *sc = SCSI_DEVICE_CLASS(klass);

    sc->init         = scsi_generic_initfn;
    sc->destroy      = scsi_destroy;
    sc->alloc_req    = scsi_new_request;
    dc->fw_name = "disk";
    dc->desc = "pass through generic scsi device (/dev/sg*)";
    dc->reset = scsi_generic_reset;
    dc->props = scsi_generic_properties;
    dc->vmsd  = &vmstate_scsi_device;
}

static TypeInfo scsi_generic_info = {
    .name          = "scsi-generic",
    .parent        = TYPE_SCSI_DEVICE,
    .instance_size = sizeof(SCSIDevice),
    .class_init    = scsi_generic_class_initfn,
};

static void scsi_generic_register_types(void)
{
    type_register_static(&scsi_generic_info);
}

type_init(scsi_generic_register_types)

#endif /* __linux__ */