cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
Log | Files | Refs | Submodules | LICENSE | sfeed.txt

scsi-bus.c (51402B)


      1#include "qemu/osdep.h"
      2#include "qapi/error.h"
      3#include "qemu/error-report.h"
      4#include "qemu/module.h"
      5#include "qemu/option.h"
      6#include "hw/qdev-properties.h"
      7#include "hw/scsi/scsi.h"
      8#include "migration/qemu-file-types.h"
      9#include "migration/vmstate.h"
     10#include "scsi/constants.h"
     11#include "sysemu/block-backend.h"
     12#include "sysemu/blockdev.h"
     13#include "sysemu/sysemu.h"
     14#include "sysemu/runstate.h"
     15#include "trace.h"
     16#include "sysemu/dma.h"
     17#include "qemu/cutils.h"
     18
     19static char *scsibus_get_dev_path(DeviceState *dev);
     20static char *scsibus_get_fw_dev_path(DeviceState *dev);
     21static void scsi_req_dequeue(SCSIRequest *req);
     22static uint8_t *scsi_target_alloc_buf(SCSIRequest *req, size_t len);
     23static void scsi_target_free_buf(SCSIRequest *req);
     24
     25static int next_scsi_bus;
     26
     27static SCSIDevice *do_scsi_device_find(SCSIBus *bus,
     28                                       int channel, int id, int lun,
     29                                       bool include_unrealized)
     30{
     31    BusChild *kid;
     32    SCSIDevice *retval = NULL;
     33
     34    QTAILQ_FOREACH_RCU(kid, &bus->qbus.children, sibling) {
     35        DeviceState *qdev = kid->child;
     36        SCSIDevice *dev = SCSI_DEVICE(qdev);
     37
     38        if (dev->channel == channel && dev->id == id) {
     39            if (dev->lun == lun) {
     40                retval = dev;
     41                break;
     42            }
     43
     44            /*
     45             * If we don't find exact match (channel/bus/lun),
     46             * we will return the first device which matches channel/bus
     47             */
     48
     49            if (!retval) {
     50                retval = dev;
     51            }
     52        }
     53    }
     54
     55    /*
     56     * This function might run on the IO thread and we might race against
     57     * main thread hot-plugging the device.
     58     * We assume that as soon as .realized is set to true we can let
     59     * the user access the device.
     60     */
     61
     62    if (retval && !include_unrealized &&
     63        !qatomic_load_acquire(&retval->qdev.realized)) {
     64        retval = NULL;
     65    }
     66
     67    return retval;
     68}
     69
     70SCSIDevice *scsi_device_find(SCSIBus *bus, int channel, int id, int lun)
     71{
     72    RCU_READ_LOCK_GUARD();
     73    return do_scsi_device_find(bus, channel, id, lun, false);
     74}
     75
     76SCSIDevice *scsi_device_get(SCSIBus *bus, int channel, int id, int lun)
     77{
     78    SCSIDevice *d;
     79    RCU_READ_LOCK_GUARD();
     80    d = do_scsi_device_find(bus, channel, id, lun, false);
     81    if (d) {
     82        object_ref(d);
     83    }
     84    return d;
     85}
     86
     87static void scsi_device_realize(SCSIDevice *s, Error **errp)
     88{
     89    SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
     90    if (sc->realize) {
     91        sc->realize(s, errp);
     92    }
     93}
     94
     95static void scsi_device_unrealize(SCSIDevice *s)
     96{
     97    SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
     98    if (sc->unrealize) {
     99        sc->unrealize(s);
    100    }
    101}
    102
    103int scsi_bus_parse_cdb(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf,
    104                       void *hba_private)
    105{
    106    SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
    107    int rc;
    108
    109    assert(cmd->len == 0);
    110    rc = scsi_req_parse_cdb(dev, cmd, buf);
    111    if (bus->info->parse_cdb) {
    112        rc = bus->info->parse_cdb(dev, cmd, buf, hba_private);
    113    }
    114    return rc;
    115}
    116
    117static SCSIRequest *scsi_device_alloc_req(SCSIDevice *s, uint32_t tag, uint32_t lun,
    118                                          uint8_t *buf, void *hba_private)
    119{
    120    SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
    121    if (sc->alloc_req) {
    122        return sc->alloc_req(s, tag, lun, buf, hba_private);
    123    }
    124
    125    return NULL;
    126}
    127
    128void scsi_device_unit_attention_reported(SCSIDevice *s)
    129{
    130    SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
    131    if (sc->unit_attention_reported) {
    132        sc->unit_attention_reported(s);
    133    }
    134}
    135
    136/* Create a scsi bus, and attach devices to it.  */
    137void scsi_bus_init_named(SCSIBus *bus, size_t bus_size, DeviceState *host,
    138                         const SCSIBusInfo *info, const char *bus_name)
    139{
    140    qbus_init(bus, bus_size, TYPE_SCSI_BUS, host, bus_name);
    141    bus->busnr = next_scsi_bus++;
    142    bus->info = info;
    143    qbus_set_bus_hotplug_handler(BUS(bus));
    144}
    145
    146static void scsi_dma_restart_bh(void *opaque)
    147{
    148    SCSIDevice *s = opaque;
    149    SCSIRequest *req, *next;
    150
    151    qemu_bh_delete(s->bh);
    152    s->bh = NULL;
    153
    154    aio_context_acquire(blk_get_aio_context(s->conf.blk));
    155    QTAILQ_FOREACH_SAFE(req, &s->requests, next, next) {
    156        scsi_req_ref(req);
    157        if (req->retry) {
    158            req->retry = false;
    159            switch (req->cmd.mode) {
    160            case SCSI_XFER_FROM_DEV:
    161            case SCSI_XFER_TO_DEV:
    162                scsi_req_continue(req);
    163                break;
    164            case SCSI_XFER_NONE:
    165                scsi_req_dequeue(req);
    166                scsi_req_enqueue(req);
    167                break;
    168            }
    169        }
    170        scsi_req_unref(req);
    171    }
    172    aio_context_release(blk_get_aio_context(s->conf.blk));
    173    /* Drop the reference that was acquired in scsi_dma_restart_cb */
    174    object_unref(OBJECT(s));
    175}
    176
    177void scsi_req_retry(SCSIRequest *req)
    178{
    179    /* No need to save a reference, because scsi_dma_restart_bh just
    180     * looks at the request list.  */
    181    req->retry = true;
    182}
    183
    184static void scsi_dma_restart_cb(void *opaque, bool running, RunState state)
    185{
    186    SCSIDevice *s = opaque;
    187
    188    if (!running) {
    189        return;
    190    }
    191    if (!s->bh) {
    192        AioContext *ctx = blk_get_aio_context(s->conf.blk);
    193        /* The reference is dropped in scsi_dma_restart_bh.*/
    194        object_ref(OBJECT(s));
    195        s->bh = aio_bh_new(ctx, scsi_dma_restart_bh, s);
    196        qemu_bh_schedule(s->bh);
    197    }
    198}
    199
    200static bool scsi_bus_is_address_free(SCSIBus *bus,
    201				     int channel, int target, int lun,
    202				     SCSIDevice **p_dev)
    203{
    204    SCSIDevice *d;
    205
    206    RCU_READ_LOCK_GUARD();
    207    d = do_scsi_device_find(bus, channel, target, lun, true);
    208    if (d && d->lun == lun) {
    209        if (p_dev) {
    210            *p_dev = d;
    211        }
    212        return false;
    213    }
    214    if (p_dev) {
    215        *p_dev = NULL;
    216    }
    217    return true;
    218}
    219
    220static bool scsi_bus_check_address(BusState *qbus, DeviceState *qdev, Error **errp)
    221{
    222    SCSIDevice *dev = SCSI_DEVICE(qdev);
    223    SCSIBus *bus = SCSI_BUS(qbus);
    224
    225    if (dev->channel > bus->info->max_channel) {
    226        error_setg(errp, "bad scsi channel id: %d", dev->channel);
    227        return false;
    228    }
    229    if (dev->id != -1 && dev->id > bus->info->max_target) {
    230        error_setg(errp, "bad scsi device id: %d", dev->id);
    231        return false;
    232    }
    233    if (dev->lun != -1 && dev->lun > bus->info->max_lun) {
    234        error_setg(errp, "bad scsi device lun: %d", dev->lun);
    235        return false;
    236    }
    237
    238    if (dev->id != -1 && dev->lun != -1) {
    239        SCSIDevice *d;
    240        if (!scsi_bus_is_address_free(bus, dev->channel, dev->id, dev->lun, &d)) {
    241            error_setg(errp, "lun already used by '%s'", d->qdev.id);
    242            return false;
    243        }
    244    }
    245
    246    return true;
    247}
    248
    249static void scsi_qdev_realize(DeviceState *qdev, Error **errp)
    250{
    251    SCSIDevice *dev = SCSI_DEVICE(qdev);
    252    SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
    253    bool is_free;
    254    Error *local_err = NULL;
    255
    256    if (dev->id == -1) {
    257        int id = -1;
    258        if (dev->lun == -1) {
    259            dev->lun = 0;
    260        }
    261        do {
    262            is_free = scsi_bus_is_address_free(bus, dev->channel, ++id, dev->lun, NULL);
    263        } while (!is_free && id < bus->info->max_target);
    264        if (!is_free) {
    265            error_setg(errp, "no free target");
    266            return;
    267        }
    268        dev->id = id;
    269    } else if (dev->lun == -1) {
    270        int lun = -1;
    271        do {
    272            is_free = scsi_bus_is_address_free(bus, dev->channel, dev->id, ++lun, NULL);
    273        } while (!is_free && lun < bus->info->max_lun);
    274        if (!is_free) {
    275            error_setg(errp, "no free lun");
    276            return;
    277        }
    278        dev->lun = lun;
    279    }
    280
    281    QTAILQ_INIT(&dev->requests);
    282    scsi_device_realize(dev, &local_err);
    283    if (local_err) {
    284        error_propagate(errp, local_err);
    285        return;
    286    }
    287    dev->vmsentry = qdev_add_vm_change_state_handler(DEVICE(dev),
    288            scsi_dma_restart_cb, dev);
    289}
    290
    291static void scsi_qdev_unrealize(DeviceState *qdev)
    292{
    293    SCSIDevice *dev = SCSI_DEVICE(qdev);
    294
    295    if (dev->vmsentry) {
    296        qemu_del_vm_change_state_handler(dev->vmsentry);
    297    }
    298
    299    scsi_device_purge_requests(dev, SENSE_CODE(NO_SENSE));
    300
    301    scsi_device_unrealize(dev);
    302
    303    blockdev_mark_auto_del(dev->conf.blk);
    304}
    305
    306/* handle legacy '-drive if=scsi,...' cmd line args */
    307SCSIDevice *scsi_bus_legacy_add_drive(SCSIBus *bus, BlockBackend *blk,
    308                                      int unit, bool removable, int bootindex,
    309                                      bool share_rw,
    310                                      BlockdevOnError rerror,
    311                                      BlockdevOnError werror,
    312                                      const char *serial, Error **errp)
    313{
    314    const char *driver;
    315    char *name;
    316    DeviceState *dev;
    317    DriveInfo *dinfo;
    318
    319    if (blk_is_sg(blk)) {
    320        driver = "scsi-generic";
    321    } else {
    322        dinfo = blk_legacy_dinfo(blk);
    323        if (dinfo && dinfo->media_cd) {
    324            driver = "scsi-cd";
    325        } else {
    326            driver = "scsi-hd";
    327        }
    328    }
    329    dev = qdev_new(driver);
    330    name = g_strdup_printf("legacy[%d]", unit);
    331    object_property_add_child(OBJECT(bus), name, OBJECT(dev));
    332    g_free(name);
    333
    334    qdev_prop_set_uint32(dev, "scsi-id", unit);
    335    if (bootindex >= 0) {
    336        object_property_set_int(OBJECT(dev), "bootindex", bootindex,
    337                                &error_abort);
    338    }
    339    if (object_property_find(OBJECT(dev), "removable")) {
    340        qdev_prop_set_bit(dev, "removable", removable);
    341    }
    342    if (serial && object_property_find(OBJECT(dev), "serial")) {
    343        qdev_prop_set_string(dev, "serial", serial);
    344    }
    345    if (!qdev_prop_set_drive_err(dev, "drive", blk, errp)) {
    346        object_unparent(OBJECT(dev));
    347        return NULL;
    348    }
    349    if (!object_property_set_bool(OBJECT(dev), "share-rw", share_rw, errp)) {
    350        object_unparent(OBJECT(dev));
    351        return NULL;
    352    }
    353
    354    qdev_prop_set_enum(dev, "rerror", rerror);
    355    qdev_prop_set_enum(dev, "werror", werror);
    356
    357    if (!qdev_realize_and_unref(dev, &bus->qbus, errp)) {
    358        object_unparent(OBJECT(dev));
    359        return NULL;
    360    }
    361    return SCSI_DEVICE(dev);
    362}
    363
    364void scsi_bus_legacy_handle_cmdline(SCSIBus *bus)
    365{
    366    Location loc;
    367    DriveInfo *dinfo;
    368    int unit;
    369
    370    loc_push_none(&loc);
    371    for (unit = 0; unit <= bus->info->max_target; unit++) {
    372        dinfo = drive_get(IF_SCSI, bus->busnr, unit);
    373        if (dinfo == NULL) {
    374            continue;
    375        }
    376        qemu_opts_loc_restore(dinfo->opts);
    377        scsi_bus_legacy_add_drive(bus, blk_by_legacy_dinfo(dinfo),
    378                                  unit, false, -1, false,
    379                                  BLOCKDEV_ON_ERROR_AUTO,
    380                                  BLOCKDEV_ON_ERROR_AUTO,
    381                                  NULL, &error_fatal);
    382    }
    383    loc_pop(&loc);
    384}
    385
    386static int32_t scsi_invalid_field(SCSIRequest *req, uint8_t *buf)
    387{
    388    scsi_req_build_sense(req, SENSE_CODE(INVALID_FIELD));
    389    scsi_req_complete(req, CHECK_CONDITION);
    390    return 0;
    391}
    392
    393static const struct SCSIReqOps reqops_invalid_field = {
    394    .size         = sizeof(SCSIRequest),
    395    .send_command = scsi_invalid_field
    396};
    397
    398/* SCSIReqOps implementation for invalid commands.  */
    399
    400static int32_t scsi_invalid_command(SCSIRequest *req, uint8_t *buf)
    401{
    402    scsi_req_build_sense(req, SENSE_CODE(INVALID_OPCODE));
    403    scsi_req_complete(req, CHECK_CONDITION);
    404    return 0;
    405}
    406
    407static const struct SCSIReqOps reqops_invalid_opcode = {
    408    .size         = sizeof(SCSIRequest),
    409    .send_command = scsi_invalid_command
    410};
    411
    412/* SCSIReqOps implementation for unit attention conditions.  */
    413
    414static int32_t scsi_unit_attention(SCSIRequest *req, uint8_t *buf)
    415{
    416    if (req->dev->unit_attention.key == UNIT_ATTENTION) {
    417        scsi_req_build_sense(req, req->dev->unit_attention);
    418    } else if (req->bus->unit_attention.key == UNIT_ATTENTION) {
    419        scsi_req_build_sense(req, req->bus->unit_attention);
    420    }
    421    scsi_req_complete(req, CHECK_CONDITION);
    422    return 0;
    423}
    424
    425static const struct SCSIReqOps reqops_unit_attention = {
    426    .size         = sizeof(SCSIRequest),
    427    .send_command = scsi_unit_attention
    428};
    429
    430/* SCSIReqOps implementation for REPORT LUNS and for commands sent to
    431   an invalid LUN.  */
    432
    433typedef struct SCSITargetReq SCSITargetReq;
    434
    435struct SCSITargetReq {
    436    SCSIRequest req;
    437    int len;
    438    uint8_t *buf;
    439    int buf_len;
    440};
    441
    442static void store_lun(uint8_t *outbuf, int lun)
    443{
    444    if (lun < 256) {
    445        /* Simple logical unit addressing method*/
    446        outbuf[0] = 0;
    447        outbuf[1] = lun;
    448    } else {
    449        /* Flat space addressing method */
    450        outbuf[0] = 0x40 | (lun >> 8);
    451        outbuf[1] = (lun & 255);
    452    }
    453}
    454
    455static bool scsi_target_emulate_report_luns(SCSITargetReq *r)
    456{
    457    BusChild *kid;
    458    int channel, id;
    459    uint8_t tmp[8] = {0};
    460    int len = 0;
    461    GByteArray *buf;
    462
    463    if (r->req.cmd.xfer < 16) {
    464        return false;
    465    }
    466    if (r->req.cmd.buf[2] > 2) {
    467        return false;
    468    }
    469
    470    /* reserve space for 63 LUNs*/
    471    buf = g_byte_array_sized_new(512);
    472
    473    channel = r->req.dev->channel;
    474    id = r->req.dev->id;
    475
    476    /* add size (will be updated later to correct value */
    477    g_byte_array_append(buf, tmp, 8);
    478    len += 8;
    479
    480    /* add LUN0 */
    481    g_byte_array_append(buf, tmp, 8);
    482    len += 8;
    483
    484    WITH_RCU_READ_LOCK_GUARD() {
    485        QTAILQ_FOREACH_RCU(kid, &r->req.bus->qbus.children, sibling) {
    486            DeviceState *qdev = kid->child;
    487            SCSIDevice *dev = SCSI_DEVICE(qdev);
    488
    489            if (dev->channel == channel && dev->id == id && dev->lun != 0) {
    490                store_lun(tmp, dev->lun);
    491                g_byte_array_append(buf, tmp, 8);
    492                len += 8;
    493            }
    494        }
    495    }
    496
    497    r->buf_len = len;
    498    r->buf = g_byte_array_free(buf, FALSE);
    499    r->len = MIN(len, r->req.cmd.xfer & ~7);
    500
    501    /* store the LUN list length */
    502    stl_be_p(&r->buf[0], len - 8);
    503    return true;
    504}
    505
    506static bool scsi_target_emulate_inquiry(SCSITargetReq *r)
    507{
    508    assert(r->req.dev->lun != r->req.lun);
    509
    510    scsi_target_alloc_buf(&r->req, SCSI_INQUIRY_LEN);
    511
    512    if (r->req.cmd.buf[1] & 0x2) {
    513        /* Command support data - optional, not implemented */
    514        return false;
    515    }
    516
    517    if (r->req.cmd.buf[1] & 0x1) {
    518        /* Vital product data */
    519        uint8_t page_code = r->req.cmd.buf[2];
    520        r->buf[r->len++] = page_code ; /* this page */
    521        r->buf[r->len++] = 0x00;
    522
    523        switch (page_code) {
    524        case 0x00: /* Supported page codes, mandatory */
    525        {
    526            int pages;
    527            pages = r->len++;
    528            r->buf[r->len++] = 0x00; /* list of supported pages (this page) */
    529            r->buf[pages] = r->len - pages - 1; /* number of pages */
    530            break;
    531        }
    532        default:
    533            return false;
    534        }
    535        /* done with EVPD */
    536        assert(r->len < r->buf_len);
    537        r->len = MIN(r->req.cmd.xfer, r->len);
    538        return true;
    539    }
    540
    541    /* Standard INQUIRY data */
    542    if (r->req.cmd.buf[2] != 0) {
    543        return false;
    544    }
    545
    546    /* PAGE CODE == 0 */
    547    r->len = MIN(r->req.cmd.xfer, SCSI_INQUIRY_LEN);
    548    memset(r->buf, 0, r->len);
    549    if (r->req.lun != 0) {
    550        r->buf[0] = TYPE_NO_LUN;
    551    } else {
    552        r->buf[0] = TYPE_NOT_PRESENT | TYPE_INACTIVE;
    553        r->buf[2] = 5; /* Version */
    554        r->buf[3] = 2 | 0x10; /* HiSup, response data format */
    555        r->buf[4] = r->len - 5; /* Additional Length = (Len - 1) - 4 */
    556        r->buf[7] = 0x10 | (r->req.bus->info->tcq ? 0x02 : 0); /* Sync, TCQ.  */
    557        memcpy(&r->buf[8], "QEMU    ", 8);
    558        memcpy(&r->buf[16], "QEMU TARGET     ", 16);
    559        pstrcpy((char *) &r->buf[32], 4, qemu_hw_version());
    560    }
    561    return true;
    562}
    563
    564static size_t scsi_sense_len(SCSIRequest *req)
    565{
    566    if (req->dev->type == TYPE_SCANNER)
    567        return SCSI_SENSE_LEN_SCANNER;
    568    else
    569        return SCSI_SENSE_LEN;
    570}
    571
    572static int32_t scsi_target_send_command(SCSIRequest *req, uint8_t *buf)
    573{
    574    SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
    575    int fixed_sense = (req->cmd.buf[1] & 1) == 0;
    576
    577    if (req->lun != 0 &&
    578        buf[0] != INQUIRY && buf[0] != REQUEST_SENSE) {
    579        scsi_req_build_sense(req, SENSE_CODE(LUN_NOT_SUPPORTED));
    580        scsi_req_complete(req, CHECK_CONDITION);
    581        return 0;
    582    }
    583    switch (buf[0]) {
    584    case REPORT_LUNS:
    585        if (!scsi_target_emulate_report_luns(r)) {
    586            goto illegal_request;
    587        }
    588        break;
    589    case INQUIRY:
    590        if (!scsi_target_emulate_inquiry(r)) {
    591            goto illegal_request;
    592        }
    593        break;
    594    case REQUEST_SENSE:
    595        scsi_target_alloc_buf(&r->req, scsi_sense_len(req));
    596        if (req->lun != 0) {
    597            const struct SCSISense sense = SENSE_CODE(LUN_NOT_SUPPORTED);
    598
    599            r->len = scsi_build_sense_buf(r->buf, req->cmd.xfer,
    600                                          sense, fixed_sense);
    601        } else {
    602            r->len = scsi_device_get_sense(r->req.dev, r->buf,
    603                                           MIN(req->cmd.xfer, r->buf_len),
    604                                           fixed_sense);
    605        }
    606        if (r->req.dev->sense_is_ua) {
    607            scsi_device_unit_attention_reported(req->dev);
    608            r->req.dev->sense_len = 0;
    609            r->req.dev->sense_is_ua = false;
    610        }
    611        break;
    612    case TEST_UNIT_READY:
    613        break;
    614    default:
    615        scsi_req_build_sense(req, SENSE_CODE(INVALID_OPCODE));
    616        scsi_req_complete(req, CHECK_CONDITION);
    617        return 0;
    618    illegal_request:
    619        scsi_req_build_sense(req, SENSE_CODE(INVALID_FIELD));
    620        scsi_req_complete(req, CHECK_CONDITION);
    621        return 0;
    622    }
    623
    624    if (!r->len) {
    625        scsi_req_complete(req, GOOD);
    626    }
    627    return r->len;
    628}
    629
    630static void scsi_target_read_data(SCSIRequest *req)
    631{
    632    SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
    633    uint32_t n;
    634
    635    n = r->len;
    636    if (n > 0) {
    637        r->len = 0;
    638        scsi_req_data(&r->req, n);
    639    } else {
    640        scsi_req_complete(&r->req, GOOD);
    641    }
    642}
    643
    644static uint8_t *scsi_target_get_buf(SCSIRequest *req)
    645{
    646    SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
    647
    648    return r->buf;
    649}
    650
    651static uint8_t *scsi_target_alloc_buf(SCSIRequest *req, size_t len)
    652{
    653    SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
    654
    655    r->buf = g_malloc(len);
    656    r->buf_len = len;
    657
    658    return r->buf;
    659}
    660
    661static void scsi_target_free_buf(SCSIRequest *req)
    662{
    663    SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
    664
    665    g_free(r->buf);
    666}
    667
    668static const struct SCSIReqOps reqops_target_command = {
    669    .size         = sizeof(SCSITargetReq),
    670    .send_command = scsi_target_send_command,
    671    .read_data    = scsi_target_read_data,
    672    .get_buf      = scsi_target_get_buf,
    673    .free_req     = scsi_target_free_buf,
    674};
    675
    676
    677SCSIRequest *scsi_req_alloc(const SCSIReqOps *reqops, SCSIDevice *d,
    678                            uint32_t tag, uint32_t lun, void *hba_private)
    679{
    680    SCSIRequest *req;
    681    SCSIBus *bus = scsi_bus_from_device(d);
    682    BusState *qbus = BUS(bus);
    683    const int memset_off = offsetof(SCSIRequest, sense)
    684                           + sizeof(req->sense);
    685
    686    req = g_malloc(reqops->size);
    687    memset((uint8_t *)req + memset_off, 0, reqops->size - memset_off);
    688    req->refcount = 1;
    689    req->bus = bus;
    690    req->dev = d;
    691    req->tag = tag;
    692    req->lun = lun;
    693    req->hba_private = hba_private;
    694    req->status = -1;
    695    req->host_status = -1;
    696    req->ops = reqops;
    697    object_ref(OBJECT(d));
    698    object_ref(OBJECT(qbus->parent));
    699    notifier_list_init(&req->cancel_notifiers);
    700    trace_scsi_req_alloc(req->dev->id, req->lun, req->tag);
    701    return req;
    702}
    703
    704SCSIRequest *scsi_req_new(SCSIDevice *d, uint32_t tag, uint32_t lun,
    705                          uint8_t *buf, void *hba_private)
    706{
    707    SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, d->qdev.parent_bus);
    708    const SCSIReqOps *ops;
    709    SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(d);
    710    SCSIRequest *req;
    711    SCSICommand cmd = { .len = 0 };
    712    int ret;
    713
    714    if ((d->unit_attention.key == UNIT_ATTENTION ||
    715         bus->unit_attention.key == UNIT_ATTENTION) &&
    716        (buf[0] != INQUIRY &&
    717         buf[0] != REPORT_LUNS &&
    718         buf[0] != GET_CONFIGURATION &&
    719         buf[0] != GET_EVENT_STATUS_NOTIFICATION &&
    720
    721         /*
    722          * If we already have a pending unit attention condition,
    723          * report this one before triggering another one.
    724          */
    725         !(buf[0] == REQUEST_SENSE && d->sense_is_ua))) {
    726        ops = &reqops_unit_attention;
    727    } else if (lun != d->lun ||
    728               buf[0] == REPORT_LUNS ||
    729               (buf[0] == REQUEST_SENSE && d->sense_len)) {
    730        ops = &reqops_target_command;
    731    } else {
    732        ops = NULL;
    733    }
    734
    735    if (ops != NULL || !sc->parse_cdb) {
    736        ret = scsi_req_parse_cdb(d, &cmd, buf);
    737    } else {
    738        ret = sc->parse_cdb(d, &cmd, buf, hba_private);
    739    }
    740
    741    if (ret != 0) {
    742        trace_scsi_req_parse_bad(d->id, lun, tag, buf[0]);
    743        req = scsi_req_alloc(&reqops_invalid_opcode, d, tag, lun, hba_private);
    744    } else {
    745        assert(cmd.len != 0);
    746        trace_scsi_req_parsed(d->id, lun, tag, buf[0],
    747                              cmd.mode, cmd.xfer);
    748        if (cmd.lba != -1) {
    749            trace_scsi_req_parsed_lba(d->id, lun, tag, buf[0],
    750                                      cmd.lba);
    751        }
    752
    753        if (cmd.xfer > INT32_MAX) {
    754            req = scsi_req_alloc(&reqops_invalid_field, d, tag, lun, hba_private);
    755        } else if (ops) {
    756            req = scsi_req_alloc(ops, d, tag, lun, hba_private);
    757        } else {
    758            req = scsi_device_alloc_req(d, tag, lun, buf, hba_private);
    759        }
    760    }
    761
    762    req->cmd = cmd;
    763    req->resid = req->cmd.xfer;
    764
    765    switch (buf[0]) {
    766    case INQUIRY:
    767        trace_scsi_inquiry(d->id, lun, tag, cmd.buf[1], cmd.buf[2]);
    768        break;
    769    case TEST_UNIT_READY:
    770        trace_scsi_test_unit_ready(d->id, lun, tag);
    771        break;
    772    case REPORT_LUNS:
    773        trace_scsi_report_luns(d->id, lun, tag);
    774        break;
    775    case REQUEST_SENSE:
    776        trace_scsi_request_sense(d->id, lun, tag);
    777        break;
    778    default:
    779        break;
    780    }
    781
    782    return req;
    783}
    784
    785uint8_t *scsi_req_get_buf(SCSIRequest *req)
    786{
    787    return req->ops->get_buf(req);
    788}
    789
    790static void scsi_clear_unit_attention(SCSIRequest *req)
    791{
    792    SCSISense *ua;
    793    if (req->dev->unit_attention.key != UNIT_ATTENTION &&
    794        req->bus->unit_attention.key != UNIT_ATTENTION) {
    795        return;
    796    }
    797
    798    /*
    799     * If an INQUIRY command enters the enabled command state,
    800     * the device server shall [not] clear any unit attention condition;
    801     * See also MMC-6, paragraphs 6.5 and 6.6.2.
    802     */
    803    if (req->cmd.buf[0] == INQUIRY ||
    804        req->cmd.buf[0] == GET_CONFIGURATION ||
    805        req->cmd.buf[0] == GET_EVENT_STATUS_NOTIFICATION) {
    806        return;
    807    }
    808
    809    if (req->dev->unit_attention.key == UNIT_ATTENTION) {
    810        ua = &req->dev->unit_attention;
    811    } else {
    812        ua = &req->bus->unit_attention;
    813    }
    814
    815    /*
    816     * If a REPORT LUNS command enters the enabled command state, [...]
    817     * the device server shall clear any pending unit attention condition
    818     * with an additional sense code of REPORTED LUNS DATA HAS CHANGED.
    819     */
    820    if (req->cmd.buf[0] == REPORT_LUNS &&
    821        !(ua->asc == SENSE_CODE(REPORTED_LUNS_CHANGED).asc &&
    822          ua->ascq == SENSE_CODE(REPORTED_LUNS_CHANGED).ascq)) {
    823        return;
    824    }
    825
    826    *ua = SENSE_CODE(NO_SENSE);
    827}
    828
    829int scsi_req_get_sense(SCSIRequest *req, uint8_t *buf, int len)
    830{
    831    int ret;
    832
    833    assert(len >= 14);
    834    if (!req->sense_len) {
    835        return 0;
    836    }
    837
    838    ret = scsi_convert_sense(req->sense, req->sense_len, buf, len, true);
    839
    840    /*
    841     * FIXME: clearing unit attention conditions upon autosense should be done
    842     * only if the UA_INTLCK_CTRL field in the Control mode page is set to 00b
    843     * (SAM-5, 5.14).
    844     *
    845     * We assume UA_INTLCK_CTRL to be 00b for HBAs that support autosense, and
    846     * 10b for HBAs that do not support it (do not call scsi_req_get_sense).
    847     * Here we handle unit attention clearing for UA_INTLCK_CTRL == 00b.
    848     */
    849    if (req->dev->sense_is_ua) {
    850        scsi_device_unit_attention_reported(req->dev);
    851        req->dev->sense_len = 0;
    852        req->dev->sense_is_ua = false;
    853    }
    854    return ret;
    855}
    856
    857int scsi_device_get_sense(SCSIDevice *dev, uint8_t *buf, int len, bool fixed)
    858{
    859    return scsi_convert_sense(dev->sense, dev->sense_len, buf, len, fixed);
    860}
    861
    862void scsi_req_build_sense(SCSIRequest *req, SCSISense sense)
    863{
    864    trace_scsi_req_build_sense(req->dev->id, req->lun, req->tag,
    865                               sense.key, sense.asc, sense.ascq);
    866    req->sense_len = scsi_build_sense(req->sense, sense);
    867}
    868
    869static void scsi_req_enqueue_internal(SCSIRequest *req)
    870{
    871    assert(!req->enqueued);
    872    scsi_req_ref(req);
    873    if (req->bus->info->get_sg_list) {
    874        req->sg = req->bus->info->get_sg_list(req);
    875    } else {
    876        req->sg = NULL;
    877    }
    878    req->enqueued = true;
    879    QTAILQ_INSERT_TAIL(&req->dev->requests, req, next);
    880}
    881
    882int32_t scsi_req_enqueue(SCSIRequest *req)
    883{
    884    int32_t rc;
    885
    886    assert(!req->retry);
    887    scsi_req_enqueue_internal(req);
    888    scsi_req_ref(req);
    889    rc = req->ops->send_command(req, req->cmd.buf);
    890    scsi_req_unref(req);
    891    return rc;
    892}
    893
    894static void scsi_req_dequeue(SCSIRequest *req)
    895{
    896    trace_scsi_req_dequeue(req->dev->id, req->lun, req->tag);
    897    req->retry = false;
    898    if (req->enqueued) {
    899        QTAILQ_REMOVE(&req->dev->requests, req, next);
    900        req->enqueued = false;
    901        scsi_req_unref(req);
    902    }
    903}
    904
    905static int scsi_get_performance_length(int num_desc, int type, int data_type)
    906{
    907    /* MMC-6, paragraph 6.7.  */
    908    switch (type) {
    909    case 0:
    910        if ((data_type & 3) == 0) {
    911            /* Each descriptor is as in Table 295 - Nominal performance.  */
    912            return 16 * num_desc + 8;
    913        } else {
    914            /* Each descriptor is as in Table 296 - Exceptions.  */
    915            return 6 * num_desc + 8;
    916        }
    917    case 1:
    918    case 4:
    919    case 5:
    920        return 8 * num_desc + 8;
    921    case 2:
    922        return 2048 * num_desc + 8;
    923    case 3:
    924        return 16 * num_desc + 8;
    925    default:
    926        return 8;
    927    }
    928}
    929
    930static int ata_passthrough_xfer_unit(SCSIDevice *dev, uint8_t *buf)
    931{
    932    int byte_block = (buf[2] >> 2) & 0x1;
    933    int type = (buf[2] >> 4) & 0x1;
    934    int xfer_unit;
    935
    936    if (byte_block) {
    937        if (type) {
    938            xfer_unit = dev->blocksize;
    939        } else {
    940            xfer_unit = 512;
    941        }
    942    } else {
    943        xfer_unit = 1;
    944    }
    945
    946    return xfer_unit;
    947}
    948
    949static int ata_passthrough_12_xfer(SCSIDevice *dev, uint8_t *buf)
    950{
    951    int length = buf[2] & 0x3;
    952    int xfer;
    953    int unit = ata_passthrough_xfer_unit(dev, buf);
    954
    955    switch (length) {
    956    case 0:
    957    case 3: /* USB-specific.  */
    958    default:
    959        xfer = 0;
    960        break;
    961    case 1:
    962        xfer = buf[3];
    963        break;
    964    case 2:
    965        xfer = buf[4];
    966        break;
    967    }
    968
    969    return xfer * unit;
    970}
    971
    972static int ata_passthrough_16_xfer(SCSIDevice *dev, uint8_t *buf)
    973{
    974    int extend = buf[1] & 0x1;
    975    int length = buf[2] & 0x3;
    976    int xfer;
    977    int unit = ata_passthrough_xfer_unit(dev, buf);
    978
    979    switch (length) {
    980    case 0:
    981    case 3: /* USB-specific.  */
    982    default:
    983        xfer = 0;
    984        break;
    985    case 1:
    986        xfer = buf[4];
    987        xfer |= (extend ? buf[3] << 8 : 0);
    988        break;
    989    case 2:
    990        xfer = buf[6];
    991        xfer |= (extend ? buf[5] << 8 : 0);
    992        break;
    993    }
    994
    995    return xfer * unit;
    996}
    997
    998static int scsi_req_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
    999{
   1000    cmd->xfer = scsi_cdb_xfer(buf);
   1001    switch (buf[0]) {
   1002    case TEST_UNIT_READY:
   1003    case REWIND:
   1004    case START_STOP:
   1005    case SET_CAPACITY:
   1006    case WRITE_FILEMARKS:
   1007    case WRITE_FILEMARKS_16:
   1008    case SPACE:
   1009    case RESERVE:
   1010    case RELEASE:
   1011    case ERASE:
   1012    case ALLOW_MEDIUM_REMOVAL:
   1013    case SEEK_10:
   1014    case SYNCHRONIZE_CACHE:
   1015    case SYNCHRONIZE_CACHE_16:
   1016    case LOCATE_16:
   1017    case LOCK_UNLOCK_CACHE:
   1018    case SET_CD_SPEED:
   1019    case SET_LIMITS:
   1020    case WRITE_LONG_10:
   1021    case UPDATE_BLOCK:
   1022    case RESERVE_TRACK:
   1023    case SET_READ_AHEAD:
   1024    case PRE_FETCH:
   1025    case PRE_FETCH_16:
   1026    case ALLOW_OVERWRITE:
   1027        cmd->xfer = 0;
   1028        break;
   1029    case VERIFY_10:
   1030    case VERIFY_12:
   1031    case VERIFY_16:
   1032        if ((buf[1] & 2) == 0) {
   1033            cmd->xfer = 0;
   1034        } else if ((buf[1] & 4) != 0) {
   1035            cmd->xfer = 1;
   1036        }
   1037        cmd->xfer *= dev->blocksize;
   1038        break;
   1039    case MODE_SENSE:
   1040        break;
   1041    case WRITE_SAME_10:
   1042    case WRITE_SAME_16:
   1043        cmd->xfer = buf[1] & 1 ? 0 : dev->blocksize;
   1044        break;
   1045    case READ_CAPACITY_10:
   1046        cmd->xfer = 8;
   1047        break;
   1048    case READ_BLOCK_LIMITS:
   1049        cmd->xfer = 6;
   1050        break;
   1051    case SEND_VOLUME_TAG:
   1052        /* GPCMD_SET_STREAMING from multimedia commands.  */
   1053        if (dev->type == TYPE_ROM) {
   1054            cmd->xfer = buf[10] | (buf[9] << 8);
   1055        } else {
   1056            cmd->xfer = buf[9] | (buf[8] << 8);
   1057        }
   1058        break;
   1059    case WRITE_6:
   1060        /* length 0 means 256 blocks */
   1061        if (cmd->xfer == 0) {
   1062            cmd->xfer = 256;
   1063        }
   1064        /* fall through */
   1065    case WRITE_10:
   1066    case WRITE_VERIFY_10:
   1067    case WRITE_12:
   1068    case WRITE_VERIFY_12:
   1069    case WRITE_16:
   1070    case WRITE_VERIFY_16:
   1071        cmd->xfer *= dev->blocksize;
   1072        break;
   1073    case READ_6:
   1074    case READ_REVERSE:
   1075        /* length 0 means 256 blocks */
   1076        if (cmd->xfer == 0) {
   1077            cmd->xfer = 256;
   1078        }
   1079        /* fall through */
   1080    case READ_10:
   1081    case READ_12:
   1082    case READ_16:
   1083        cmd->xfer *= dev->blocksize;
   1084        break;
   1085    case FORMAT_UNIT:
   1086        /* MMC mandates the parameter list to be 12-bytes long.  Parameters
   1087         * for block devices are restricted to the header right now.  */
   1088        if (dev->type == TYPE_ROM && (buf[1] & 16)) {
   1089            cmd->xfer = 12;
   1090        } else {
   1091            cmd->xfer = (buf[1] & 16) == 0 ? 0 : (buf[1] & 32 ? 8 : 4);
   1092        }
   1093        break;
   1094    case INQUIRY:
   1095    case RECEIVE_DIAGNOSTIC:
   1096    case SEND_DIAGNOSTIC:
   1097        cmd->xfer = buf[4] | (buf[3] << 8);
   1098        break;
   1099    case READ_CD:
   1100    case READ_BUFFER:
   1101    case WRITE_BUFFER:
   1102    case SEND_CUE_SHEET:
   1103        cmd->xfer = buf[8] | (buf[7] << 8) | (buf[6] << 16);
   1104        break;
   1105    case PERSISTENT_RESERVE_OUT:
   1106        cmd->xfer = ldl_be_p(&buf[5]) & 0xffffffffULL;
   1107        break;
   1108    case ERASE_12:
   1109        if (dev->type == TYPE_ROM) {
   1110            /* MMC command GET PERFORMANCE.  */
   1111            cmd->xfer = scsi_get_performance_length(buf[9] | (buf[8] << 8),
   1112                                                    buf[10], buf[1] & 0x1f);
   1113        }
   1114        break;
   1115    case MECHANISM_STATUS:
   1116    case READ_DVD_STRUCTURE:
   1117    case SEND_DVD_STRUCTURE:
   1118    case MAINTENANCE_OUT:
   1119    case MAINTENANCE_IN:
   1120        if (dev->type == TYPE_ROM) {
   1121            /* GPCMD_REPORT_KEY and GPCMD_SEND_KEY from multi media commands */
   1122            cmd->xfer = buf[9] | (buf[8] << 8);
   1123        }
   1124        break;
   1125    case ATA_PASSTHROUGH_12:
   1126        if (dev->type == TYPE_ROM) {
   1127            /* BLANK command of MMC */
   1128            cmd->xfer = 0;
   1129        } else {
   1130            cmd->xfer = ata_passthrough_12_xfer(dev, buf);
   1131        }
   1132        break;
   1133    case ATA_PASSTHROUGH_16:
   1134        cmd->xfer = ata_passthrough_16_xfer(dev, buf);
   1135        break;
   1136    }
   1137    return 0;
   1138}
   1139
   1140static int scsi_req_stream_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
   1141{
   1142    switch (buf[0]) {
   1143    /* stream commands */
   1144    case ERASE_12:
   1145    case ERASE_16:
   1146        cmd->xfer = 0;
   1147        break;
   1148    case READ_6:
   1149    case READ_REVERSE:
   1150    case RECOVER_BUFFERED_DATA:
   1151    case WRITE_6:
   1152        cmd->xfer = buf[4] | (buf[3] << 8) | (buf[2] << 16);
   1153        if (buf[1] & 0x01) { /* fixed */
   1154            cmd->xfer *= dev->blocksize;
   1155        }
   1156        break;
   1157    case READ_16:
   1158    case READ_REVERSE_16:
   1159    case VERIFY_16:
   1160    case WRITE_16:
   1161        cmd->xfer = buf[14] | (buf[13] << 8) | (buf[12] << 16);
   1162        if (buf[1] & 0x01) { /* fixed */
   1163            cmd->xfer *= dev->blocksize;
   1164        }
   1165        break;
   1166    case REWIND:
   1167    case LOAD_UNLOAD:
   1168        cmd->xfer = 0;
   1169        break;
   1170    case SPACE_16:
   1171        cmd->xfer = buf[13] | (buf[12] << 8);
   1172        break;
   1173    case READ_POSITION:
   1174        switch (buf[1] & 0x1f) /* operation code */ {
   1175        case SHORT_FORM_BLOCK_ID:
   1176        case SHORT_FORM_VENDOR_SPECIFIC:
   1177            cmd->xfer = 20;
   1178            break;
   1179        case LONG_FORM:
   1180            cmd->xfer = 32;
   1181            break;
   1182        case EXTENDED_FORM:
   1183            cmd->xfer = buf[8] | (buf[7] << 8);
   1184            break;
   1185        default:
   1186            return -1;
   1187        }
   1188
   1189        break;
   1190    case FORMAT_UNIT:
   1191        cmd->xfer = buf[4] | (buf[3] << 8);
   1192        break;
   1193    /* generic commands */
   1194    default:
   1195        return scsi_req_xfer(cmd, dev, buf);
   1196    }
   1197    return 0;
   1198}
   1199
   1200static int scsi_req_medium_changer_xfer(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
   1201{
   1202    switch (buf[0]) {
   1203    /* medium changer commands */
   1204    case EXCHANGE_MEDIUM:
   1205    case INITIALIZE_ELEMENT_STATUS:
   1206    case INITIALIZE_ELEMENT_STATUS_WITH_RANGE:
   1207    case MOVE_MEDIUM:
   1208    case POSITION_TO_ELEMENT:
   1209        cmd->xfer = 0;
   1210        break;
   1211    case READ_ELEMENT_STATUS:
   1212        cmd->xfer = buf[9] | (buf[8] << 8) | (buf[7] << 16);
   1213        break;
   1214
   1215    /* generic commands */
   1216    default:
   1217        return scsi_req_xfer(cmd, dev, buf);
   1218    }
   1219    return 0;
   1220}
   1221
   1222static int scsi_req_scanner_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
   1223{
   1224    switch (buf[0]) {
   1225    /* Scanner commands */
   1226    case OBJECT_POSITION:
   1227        cmd->xfer = 0;
   1228        break;
   1229    case SCAN:
   1230        cmd->xfer = buf[4];
   1231        break;
   1232    case READ_10:
   1233    case SEND:
   1234    case GET_WINDOW:
   1235    case SET_WINDOW:
   1236        cmd->xfer = buf[8] | (buf[7] << 8) | (buf[6] << 16);
   1237        break;
   1238    default:
   1239        /* GET_DATA_BUFFER_STATUS xfer handled by scsi_req_xfer */
   1240        return scsi_req_xfer(cmd, dev, buf);
   1241    }
   1242
   1243    return 0;
   1244}
   1245
   1246static void scsi_cmd_xfer_mode(SCSICommand *cmd)
   1247{
   1248    if (!cmd->xfer) {
   1249        cmd->mode = SCSI_XFER_NONE;
   1250        return;
   1251    }
   1252    switch (cmd->buf[0]) {
   1253    case WRITE_6:
   1254    case WRITE_10:
   1255    case WRITE_VERIFY_10:
   1256    case WRITE_12:
   1257    case WRITE_VERIFY_12:
   1258    case WRITE_16:
   1259    case WRITE_VERIFY_16:
   1260    case VERIFY_10:
   1261    case VERIFY_12:
   1262    case VERIFY_16:
   1263    case COPY:
   1264    case COPY_VERIFY:
   1265    case COMPARE:
   1266    case CHANGE_DEFINITION:
   1267    case LOG_SELECT:
   1268    case MODE_SELECT:
   1269    case MODE_SELECT_10:
   1270    case SEND_DIAGNOSTIC:
   1271    case WRITE_BUFFER:
   1272    case FORMAT_UNIT:
   1273    case REASSIGN_BLOCKS:
   1274    case SEARCH_EQUAL:
   1275    case SEARCH_HIGH:
   1276    case SEARCH_LOW:
   1277    case UPDATE_BLOCK:
   1278    case WRITE_LONG_10:
   1279    case WRITE_SAME_10:
   1280    case WRITE_SAME_16:
   1281    case UNMAP:
   1282    case SEARCH_HIGH_12:
   1283    case SEARCH_EQUAL_12:
   1284    case SEARCH_LOW_12:
   1285    case MEDIUM_SCAN:
   1286    case SEND_VOLUME_TAG:
   1287    case SEND_CUE_SHEET:
   1288    case SEND_DVD_STRUCTURE:
   1289    case PERSISTENT_RESERVE_OUT:
   1290    case MAINTENANCE_OUT:
   1291    case SET_WINDOW:
   1292    case SCAN:
   1293        /* SCAN conflicts with START_STOP.  START_STOP has cmd->xfer set to 0 for
   1294         * non-scanner devices, so we only get here for SCAN and not for START_STOP.
   1295         */
   1296        cmd->mode = SCSI_XFER_TO_DEV;
   1297        break;
   1298    case ATA_PASSTHROUGH_12:
   1299    case ATA_PASSTHROUGH_16:
   1300        /* T_DIR */
   1301        cmd->mode = (cmd->buf[2] & 0x8) ?
   1302                   SCSI_XFER_FROM_DEV : SCSI_XFER_TO_DEV;
   1303        break;
   1304    default:
   1305        cmd->mode = SCSI_XFER_FROM_DEV;
   1306        break;
   1307    }
   1308}
   1309
   1310int scsi_req_parse_cdb(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf)
   1311{
   1312    int rc;
   1313    int len;
   1314
   1315    cmd->lba = -1;
   1316    len = scsi_cdb_length(buf);
   1317    if (len < 0) {
   1318        return -1;
   1319    }
   1320
   1321    cmd->len = len;
   1322    switch (dev->type) {
   1323    case TYPE_TAPE:
   1324        rc = scsi_req_stream_xfer(cmd, dev, buf);
   1325        break;
   1326    case TYPE_MEDIUM_CHANGER:
   1327        rc = scsi_req_medium_changer_xfer(cmd, dev, buf);
   1328        break;
   1329    case TYPE_SCANNER:
   1330        rc = scsi_req_scanner_length(cmd, dev, buf);
   1331        break;
   1332    default:
   1333        rc = scsi_req_xfer(cmd, dev, buf);
   1334        break;
   1335    }
   1336
   1337    if (rc != 0)
   1338        return rc;
   1339
   1340    memcpy(cmd->buf, buf, cmd->len);
   1341    scsi_cmd_xfer_mode(cmd);
   1342    cmd->lba = scsi_cmd_lba(cmd);
   1343    return 0;
   1344}
   1345
   1346void scsi_device_report_change(SCSIDevice *dev, SCSISense sense)
   1347{
   1348    SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
   1349
   1350    scsi_device_set_ua(dev, sense);
   1351    if (bus->info->change) {
   1352        bus->info->change(bus, dev, sense);
   1353    }
   1354}
   1355
   1356SCSIRequest *scsi_req_ref(SCSIRequest *req)
   1357{
   1358    assert(req->refcount > 0);
   1359    req->refcount++;
   1360    return req;
   1361}
   1362
   1363void scsi_req_unref(SCSIRequest *req)
   1364{
   1365    assert(req->refcount > 0);
   1366    if (--req->refcount == 0) {
   1367        BusState *qbus = req->dev->qdev.parent_bus;
   1368        SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, qbus);
   1369
   1370        if (bus->info->free_request && req->hba_private) {
   1371            bus->info->free_request(bus, req->hba_private);
   1372        }
   1373        if (req->ops->free_req) {
   1374            req->ops->free_req(req);
   1375        }
   1376        object_unref(OBJECT(req->dev));
   1377        object_unref(OBJECT(qbus->parent));
   1378        g_free(req);
   1379    }
   1380}
   1381
   1382/* Tell the device that we finished processing this chunk of I/O.  It
   1383   will start the next chunk or complete the command.  */
   1384void scsi_req_continue(SCSIRequest *req)
   1385{
   1386    if (req->io_canceled) {
   1387        trace_scsi_req_continue_canceled(req->dev->id, req->lun, req->tag);
   1388        return;
   1389    }
   1390    trace_scsi_req_continue(req->dev->id, req->lun, req->tag);
   1391    if (req->cmd.mode == SCSI_XFER_TO_DEV) {
   1392        req->ops->write_data(req);
   1393    } else {
   1394        req->ops->read_data(req);
   1395    }
   1396}
   1397
   1398/* Called by the devices when data is ready for the HBA.  The HBA should
   1399   start a DMA operation to read or fill the device's data buffer.
   1400   Once it completes, calling scsi_req_continue will restart I/O.  */
   1401void scsi_req_data(SCSIRequest *req, int len)
   1402{
   1403    uint8_t *buf;
   1404    if (req->io_canceled) {
   1405        trace_scsi_req_data_canceled(req->dev->id, req->lun, req->tag, len);
   1406        return;
   1407    }
   1408    trace_scsi_req_data(req->dev->id, req->lun, req->tag, len);
   1409    assert(req->cmd.mode != SCSI_XFER_NONE);
   1410    if (!req->sg) {
   1411        req->resid -= len;
   1412        req->bus->info->transfer_data(req, len);
   1413        return;
   1414    }
   1415
   1416    /* If the device calls scsi_req_data and the HBA specified a
   1417     * scatter/gather list, the transfer has to happen in a single
   1418     * step.  */
   1419    assert(!req->dma_started);
   1420    req->dma_started = true;
   1421
   1422    buf = scsi_req_get_buf(req);
   1423    if (req->cmd.mode == SCSI_XFER_FROM_DEV) {
   1424        req->resid = dma_buf_read(buf, len, req->sg);
   1425    } else {
   1426        req->resid = dma_buf_write(buf, len, req->sg);
   1427    }
   1428    scsi_req_continue(req);
   1429}
   1430
   1431void scsi_req_print(SCSIRequest *req)
   1432{
   1433    FILE *fp = stderr;
   1434    int i;
   1435
   1436    fprintf(fp, "[%s id=%d] %s",
   1437            req->dev->qdev.parent_bus->name,
   1438            req->dev->id,
   1439            scsi_command_name(req->cmd.buf[0]));
   1440    for (i = 1; i < req->cmd.len; i++) {
   1441        fprintf(fp, " 0x%02x", req->cmd.buf[i]);
   1442    }
   1443    switch (req->cmd.mode) {
   1444    case SCSI_XFER_NONE:
   1445        fprintf(fp, " - none\n");
   1446        break;
   1447    case SCSI_XFER_FROM_DEV:
   1448        fprintf(fp, " - from-dev len=%zd\n", req->cmd.xfer);
   1449        break;
   1450    case SCSI_XFER_TO_DEV:
   1451        fprintf(fp, " - to-dev len=%zd\n", req->cmd.xfer);
   1452        break;
   1453    default:
   1454        fprintf(fp, " - Oops\n");
   1455        break;
   1456    }
   1457}
   1458
   1459void scsi_req_complete_failed(SCSIRequest *req, int host_status)
   1460{
   1461    SCSISense sense;
   1462    int status;
   1463
   1464    assert(req->status == -1 && req->host_status == -1);
   1465    assert(req->ops != &reqops_unit_attention);
   1466
   1467    if (!req->bus->info->fail) {
   1468        status = scsi_sense_from_host_status(req->host_status, &sense);
   1469        if (status == CHECK_CONDITION) {
   1470            scsi_req_build_sense(req, sense);
   1471        }
   1472        scsi_req_complete(req, status);
   1473        return;
   1474    }
   1475
   1476    req->host_status = host_status;
   1477    scsi_req_ref(req);
   1478    scsi_req_dequeue(req);
   1479    req->bus->info->fail(req);
   1480
   1481    /* Cancelled requests might end up being completed instead of cancelled */
   1482    notifier_list_notify(&req->cancel_notifiers, req);
   1483    scsi_req_unref(req);
   1484}
   1485
   1486void scsi_req_complete(SCSIRequest *req, int status)
   1487{
   1488    assert(req->status == -1 && req->host_status == -1);
   1489    req->status = status;
   1490    req->host_status = SCSI_HOST_OK;
   1491
   1492    assert(req->sense_len <= sizeof(req->sense));
   1493    if (status == GOOD) {
   1494        req->sense_len = 0;
   1495    }
   1496
   1497    if (req->sense_len) {
   1498        memcpy(req->dev->sense, req->sense, req->sense_len);
   1499        req->dev->sense_len = req->sense_len;
   1500        req->dev->sense_is_ua = (req->ops == &reqops_unit_attention);
   1501    } else {
   1502        req->dev->sense_len = 0;
   1503        req->dev->sense_is_ua = false;
   1504    }
   1505
   1506    /*
   1507     * Unit attention state is now stored in the device's sense buffer
   1508     * if the HBA didn't do autosense.  Clear the pending unit attention
   1509     * flags.
   1510     */
   1511    scsi_clear_unit_attention(req);
   1512
   1513    scsi_req_ref(req);
   1514    scsi_req_dequeue(req);
   1515    req->bus->info->complete(req, req->resid);
   1516
   1517    /* Cancelled requests might end up being completed instead of cancelled */
   1518    notifier_list_notify(&req->cancel_notifiers, req);
   1519    scsi_req_unref(req);
   1520}
   1521
   1522/* Called by the devices when the request is canceled. */
   1523void scsi_req_cancel_complete(SCSIRequest *req)
   1524{
   1525    assert(req->io_canceled);
   1526    if (req->bus->info->cancel) {
   1527        req->bus->info->cancel(req);
   1528    }
   1529    notifier_list_notify(&req->cancel_notifiers, req);
   1530    scsi_req_unref(req);
   1531}
   1532
   1533/* Cancel @req asynchronously. @notifier is added to @req's cancellation
   1534 * notifier list, the bus will be notified the requests cancellation is
   1535 * completed.
   1536 * */
   1537void scsi_req_cancel_async(SCSIRequest *req, Notifier *notifier)
   1538{
   1539    trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
   1540    if (notifier) {
   1541        notifier_list_add(&req->cancel_notifiers, notifier);
   1542    }
   1543    if (req->io_canceled) {
   1544        /* A blk_aio_cancel_async is pending; when it finishes,
   1545         * scsi_req_cancel_complete will be called and will
   1546         * call the notifier we just added.  Just wait for that.
   1547         */
   1548        assert(req->aiocb);
   1549        return;
   1550    }
   1551    /* Dropped in scsi_req_cancel_complete.  */
   1552    scsi_req_ref(req);
   1553    scsi_req_dequeue(req);
   1554    req->io_canceled = true;
   1555    if (req->aiocb) {
   1556        blk_aio_cancel_async(req->aiocb);
   1557    } else {
   1558        scsi_req_cancel_complete(req);
   1559    }
   1560}
   1561
   1562void scsi_req_cancel(SCSIRequest *req)
   1563{
   1564    trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
   1565    if (!req->enqueued) {
   1566        return;
   1567    }
   1568    assert(!req->io_canceled);
   1569    /* Dropped in scsi_req_cancel_complete.  */
   1570    scsi_req_ref(req);
   1571    scsi_req_dequeue(req);
   1572    req->io_canceled = true;
   1573    if (req->aiocb) {
   1574        blk_aio_cancel(req->aiocb);
   1575    } else {
   1576        scsi_req_cancel_complete(req);
   1577    }
   1578}
   1579
   1580static int scsi_ua_precedence(SCSISense sense)
   1581{
   1582    if (sense.key != UNIT_ATTENTION) {
   1583        return INT_MAX;
   1584    }
   1585    if (sense.asc == 0x29 && sense.ascq == 0x04) {
   1586        /* DEVICE INTERNAL RESET goes with POWER ON OCCURRED */
   1587        return 1;
   1588    } else if (sense.asc == 0x3F && sense.ascq == 0x01) {
   1589        /* MICROCODE HAS BEEN CHANGED goes with SCSI BUS RESET OCCURRED */
   1590        return 2;
   1591    } else if (sense.asc == 0x29 && (sense.ascq == 0x05 || sense.ascq == 0x06)) {
   1592        /* These two go with "all others". */
   1593        ;
   1594    } else if (sense.asc == 0x29 && sense.ascq <= 0x07) {
   1595        /* POWER ON, RESET OR BUS DEVICE RESET OCCURRED = 0
   1596         * POWER ON OCCURRED = 1
   1597         * SCSI BUS RESET OCCURRED = 2
   1598         * BUS DEVICE RESET FUNCTION OCCURRED = 3
   1599         * I_T NEXUS LOSS OCCURRED = 7
   1600         */
   1601        return sense.ascq;
   1602    } else if (sense.asc == 0x2F && sense.ascq == 0x01) {
   1603        /* COMMANDS CLEARED BY POWER LOSS NOTIFICATION  */
   1604        return 8;
   1605    }
   1606    return (sense.asc << 8) | sense.ascq;
   1607}
   1608
   1609void scsi_device_set_ua(SCSIDevice *sdev, SCSISense sense)
   1610{
   1611    int prec1, prec2;
   1612    if (sense.key != UNIT_ATTENTION) {
   1613        return;
   1614    }
   1615    trace_scsi_device_set_ua(sdev->id, sdev->lun, sense.key,
   1616                             sense.asc, sense.ascq);
   1617
   1618    /*
   1619     * Override a pre-existing unit attention condition, except for a more
   1620     * important reset condition.
   1621    */
   1622    prec1 = scsi_ua_precedence(sdev->unit_attention);
   1623    prec2 = scsi_ua_precedence(sense);
   1624    if (prec2 < prec1) {
   1625        sdev->unit_attention = sense;
   1626    }
   1627}
   1628
   1629void scsi_device_purge_requests(SCSIDevice *sdev, SCSISense sense)
   1630{
   1631    SCSIRequest *req;
   1632
   1633    aio_context_acquire(blk_get_aio_context(sdev->conf.blk));
   1634    while (!QTAILQ_EMPTY(&sdev->requests)) {
   1635        req = QTAILQ_FIRST(&sdev->requests);
   1636        scsi_req_cancel_async(req, NULL);
   1637    }
   1638    blk_drain(sdev->conf.blk);
   1639    aio_context_release(blk_get_aio_context(sdev->conf.blk));
   1640    scsi_device_set_ua(sdev, sense);
   1641}
   1642
   1643static char *scsibus_get_dev_path(DeviceState *dev)
   1644{
   1645    SCSIDevice *d = SCSI_DEVICE(dev);
   1646    DeviceState *hba = dev->parent_bus->parent;
   1647    char *id;
   1648    char *path;
   1649
   1650    id = qdev_get_dev_path(hba);
   1651    if (id) {
   1652        path = g_strdup_printf("%s/%d:%d:%d", id, d->channel, d->id, d->lun);
   1653    } else {
   1654        path = g_strdup_printf("%d:%d:%d", d->channel, d->id, d->lun);
   1655    }
   1656    g_free(id);
   1657    return path;
   1658}
   1659
   1660static char *scsibus_get_fw_dev_path(DeviceState *dev)
   1661{
   1662    SCSIDevice *d = SCSI_DEVICE(dev);
   1663    return g_strdup_printf("channel@%x/%s@%x,%x", d->channel,
   1664                           qdev_fw_name(dev), d->id, d->lun);
   1665}
   1666
   1667/* SCSI request list.  For simplicity, pv points to the whole device */
   1668
   1669static int put_scsi_requests(QEMUFile *f, void *pv, size_t size,
   1670                             const VMStateField *field, JSONWriter *vmdesc)
   1671{
   1672    SCSIDevice *s = pv;
   1673    SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, s->qdev.parent_bus);
   1674    SCSIRequest *req;
   1675
   1676    QTAILQ_FOREACH(req, &s->requests, next) {
   1677        assert(!req->io_canceled);
   1678        assert(req->status == -1 && req->host_status == -1);
   1679        assert(req->enqueued);
   1680
   1681        qemu_put_sbyte(f, req->retry ? 1 : 2);
   1682        qemu_put_buffer(f, req->cmd.buf, sizeof(req->cmd.buf));
   1683        qemu_put_be32s(f, &req->tag);
   1684        qemu_put_be32s(f, &req->lun);
   1685        if (bus->info->save_request) {
   1686            bus->info->save_request(f, req);
   1687        }
   1688        if (req->ops->save_request) {
   1689            req->ops->save_request(f, req);
   1690        }
   1691    }
   1692    qemu_put_sbyte(f, 0);
   1693
   1694    return 0;
   1695}
   1696
   1697static int get_scsi_requests(QEMUFile *f, void *pv, size_t size,
   1698                             const VMStateField *field)
   1699{
   1700    SCSIDevice *s = pv;
   1701    SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, s->qdev.parent_bus);
   1702    int8_t sbyte;
   1703
   1704    while ((sbyte = qemu_get_sbyte(f)) > 0) {
   1705        uint8_t buf[SCSI_CMD_BUF_SIZE];
   1706        uint32_t tag;
   1707        uint32_t lun;
   1708        SCSIRequest *req;
   1709
   1710        qemu_get_buffer(f, buf, sizeof(buf));
   1711        qemu_get_be32s(f, &tag);
   1712        qemu_get_be32s(f, &lun);
   1713        req = scsi_req_new(s, tag, lun, buf, NULL);
   1714        req->retry = (sbyte == 1);
   1715        if (bus->info->load_request) {
   1716            req->hba_private = bus->info->load_request(f, req);
   1717        }
   1718        if (req->ops->load_request) {
   1719            req->ops->load_request(f, req);
   1720        }
   1721
   1722        /* Just restart it later.  */
   1723        scsi_req_enqueue_internal(req);
   1724
   1725        /* At this point, the request will be kept alive by the reference
   1726         * added by scsi_req_enqueue_internal, so we can release our reference.
   1727         * The HBA of course will add its own reference in the load_request
   1728         * callback if it needs to hold on the SCSIRequest.
   1729         */
   1730        scsi_req_unref(req);
   1731    }
   1732
   1733    return 0;
   1734}
   1735
   1736static const VMStateInfo vmstate_info_scsi_requests = {
   1737    .name = "scsi-requests",
   1738    .get  = get_scsi_requests,
   1739    .put  = put_scsi_requests,
   1740};
   1741
   1742static bool scsi_sense_state_needed(void *opaque)
   1743{
   1744    SCSIDevice *s = opaque;
   1745
   1746    return s->sense_len > SCSI_SENSE_BUF_SIZE_OLD;
   1747}
   1748
   1749static const VMStateDescription vmstate_scsi_sense_state = {
   1750    .name = "SCSIDevice/sense",
   1751    .version_id = 1,
   1752    .minimum_version_id = 1,
   1753    .needed = scsi_sense_state_needed,
   1754    .fields = (VMStateField[]) {
   1755        VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice,
   1756                                SCSI_SENSE_BUF_SIZE_OLD,
   1757                                SCSI_SENSE_BUF_SIZE - SCSI_SENSE_BUF_SIZE_OLD),
   1758        VMSTATE_END_OF_LIST()
   1759    }
   1760};
   1761
   1762const VMStateDescription vmstate_scsi_device = {
   1763    .name = "SCSIDevice",
   1764    .version_id = 1,
   1765    .minimum_version_id = 1,
   1766    .fields = (VMStateField[]) {
   1767        VMSTATE_UINT8(unit_attention.key, SCSIDevice),
   1768        VMSTATE_UINT8(unit_attention.asc, SCSIDevice),
   1769        VMSTATE_UINT8(unit_attention.ascq, SCSIDevice),
   1770        VMSTATE_BOOL(sense_is_ua, SCSIDevice),
   1771        VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice, 0, SCSI_SENSE_BUF_SIZE_OLD),
   1772        VMSTATE_UINT32(sense_len, SCSIDevice),
   1773        {
   1774            .name         = "requests",
   1775            .version_id   = 0,
   1776            .field_exists = NULL,
   1777            .size         = 0,   /* ouch */
   1778            .info         = &vmstate_info_scsi_requests,
   1779            .flags        = VMS_SINGLE,
   1780            .offset       = 0,
   1781        },
   1782        VMSTATE_END_OF_LIST()
   1783    },
   1784    .subsections = (const VMStateDescription*[]) {
   1785        &vmstate_scsi_sense_state,
   1786        NULL
   1787    }
   1788};
   1789
   1790static Property scsi_props[] = {
   1791    DEFINE_PROP_UINT32("channel", SCSIDevice, channel, 0),
   1792    DEFINE_PROP_UINT32("scsi-id", SCSIDevice, id, -1),
   1793    DEFINE_PROP_UINT32("lun", SCSIDevice, lun, -1),
   1794    DEFINE_PROP_END_OF_LIST(),
   1795};
   1796
   1797static void scsi_device_class_init(ObjectClass *klass, void *data)
   1798{
   1799    DeviceClass *k = DEVICE_CLASS(klass);
   1800    set_bit(DEVICE_CATEGORY_STORAGE, k->categories);
   1801    k->bus_type  = TYPE_SCSI_BUS;
   1802    k->realize   = scsi_qdev_realize;
   1803    k->unrealize = scsi_qdev_unrealize;
   1804    device_class_set_props(k, scsi_props);
   1805}
   1806
   1807static void scsi_dev_instance_init(Object *obj)
   1808{
   1809    DeviceState *dev = DEVICE(obj);
   1810    SCSIDevice *s = SCSI_DEVICE(dev);
   1811
   1812    device_add_bootindex_property(obj, &s->conf.bootindex,
   1813                                  "bootindex", NULL,
   1814                                  &s->qdev);
   1815}
   1816
   1817static const TypeInfo scsi_device_type_info = {
   1818    .name = TYPE_SCSI_DEVICE,
   1819    .parent = TYPE_DEVICE,
   1820    .instance_size = sizeof(SCSIDevice),
   1821    .abstract = true,
   1822    .class_size = sizeof(SCSIDeviceClass),
   1823    .class_init = scsi_device_class_init,
   1824    .instance_init = scsi_dev_instance_init,
   1825};
   1826
   1827static void scsi_bus_class_init(ObjectClass *klass, void *data)
   1828{
   1829    BusClass *k = BUS_CLASS(klass);
   1830    HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
   1831
   1832    k->get_dev_path = scsibus_get_dev_path;
   1833    k->get_fw_dev_path = scsibus_get_fw_dev_path;
   1834    k->check_address = scsi_bus_check_address;
   1835    hc->unplug = qdev_simple_device_unplug_cb;
   1836}
   1837
   1838static const TypeInfo scsi_bus_info = {
   1839    .name = TYPE_SCSI_BUS,
   1840    .parent = TYPE_BUS,
   1841    .instance_size = sizeof(SCSIBus),
   1842    .class_init = scsi_bus_class_init,
   1843    .interfaces = (InterfaceInfo[]) {
   1844        { TYPE_HOTPLUG_HANDLER },
   1845        { }
   1846    }
   1847};
   1848
   1849static void scsi_register_types(void)
   1850{
   1851    type_register_static(&scsi_bus_info);
   1852    type_register_static(&scsi_device_type_info);
   1853}
   1854
   1855type_init(scsi_register_types)