hw: move target-independent files to subdirectories

This patch tackles all files that are compiled once, moving
them to subdirectories of hw/.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 1889 insertions, 0 deletions

diff --git a/hw/scsi/scsi-bus.c b/hw/scsi/scsi-bus.c
new file mode 100644
index 0000000000..6239ee1465
--- /dev/null
+++ b/hw/scsi/scsi-bus.c
@@ -0,0 +1,1889 @@
+#include "hw/hw.h"
+#include "qemu/error-report.h"
+#include "hw/scsi/scsi.h"
+#include "block/scsi.h"
+#include "hw/qdev.h"
+#include "sysemu/blockdev.h"
+#include "trace.h"
+#include "sysemu/dma.h"
+
+static char *scsibus_get_dev_path(DeviceState *dev);
+static char *scsibus_get_fw_dev_path(DeviceState *dev);
+static int scsi_req_parse(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf);
+static void scsi_req_dequeue(SCSIRequest *req);
+
+static Property scsi_props[] = {
+    DEFINE_PROP_UINT32("channel", SCSIDevice, channel, 0),
+    DEFINE_PROP_UINT32("scsi-id", SCSIDevice, id, -1),
+    DEFINE_PROP_UINT32("lun", SCSIDevice, lun, -1),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void scsi_bus_class_init(ObjectClass *klass, void *data)
+{
+    BusClass *k = BUS_CLASS(klass);
+
+    k->get_dev_path = scsibus_get_dev_path;
+    k->get_fw_dev_path = scsibus_get_fw_dev_path;
+}
+
+static const TypeInfo scsi_bus_info = {
+    .name = TYPE_SCSI_BUS,
+    .parent = TYPE_BUS,
+    .instance_size = sizeof(SCSIBus),
+    .class_init = scsi_bus_class_init,
+};
+static int next_scsi_bus;
+
+static int scsi_device_init(SCSIDevice *s)
+{
+    SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
+    if (sc->init) {
+        return sc->init(s);
+    }
+    return 0;
+}
+
+static void scsi_device_destroy(SCSIDevice *s)
+{
+    SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
+    if (sc->destroy) {
+        sc->destroy(s);
+    }
+}
+
+static SCSIRequest *scsi_device_alloc_req(SCSIDevice *s, uint32_t tag, uint32_t lun,
+                                          uint8_t *buf, void *hba_private)
+{
+    SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
+    if (sc->alloc_req) {
+        return sc->alloc_req(s, tag, lun, buf, hba_private);
+    }
+
+    return NULL;
+}
+
+static void scsi_device_unit_attention_reported(SCSIDevice *s)
+{
+    SCSIDeviceClass *sc = SCSI_DEVICE_GET_CLASS(s);
+    if (sc->unit_attention_reported) {
+        sc->unit_attention_reported(s);
+    }
+}
+
+/* Create a scsi bus, and attach devices to it.  */
+void scsi_bus_new(SCSIBus *bus, DeviceState *host, const SCSIBusInfo *info)
+{
+    qbus_create_inplace(&bus->qbus, TYPE_SCSI_BUS, host, NULL);
+    bus->busnr = next_scsi_bus++;
+    bus->info = info;
+    bus->qbus.allow_hotplug = 1;
+}
+
+static void scsi_dma_restart_bh(void *opaque)
+{
+    SCSIDevice *s = opaque;
+    SCSIRequest *req, *next;
+
+    qemu_bh_delete(s->bh);
+    s->bh = NULL;
+
+    QTAILQ_FOREACH_SAFE(req, &s->requests, next, next) {
+        scsi_req_ref(req);
+        if (req->retry) {
+            req->retry = false;
+            switch (req->cmd.mode) {
+            case SCSI_XFER_FROM_DEV:
+            case SCSI_XFER_TO_DEV:
+                scsi_req_continue(req);
+                break;
+            case SCSI_XFER_NONE:
+                assert(!req->sg);
+                scsi_req_dequeue(req);
+                scsi_req_enqueue(req);
+                break;
+            }
+        }
+        scsi_req_unref(req);
+    }
+}
+
+void scsi_req_retry(SCSIRequest *req)
+{
+    /* No need to save a reference, because scsi_dma_restart_bh just
+     * looks at the request list.  */
+    req->retry = true;
+}
+
+static void scsi_dma_restart_cb(void *opaque, int running, RunState state)
+{
+    SCSIDevice *s = opaque;
+
+    if (!running) {
+        return;
+    }
+    if (!s->bh) {
+        s->bh = qemu_bh_new(scsi_dma_restart_bh, s);
+        qemu_bh_schedule(s->bh);
+    }
+}
+
+static int scsi_qdev_init(DeviceState *qdev)
+{
+    SCSIDevice *dev = SCSI_DEVICE(qdev);
+    SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
+    SCSIDevice *d;
+    int rc = -1;
+
+    if (dev->channel > bus->info->max_channel) {
+        error_report("bad scsi channel id: %d", dev->channel);
+        goto err;
+    }
+    if (dev->id != -1 && dev->id > bus->info->max_target) {
+        error_report("bad scsi device id: %d", dev->id);
+        goto err;
+    }
+    if (dev->lun != -1 && dev->lun > bus->info->max_lun) {
+        error_report("bad scsi device lun: %d", dev->lun);
+        goto err;
+    }
+
+    if (dev->id == -1) {
+        int id = -1;
+        if (dev->lun == -1) {
+            dev->lun = 0;
+        }
+        do {
+            d = scsi_device_find(bus, dev->channel, ++id, dev->lun);
+        } while (d && d->lun == dev->lun && id < bus->info->max_target);
+        if (d && d->lun == dev->lun) {
+            error_report("no free target");
+            goto err;
+        }
+        dev->id = id;
+    } else if (dev->lun == -1) {
+        int lun = -1;
+        do {
+            d = scsi_device_find(bus, dev->channel, dev->id, ++lun);
+        } while (d && d->lun == lun && lun < bus->info->max_lun);
+        if (d && d->lun == lun) {
+            error_report("no free lun");
+            goto err;
+        }
+        dev->lun = lun;
+    } else {
+        d = scsi_device_find(bus, dev->channel, dev->id, dev->lun);
+        assert(d);
+        if (d->lun == dev->lun && dev != d) {
+            qdev_free(&d->qdev);
+        }
+    }
+
+    QTAILQ_INIT(&dev->requests);
+    rc = scsi_device_init(dev);
+    if (rc == 0) {
+        dev->vmsentry = qemu_add_vm_change_state_handler(scsi_dma_restart_cb,
+                                                         dev);
+    }
+
+    if (bus->info->hotplug) {
+        bus->info->hotplug(bus, dev);
+    }
+
+err:
+    return rc;
+}
+
+static int scsi_qdev_exit(DeviceState *qdev)
+{
+    SCSIDevice *dev = SCSI_DEVICE(qdev);
+
+    if (dev->vmsentry) {
+        qemu_del_vm_change_state_handler(dev->vmsentry);
+    }
+    scsi_device_destroy(dev);
+    return 0;
+}
+
+/* handle legacy '-drive if=scsi,...' cmd line args */
+SCSIDevice *scsi_bus_legacy_add_drive(SCSIBus *bus, BlockDriverState *bdrv,
+                                      int unit, bool removable, int bootindex,
+                                      const char *serial)
+{
+    const char *driver;
+    DeviceState *dev;
+
+    driver = bdrv_is_sg(bdrv) ? "scsi-generic" : "scsi-disk";
+    dev = qdev_create(&bus->qbus, driver);
+    qdev_prop_set_uint32(dev, "scsi-id", unit);
+    if (bootindex >= 0) {
+        qdev_prop_set_int32(dev, "bootindex", bootindex);
+    }
+    if (object_property_find(OBJECT(dev), "removable", NULL)) {
+        qdev_prop_set_bit(dev, "removable", removable);
+    }
+    if (serial) {
+        qdev_prop_set_string(dev, "serial", serial);
+    }
+    if (qdev_prop_set_drive(dev, "drive", bdrv) < 0) {
+        qdev_free(dev);
+        return NULL;
+    }
+    if (qdev_init(dev) < 0)
+        return NULL;
+    return SCSI_DEVICE(dev);
+}
+
+int scsi_bus_legacy_handle_cmdline(SCSIBus *bus)
+{
+    Location loc;
+    DriveInfo *dinfo;
+    int res = 0, unit;
+
+    loc_push_none(&loc);
+    for (unit = 0; unit <= bus->info->max_target; unit++) {
+        dinfo = drive_get(IF_SCSI, bus->busnr, unit);
+        if (dinfo == NULL) {
+            continue;
+        }
+        qemu_opts_loc_restore(dinfo->opts);
+        if (!scsi_bus_legacy_add_drive(bus, dinfo->bdrv, unit, false, -1, NULL)) {
+            res = -1;
+            break;
+        }
+    }
+    loc_pop(&loc);
+    return res;
+}
+
+static int32_t scsi_invalid_field(SCSIRequest *req, uint8_t *buf)
+{
+    scsi_req_build_sense(req, SENSE_CODE(INVALID_FIELD));
+    scsi_req_complete(req, CHECK_CONDITION);
+    return 0;
+}
+
+static const struct SCSIReqOps reqops_invalid_field = {
+    .size         = sizeof(SCSIRequest),
+    .send_command = scsi_invalid_field
+};
+
+/* SCSIReqOps implementation for invalid commands.  */
+
+static int32_t scsi_invalid_command(SCSIRequest *req, uint8_t *buf)
+{
+    scsi_req_build_sense(req, SENSE_CODE(INVALID_OPCODE));
+    scsi_req_complete(req, CHECK_CONDITION);
+    return 0;
+}
+
+static const struct SCSIReqOps reqops_invalid_opcode = {
+    .size         = sizeof(SCSIRequest),
+    .send_command = scsi_invalid_command
+};
+
+/* SCSIReqOps implementation for unit attention conditions.  */
+
+static int32_t scsi_unit_attention(SCSIRequest *req, uint8_t *buf)
+{
+    if (req->dev->unit_attention.key == UNIT_ATTENTION) {
+        scsi_req_build_sense(req, req->dev->unit_attention);
+    } else if (req->bus->unit_attention.key == UNIT_ATTENTION) {
+        scsi_req_build_sense(req, req->bus->unit_attention);
+    }
+    scsi_req_complete(req, CHECK_CONDITION);
+    return 0;
+}
+
+static const struct SCSIReqOps reqops_unit_attention = {
+    .size         = sizeof(SCSIRequest),
+    .send_command = scsi_unit_attention
+};
+
+/* SCSIReqOps implementation for REPORT LUNS and for commands sent to
+   an invalid LUN.  */
+
+typedef struct SCSITargetReq SCSITargetReq;
+
+struct SCSITargetReq {
+    SCSIRequest req;
+    int len;
+    uint8_t buf[2056];
+};
+
+static void store_lun(uint8_t *outbuf, int lun)
+{
+    if (lun < 256) {
+        outbuf[1] = lun;
+        return;
+    }
+    outbuf[1] = (lun & 255);
+    outbuf[0] = (lun >> 8) | 0x40;
+}
+
+static bool scsi_target_emulate_report_luns(SCSITargetReq *r)
+{
+    BusChild *kid;
+    int i, len, n;
+    int channel, id;
+    bool found_lun0;
+
+    if (r->req.cmd.xfer < 16) {
+        return false;
+    }
+    if (r->req.cmd.buf[2] > 2) {
+        return false;
+    }
+    channel = r->req.dev->channel;
+    id = r->req.dev->id;
+    found_lun0 = false;
+    n = 0;
+    QTAILQ_FOREACH(kid, &r->req.bus->qbus.children, sibling) {
+        DeviceState *qdev = kid->child;
+        SCSIDevice *dev = SCSI_DEVICE(qdev);
+
+        if (dev->channel == channel && dev->id == id) {
+            if (dev->lun == 0) {
+                found_lun0 = true;
+            }
+            n += 8;
+        }
+    }
+    if (!found_lun0) {
+        n += 8;
+    }
+    len = MIN(n + 8, r->req.cmd.xfer & ~7);
+    if (len > sizeof(r->buf)) {
+        /* TODO: > 256 LUNs? */
+        return false;
+    }
+
+    memset(r->buf, 0, len);
+    stl_be_p(&r->buf, n);
+    i = found_lun0 ? 8 : 16;
+    QTAILQ_FOREACH(kid, &r->req.bus->qbus.children, sibling) {
+        DeviceState *qdev = kid->child;
+        SCSIDevice *dev = SCSI_DEVICE(qdev);
+
+        if (dev->channel == channel && dev->id == id) {
+            store_lun(&r->buf[i], dev->lun);
+            i += 8;
+        }
+    }
+    assert(i == n + 8);
+    r->len = len;
+    return true;
+}
+
+static bool scsi_target_emulate_inquiry(SCSITargetReq *r)
+{
+    assert(r->req.dev->lun != r->req.lun);
+    if (r->req.cmd.buf[1] & 0x2) {
+        /* Command support data - optional, not implemented */
+        return false;
+    }
+
+    if (r->req.cmd.buf[1] & 0x1) {
+        /* Vital product data */
+        uint8_t page_code = r->req.cmd.buf[2];
+        r->buf[r->len++] = page_code ; /* this page */
+        r->buf[r->len++] = 0x00;
+
+        switch (page_code) {
+        case 0x00: /* Supported page codes, mandatory */
+        {
+            int pages;
+            pages = r->len++;
+            r->buf[r->len++] = 0x00; /* list of supported pages (this page) */
+            r->buf[pages] = r->len - pages - 1; /* number of pages */
+            break;
+        }
+        default:
+            return false;
+        }
+        /* done with EVPD */
+        assert(r->len < sizeof(r->buf));
+        r->len = MIN(r->req.cmd.xfer, r->len);
+        return true;
+    }
+
+    /* Standard INQUIRY data */
+    if (r->req.cmd.buf[2] != 0) {
+        return false;
+    }
+
+    /* PAGE CODE == 0 */
+    r->len = MIN(r->req.cmd.xfer, 36);
+    memset(r->buf, 0, r->len);
+    if (r->req.lun != 0) {
+        r->buf[0] = TYPE_NO_LUN;
+    } else {
+        r->buf[0] = TYPE_NOT_PRESENT | TYPE_INACTIVE;
+        r->buf[2] = 5; /* Version */
+        r->buf[3] = 2 | 0x10; /* HiSup, response data format */
+        r->buf[4] = r->len - 5; /* Additional Length = (Len - 1) - 4 */
+        r->buf[7] = 0x10 | (r->req.bus->info->tcq ? 0x02 : 0); /* Sync, TCQ.  */
+        memcpy(&r->buf[8], "QEMU    ", 8);
+        memcpy(&r->buf[16], "QEMU TARGET     ", 16);
+        pstrcpy((char *) &r->buf[32], 4, qemu_get_version());
+    }
+    return true;
+}
+
+static int32_t scsi_target_send_command(SCSIRequest *req, uint8_t *buf)
+{
+    SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
+
+    switch (buf[0]) {
+    case REPORT_LUNS:
+        if (!scsi_target_emulate_report_luns(r)) {
+            goto illegal_request;
+        }
+        break;
+    case INQUIRY:
+        if (!scsi_target_emulate_inquiry(r)) {
+            goto illegal_request;
+        }
+        break;
+    case REQUEST_SENSE:
+        r->len = scsi_device_get_sense(r->req.dev, r->buf,
+                                       MIN(req->cmd.xfer, sizeof r->buf),
+                                       (req->cmd.buf[1] & 1) == 0);
+        if (r->req.dev->sense_is_ua) {
+            scsi_device_unit_attention_reported(req->dev);
+            r->req.dev->sense_len = 0;
+            r->req.dev->sense_is_ua = false;
+        }
+        break;
+    default:
+        scsi_req_build_sense(req, SENSE_CODE(LUN_NOT_SUPPORTED));
+        scsi_req_complete(req, CHECK_CONDITION);
+        return 0;
+    illegal_request:
+        scsi_req_build_sense(req, SENSE_CODE(INVALID_FIELD));
+        scsi_req_complete(req, CHECK_CONDITION);
+        return 0;
+    }
+
+    if (!r->len) {
+        scsi_req_complete(req, GOOD);
+    }
+    return r->len;
+}
+
+static void scsi_target_read_data(SCSIRequest *req)
+{
+    SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
+    uint32_t n;
+
+    n = r->len;
+    if (n > 0) {
+        r->len = 0;
+        scsi_req_data(&r->req, n);
+    } else {
+        scsi_req_complete(&r->req, GOOD);
+    }
+}
+
+static uint8_t *scsi_target_get_buf(SCSIRequest *req)
+{
+    SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
+
+    return r->buf;
+}
+
+static const struct SCSIReqOps reqops_target_command = {
+    .size         = sizeof(SCSITargetReq),
+    .send_command = scsi_target_send_command,
+    .read_data    = scsi_target_read_data,
+    .get_buf      = scsi_target_get_buf,
+};
+
+
+SCSIRequest *scsi_req_alloc(const SCSIReqOps *reqops, SCSIDevice *d,
+                            uint32_t tag, uint32_t lun, void *hba_private)
+{
+    SCSIRequest *req;
+
+    req = g_malloc0(reqops->size);
+    req->refcount = 1;
+    req->bus = scsi_bus_from_device(d);
+    req->dev = d;
+    req->tag = tag;
+    req->lun = lun;
+    req->hba_private = hba_private;
+    req->status = -1;
+    req->sense_len = 0;
+    req->ops = reqops;
+    trace_scsi_req_alloc(req->dev->id, req->lun, req->tag);
+    return req;
+}
+
+SCSIRequest *scsi_req_new(SCSIDevice *d, uint32_t tag, uint32_t lun,
+                          uint8_t *buf, void *hba_private)
+{
+    SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, d->qdev.parent_bus);
+    SCSIRequest *req;
+    SCSICommand cmd;
+
+    if (scsi_req_parse(&cmd, d, buf) != 0) {
+        trace_scsi_req_parse_bad(d->id, lun, tag, buf[0]);
+        req = scsi_req_alloc(&reqops_invalid_opcode, d, tag, lun, hba_private);
+    } else {
+        trace_scsi_req_parsed(d->id, lun, tag, buf[0],
+                              cmd.mode, cmd.xfer);
+        if (cmd.lba != -1) {
+            trace_scsi_req_parsed_lba(d->id, lun, tag, buf[0],
+                                      cmd.lba);
+        }
+
+        if (cmd.xfer > INT32_MAX) {
+            req = scsi_req_alloc(&reqops_invalid_field, d, tag, lun, hba_private);
+        } else if ((d->unit_attention.key == UNIT_ATTENTION ||
+                   bus->unit_attention.key == UNIT_ATTENTION) &&
+                  (buf[0] != INQUIRY &&
+                   buf[0] != REPORT_LUNS &&
+                   buf[0] != GET_CONFIGURATION &&
+                   buf[0] != GET_EVENT_STATUS_NOTIFICATION &&
+
+                   /*
+                    * If we already have a pending unit attention condition,
+                    * report this one before triggering another one.
+                    */
+                   !(buf[0] == REQUEST_SENSE && d->sense_is_ua))) {
+            req = scsi_req_alloc(&reqops_unit_attention, d, tag, lun,
+                                 hba_private);
+        } else if (lun != d->lun ||
+                   buf[0] == REPORT_LUNS ||
+                   (buf[0] == REQUEST_SENSE && d->sense_len)) {
+            req = scsi_req_alloc(&reqops_target_command, d, tag, lun,
+                                 hba_private);
+        } else {
+            req = scsi_device_alloc_req(d, tag, lun, buf, hba_private);
+        }
+    }
+
+    req->cmd = cmd;
+    req->resid = req->cmd.xfer;
+
+    switch (buf[0]) {
+    case INQUIRY:
+        trace_scsi_inquiry(d->id, lun, tag, cmd.buf[1], cmd.buf[2]);
+        break;
+    case TEST_UNIT_READY:
+        trace_scsi_test_unit_ready(d->id, lun, tag);
+        break;
+    case REPORT_LUNS:
+        trace_scsi_report_luns(d->id, lun, tag);
+        break;
+    case REQUEST_SENSE:
+        trace_scsi_request_sense(d->id, lun, tag);
+        break;
+    default:
+        break;
+    }
+
+    return req;
+}
+
+uint8_t *scsi_req_get_buf(SCSIRequest *req)
+{
+    return req->ops->get_buf(req);
+}
+
+static void scsi_clear_unit_attention(SCSIRequest *req)
+{
+    SCSISense *ua;
+    if (req->dev->unit_attention.key != UNIT_ATTENTION &&
+        req->bus->unit_attention.key != UNIT_ATTENTION) {
+        return;
+    }
+
+    /*
+     * If an INQUIRY command enters the enabled command state,
+     * the device server shall [not] clear any unit attention condition;
+     * See also MMC-6, paragraphs 6.5 and 6.6.2.
+     */
+    if (req->cmd.buf[0] == INQUIRY ||
+        req->cmd.buf[0] == GET_CONFIGURATION ||
+        req->cmd.buf[0] == GET_EVENT_STATUS_NOTIFICATION) {
+        return;
+    }
+
+    if (req->dev->unit_attention.key == UNIT_ATTENTION) {
+        ua = &req->dev->unit_attention;
+    } else {
+        ua = &req->bus->unit_attention;
+    }
+
+    /*
+     * If a REPORT LUNS command enters the enabled command state, [...]
+     * the device server shall clear any pending unit attention condition
+     * with an additional sense code of REPORTED LUNS DATA HAS CHANGED.
+     */
+    if (req->cmd.buf[0] == REPORT_LUNS &&
+        !(ua->asc == SENSE_CODE(REPORTED_LUNS_CHANGED).asc &&
+          ua->ascq == SENSE_CODE(REPORTED_LUNS_CHANGED).ascq)) {
+        return;
+    }
+
+    *ua = SENSE_CODE(NO_SENSE);
+}
+
+int scsi_req_get_sense(SCSIRequest *req, uint8_t *buf, int len)
+{
+    int ret;
+
+    assert(len >= 14);
+    if (!req->sense_len) {
+        return 0;
+    }
+
+    ret = scsi_build_sense(req->sense, req->sense_len, buf, len, true);
+
+    /*
+     * FIXME: clearing unit attention conditions upon autosense should be done
+     * only if the UA_INTLCK_CTRL field in the Control mode page is set to 00b
+     * (SAM-5, 5.14).
+     *
+     * We assume UA_INTLCK_CTRL to be 00b for HBAs that support autosense, and
+     * 10b for HBAs that do not support it (do not call scsi_req_get_sense).
+     * Here we handle unit attention clearing for UA_INTLCK_CTRL == 00b.
+     */
+    if (req->dev->sense_is_ua) {
+        scsi_device_unit_attention_reported(req->dev);
+        req->dev->sense_len = 0;
+        req->dev->sense_is_ua = false;
+    }
+    return ret;
+}
+
+int scsi_device_get_sense(SCSIDevice *dev, uint8_t *buf, int len, bool fixed)
+{
+    return scsi_build_sense(dev->sense, dev->sense_len, buf, len, fixed);
+}
+
+void scsi_req_build_sense(SCSIRequest *req, SCSISense sense)
+{
+    trace_scsi_req_build_sense(req->dev->id, req->lun, req->tag,
+                               sense.key, sense.asc, sense.ascq);
+    memset(req->sense, 0, 18);
+    req->sense[0] = 0x70;
+    req->sense[2] = sense.key;
+    req->sense[7] = 10;
+    req->sense[12] = sense.asc;
+    req->sense[13] = sense.ascq;
+    req->sense_len = 18;
+}
+
+static void scsi_req_enqueue_internal(SCSIRequest *req)
+{
+    assert(!req->enqueued);
+    scsi_req_ref(req);
+    if (req->bus->info->get_sg_list) {
+        req->sg = req->bus->info->get_sg_list(req);
+    } else {
+        req->sg = NULL;
+    }
+    req->enqueued = true;
+    QTAILQ_INSERT_TAIL(&req->dev->requests, req, next);
+}
+
+int32_t scsi_req_enqueue(SCSIRequest *req)
+{
+    int32_t rc;
+
+    assert(!req->retry);
+    scsi_req_enqueue_internal(req);
+    scsi_req_ref(req);
+    rc = req->ops->send_command(req, req->cmd.buf);
+    scsi_req_unref(req);
+    return rc;
+}
+
+static void scsi_req_dequeue(SCSIRequest *req)
+{
+    trace_scsi_req_dequeue(req->dev->id, req->lun, req->tag);
+    req->retry = false;
+    if (req->enqueued) {
+        QTAILQ_REMOVE(&req->dev->requests, req, next);
+        req->enqueued = false;
+        scsi_req_unref(req);
+    }
+}
+
+static int scsi_get_performance_length(int num_desc, int type, int data_type)
+{
+    /* MMC-6, paragraph 6.7.  */
+    switch (type) {
+    case 0:
+        if ((data_type & 3) == 0) {
+            /* Each descriptor is as in Table 295 - Nominal performance.  */
+            return 16 * num_desc + 8;
+        } else {
+            /* Each descriptor is as in Table 296 - Exceptions.  */
+            return 6 * num_desc + 8;
+        }
+    case 1:
+    case 4:
+    case 5:
+        return 8 * num_desc + 8;
+    case 2:
+        return 2048 * num_desc + 8;
+    case 3:
+        return 16 * num_desc + 8;
+    default:
+        return 8;
+    }
+}
+
+static int ata_passthrough_xfer_unit(SCSIDevice *dev, uint8_t *buf)
+{
+    int byte_block = (buf[2] >> 2) & 0x1;
+    int type = (buf[2] >> 4) & 0x1;
+    int xfer_unit;
+
+    if (byte_block) {
+        if (type) {
+            xfer_unit = dev->blocksize;
+        } else {
+            xfer_unit = 512;
+        }
+    } else {
+        xfer_unit = 1;
+    }
+
+    return xfer_unit;
+}
+
+static int ata_passthrough_12_xfer_size(SCSIDevice *dev, uint8_t *buf)
+{
+    int length = buf[2] & 0x3;
+    int xfer;
+    int unit = ata_passthrough_xfer_unit(dev, buf);
+
+    switch (length) {
+    case 0:
+    case 3: /* USB-specific.  */
+    default:
+        xfer = 0;
+        break;
+    case 1:
+        xfer = buf[3];
+        break;
+    case 2:
+        xfer = buf[4];
+        break;
+    }
+
+    return xfer * unit;
+}
+
+static int ata_passthrough_16_xfer_size(SCSIDevice *dev, uint8_t *buf)
+{
+    int extend = buf[1] & 0x1;
+    int length = buf[2] & 0x3;
+    int xfer;
+    int unit = ata_passthrough_xfer_unit(dev, buf);
+
+    switch (length) {
+    case 0:
+    case 3: /* USB-specific.  */
+    default:
+        xfer = 0;
+        break;
+    case 1:
+        xfer = buf[4];
+        xfer |= (extend ? buf[3] << 8 : 0);
+        break;
+    case 2:
+        xfer = buf[6];
+        xfer |= (extend ? buf[5] << 8 : 0);
+        break;
+    }
+
+    return xfer * unit;
+}
+
+uint32_t scsi_data_cdb_length(uint8_t *buf)
+{
+    if ((buf[0] >> 5) == 0 && buf[4] == 0) {
+        return 256;
+    } else {
+        return scsi_cdb_length(buf);
+    }
+}
+
+uint32_t scsi_cdb_length(uint8_t *buf)
+{
+    switch (buf[0] >> 5) {
+    case 0:
+        return buf[4];
+        break;
+    case 1:
+    case 2:
+        return lduw_be_p(&buf[7]);
+        break;
+    case 4:
+        return ldl_be_p(&buf[10]) & 0xffffffffULL;
+        break;
+    case 5:
+        return ldl_be_p(&buf[6]) & 0xffffffffULL;
+        break;
+    default:
+        return -1;
+    }
+}
+
+static int scsi_req_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
+{
+    cmd->xfer = scsi_cdb_length(buf);
+    switch (buf[0]) {
+    case TEST_UNIT_READY:
+    case REWIND:
+    case START_STOP:
+    case SET_CAPACITY:
+    case WRITE_FILEMARKS:
+    case WRITE_FILEMARKS_16:
+    case SPACE:
+    case RESERVE:
+    case RELEASE:
+    case ERASE:
+    case ALLOW_MEDIUM_REMOVAL:
+    case VERIFY_10:
+    case SEEK_10:
+    case SYNCHRONIZE_CACHE:
+    case SYNCHRONIZE_CACHE_16:
+    case LOCATE_16:
+    case LOCK_UNLOCK_CACHE:
+    case SET_CD_SPEED:
+    case SET_LIMITS:
+    case WRITE_LONG_10:
+    case UPDATE_BLOCK:
+    case RESERVE_TRACK:
+    case SET_READ_AHEAD:
+    case PRE_FETCH:
+    case PRE_FETCH_16:
+    case ALLOW_OVERWRITE:
+        cmd->xfer = 0;
+        break;
+    case MODE_SENSE:
+        break;
+    case WRITE_SAME_10:
+    case WRITE_SAME_16:
+        cmd->xfer = dev->blocksize;
+        break;
+    case READ_CAPACITY_10:
+        cmd->xfer = 8;
+        break;
+    case READ_BLOCK_LIMITS:
+        cmd->xfer = 6;
+        break;
+    case SEND_VOLUME_TAG:
+        /* GPCMD_SET_STREAMING from multimedia commands.  */
+        if (dev->type == TYPE_ROM) {
+            cmd->xfer = buf[10] | (buf[9] << 8);
+        } else {
+            cmd->xfer = buf[9] | (buf[8] << 8);
+        }
+        break;
+    case WRITE_6:
+        /* length 0 means 256 blocks */
+        if (cmd->xfer == 0) {
+            cmd->xfer = 256;
+        }
+    case WRITE_10:
+    case WRITE_VERIFY_10:
+    case WRITE_12:
+    case WRITE_VERIFY_12:
+    case WRITE_16:
+    case WRITE_VERIFY_16:
+        cmd->xfer *= dev->blocksize;
+        break;
+    case READ_6:
+    case READ_REVERSE:
+        /* length 0 means 256 blocks */
+        if (cmd->xfer == 0) {
+            cmd->xfer = 256;
+        }
+    case READ_10:
+    case RECOVER_BUFFERED_DATA:
+    case READ_12:
+    case READ_16:
+        cmd->xfer *= dev->blocksize;
+        break;
+    case FORMAT_UNIT:
+        /* MMC mandates the parameter list to be 12-bytes long.  Parameters
+         * for block devices are restricted to the header right now.  */
+        if (dev->type == TYPE_ROM && (buf[1] & 16)) {
+            cmd->xfer = 12;
+        } else {
+            cmd->xfer = (buf[1] & 16) == 0 ? 0 : (buf[1] & 32 ? 8 : 4);
+        }
+        break;
+    case INQUIRY:
+    case RECEIVE_DIAGNOSTIC:
+    case SEND_DIAGNOSTIC:
+        cmd->xfer = buf[4] | (buf[3] << 8);
+        break;
+    case READ_CD:
+    case READ_BUFFER:
+    case WRITE_BUFFER:
+    case SEND_CUE_SHEET:
+        cmd->xfer = buf[8] | (buf[7] << 8) | (buf[6] << 16);
+        break;
+    case PERSISTENT_RESERVE_OUT:
+        cmd->xfer = ldl_be_p(&buf[5]) & 0xffffffffULL;
+        break;
+    case ERASE_12:
+        if (dev->type == TYPE_ROM) {
+            /* MMC command GET PERFORMANCE.  */
+            cmd->xfer = scsi_get_performance_length(buf[9] | (buf[8] << 8),
+                                                    buf[10], buf[1] & 0x1f);
+        }
+        break;
+    case MECHANISM_STATUS:
+    case READ_DVD_STRUCTURE:
+    case SEND_DVD_STRUCTURE:
+    case MAINTENANCE_OUT:
+    case MAINTENANCE_IN:
+        if (dev->type == TYPE_ROM) {
+            /* GPCMD_REPORT_KEY and GPCMD_SEND_KEY from multi media commands */
+            cmd->xfer = buf[9] | (buf[8] << 8);
+        }
+        break;
+    case ATA_PASSTHROUGH_12:
+        if (dev->type == TYPE_ROM) {
+            /* BLANK command of MMC */
+            cmd->xfer = 0;
+        } else {
+            cmd->xfer = ata_passthrough_12_xfer_size(dev, buf);
+        }
+        break;
+    case ATA_PASSTHROUGH_16:
+        cmd->xfer = ata_passthrough_16_xfer_size(dev, buf);
+        break;
+    }
+    return 0;
+}
+
+static int scsi_req_stream_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
+{
+    switch (buf[0]) {
+    /* stream commands */
+    case ERASE_12:
+    case ERASE_16:
+        cmd->xfer = 0;
+        break;
+    case READ_6:
+    case READ_REVERSE:
+    case RECOVER_BUFFERED_DATA:
+    case WRITE_6:
+        cmd->xfer = buf[4] | (buf[3] << 8) | (buf[2] << 16);
+        if (buf[1] & 0x01) { /* fixed */
+            cmd->xfer *= dev->blocksize;
+        }
+        break;
+    case READ_16:
+    case READ_REVERSE_16:
+    case VERIFY_16:
+    case WRITE_16:
+        cmd->xfer = buf[14] | (buf[13] << 8) | (buf[12] << 16);
+        if (buf[1] & 0x01) { /* fixed */
+            cmd->xfer *= dev->blocksize;
+        }
+        break;
+    case REWIND:
+    case LOAD_UNLOAD:
+        cmd->xfer = 0;
+        break;
+    case SPACE_16:
+        cmd->xfer = buf[13] | (buf[12] << 8);
+        break;
+    case READ_POSITION:
+        switch (buf[1] & 0x1f) /* operation code */ {
+        case SHORT_FORM_BLOCK_ID:
+        case SHORT_FORM_VENDOR_SPECIFIC:
+            cmd->xfer = 20;
+            break;
+        case LONG_FORM:
+            cmd->xfer = 32;
+            break;
+        case EXTENDED_FORM:
+            cmd->xfer = buf[8] | (buf[7] << 8);
+            break;
+        default:
+            return -1;
+        }
+
+        break;
+    case FORMAT_UNIT:
+        cmd->xfer = buf[4] | (buf[3] << 8);
+        break;
+    /* generic commands */
+    default:
+        return scsi_req_length(cmd, dev, buf);
+    }
+    return 0;
+}
+
+static int scsi_req_medium_changer_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
+{
+    switch (buf[0]) {
+    /* medium changer commands */
+    case EXCHANGE_MEDIUM:
+    case INITIALIZE_ELEMENT_STATUS:
+    case INITIALIZE_ELEMENT_STATUS_WITH_RANGE:
+    case MOVE_MEDIUM:
+    case POSITION_TO_ELEMENT:
+        cmd->xfer = 0;
+        break;
+    case READ_ELEMENT_STATUS:
+        cmd->xfer = buf[9] | (buf[8] << 8) | (buf[7] << 16);
+        break;
+
+    /* generic commands */
+    default:
+        return scsi_req_length(cmd, dev, buf);
+    }
+    return 0;
+}
+
+
+static void scsi_cmd_xfer_mode(SCSICommand *cmd)
+{
+    if (!cmd->xfer) {
+        cmd->mode = SCSI_XFER_NONE;
+        return;
+    }
+    switch (cmd->buf[0]) {
+    case WRITE_6:
+    case WRITE_10:
+    case WRITE_VERIFY_10:
+    case WRITE_12:
+    case WRITE_VERIFY_12:
+    case WRITE_16:
+    case WRITE_VERIFY_16:
+    case COPY:
+    case COPY_VERIFY:
+    case COMPARE:
+    case CHANGE_DEFINITION:
+    case LOG_SELECT:
+    case MODE_SELECT:
+    case MODE_SELECT_10:
+    case SEND_DIAGNOSTIC:
+    case WRITE_BUFFER:
+    case FORMAT_UNIT:
+    case REASSIGN_BLOCKS:
+    case SEARCH_EQUAL:
+    case SEARCH_HIGH:
+    case SEARCH_LOW:
+    case UPDATE_BLOCK:
+    case WRITE_LONG_10:
+    case WRITE_SAME_10:
+    case WRITE_SAME_16:
+    case UNMAP:
+    case SEARCH_HIGH_12:
+    case SEARCH_EQUAL_12:
+    case SEARCH_LOW_12:
+    case MEDIUM_SCAN:
+    case SEND_VOLUME_TAG:
+    case SEND_CUE_SHEET:
+    case SEND_DVD_STRUCTURE:
+    case PERSISTENT_RESERVE_OUT:
+    case MAINTENANCE_OUT:
+        cmd->mode = SCSI_XFER_TO_DEV;
+        break;
+    case ATA_PASSTHROUGH_12:
+    case ATA_PASSTHROUGH_16:
+        /* T_DIR */
+        cmd->mode = (cmd->buf[2] & 0x8) ?
+                   SCSI_XFER_FROM_DEV : SCSI_XFER_TO_DEV;
+        break;
+    default:
+        cmd->mode = SCSI_XFER_FROM_DEV;
+        break;
+    }
+}
+
+static uint64_t scsi_cmd_lba(SCSICommand *cmd)
+{
+    uint8_t *buf = cmd->buf;
+    uint64_t lba;
+
+    switch (buf[0] >> 5) {
+    case 0:
+        lba = ldl_be_p(&buf[0]) & 0x1fffff;
+        break;
+    case 1:
+    case 2:
+    case 5:
+        lba = ldl_be_p(&buf[2]) & 0xffffffffULL;
+        break;
+    case 4:
+        lba = ldq_be_p(&buf[2]);
+        break;
+    default:
+        lba = -1;
+
+    }
+    return lba;
+}
+
+int scsi_req_parse(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
+{
+    int rc;
+
+    switch (buf[0] >> 5) {
+    case 0:
+        cmd->len = 6;
+        break;
+    case 1:
+    case 2:
+        cmd->len = 10;
+        break;
+    case 4:
+        cmd->len = 16;
+        break;
+    case 5:
+        cmd->len = 12;
+        break;
+    default:
+        return -1;
+    }
+
+    switch (dev->type) {
+    case TYPE_TAPE:
+        rc = scsi_req_stream_length(cmd, dev, buf);
+        break;
+    case TYPE_MEDIUM_CHANGER:
+        rc = scsi_req_medium_changer_length(cmd, dev, buf);
+        break;
+    default:
+        rc = scsi_req_length(cmd, dev, buf);
+        break;
+    }
+
+    if (rc != 0)
+        return rc;
+
+    memcpy(cmd->buf, buf, cmd->len);
+    scsi_cmd_xfer_mode(cmd);
+    cmd->lba = scsi_cmd_lba(cmd);
+    return 0;
+}
+
+void scsi_device_report_change(SCSIDevice *dev, SCSISense sense)
+{
+    SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
+
+    scsi_device_set_ua(dev, sense);
+    if (bus->info->change) {
+        bus->info->change(bus, dev, sense);
+    }
+}
+
+/*
+ * Predefined sense codes
+ */
+
+/* No sense data available */
+const struct SCSISense sense_code_NO_SENSE = {
+    .key = NO_SENSE , .asc = 0x00 , .ascq = 0x00
+};
+
+/* LUN not ready, Manual intervention required */
+const struct SCSISense sense_code_LUN_NOT_READY = {
+    .key = NOT_READY, .asc = 0x04, .ascq = 0x03
+};
+
+/* LUN not ready, Medium not present */
+const struct SCSISense sense_code_NO_MEDIUM = {
+    .key = NOT_READY, .asc = 0x3a, .ascq = 0x00
+};
+
+/* LUN not ready, medium removal prevented */
+const struct SCSISense sense_code_NOT_READY_REMOVAL_PREVENTED = {
+    .key = NOT_READY, .asc = 0x53, .ascq = 0x02
+};
+
+/* Hardware error, internal target failure */
+const struct SCSISense sense_code_TARGET_FAILURE = {
+    .key = HARDWARE_ERROR, .asc = 0x44, .ascq = 0x00
+};
+
+/* Illegal request, invalid command operation code */
+const struct SCSISense sense_code_INVALID_OPCODE = {
+    .key = ILLEGAL_REQUEST, .asc = 0x20, .ascq = 0x00
+};
+
+/* Illegal request, LBA out of range */
+const struct SCSISense sense_code_LBA_OUT_OF_RANGE = {
+    .key = ILLEGAL_REQUEST, .asc = 0x21, .ascq = 0x00
+};
+
+/* Illegal request, Invalid field in CDB */
+const struct SCSISense sense_code_INVALID_FIELD = {
+    .key = ILLEGAL_REQUEST, .asc = 0x24, .ascq = 0x00
+};
+
+/* Illegal request, Invalid field in parameter list */
+const struct SCSISense sense_code_INVALID_PARAM = {
+    .key = ILLEGAL_REQUEST, .asc = 0x26, .ascq = 0x00
+};
+
+/* Illegal request, Parameter list length error */
+const struct SCSISense sense_code_INVALID_PARAM_LEN = {
+    .key = ILLEGAL_REQUEST, .asc = 0x1a, .ascq = 0x00
+};
+
+/* Illegal request, LUN not supported */
+const struct SCSISense sense_code_LUN_NOT_SUPPORTED = {
+    .key = ILLEGAL_REQUEST, .asc = 0x25, .ascq = 0x00
+};
+
+/* Illegal request, Saving parameters not supported */
+const struct SCSISense sense_code_SAVING_PARAMS_NOT_SUPPORTED = {
+    .key = ILLEGAL_REQUEST, .asc = 0x39, .ascq = 0x00
+};
+
+/* Illegal request, Incompatible medium installed */
+const struct SCSISense sense_code_INCOMPATIBLE_FORMAT = {
+    .key = ILLEGAL_REQUEST, .asc = 0x30, .ascq = 0x00
+};
+
+/* Illegal request, medium removal prevented */
+const struct SCSISense sense_code_ILLEGAL_REQ_REMOVAL_PREVENTED = {
+    .key = ILLEGAL_REQUEST, .asc = 0x53, .ascq = 0x02
+};
+
+/* Command aborted, I/O process terminated */
+const struct SCSISense sense_code_IO_ERROR = {
+    .key = ABORTED_COMMAND, .asc = 0x00, .ascq = 0x06
+};
+
+/* Command aborted, I_T Nexus loss occurred */
+const struct SCSISense sense_code_I_T_NEXUS_LOSS = {
+    .key = ABORTED_COMMAND, .asc = 0x29, .ascq = 0x07
+};
+
+/* Command aborted, Logical Unit failure */
+const struct SCSISense sense_code_LUN_FAILURE = {
+    .key = ABORTED_COMMAND, .asc = 0x3e, .ascq = 0x01
+};
+
+/* Unit attention, Capacity data has changed */
+const struct SCSISense sense_code_CAPACITY_CHANGED = {
+    .key = UNIT_ATTENTION, .asc = 0x2a, .ascq = 0x09
+};
+
+/* Unit attention, Power on, reset or bus device reset occurred */
+const struct SCSISense sense_code_RESET = {
+    .key = UNIT_ATTENTION, .asc = 0x29, .ascq = 0x00
+};
+
+/* Unit attention, No medium */
+const struct SCSISense sense_code_UNIT_ATTENTION_NO_MEDIUM = {
+    .key = UNIT_ATTENTION, .asc = 0x3a, .ascq = 0x00
+};
+
+/* Unit attention, Medium may have changed */
+const struct SCSISense sense_code_MEDIUM_CHANGED = {
+    .key = UNIT_ATTENTION, .asc = 0x28, .ascq = 0x00
+};
+
+/* Unit attention, Reported LUNs data has changed */
+const struct SCSISense sense_code_REPORTED_LUNS_CHANGED = {
+    .key = UNIT_ATTENTION, .asc = 0x3f, .ascq = 0x0e
+};
+
+/* Unit attention, Device internal reset */
+const struct SCSISense sense_code_DEVICE_INTERNAL_RESET = {
+    .key = UNIT_ATTENTION, .asc = 0x29, .ascq = 0x04
+};
+
+/* Data Protection, Write Protected */
+const struct SCSISense sense_code_WRITE_PROTECTED = {
+    .key = DATA_PROTECT, .asc = 0x27, .ascq = 0x00
+};
+
+/*
+ * scsi_build_sense
+ *
+ * Convert between fixed and descriptor sense buffers
+ */
+int scsi_build_sense(uint8_t *in_buf, int in_len,
+                     uint8_t *buf, int len, bool fixed)
+{
+    bool fixed_in;
+    SCSISense sense;
+    if (!fixed && len < 8) {
+        return 0;
+    }
+
+    if (in_len == 0) {
+        sense.key = NO_SENSE;
+        sense.asc = 0;
+        sense.ascq = 0;
+    } else {
+        fixed_in = (in_buf[0] & 2) == 0;
+
+        if (fixed == fixed_in) {
+            memcpy(buf, in_buf, MIN(len, in_len));
+            return MIN(len, in_len);
+        }
+
+        if (fixed_in) {
+            sense.key = in_buf[2];
+            sense.asc = in_buf[12];
+            sense.ascq = in_buf[13];
+        } else {
+            sense.key = in_buf[1];
+            sense.asc = in_buf[2];
+            sense.ascq = in_buf[3];
+        }
+    }
+
+    memset(buf, 0, len);
+    if (fixed) {
+        /* Return fixed format sense buffer */
+        buf[0] = 0x70;
+        buf[2] = sense.key;
+        buf[7] = 10;
+        buf[12] = sense.asc;
+        buf[13] = sense.ascq;
+        return MIN(len, 18);
+    } else {
+        /* Return descriptor format sense buffer */
+        buf[0] = 0x72;
+        buf[1] = sense.key;
+        buf[2] = sense.asc;
+        buf[3] = sense.ascq;
+        return 8;
+    }
+}
+
+static const char *scsi_command_name(uint8_t cmd)
+{
+    static const char *names[] = {
+        [ TEST_UNIT_READY          ] = "TEST_UNIT_READY",
+        [ REWIND                   ] = "REWIND",
+        [ REQUEST_SENSE            ] = "REQUEST_SENSE",
+        [ FORMAT_UNIT              ] = "FORMAT_UNIT",
+        [ READ_BLOCK_LIMITS        ] = "READ_BLOCK_LIMITS",
+        [ REASSIGN_BLOCKS          ] = "REASSIGN_BLOCKS/INITIALIZE ELEMENT STATUS",
+        /* LOAD_UNLOAD and INITIALIZE_ELEMENT_STATUS use the same operation code */
+        [ READ_6                   ] = "READ_6",
+        [ WRITE_6                  ] = "WRITE_6",
+        [ SET_CAPACITY             ] = "SET_CAPACITY",
+        [ READ_REVERSE             ] = "READ_REVERSE",
+        [ WRITE_FILEMARKS          ] = "WRITE_FILEMARKS",
+        [ SPACE                    ] = "SPACE",
+        [ INQUIRY                  ] = "INQUIRY",
+        [ RECOVER_BUFFERED_DATA    ] = "RECOVER_BUFFERED_DATA",
+        [ MAINTENANCE_IN           ] = "MAINTENANCE_IN",
+        [ MAINTENANCE_OUT          ] = "MAINTENANCE_OUT",
+        [ MODE_SELECT              ] = "MODE_SELECT",
+        [ RESERVE                  ] = "RESERVE",
+        [ RELEASE                  ] = "RELEASE",
+        [ COPY                     ] = "COPY",
+        [ ERASE                    ] = "ERASE",
+        [ MODE_SENSE               ] = "MODE_SENSE",
+        [ START_STOP               ] = "START_STOP/LOAD_UNLOAD",
+        /* LOAD_UNLOAD and START_STOP use the same operation code */
+        [ RECEIVE_DIAGNOSTIC       ] = "RECEIVE_DIAGNOSTIC",
+        [ SEND_DIAGNOSTIC          ] = "SEND_DIAGNOSTIC",
+        [ ALLOW_MEDIUM_REMOVAL     ] = "ALLOW_MEDIUM_REMOVAL",
+        [ READ_CAPACITY_10         ] = "READ_CAPACITY_10",
+        [ READ_10                  ] = "READ_10",
+        [ WRITE_10                 ] = "WRITE_10",
+        [ SEEK_10                  ] = "SEEK_10/POSITION_TO_ELEMENT",
+        /* SEEK_10 and POSITION_TO_ELEMENT use the same operation code */
+        [ WRITE_VERIFY_10          ] = "WRITE_VERIFY_10",
+        [ VERIFY_10                ] = "VERIFY_10",
+        [ SEARCH_HIGH              ] = "SEARCH_HIGH",
+        [ SEARCH_EQUAL             ] = "SEARCH_EQUAL",
+        [ SEARCH_LOW               ] = "SEARCH_LOW",
+        [ SET_LIMITS               ] = "SET_LIMITS",
+        [ PRE_FETCH                ] = "PRE_FETCH/READ_POSITION",
+        /* READ_POSITION and PRE_FETCH use the same operation code */
+        [ SYNCHRONIZE_CACHE        ] = "SYNCHRONIZE_CACHE",
+        [ LOCK_UNLOCK_CACHE        ] = "LOCK_UNLOCK_CACHE",
+        [ READ_DEFECT_DATA         ] = "READ_DEFECT_DATA/INITIALIZE_ELEMENT_STATUS_WITH_RANGE",
+        /* READ_DEFECT_DATA and INITIALIZE_ELEMENT_STATUS_WITH_RANGE use the same operation code */
+        [ MEDIUM_SCAN              ] = "MEDIUM_SCAN",
+        [ COMPARE                  ] = "COMPARE",
+        [ COPY_VERIFY              ] = "COPY_VERIFY",
+        [ WRITE_BUFFER             ] = "WRITE_BUFFER",
+        [ READ_BUFFER              ] = "READ_BUFFER",
+        [ UPDATE_BLOCK             ] = "UPDATE_BLOCK",
+        [ READ_LONG_10             ] = "READ_LONG_10",
+        [ WRITE_LONG_10            ] = "WRITE_LONG_10",
+        [ CHANGE_DEFINITION        ] = "CHANGE_DEFINITION",
+        [ WRITE_SAME_10            ] = "WRITE_SAME_10",
+        [ UNMAP                    ] = "UNMAP",
+        [ READ_TOC                 ] = "READ_TOC",
+        [ REPORT_DENSITY_SUPPORT   ] = "REPORT_DENSITY_SUPPORT",
+        [ SANITIZE                 ] = "SANITIZE",
+        [ GET_CONFIGURATION        ] = "GET_CONFIGURATION",
+        [ LOG_SELECT               ] = "LOG_SELECT",
+        [ LOG_SENSE                ] = "LOG_SENSE",
+        [ MODE_SELECT_10           ] = "MODE_SELECT_10",
+        [ RESERVE_10               ] = "RESERVE_10",
+        [ RELEASE_10               ] = "RELEASE_10",
+        [ MODE_SENSE_10            ] = "MODE_SENSE_10",
+        [ PERSISTENT_RESERVE_IN    ] = "PERSISTENT_RESERVE_IN",
+        [ PERSISTENT_RESERVE_OUT   ] = "PERSISTENT_RESERVE_OUT",
+        [ WRITE_FILEMARKS_16       ] = "WRITE_FILEMARKS_16",
+        [ EXTENDED_COPY            ] = "EXTENDED_COPY",
+        [ ATA_PASSTHROUGH_16       ] = "ATA_PASSTHROUGH_16",
+        [ ACCESS_CONTROL_IN        ] = "ACCESS_CONTROL_IN",
+        [ ACCESS_CONTROL_OUT       ] = "ACCESS_CONTROL_OUT",
+        [ READ_16                  ] = "READ_16",
+        [ COMPARE_AND_WRITE        ] = "COMPARE_AND_WRITE",
+        [ WRITE_16                 ] = "WRITE_16",
+        [ WRITE_VERIFY_16          ] = "WRITE_VERIFY_16",
+        [ VERIFY_16                ] = "VERIFY_16",
+        [ PRE_FETCH_16             ] = "PRE_FETCH_16",
+        [ SYNCHRONIZE_CACHE_16     ] = "SPACE_16/SYNCHRONIZE_CACHE_16",
+        /* SPACE_16 and SYNCHRONIZE_CACHE_16 use the same operation code */
+        [ LOCATE_16                ] = "LOCATE_16",
+        [ WRITE_SAME_16            ] = "ERASE_16/WRITE_SAME_16",
+        /* ERASE_16 and WRITE_SAME_16 use the same operation code */
+        [ SERVICE_ACTION_IN_16     ] = "SERVICE_ACTION_IN_16",
+        [ WRITE_LONG_16            ] = "WRITE_LONG_16",
+        [ REPORT_LUNS              ] = "REPORT_LUNS",
+        [ ATA_PASSTHROUGH_12       ] = "BLANK/ATA_PASSTHROUGH_12",
+        [ MOVE_MEDIUM              ] = "MOVE_MEDIUM",
+        [ EXCHANGE_MEDIUM          ] = "EXCHANGE MEDIUM",
+        [ READ_12                  ] = "READ_12",
+        [ WRITE_12                 ] = "WRITE_12",
+        [ ERASE_12                 ] = "ERASE_12/GET_PERFORMANCE",
+        /* ERASE_12 and GET_PERFORMANCE use the same operation code */
+        [ SERVICE_ACTION_IN_12     ] = "SERVICE_ACTION_IN_12",
+        [ WRITE_VERIFY_12          ] = "WRITE_VERIFY_12",
+        [ VERIFY_12                ] = "VERIFY_12",
+        [ SEARCH_HIGH_12           ] = "SEARCH_HIGH_12",
+        [ SEARCH_EQUAL_12          ] = "SEARCH_EQUAL_12",
+        [ SEARCH_LOW_12            ] = "SEARCH_LOW_12",
+        [ READ_ELEMENT_STATUS      ] = "READ_ELEMENT_STATUS",
+        [ SEND_VOLUME_TAG          ] = "SEND_VOLUME_TAG/SET_STREAMING",
+        /* SEND_VOLUME_TAG and SET_STREAMING use the same operation code */
+        [ READ_CD                  ] = "READ_CD",
+        [ READ_DEFECT_DATA_12      ] = "READ_DEFECT_DATA_12",
+        [ READ_DVD_STRUCTURE       ] = "READ_DVD_STRUCTURE",
+        [ RESERVE_TRACK            ] = "RESERVE_TRACK",
+        [ SEND_CUE_SHEET           ] = "SEND_CUE_SHEET",
+        [ SEND_DVD_STRUCTURE       ] = "SEND_DVD_STRUCTURE",
+        [ SET_CD_SPEED             ] = "SET_CD_SPEED",
+        [ SET_READ_AHEAD           ] = "SET_READ_AHEAD",
+        [ ALLOW_OVERWRITE          ] = "ALLOW_OVERWRITE",
+        [ MECHANISM_STATUS         ] = "MECHANISM_STATUS",
+    };
+
+    if (cmd >= ARRAY_SIZE(names) || names[cmd] == NULL)
+        return "*UNKNOWN*";
+    return names[cmd];
+}
+
+SCSIRequest *scsi_req_ref(SCSIRequest *req)
+{
+    assert(req->refcount > 0);
+    req->refcount++;
+    return req;
+}
+
+void scsi_req_unref(SCSIRequest *req)
+{
+    assert(req->refcount > 0);
+    if (--req->refcount == 0) {
+        SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, req->dev->qdev.parent_bus);
+        if (bus->info->free_request && req->hba_private) {
+            bus->info->free_request(bus, req->hba_private);
+        }
+        if (req->ops->free_req) {
+            req->ops->free_req(req);
+        }
+        g_free(req);
+    }
+}
+
+/* Tell the device that we finished processing this chunk of I/O.  It
+   will start the next chunk or complete the command.  */
+void scsi_req_continue(SCSIRequest *req)
+{
+    if (req->io_canceled) {
+        trace_scsi_req_continue_canceled(req->dev->id, req->lun, req->tag);
+        return;
+    }
+    trace_scsi_req_continue(req->dev->id, req->lun, req->tag);
+    if (req->cmd.mode == SCSI_XFER_TO_DEV) {
+        req->ops->write_data(req);
+    } else {
+        req->ops->read_data(req);
+    }
+}
+
+/* Called by the devices when data is ready for the HBA.  The HBA should
+   start a DMA operation to read or fill the device's data buffer.
+   Once it completes, calling scsi_req_continue will restart I/O.  */
+void scsi_req_data(SCSIRequest *req, int len)
+{
+    uint8_t *buf;
+    if (req->io_canceled) {
+        trace_scsi_req_data_canceled(req->dev->id, req->lun, req->tag, len);
+        return;
+    }
+    trace_scsi_req_data(req->dev->id, req->lun, req->tag, len);
+    assert(req->cmd.mode != SCSI_XFER_NONE);
+    if (!req->sg) {
+        req->resid -= len;
+        req->bus->info->transfer_data(req, len);
+        return;
+    }
+
+    /* If the device calls scsi_req_data and the HBA specified a
+     * scatter/gather list, the transfer has to happen in a single
+     * step.  */
+    assert(!req->dma_started);
+    req->dma_started = true;
+
+    buf = scsi_req_get_buf(req);
+    if (req->cmd.mode == SCSI_XFER_FROM_DEV) {
+        req->resid = dma_buf_read(buf, len, req->sg);
+    } else {
+        req->resid = dma_buf_write(buf, len, req->sg);
+    }
+    scsi_req_continue(req);
+}
+
+void scsi_req_print(SCSIRequest *req)
+{
+    FILE *fp = stderr;
+    int i;
+
+    fprintf(fp, "[%s id=%d] %s",
+            req->dev->qdev.parent_bus->name,
+            req->dev->id,
+            scsi_command_name(req->cmd.buf[0]));
+    for (i = 1; i < req->cmd.len; i++) {
+        fprintf(fp, " 0x%02x", req->cmd.buf[i]);
+    }
+    switch (req->cmd.mode) {
+    case SCSI_XFER_NONE:
+        fprintf(fp, " - none\n");
+        break;
+    case SCSI_XFER_FROM_DEV:
+        fprintf(fp, " - from-dev len=%zd\n", req->cmd.xfer);
+        break;
+    case SCSI_XFER_TO_DEV:
+        fprintf(fp, " - to-dev len=%zd\n", req->cmd.xfer);
+        break;
+    default:
+        fprintf(fp, " - Oops\n");
+        break;
+    }
+}
+
+void scsi_req_complete(SCSIRequest *req, int status)
+{
+    assert(req->status == -1);
+    req->status = status;
+
+    assert(req->sense_len <= sizeof(req->sense));
+    if (status == GOOD) {
+        req->sense_len = 0;
+    }
+
+    if (req->sense_len) {
+        memcpy(req->dev->sense, req->sense, req->sense_len);
+        req->dev->sense_len = req->sense_len;
+        req->dev->sense_is_ua = (req->ops == &reqops_unit_attention);
+    } else {
+        req->dev->sense_len = 0;
+        req->dev->sense_is_ua = false;
+    }
+
+    /*
+     * Unit attention state is now stored in the device's sense buffer
+     * if the HBA didn't do autosense.  Clear the pending unit attention
+     * flags.
+     */
+    scsi_clear_unit_attention(req);
+
+    scsi_req_ref(req);
+    scsi_req_dequeue(req);
+    req->bus->info->complete(req, req->status, req->resid);
+    scsi_req_unref(req);
+}
+
+void scsi_req_cancel(SCSIRequest *req)
+{
+    trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
+    if (!req->enqueued) {
+        return;
+    }
+    scsi_req_ref(req);
+    scsi_req_dequeue(req);
+    req->io_canceled = true;
+    if (req->ops->cancel_io) {
+        req->ops->cancel_io(req);
+    }
+    if (req->bus->info->cancel) {
+        req->bus->info->cancel(req);
+    }
+    scsi_req_unref(req);
+}
+
+void scsi_req_abort(SCSIRequest *req, int status)
+{
+    if (!req->enqueued) {
+        return;
+    }
+    scsi_req_ref(req);
+    scsi_req_dequeue(req);
+    req->io_canceled = true;
+    if (req->ops->cancel_io) {
+        req->ops->cancel_io(req);
+    }
+    scsi_req_complete(req, status);
+    scsi_req_unref(req);
+}
+
+static int scsi_ua_precedence(SCSISense sense)
+{
+    if (sense.key != UNIT_ATTENTION) {
+        return INT_MAX;
+    }
+    if (sense.asc == 0x29 && sense.ascq == 0x04) {
+        /* DEVICE INTERNAL RESET goes with POWER ON OCCURRED */
+        return 1;
+    } else if (sense.asc == 0x3F && sense.ascq == 0x01) {
+        /* MICROCODE HAS BEEN CHANGED goes with SCSI BUS RESET OCCURRED */
+        return 2;
+    } else if (sense.asc == 0x29 && (sense.ascq == 0x05 || sense.ascq == 0x06)) {
+        /* These two go with "all others". */
+        ;
+    } else if (sense.asc == 0x29 && sense.ascq <= 0x07) {
+        /* POWER ON, RESET OR BUS DEVICE RESET OCCURRED = 0
+         * POWER ON OCCURRED = 1
+         * SCSI BUS RESET OCCURRED = 2
+         * BUS DEVICE RESET FUNCTION OCCURRED = 3
+         * I_T NEXUS LOSS OCCURRED = 7
+         */
+        return sense.ascq;
+    } else if (sense.asc == 0x2F && sense.ascq == 0x01) {
+        /* COMMANDS CLEARED BY POWER LOSS NOTIFICATION  */
+        return 8;
+    }
+    return (sense.asc << 8) | sense.ascq;
+}
+
+void scsi_device_set_ua(SCSIDevice *sdev, SCSISense sense)
+{
+    int prec1, prec2;
+    if (sense.key != UNIT_ATTENTION) {
+        return;
+    }
+    trace_scsi_device_set_ua(sdev->id, sdev->lun, sense.key,
+                             sense.asc, sense.ascq);
+
+    /*
+     * Override a pre-existing unit attention condition, except for a more
+     * important reset condition.
+    */
+    prec1 = scsi_ua_precedence(sdev->unit_attention);
+    prec2 = scsi_ua_precedence(sense);
+    if (prec2 < prec1) {
+        sdev->unit_attention = sense;
+    }
+}
+
+void scsi_device_purge_requests(SCSIDevice *sdev, SCSISense sense)
+{
+    SCSIRequest *req;
+
+    while (!QTAILQ_EMPTY(&sdev->requests)) {
+        req = QTAILQ_FIRST(&sdev->requests);
+        scsi_req_cancel(req);
+    }
+
+    scsi_device_set_ua(sdev, sense);
+}
+
+static char *scsibus_get_dev_path(DeviceState *dev)
+{
+    SCSIDevice *d = DO_UPCAST(SCSIDevice, qdev, dev);
+    DeviceState *hba = dev->parent_bus->parent;
+    char *id;
+    char *path;
+
+    id = qdev_get_dev_path(hba);
+    if (id) {
+        path = g_strdup_printf("%s/%d:%d:%d", id, d->channel, d->id, d->lun);
+    } else {
+        path = g_strdup_printf("%d:%d:%d", d->channel, d->id, d->lun);
+    }
+    g_free(id);
+    return path;
+}
+
+static char *scsibus_get_fw_dev_path(DeviceState *dev)
+{
+    SCSIDevice *d = SCSI_DEVICE(dev);
+    return g_strdup_printf("channel@%x/%s@%x,%x", d->channel,
+                           qdev_fw_name(dev), d->id, d->lun);
+}
+
+SCSIDevice *scsi_device_find(SCSIBus *bus, int channel, int id, int lun)
+{
+    BusChild *kid;
+    SCSIDevice *target_dev = NULL;
+
+    QTAILQ_FOREACH_REVERSE(kid, &bus->qbus.children, ChildrenHead, sibling) {
+        DeviceState *qdev = kid->child;
+        SCSIDevice *dev = SCSI_DEVICE(qdev);
+
+        if (dev->channel == channel && dev->id == id) {
+            if (dev->lun == lun) {
+                return dev;
+            }
+            target_dev = dev;
+        }
+    }
+    return target_dev;
+}
+
+/* SCSI request list.  For simplicity, pv points to the whole device */
+
+static void put_scsi_requests(QEMUFile *f, void *pv, size_t size)
+{
+    SCSIDevice *s = pv;
+    SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, s->qdev.parent_bus);
+    SCSIRequest *req;
+
+    QTAILQ_FOREACH(req, &s->requests, next) {
+        assert(!req->io_canceled);
+        assert(req->status == -1);
+        assert(req->enqueued);
+
+        qemu_put_sbyte(f, req->retry ? 1 : 2);
+        qemu_put_buffer(f, req->cmd.buf, sizeof(req->cmd.buf));
+        qemu_put_be32s(f, &req->tag);
+        qemu_put_be32s(f, &req->lun);
+        if (bus->info->save_request) {
+            bus->info->save_request(f, req);
+        }
+        if (req->ops->save_request) {
+            req->ops->save_request(f, req);
+        }
+    }
+    qemu_put_sbyte(f, 0);
+}
+
+static int get_scsi_requests(QEMUFile *f, void *pv, size_t size)
+{
+    SCSIDevice *s = pv;
+    SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, s->qdev.parent_bus);
+    int8_t sbyte;
+
+    while ((sbyte = qemu_get_sbyte(f)) > 0) {
+        uint8_t buf[SCSI_CMD_BUF_SIZE];
+        uint32_t tag;
+        uint32_t lun;
+        SCSIRequest *req;
+
+        qemu_get_buffer(f, buf, sizeof(buf));
+        qemu_get_be32s(f, &tag);
+        qemu_get_be32s(f, &lun);
+        req = scsi_req_new(s, tag, lun, buf, NULL);
+        req->retry = (sbyte == 1);
+        if (bus->info->load_request) {
+            req->hba_private = bus->info->load_request(f, req);
+        }
+        if (req->ops->load_request) {
+            req->ops->load_request(f, req);
+        }
+
+        /* Just restart it later.  */
+        scsi_req_enqueue_internal(req);
+
+        /* At this point, the request will be kept alive by the reference
+         * added by scsi_req_enqueue_internal, so we can release our reference.
+         * The HBA of course will add its own reference in the load_request
+         * callback if it needs to hold on the SCSIRequest.
+         */
+        scsi_req_unref(req);
+    }
+
+    return 0;
+}
+
+static int scsi_qdev_unplug(DeviceState *qdev)
+{
+    SCSIDevice *dev = SCSI_DEVICE(qdev);
+    SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
+
+    if (bus->info->hot_unplug) {
+        bus->info->hot_unplug(bus, dev);
+    }
+    return qdev_simple_unplug_cb(qdev);
+}
+
+static const VMStateInfo vmstate_info_scsi_requests = {
+    .name = "scsi-requests",
+    .get  = get_scsi_requests,
+    .put  = put_scsi_requests,
+};
+
+const VMStateDescription vmstate_scsi_device = {
+    .name = "SCSIDevice",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .minimum_version_id_old = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT8(unit_attention.key, SCSIDevice),
+        VMSTATE_UINT8(unit_attention.asc, SCSIDevice),
+        VMSTATE_UINT8(unit_attention.ascq, SCSIDevice),
+        VMSTATE_BOOL(sense_is_ua, SCSIDevice),
+        VMSTATE_UINT8_ARRAY(sense, SCSIDevice, SCSI_SENSE_BUF_SIZE),
+        VMSTATE_UINT32(sense_len, SCSIDevice),
+        {
+            .name         = "requests",
+            .version_id   = 0,
+            .field_exists = NULL,
+            .size         = 0,   /* ouch */
+            .info         = &vmstate_info_scsi_requests,
+            .flags        = VMS_SINGLE,
+            .offset       = 0,
+        },
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void scsi_device_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *k = DEVICE_CLASS(klass);
+    k->bus_type = TYPE_SCSI_BUS;
+    k->init     = scsi_qdev_init;
+    k->unplug   = scsi_qdev_unplug;
+    k->exit     = scsi_qdev_exit;
+    k->props    = scsi_props;
+}
+
+static const TypeInfo scsi_device_type_info = {
+    .name = TYPE_SCSI_DEVICE,
+    .parent = TYPE_DEVICE,
+    .instance_size = sizeof(SCSIDevice),
+    .abstract = true,
+    .class_size = sizeof(SCSIDeviceClass),
+    .class_init = scsi_device_class_init,
+};
+
+static void scsi_register_types(void)
+{
+    type_register_static(&scsi_bus_info);
+    type_register_static(&scsi_device_type_info);
+}
+
+type_init(scsi_register_types)