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-rw-r--r--hw/usb/dev-uas.c779
1 files changed, 779 insertions, 0 deletions
diff --git a/hw/usb/dev-uas.c b/hw/usb/dev-uas.c
new file mode 100644
index 0000000000..9b02ff48fa
--- /dev/null
+++ b/hw/usb/dev-uas.c
@@ -0,0 +1,779 @@
+/*
+ * UAS (USB Attached SCSI) emulation
+ *
+ * Copyright Red Hat, Inc. 2012
+ *
+ * Author: Gerd Hoffmann <kraxel@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu-common.h"
+#include "qemu-option.h"
+#include "qemu-config.h"
+#include "trace.h"
+
+#include "hw/usb.h"
+#include "hw/usb/desc.h"
+#include "hw/scsi.h"
+#include "hw/scsi-defs.h"
+
+/* --------------------------------------------------------------------- */
+
+#define UAS_UI_COMMAND              0x01
+#define UAS_UI_SENSE                0x03
+#define UAS_UI_RESPONSE             0x04
+#define UAS_UI_TASK_MGMT            0x05
+#define UAS_UI_READ_READY           0x06
+#define UAS_UI_WRITE_READY          0x07
+
+#define UAS_RC_TMF_COMPLETE         0x00
+#define UAS_RC_INVALID_INFO_UNIT    0x02
+#define UAS_RC_TMF_NOT_SUPPORTED    0x04
+#define UAS_RC_TMF_FAILED           0x05
+#define UAS_RC_TMF_SUCCEEDED        0x08
+#define UAS_RC_INCORRECT_LUN        0x09
+#define UAS_RC_OVERLAPPED_TAG       0x0a
+
+#define UAS_TMF_ABORT_TASK          0x01
+#define UAS_TMF_ABORT_TASK_SET      0x02
+#define UAS_TMF_CLEAR_TASK_SET      0x04
+#define UAS_TMF_LOGICAL_UNIT_RESET  0x08
+#define UAS_TMF_I_T_NEXUS_RESET     0x10
+#define UAS_TMF_CLEAR_ACA           0x40
+#define UAS_TMF_QUERY_TASK          0x80
+#define UAS_TMF_QUERY_TASK_SET      0x81
+#define UAS_TMF_QUERY_ASYNC_EVENT   0x82
+
+#define UAS_PIPE_ID_COMMAND         0x01
+#define UAS_PIPE_ID_STATUS          0x02
+#define UAS_PIPE_ID_DATA_IN         0x03
+#define UAS_PIPE_ID_DATA_OUT        0x04
+
+typedef struct {
+    uint8_t    id;
+    uint8_t    reserved;
+    uint16_t   tag;
+} QEMU_PACKED  uas_ui_header;
+
+typedef struct {
+    uint8_t    prio_taskattr;   /* 6:3 priority, 2:0 task attribute   */
+    uint8_t    reserved_1;
+    uint8_t    add_cdb_length;  /* 7:2 additional adb length (dwords) */
+    uint8_t    reserved_2;
+    uint64_t   lun;
+    uint8_t    cdb[16];
+    uint8_t    add_cdb[];
+} QEMU_PACKED  uas_ui_command;
+
+typedef struct {
+    uint16_t   status_qualifier;
+    uint8_t    status;
+    uint8_t    reserved[7];
+    uint16_t   sense_length;
+    uint8_t    sense_data[18];
+} QEMU_PACKED  uas_ui_sense;
+
+typedef struct {
+    uint16_t   add_response_info;
+    uint8_t    response_code;
+} QEMU_PACKED  uas_ui_response;
+
+typedef struct {
+    uint8_t    function;
+    uint8_t    reserved;
+    uint16_t   task_tag;
+    uint64_t   lun;
+} QEMU_PACKED  uas_ui_task_mgmt;
+
+typedef struct {
+    uas_ui_header  hdr;
+    union {
+        uas_ui_command   command;
+        uas_ui_sense     sense;
+        uas_ui_task_mgmt task;
+        uas_ui_response  response;
+    };
+} QEMU_PACKED  uas_ui;
+
+/* --------------------------------------------------------------------- */
+
+typedef struct UASDevice UASDevice;
+typedef struct UASRequest UASRequest;
+typedef struct UASStatus UASStatus;
+
+struct UASDevice {
+    USBDevice                 dev;
+    SCSIBus                   bus;
+    UASRequest                *datain;
+    UASRequest                *dataout;
+    USBPacket                 *status;
+    QEMUBH                    *status_bh;
+    QTAILQ_HEAD(, UASStatus)  results;
+    QTAILQ_HEAD(, UASRequest) requests;
+};
+
+struct UASRequest {
+    uint16_t     tag;
+    uint64_t     lun;
+    UASDevice    *uas;
+    SCSIDevice   *dev;
+    SCSIRequest  *req;
+    USBPacket    *data;
+    bool         data_async;
+    bool         active;
+    bool         complete;
+    uint32_t     buf_off;
+    uint32_t     buf_size;
+    uint32_t     data_off;
+    uint32_t     data_size;
+    QTAILQ_ENTRY(UASRequest)  next;
+};
+
+struct UASStatus {
+    uas_ui                    status;
+    uint32_t                  length;
+    QTAILQ_ENTRY(UASStatus)   next;
+};
+
+/* --------------------------------------------------------------------- */
+
+enum {
+    STR_MANUFACTURER = 1,
+    STR_PRODUCT,
+    STR_SERIALNUMBER,
+    STR_CONFIG_HIGH,
+};
+
+static const USBDescStrings desc_strings = {
+    [STR_MANUFACTURER] = "QEMU",
+    [STR_PRODUCT]      = "USB Attached SCSI HBA",
+    [STR_SERIALNUMBER] = "27842",
+    [STR_CONFIG_HIGH]  = "High speed config (usb 2.0)",
+};
+
+static const USBDescIface desc_iface_high = {
+    .bInterfaceNumber              = 0,
+    .bNumEndpoints                 = 4,
+    .bInterfaceClass               = USB_CLASS_MASS_STORAGE,
+    .bInterfaceSubClass            = 0x06, /* SCSI */
+    .bInterfaceProtocol            = 0x62, /* UAS  */
+    .eps = (USBDescEndpoint[]) {
+        {
+            .bEndpointAddress      = USB_DIR_OUT | UAS_PIPE_ID_COMMAND,
+            .bmAttributes          = USB_ENDPOINT_XFER_BULK,
+            .wMaxPacketSize        = 512,
+            .extra = (uint8_t[]) {
+                0x04,  /*  u8  bLength */
+                0x24,  /*  u8  bDescriptorType */
+                UAS_PIPE_ID_COMMAND,
+                0x00,  /*  u8  bReserved */
+            },
+        },{
+            .bEndpointAddress      = USB_DIR_IN | UAS_PIPE_ID_STATUS,
+            .bmAttributes          = USB_ENDPOINT_XFER_BULK,
+            .wMaxPacketSize        = 512,
+            .extra = (uint8_t[]) {
+                0x04,  /*  u8  bLength */
+                0x24,  /*  u8  bDescriptorType */
+                UAS_PIPE_ID_STATUS,
+                0x00,  /*  u8  bReserved */
+            },
+        },{
+            .bEndpointAddress      = USB_DIR_IN | UAS_PIPE_ID_DATA_IN,
+            .bmAttributes          = USB_ENDPOINT_XFER_BULK,
+            .wMaxPacketSize        = 512,
+            .extra = (uint8_t[]) {
+                0x04,  /*  u8  bLength */
+                0x24,  /*  u8  bDescriptorType */
+                UAS_PIPE_ID_DATA_IN,
+                0x00,  /*  u8  bReserved */
+            },
+        },{
+            .bEndpointAddress      = USB_DIR_OUT | UAS_PIPE_ID_DATA_OUT,
+            .bmAttributes          = USB_ENDPOINT_XFER_BULK,
+            .wMaxPacketSize        = 512,
+            .extra = (uint8_t[]) {
+                0x04,  /*  u8  bLength */
+                0x24,  /*  u8  bDescriptorType */
+                UAS_PIPE_ID_DATA_OUT,
+                0x00,  /*  u8  bReserved */
+            },
+        },
+    }
+};
+
+static const USBDescDevice desc_device_high = {
+    .bcdUSB                        = 0x0200,
+    .bMaxPacketSize0               = 64,
+    .bNumConfigurations            = 1,
+    .confs = (USBDescConfig[]) {
+        {
+            .bNumInterfaces        = 1,
+            .bConfigurationValue   = 1,
+            .iConfiguration        = STR_CONFIG_HIGH,
+            .bmAttributes          = 0xc0,
+            .nif = 1,
+            .ifs = &desc_iface_high,
+        },
+    },
+};
+
+static const USBDesc desc = {
+    .id = {
+        .idVendor          = 0x46f4, /* CRC16() of "QEMU" */
+        .idProduct         = 0x0002,
+        .bcdDevice         = 0,
+        .iManufacturer     = STR_MANUFACTURER,
+        .iProduct          = STR_PRODUCT,
+        .iSerialNumber     = STR_SERIALNUMBER,
+    },
+    .high = &desc_device_high,
+    .str  = desc_strings,
+};
+
+/* --------------------------------------------------------------------- */
+
+static UASStatus *usb_uas_alloc_status(uint8_t id, uint16_t tag)
+{
+    UASStatus *st = g_new0(UASStatus, 1);
+
+    st->status.hdr.id = id;
+    st->status.hdr.tag = cpu_to_be16(tag);
+    st->length = sizeof(uas_ui_header);
+    return st;
+}
+
+static void usb_uas_send_status_bh(void *opaque)
+{
+    UASDevice *uas = opaque;
+    UASStatus *st = QTAILQ_FIRST(&uas->results);
+    USBPacket *p = uas->status;
+
+    assert(p != NULL);
+    assert(st != NULL);
+
+    uas->status = NULL;
+    usb_packet_copy(p, &st->status, st->length);
+    p->result = st->length;
+    QTAILQ_REMOVE(&uas->results, st, next);
+    g_free(st);
+
+    usb_packet_complete(&uas->dev, p);
+}
+
+static void usb_uas_queue_status(UASDevice *uas, UASStatus *st, int length)
+{
+    st->length += length;
+    QTAILQ_INSERT_TAIL(&uas->results, st, next);
+    if (uas->status) {
+        /*
+         * Just schedule bh make sure any in-flight data transaction
+         * is finished before completing (sending) the status packet.
+         */
+        qemu_bh_schedule(uas->status_bh);
+    } else {
+        USBEndpoint *ep = usb_ep_get(&uas->dev, USB_TOKEN_IN,
+                                     UAS_PIPE_ID_STATUS);
+        usb_wakeup(ep);
+    }
+}
+
+static void usb_uas_queue_response(UASDevice *uas, uint16_t tag,
+                                   uint8_t code, uint16_t add_info)
+{
+    UASStatus *st = usb_uas_alloc_status(UAS_UI_RESPONSE, tag);
+
+    trace_usb_uas_response(uas->dev.addr, tag, code);
+    st->status.response.response_code = code;
+    st->status.response.add_response_info = cpu_to_be16(add_info);
+    usb_uas_queue_status(uas, st, sizeof(uas_ui_response));
+}
+
+static void usb_uas_queue_sense(UASRequest *req, uint8_t status)
+{
+    UASStatus *st = usb_uas_alloc_status(UAS_UI_SENSE, req->tag);
+    int len, slen = 0;
+
+    trace_usb_uas_sense(req->uas->dev.addr, req->tag, status);
+    st->status.sense.status = status;
+    st->status.sense.status_qualifier = cpu_to_be16(0);
+    if (status != GOOD) {
+        slen = scsi_req_get_sense(req->req, st->status.sense.sense_data,
+                                  sizeof(st->status.sense.sense_data));
+        st->status.sense.sense_length = cpu_to_be16(slen);
+    }
+    len = sizeof(uas_ui_sense) - sizeof(st->status.sense.sense_data) + slen;
+    usb_uas_queue_status(req->uas, st, len);
+}
+
+static void usb_uas_queue_read_ready(UASRequest *req)
+{
+    UASStatus *st = usb_uas_alloc_status(UAS_UI_READ_READY, req->tag);
+
+    trace_usb_uas_read_ready(req->uas->dev.addr, req->tag);
+    usb_uas_queue_status(req->uas, st, 0);
+}
+
+static void usb_uas_queue_write_ready(UASRequest *req)
+{
+    UASStatus *st = usb_uas_alloc_status(UAS_UI_WRITE_READY, req->tag);
+
+    trace_usb_uas_write_ready(req->uas->dev.addr, req->tag);
+    usb_uas_queue_status(req->uas, st, 0);
+}
+
+/* --------------------------------------------------------------------- */
+
+static int usb_uas_get_lun(uint64_t lun64)
+{
+    return (lun64 >> 48) & 0xff;
+}
+
+static SCSIDevice *usb_uas_get_dev(UASDevice *uas, uint64_t lun64)
+{
+    if ((lun64 >> 56) != 0x00) {
+        return NULL;
+    }
+    return scsi_device_find(&uas->bus, 0, 0, usb_uas_get_lun(lun64));
+}
+
+static void usb_uas_complete_data_packet(UASRequest *req)
+{
+    USBPacket *p;
+
+    if (!req->data_async) {
+        return;
+    }
+    p = req->data;
+    req->data = NULL;
+    req->data_async = false;
+    usb_packet_complete(&req->uas->dev, p);
+}
+
+static void usb_uas_copy_data(UASRequest *req)
+{
+    uint32_t length;
+
+    length = MIN(req->buf_size - req->buf_off,
+                 req->data->iov.size - req->data->result);
+    trace_usb_uas_xfer_data(req->uas->dev.addr, req->tag, length,
+                            req->data->result, req->data->iov.size,
+                            req->buf_off, req->buf_size);
+    usb_packet_copy(req->data, scsi_req_get_buf(req->req) + req->buf_off,
+                    length);
+    req->buf_off += length;
+    req->data_off += length;
+
+    if (req->data->result == req->data->iov.size) {
+        usb_uas_complete_data_packet(req);
+    }
+    if (req->buf_size && req->buf_off == req->buf_size) {
+        req->buf_off = 0;
+        req->buf_size = 0;
+        scsi_req_continue(req->req);
+    }
+}
+
+static void usb_uas_start_next_transfer(UASDevice *uas)
+{
+    UASRequest *req;
+
+    QTAILQ_FOREACH(req, &uas->requests, next) {
+        if (req->active || req->complete) {
+            continue;
+        }
+        if (req->req->cmd.mode == SCSI_XFER_FROM_DEV && uas->datain == NULL) {
+            uas->datain = req;
+            usb_uas_queue_read_ready(req);
+            req->active = true;
+            return;
+        }
+        if (req->req->cmd.mode == SCSI_XFER_TO_DEV && uas->dataout == NULL) {
+            uas->dataout = req;
+            usb_uas_queue_write_ready(req);
+            req->active = true;
+            return;
+        }
+    }
+}
+
+static UASRequest *usb_uas_alloc_request(UASDevice *uas, uas_ui *ui)
+{
+    UASRequest *req;
+
+    req = g_new0(UASRequest, 1);
+    req->uas = uas;
+    req->tag = be16_to_cpu(ui->hdr.tag);
+    req->lun = be64_to_cpu(ui->command.lun);
+    req->dev = usb_uas_get_dev(req->uas, req->lun);
+    return req;
+}
+
+static void usb_uas_scsi_free_request(SCSIBus *bus, void *priv)
+{
+    UASRequest *req = priv;
+    UASDevice *uas = req->uas;
+
+    if (req == uas->datain) {
+        uas->datain = NULL;
+    }
+    if (req == uas->dataout) {
+        uas->dataout = NULL;
+    }
+    QTAILQ_REMOVE(&uas->requests, req, next);
+    g_free(req);
+}
+
+static UASRequest *usb_uas_find_request(UASDevice *uas, uint16_t tag)
+{
+    UASRequest *req;
+
+    QTAILQ_FOREACH(req, &uas->requests, next) {
+        if (req->tag == tag) {
+            return req;
+        }
+    }
+    return NULL;
+}
+
+static void usb_uas_scsi_transfer_data(SCSIRequest *r, uint32_t len)
+{
+    UASRequest *req = r->hba_private;
+
+    trace_usb_uas_scsi_data(req->uas->dev.addr, req->tag, len);
+    req->buf_off = 0;
+    req->buf_size = len;
+    if (req->data) {
+        usb_uas_copy_data(req);
+    } else {
+        usb_uas_start_next_transfer(req->uas);
+    }
+}
+
+static void usb_uas_scsi_command_complete(SCSIRequest *r,
+                                          uint32_t status, size_t resid)
+{
+    UASRequest *req = r->hba_private;
+    UASDevice *uas = req->uas;
+
+    trace_usb_uas_scsi_complete(req->uas->dev.addr, req->tag, status, resid);
+    req->complete = true;
+    if (req->data) {
+        usb_uas_complete_data_packet(req);
+    }
+    usb_uas_queue_sense(req, status);
+    scsi_req_unref(req->req);
+    usb_uas_start_next_transfer(uas);
+}
+
+static void usb_uas_scsi_request_cancelled(SCSIRequest *r)
+{
+    UASRequest *req = r->hba_private;
+
+    /* FIXME: queue notification to status pipe? */
+    scsi_req_unref(req->req);
+}
+
+static const struct SCSIBusInfo usb_uas_scsi_info = {
+    .tcq = true,
+    .max_target = 0,
+    .max_lun = 255,
+
+    .transfer_data = usb_uas_scsi_transfer_data,
+    .complete = usb_uas_scsi_command_complete,
+    .cancel = usb_uas_scsi_request_cancelled,
+    .free_request = usb_uas_scsi_free_request,
+};
+
+/* --------------------------------------------------------------------- */
+
+static void usb_uas_handle_reset(USBDevice *dev)
+{
+    UASDevice *uas = DO_UPCAST(UASDevice, dev, dev);
+    UASRequest *req, *nreq;
+    UASStatus *st, *nst;
+
+    trace_usb_uas_reset(dev->addr);
+    QTAILQ_FOREACH_SAFE(req, &uas->requests, next, nreq) {
+        scsi_req_cancel(req->req);
+    }
+    QTAILQ_FOREACH_SAFE(st, &uas->results, next, nst) {
+        QTAILQ_REMOVE(&uas->results, st, next);
+        g_free(st);
+    }
+}
+
+static int usb_uas_handle_control(USBDevice *dev, USBPacket *p,
+               int request, int value, int index, int length, uint8_t *data)
+{
+    int ret;
+
+    ret = usb_desc_handle_control(dev, p, request, value, index, length, data);
+    if (ret >= 0) {
+        return ret;
+    }
+    fprintf(stderr, "%s: unhandled control request\n", __func__);
+    return USB_RET_STALL;
+}
+
+static void usb_uas_cancel_io(USBDevice *dev, USBPacket *p)
+{
+    UASDevice *uas = DO_UPCAST(UASDevice, dev, dev);
+    UASRequest *req, *nreq;
+
+    if (uas->status == p) {
+        uas->status = NULL;
+        qemu_bh_cancel(uas->status_bh);
+        return;
+    }
+    QTAILQ_FOREACH_SAFE(req, &uas->requests, next, nreq) {
+        if (req->data == p) {
+            req->data = NULL;
+            return;
+        }
+    }
+    assert(!"canceled usb packet not found");
+}
+
+static void usb_uas_command(UASDevice *uas, uas_ui *ui)
+{
+    UASRequest *req;
+    uint32_t len;
+
+    req = usb_uas_find_request(uas, be16_to_cpu(ui->hdr.tag));
+    if (req) {
+        goto overlapped_tag;
+    }
+    req = usb_uas_alloc_request(uas, ui);
+    if (req->dev == NULL) {
+        goto bad_target;
+    }
+
+    trace_usb_uas_command(uas->dev.addr, req->tag,
+                          usb_uas_get_lun(req->lun),
+                          req->lun >> 32, req->lun & 0xffffffff);
+    QTAILQ_INSERT_TAIL(&uas->requests, req, next);
+    req->req = scsi_req_new(req->dev, req->tag,
+                            usb_uas_get_lun(req->lun),
+                            ui->command.cdb, req);
+    len = scsi_req_enqueue(req->req);
+    if (len) {
+        req->data_size = len;
+        scsi_req_continue(req->req);
+    }
+    return;
+
+overlapped_tag:
+    usb_uas_queue_response(uas, req->tag, UAS_RC_OVERLAPPED_TAG, 0);
+    return;
+
+bad_target:
+    /*
+     * FIXME: Seems to upset linux, is this wrong?
+     * NOTE: Happens only with no scsi devices at the bus, not sure
+     *       this is a valid UAS setup in the first place.
+     */
+    usb_uas_queue_response(uas, req->tag, UAS_RC_INVALID_INFO_UNIT, 0);
+    g_free(req);
+    return;
+}
+
+static void usb_uas_task(UASDevice *uas, uas_ui *ui)
+{
+    uint16_t tag = be16_to_cpu(ui->hdr.tag);
+    uint64_t lun64 = be64_to_cpu(ui->task.lun);
+    SCSIDevice *dev = usb_uas_get_dev(uas, lun64);
+    int lun = usb_uas_get_lun(lun64);
+    UASRequest *req;
+    uint16_t task_tag;
+
+    req = usb_uas_find_request(uas, be16_to_cpu(ui->hdr.tag));
+    if (req) {
+        goto overlapped_tag;
+    }
+
+    switch (ui->task.function) {
+    case UAS_TMF_ABORT_TASK:
+        task_tag = be16_to_cpu(ui->task.task_tag);
+        trace_usb_uas_tmf_abort_task(uas->dev.addr, tag, task_tag);
+        if (dev == NULL) {
+            goto bad_target;
+        }
+        if (dev->lun != lun) {
+            goto incorrect_lun;
+        }
+        req = usb_uas_find_request(uas, task_tag);
+        if (req && req->dev == dev) {
+            scsi_req_cancel(req->req);
+        }
+        usb_uas_queue_response(uas, tag, UAS_RC_TMF_COMPLETE, 0);
+        break;
+
+    case UAS_TMF_LOGICAL_UNIT_RESET:
+        trace_usb_uas_tmf_logical_unit_reset(uas->dev.addr, tag, lun);
+        if (dev == NULL) {
+            goto bad_target;
+        }
+        if (dev->lun != lun) {
+            goto incorrect_lun;
+        }
+        qdev_reset_all(&dev->qdev);
+        usb_uas_queue_response(uas, tag, UAS_RC_TMF_COMPLETE, 0);
+        break;
+
+    default:
+        trace_usb_uas_tmf_unsupported(uas->dev.addr, tag, ui->task.function);
+        usb_uas_queue_response(uas, tag, UAS_RC_TMF_NOT_SUPPORTED, 0);
+        break;
+    }
+    return;
+
+overlapped_tag:
+    usb_uas_queue_response(uas, req->tag, UAS_RC_OVERLAPPED_TAG, 0);
+    return;
+
+bad_target:
+    /* FIXME: correct?  [see long comment in usb_uas_command()] */
+    usb_uas_queue_response(uas, tag, UAS_RC_INVALID_INFO_UNIT, 0);
+    return;
+
+incorrect_lun:
+    usb_uas_queue_response(uas, tag, UAS_RC_INCORRECT_LUN, 0);
+    return;
+}
+
+static int usb_uas_handle_data(USBDevice *dev, USBPacket *p)
+{
+    UASDevice *uas = DO_UPCAST(UASDevice, dev, dev);
+    uas_ui ui;
+    UASStatus *st;
+    UASRequest *req;
+    int length, ret = 0;
+
+    switch (p->ep->nr) {
+    case UAS_PIPE_ID_COMMAND:
+        length = MIN(sizeof(ui), p->iov.size);
+        usb_packet_copy(p, &ui, length);
+        switch (ui.hdr.id) {
+        case UAS_UI_COMMAND:
+            usb_uas_command(uas, &ui);
+            ret = length;
+            break;
+        case UAS_UI_TASK_MGMT:
+            usb_uas_task(uas, &ui);
+            ret = length;
+            break;
+        default:
+            fprintf(stderr, "%s: unknown command ui: id 0x%x\n",
+                    __func__, ui.hdr.id);
+            ret = USB_RET_STALL;
+            break;
+        }
+        break;
+    case UAS_PIPE_ID_STATUS:
+        st = QTAILQ_FIRST(&uas->results);
+        if (st == NULL) {
+            assert(uas->status == NULL);
+            uas->status = p;
+            ret = USB_RET_ASYNC;
+            break;
+        }
+        usb_packet_copy(p, &st->status, st->length);
+        ret = st->length;
+        QTAILQ_REMOVE(&uas->results, st, next);
+        g_free(st);
+        break;
+    case UAS_PIPE_ID_DATA_IN:
+    case UAS_PIPE_ID_DATA_OUT:
+        req = (p->ep->nr == UAS_PIPE_ID_DATA_IN) ? uas->datain : uas->dataout;
+        if (req == NULL) {
+            fprintf(stderr, "%s: no inflight request\n", __func__);
+            ret = USB_RET_STALL;
+            break;
+        }
+        scsi_req_ref(req->req);
+        req->data = p;
+        usb_uas_copy_data(req);
+        if (p->result == p->iov.size || req->complete) {
+            req->data = NULL;
+            ret = p->result;
+        } else {
+            req->data_async = true;
+            ret = USB_RET_ASYNC;
+        }
+        scsi_req_unref(req->req);
+        usb_uas_start_next_transfer(uas);
+        break;
+    default:
+        fprintf(stderr, "%s: invalid endpoint %d\n", __func__, p->ep->nr);
+        ret = USB_RET_STALL;
+        break;
+    }
+    return ret;
+}
+
+static void usb_uas_handle_destroy(USBDevice *dev)
+{
+    UASDevice *uas = DO_UPCAST(UASDevice, dev, dev);
+
+    qemu_bh_delete(uas->status_bh);
+}
+
+static int usb_uas_init(USBDevice *dev)
+{
+    UASDevice *uas = DO_UPCAST(UASDevice, dev, dev);
+
+    usb_desc_create_serial(dev);
+    usb_desc_init(dev);
+
+    QTAILQ_INIT(&uas->results);
+    QTAILQ_INIT(&uas->requests);
+    uas->status_bh = qemu_bh_new(usb_uas_send_status_bh, uas);
+
+    scsi_bus_new(&uas->bus, &uas->dev.qdev, &usb_uas_scsi_info);
+
+    return 0;
+}
+
+static const VMStateDescription vmstate_usb_uas = {
+    .name = "usb-uas",
+    .unmigratable = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_USB_DEVICE(dev, UASDevice),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void usb_uas_class_initfn(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    USBDeviceClass *uc = USB_DEVICE_CLASS(klass);
+
+    uc->init           = usb_uas_init;
+    uc->product_desc   = desc_strings[STR_PRODUCT];
+    uc->usb_desc       = &desc;
+    uc->cancel_packet  = usb_uas_cancel_io;
+    uc->handle_attach  = usb_desc_attach;
+    uc->handle_reset   = usb_uas_handle_reset;
+    uc->handle_control = usb_uas_handle_control;
+    uc->handle_data    = usb_uas_handle_data;
+    uc->handle_destroy = usb_uas_handle_destroy;
+    dc->fw_name = "storage";
+    dc->vmsd = &vmstate_usb_uas;
+}
+
+static TypeInfo uas_info = {
+    .name          = "usb-uas",
+    .parent        = TYPE_USB_DEVICE,
+    .instance_size = sizeof(UASDevice),
+    .class_init    = usb_uas_class_initfn,
+};
+
+static void usb_uas_register_types(void)
+{
+    type_register_static(&uas_info);
+}
+
+type_init(usb_uas_register_types)