Archipelago » qemu

/*

 * USB Mass Storage Device emulation

 *

 * Copyright (c) 2006 CodeSourcery.

 * Written by Paul Brook

 *

 * This code is licensed under the LGPL.

 */

#include "qemu-common.h"

#include "qemu-option.h"

#include "qemu-config.h"

#include "usb.h"

#include "usb-desc.h"

#include "scsi.h"

#include "console.h"

#include "monitor.h"

#include "sysemu.h"

#include "blockdev.h"

//#define DEBUG_MSD

#ifdef DEBUG_MSD

#define DPRINTF(fmt, ...) \

do { printf("usb-msd: " fmt , ## __VA_ARGS__); } while (0)

#else

#define DPRINTF(fmt, ...) do {} while(0)

#endif

/* USB requests.  */

#define MassStorageReset  0xff

#define GetMaxLun         0xfe

enum USBMSDMode {

    USB_MSDM_CBW, /* Command Block.  */

    USB_MSDM_DATAOUT, /* Transfer data to device.  */

    USB_MSDM_DATAIN, /* Transfer data from device.  */

    USB_MSDM_CSW /* Command Status.  */

};

struct usb_msd_csw {

    uint32_t sig;

    uint32_t tag;

    uint32_t residue;

    uint8_t status;

};

typedef struct {

    USBDevice dev;

    enum USBMSDMode mode;

    uint32_t scsi_len;

    uint8_t *scsi_buf;

    uint32_t data_len;

    uint32_t residue;

    struct usb_msd_csw csw;

    SCSIRequest *req;

    SCSIBus bus;

    BlockConf conf;

    char *serial;

    SCSIDevice *scsi_dev;

    uint32_t removable;

    /* For async completion.  */

    USBPacket *packet;

} MSDState;

struct usb_msd_cbw {

    uint32_t sig;

    uint32_t tag;

    uint32_t data_len;

    uint8_t flags;

    uint8_t lun;

    uint8_t cmd_len;

    uint8_t cmd[16];

};

enum {

    STR_MANUFACTURER = 1,

    STR_PRODUCT,

    STR_SERIALNUMBER,

    STR_CONFIG_FULL,

    STR_CONFIG_HIGH,

};

static const USBDescStrings desc_strings = {

    [STR_MANUFACTURER] = "QEMU " QEMU_VERSION,

    [STR_PRODUCT]      = "QEMU USB HARDDRIVE",

    [STR_SERIALNUMBER] = "1",

    [STR_CONFIG_FULL]  = "Full speed config (usb 1.1)",

    [STR_CONFIG_HIGH]  = "High speed config (usb 2.0)",

};

static const USBDescIface desc_iface_full = {

    .bInterfaceNumber              = 0,

    .bNumEndpoints                 = 2,

    .bInterfaceClass               = USB_CLASS_MASS_STORAGE,

    .bInterfaceSubClass            = 0x06, /* SCSI */

    .bInterfaceProtocol            = 0x50, /* Bulk */

    .eps = (USBDescEndpoint[]) {

        {

            .bEndpointAddress      = USB_DIR_IN | 0x01,

            .bmAttributes          = USB_ENDPOINT_XFER_BULK,

            .wMaxPacketSize        = 64,

        },{

            .bEndpointAddress      = USB_DIR_OUT | 0x02,

            .bmAttributes          = USB_ENDPOINT_XFER_BULK,

            .wMaxPacketSize        = 64,

        },

    }

};

static const USBDescDevice desc_device_full = {

    .bcdUSB                        = 0x0200,

    .bMaxPacketSize0               = 8,

    .bNumConfigurations            = 1,

    .confs = (USBDescConfig[]) {

        {

            .bNumInterfaces        = 1,

            .bConfigurationValue   = 1,

            .iConfiguration        = STR_CONFIG_FULL,

            .bmAttributes          = 0xc0,

            .nif = 1,

            .ifs = &desc_iface_full,

        },

    },

};

static const USBDescIface desc_iface_high = {

    .bInterfaceNumber              = 0,

    .bNumEndpoints                 = 2,

    .bInterfaceClass               = USB_CLASS_MASS_STORAGE,

    .bInterfaceSubClass            = 0x06, /* SCSI */

    .bInterfaceProtocol            = 0x50, /* Bulk */

    .eps = (USBDescEndpoint[]) {

        {

            .bEndpointAddress      = USB_DIR_IN | 0x01,

            .bmAttributes          = USB_ENDPOINT_XFER_BULK,

            .wMaxPacketSize        = 512,

        },{

            .bEndpointAddress      = USB_DIR_OUT | 0x02,

            .bmAttributes          = USB_ENDPOINT_XFER_BULK,

            .wMaxPacketSize        = 512,

        },

    }

};

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         = 0x0001,

        .bcdDevice         = 0,

        .iManufacturer     = STR_MANUFACTURER,

        .iProduct          = STR_PRODUCT,

        .iSerialNumber     = STR_SERIALNUMBER,

    },

    .full = &desc_device_full,

    .high = &desc_device_high,

    .str  = desc_strings,

};

static void usb_msd_copy_data(MSDState *s, USBPacket *p)

{

    uint32_t len;

    len = p->iov.size - p->result;

    if (len > s->scsi_len)

        len = s->scsi_len;

    usb_packet_copy(p, s->scsi_buf, len);

    s->scsi_len -= len;

    s->scsi_buf += len;

    s->data_len -= len;

    if (s->scsi_len == 0 || s->data_len == 0) {

        scsi_req_continue(s->req);

    }

}

static void usb_msd_send_status(MSDState *s, USBPacket *p)

{

    int len;

    DPRINTF("Command status %d tag 0x%x, len %zd\n",

            s->csw.status, s->csw.tag, p->iov.size);

    assert(s->csw.sig == 0x53425355);

    len = MIN(sizeof(s->csw), p->iov.size);

    usb_packet_copy(p, &s->csw, len);

    memset(&s->csw, 0, sizeof(s->csw));

}

static void usb_msd_transfer_data(SCSIRequest *req, uint32_t len)

{

    MSDState *s = DO_UPCAST(MSDState, dev.qdev, req->bus->qbus.parent);

    USBPacket *p = s->packet;

    assert((s->mode == USB_MSDM_DATAOUT) == (req->cmd.mode == SCSI_XFER_TO_DEV));

    s->scsi_len = len;

    s->scsi_buf = scsi_req_get_buf(req);

    if (p) {

        usb_msd_copy_data(s, p);

        p = s->packet;

        if (p && p->result == p->iov.size) {

            /* Set s->packet to NULL before calling usb_packet_complete

               because another request may be issued before

               usb_packet_complete returns.  */

            DPRINTF("Packet complete %p\n", p);

            s->packet = NULL;

            usb_packet_complete(&s->dev, p);

        }

    }

}

static void usb_msd_command_complete(SCSIRequest *req, uint32_t status)

{

    MSDState *s = DO_UPCAST(MSDState, dev.qdev, req->bus->qbus.parent);

    USBPacket *p = s->packet;

    DPRINTF("Command complete %d tag 0x%x\n", status, req->tag);

    s->residue = s->data_len;

    s->csw.sig = cpu_to_le32(0x53425355);

    s->csw.tag = cpu_to_le32(req->tag);

    s->csw.residue = s->residue;

    s->csw.status = status != 0;

    if (s->packet) {

        if (s->data_len == 0 && s->mode == USB_MSDM_DATAOUT) {

            /* A deferred packet with no write data remaining must be

               the status read packet.  */

            usb_msd_send_status(s, p);

            s->mode = USB_MSDM_CBW;

        } else {

            if (s->data_len) {

                int len = (p->iov.size - p->result);

                usb_packet_skip(p, len);

                s->data_len -= len;

            }

            if (s->data_len == 0) {

                s->mode = USB_MSDM_CSW;

            }

        }

        s->packet = NULL;

        usb_packet_complete(&s->dev, p);

    } else if (s->data_len == 0) {

        s->mode = USB_MSDM_CSW;

    }

    scsi_req_unref(req);

    s->req = NULL;

}

static void usb_msd_request_cancelled(SCSIRequest *req)

{

    MSDState *s = DO_UPCAST(MSDState, dev.qdev, req->bus->qbus.parent);

    if (req == s->req) {

        scsi_req_unref(s->req);

        s->req = NULL;

        s->packet = NULL;

        s->scsi_len = 0;

    }

}

static void usb_msd_handle_reset(USBDevice *dev)

{

    MSDState *s = (MSDState *)dev;

    DPRINTF("Reset\n");

    if (s->req) {

        scsi_req_cancel(s->req);

    }

    assert(s->req == NULL);

    if (s->packet) {

        USBPacket *p = s->packet;

        s->packet = NULL;

        p->result = USB_RET_STALL;

        usb_packet_complete(dev, p);

    }

    s->mode = USB_MSDM_CBW;

}

static int usb_msd_handle_control(USBDevice *dev, USBPacket *p,

               int request, int value, int index, int length, uint8_t *data)

{

    MSDState *s = (MSDState *)dev;

    int ret;

    ret = usb_desc_handle_control(dev, p, request, value, index, length, data);

    if (ret >= 0) {

        return ret;

    }

    ret = 0;

    switch (request) {

    case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:

        ret = 0;

        break;

        /* Class specific requests.  */

    case ClassInterfaceOutRequest | MassStorageReset:

        /* Reset state ready for the next CBW.  */

        s->mode = USB_MSDM_CBW;

        ret = 0;

        break;

    case ClassInterfaceRequest | GetMaxLun:

        data[0] = 0;

        ret = 1;

        break;

    default:

        ret = USB_RET_STALL;

        break;

    }

    return ret;

}

static void usb_msd_cancel_io(USBDevice *dev, USBPacket *p)

{

    MSDState *s = DO_UPCAST(MSDState, dev, dev);

    if (s->req) {

        scsi_req_cancel(s->req);

    }

}

static int usb_msd_handle_data(USBDevice *dev, USBPacket *p)

{

    MSDState *s = (MSDState *)dev;

    uint32_t tag;

    int ret = 0;

    struct usb_msd_cbw cbw;

    uint8_t devep = p->devep;

    switch (p->pid) {

    case USB_TOKEN_OUT:

        if (devep != 2)

            goto fail;

        switch (s->mode) {

        case USB_MSDM_CBW:

            if (p->iov.size != 31) {

                fprintf(stderr, "usb-msd: Bad CBW size");

                goto fail;

            }

            usb_packet_copy(p, &cbw, 31);

            if (le32_to_cpu(cbw.sig) != 0x43425355) {

                fprintf(stderr, "usb-msd: Bad signature %08x\n",

                        le32_to_cpu(cbw.sig));

                goto fail;

            }

            DPRINTF("Command on LUN %d\n", cbw.lun);

            if (cbw.lun != 0) {

                fprintf(stderr, "usb-msd: Bad LUN %d\n", cbw.lun);

                goto fail;

            }

            tag = le32_to_cpu(cbw.tag);

            s->data_len = le32_to_cpu(cbw.data_len);

            if (s->data_len == 0) {

                s->mode = USB_MSDM_CSW;

            } else if (cbw.flags & 0x80) {

                s->mode = USB_MSDM_DATAIN;

            } else {

                s->mode = USB_MSDM_DATAOUT;

            }

            DPRINTF("Command tag 0x%x flags %08x len %d data %d\n",

                    tag, cbw.flags, cbw.cmd_len, s->data_len);

            s->residue = 0;

            s->scsi_len = 0;

            s->req = scsi_req_new(s->scsi_dev, tag, 0, cbw.cmd, NULL);

            scsi_req_enqueue(s->req);

            if (s->req && s->req->cmd.xfer != SCSI_XFER_NONE) {

                scsi_req_continue(s->req);

            }

            ret = p->result;

            break;

        case USB_MSDM_DATAOUT:

            DPRINTF("Data out %zd/%d\n", p->iov.size, s->data_len);

            if (p->iov.size > s->data_len) {

                goto fail;

            }

            if (s->scsi_len) {

                usb_msd_copy_data(s, p);

            }

            if (s->residue) {

                int len = p->iov.size - p->result;

                if (len) {

                    usb_packet_skip(p, len);

                    s->data_len -= len;

                    if (s->data_len == 0) {

                        s->mode = USB_MSDM_CSW;

                    }

                }

            }

            if (p->result < p->iov.size) {

                DPRINTF("Deferring packet %p\n", p);

                s->packet = p;

                ret = USB_RET_ASYNC;

            } else {

                ret = p->result;

            }

            break;

        default:

            DPRINTF("Unexpected write (len %zd)\n", p->iov.size);

            goto fail;

        }

        break;

    case USB_TOKEN_IN:

        if (devep != 1)

            goto fail;

        switch (s->mode) {

        case USB_MSDM_DATAOUT:

            if (s->data_len != 0 || p->iov.size < 13) {

                goto fail;

            }

            /* Waiting for SCSI write to complete.  */

            s->packet = p;

            ret = USB_RET_ASYNC;

            break;

        case USB_MSDM_CSW:

            if (p->iov.size < 13) {

                goto fail;

            }

            if (s->req) {

                /* still in flight */

                s->packet = p;

                ret = USB_RET_ASYNC;

            } else {

                usb_msd_send_status(s, p);

                s->mode = USB_MSDM_CBW;

                ret = 13;

            }

            break;

        case USB_MSDM_DATAIN:

            DPRINTF("Data in %zd/%d, scsi_len %d\n",

                    p->iov.size, s->data_len, s->scsi_len);

            if (s->scsi_len) {

                usb_msd_copy_data(s, p);

            }

            if (s->residue) {

                int len = p->iov.size - p->result;

                if (len) {

                    usb_packet_skip(p, len);

                    s->data_len -= len;

                    if (s->data_len == 0) {

                        s->mode = USB_MSDM_CSW;

                    }

                }

            }

            if (p->result < p->iov.size) {

                DPRINTF("Deferring packet %p\n", p);

                s->packet = p;

                ret = USB_RET_ASYNC;

            } else {

                ret = p->result;

            }

            break;

        default:

            DPRINTF("Unexpected read (len %zd)\n", p->iov.size);

            goto fail;

        }

        break;

    default:

        DPRINTF("Bad token\n");

    fail:

        ret = USB_RET_STALL;

        break;

    }

    return ret;

}

static void usb_msd_password_cb(void *opaque, int err)

{

    MSDState *s = opaque;

    if (!err)

        err = usb_device_attach(&s->dev);

    if (err)

        qdev_unplug(&s->dev.qdev);

}

static const struct SCSIBusInfo usb_msd_scsi_info = {

    .tcq = false,

    .max_target = 0,

    .max_lun = 0,

    .transfer_data = usb_msd_transfer_data,

    .complete = usb_msd_command_complete,

    .cancel = usb_msd_request_cancelled

};

static int usb_msd_initfn(USBDevice *dev)

{

    MSDState *s = DO_UPCAST(MSDState, dev, dev);

    BlockDriverState *bs = s->conf.bs;

    DriveInfo *dinfo;

    if (!bs) {

        error_report("drive property not set");

        return -1;

    }

    /*

     * Hack alert: this pretends to be a block device, but it's really

     * a SCSI bus that can serve only a single device, which it

     * creates automatically.  But first it needs to detach from its

     * blockdev, or else scsi_bus_legacy_add_drive() dies when it

     * attaches again.

     *

     * The hack is probably a bad idea.

     */

    bdrv_detach_dev(bs, &s->dev.qdev);

    s->conf.bs = NULL;

    if (!s->serial) {

        /* try to fall back to value set with legacy -drive serial=... */

        dinfo = drive_get_by_blockdev(bs);

        if (*dinfo->serial) {

            s->serial = strdup(dinfo->serial);

        }

    }

    if (s->serial) {

        usb_desc_set_string(dev, STR_SERIALNUMBER, s->serial);

    }

    usb_desc_init(dev);

    scsi_bus_new(&s->bus, &s->dev.qdev, &usb_msd_scsi_info);

    s->scsi_dev = scsi_bus_legacy_add_drive(&s->bus, bs, 0, !!s->removable,

                                            s->conf.bootindex);

    if (!s->scsi_dev) {

        return -1;

    }

    s->bus.qbus.allow_hotplug = 0;

    usb_msd_handle_reset(dev);

    if (bdrv_key_required(bs)) {

        if (cur_mon) {

            monitor_read_bdrv_key_start(cur_mon, bs, usb_msd_password_cb, s);

            s->dev.auto_attach = 0;

        } else {

            autostart = 0;

        }

    }

    return 0;

}

static USBDevice *usb_msd_init(const char *filename)

{

    static int nr=0;

    char id[8];

    QemuOpts *opts;

    DriveInfo *dinfo;

    USBDevice *dev;

    const char *p1;

    char fmt[32];

    /* parse -usbdevice disk: syntax into drive opts */

    snprintf(id, sizeof(id), "usb%d", nr++);

    opts = qemu_opts_create(qemu_find_opts("drive"), id, 0);

    p1 = strchr(filename, ':');

    if (p1++) {

        const char *p2;

        if (strstart(filename, "format=", &p2)) {

            int len = MIN(p1 - p2, sizeof(fmt));

            pstrcpy(fmt, len, p2);

            qemu_opt_set(opts, "format", fmt);

        } else if (*filename != ':') {

            printf("unrecognized USB mass-storage option %s\n", filename);

            return NULL;

        }

        filename = p1;

    }

    if (!*filename) {

        printf("block device specification needed\n");

        return NULL;

    }

    qemu_opt_set(opts, "file", filename);

    qemu_opt_set(opts, "if", "none");

    /* create host drive */

    dinfo = drive_init(opts, 0);

    if (!dinfo) {

        qemu_opts_del(opts);

        return NULL;

    }

    /* create guest device */

    dev = usb_create(NULL /* FIXME */, "usb-storage");

    if (!dev) {

        return NULL;

    }

    if (qdev_prop_set_drive(&dev->qdev, "drive", dinfo->bdrv) < 0) {

        qdev_free(&dev->qdev);

        return NULL;

    }

    if (qdev_init(&dev->qdev) < 0)

        return NULL;

    return dev;

}

static const VMStateDescription vmstate_usb_msd = {

    .name = "usb-storage",

    .unmigratable = 1, /* FIXME: handle transactions which are in flight */

    .version_id = 1,

    .minimum_version_id = 1,

    .fields = (VMStateField []) {

        VMSTATE_USB_DEVICE(dev, MSDState),

        VMSTATE_END_OF_LIST()

    }

};

static void usb_msd_class_initfn(ObjectClass *klass, void *data)

{

    USBDeviceClass *uc = USB_DEVICE_CLASS(klass);

    uc->init           = usb_msd_initfn;

    uc->product_desc   = "QEMU USB MSD";

    uc->usb_desc       = &desc;

    uc->handle_packet  = usb_generic_handle_packet;

    uc->cancel_packet  = usb_msd_cancel_io;

    uc->handle_attach  = usb_desc_attach;

    uc->handle_reset   = usb_msd_handle_reset;

    uc->handle_control = usb_msd_handle_control;

    uc->handle_data    = usb_msd_handle_data;

}

static struct DeviceInfo msd_info = {

    .name      = "usb-storage",

    .fw_name   = "storage",

    .size      = sizeof(MSDState),

    .vmsd      = &vmstate_usb_msd,

    .class_init= usb_msd_class_initfn,

    .props     = (Property[]) {

        DEFINE_BLOCK_PROPERTIES(MSDState, conf),

        DEFINE_PROP_STRING("serial", MSDState, serial),

        DEFINE_PROP_BIT("removable", MSDState, removable, 0, false),

        DEFINE_PROP_END_OF_LIST(),

    },

};

static void usb_msd_register_devices(void)

{

    usb_qdev_register(&msd_info, "disk", usb_msd_init);

}

device_init(usb_msd_register_devices)