Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

1 files changed, 1978 insertions, 0 deletions

diff --git a/hw/usb/host-libusb.c b/hw/usb/host-libusb.c
new file mode 100644
index 000000000..d0d46dd0a
--- /dev/null
+++ b/hw/usb/host-libusb.c
@@ -0,0 +1,1978 @@
+/*
+ * Linux host USB redirector
+ *
+ * Copyright (c) 2005 Fabrice Bellard
+ *
+ * Copyright (c) 2008 Max Krasnyansky
+ *      Support for host device auto connect & disconnect
+ *      Major rewrite to support fully async operation
+ *
+ * Copyright 2008 TJ <linux@tjworld.net>
+ *      Added flexible support for /dev/bus/usb /sys/bus/usb/devices in addition
+ *      to the legacy /proc/bus/usb USB device discovery and handling
+ *
+ * (c) 2012 Gerd Hoffmann <kraxel@redhat.com>
+ *      Completely rewritten to use libusb instead of usbfs ioctls.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu/osdep.h"
+#include "qom/object.h"
+#ifndef CONFIG_WIN32
+#include <poll.h>
+#endif
+#include <libusb.h>
+
+#ifdef CONFIG_LINUX
+#include <sys/ioctl.h>
+#include <linux/usbdevice_fs.h>
+#endif
+
+#include "qapi/error.h"
+#include "migration/vmstate.h"
+#include "monitor/monitor.h"
+#include "qemu/error-report.h"
+#include "qemu/main-loop.h"
+#include "qemu/module.h"
+#include "sysemu/runstate.h"
+#include "sysemu/sysemu.h"
+#include "trace.h"
+
+#include "hw/qdev-properties.h"
+#include "hw/usb.h"
+
+/* ------------------------------------------------------------------------ */
+
+#define TYPE_USB_HOST_DEVICE "usb-host"
+OBJECT_DECLARE_SIMPLE_TYPE(USBHostDevice, USB_HOST_DEVICE)
+
+typedef struct USBHostRequest USBHostRequest;
+typedef struct USBHostIsoXfer USBHostIsoXfer;
+typedef struct USBHostIsoRing USBHostIsoRing;
+
+struct USBAutoFilter {
+    uint32_t bus_num;
+    uint32_t addr;
+    char     *port;
+    uint32_t vendor_id;
+    uint32_t product_id;
+};
+
+enum USBHostDeviceOptions {
+    USB_HOST_OPT_PIPELINE,
+};
+
+struct USBHostDevice {
+    USBDevice parent_obj;
+
+    /* properties */
+    struct USBAutoFilter             match;
+    char                             *hostdevice;
+    int32_t                          bootindex;
+    uint32_t                         iso_urb_count;
+    uint32_t                         iso_urb_frames;
+    uint32_t                         options;
+    uint32_t                         loglevel;
+    bool                             needs_autoscan;
+    bool                             allow_one_guest_reset;
+    bool                             allow_all_guest_resets;
+    bool                             suppress_remote_wake;
+
+    /* state */
+    QTAILQ_ENTRY(USBHostDevice)      next;
+    int                              seen, errcount;
+    int                              bus_num;
+    int                              addr;
+    char                             port[16];
+
+    int                              hostfd;
+    libusb_device                    *dev;
+    libusb_device_handle             *dh;
+    struct libusb_device_descriptor  ddesc;
+
+    struct {
+        bool                         detached;
+        bool                         claimed;
+    } ifs[USB_MAX_INTERFACES];
+
+    /* callbacks & friends */
+    QEMUBH                           *bh_nodev;
+    QEMUBH                           *bh_postld;
+    bool                             bh_postld_pending;
+    Notifier                         exit;
+
+    /* request queues */
+    QTAILQ_HEAD(, USBHostRequest)    requests;
+    QTAILQ_HEAD(, USBHostIsoRing)    isorings;
+};
+
+struct USBHostRequest {
+    USBHostDevice                    *host;
+    USBPacket                        *p;
+    bool                             in;
+    struct libusb_transfer           *xfer;
+    unsigned char                    *buffer;
+    unsigned char                    *cbuf;
+    unsigned int                     clen;
+    bool                             usb3ep0quirk;
+    QTAILQ_ENTRY(USBHostRequest)     next;
+};
+
+struct USBHostIsoXfer {
+    USBHostIsoRing                   *ring;
+    struct libusb_transfer           *xfer;
+    bool                             copy_complete;
+    unsigned int                     packet;
+    QTAILQ_ENTRY(USBHostIsoXfer)     next;
+};
+
+struct USBHostIsoRing {
+    USBHostDevice                    *host;
+    USBEndpoint                      *ep;
+    QTAILQ_HEAD(, USBHostIsoXfer)    unused;
+    QTAILQ_HEAD(, USBHostIsoXfer)    inflight;
+    QTAILQ_HEAD(, USBHostIsoXfer)    copy;
+    QTAILQ_ENTRY(USBHostIsoRing)     next;
+};
+
+static QTAILQ_HEAD(, USBHostDevice) hostdevs =
+    QTAILQ_HEAD_INITIALIZER(hostdevs);
+
+static void usb_host_auto_check(void *unused);
+static void usb_host_release_interfaces(USBHostDevice *s);
+static void usb_host_nodev(USBHostDevice *s);
+static void usb_host_detach_kernel(USBHostDevice *s);
+static void usb_host_attach_kernel(USBHostDevice *s);
+
+/* ------------------------------------------------------------------------ */
+
+#ifndef LIBUSB_LOG_LEVEL_WARNING /* older libusb didn't define these */
+#define LIBUSB_LOG_LEVEL_WARNING 2
+#endif
+
+/* ------------------------------------------------------------------------ */
+
+#define CONTROL_TIMEOUT  10000        /* 10 sec    */
+#define BULK_TIMEOUT         0        /* unlimited */
+#define INTR_TIMEOUT         0        /* unlimited */
+
+#ifndef LIBUSB_API_VERSION
+# define LIBUSB_API_VERSION LIBUSBX_API_VERSION
+#endif
+#if LIBUSB_API_VERSION >= 0x01000103
+# define HAVE_STREAMS 1
+#endif
+#if LIBUSB_API_VERSION >= 0x01000106
+# define HAVE_SUPER_PLUS 1
+#endif
+
+static const char *speed_name[] = {
+    [LIBUSB_SPEED_UNKNOWN] = "?",
+    [LIBUSB_SPEED_LOW]     = "1.5",
+    [LIBUSB_SPEED_FULL]    = "12",
+    [LIBUSB_SPEED_HIGH]    = "480",
+    [LIBUSB_SPEED_SUPER]   = "5000",
+#ifdef HAVE_SUPER_PLUS
+    [LIBUSB_SPEED_SUPER_PLUS] = "5000+",
+#endif
+};
+
+static const unsigned int speed_map[] = {
+    [LIBUSB_SPEED_LOW]     = USB_SPEED_LOW,
+    [LIBUSB_SPEED_FULL]    = USB_SPEED_FULL,
+    [LIBUSB_SPEED_HIGH]    = USB_SPEED_HIGH,
+    [LIBUSB_SPEED_SUPER]   = USB_SPEED_SUPER,
+#ifdef HAVE_SUPER_PLUS
+    [LIBUSB_SPEED_SUPER_PLUS] = USB_SPEED_SUPER,
+#endif
+};
+
+static const unsigned int status_map[] = {
+    [LIBUSB_TRANSFER_COMPLETED] = USB_RET_SUCCESS,
+    [LIBUSB_TRANSFER_ERROR]     = USB_RET_IOERROR,
+    [LIBUSB_TRANSFER_TIMED_OUT] = USB_RET_IOERROR,
+    [LIBUSB_TRANSFER_CANCELLED] = USB_RET_IOERROR,
+    [LIBUSB_TRANSFER_STALL]     = USB_RET_STALL,
+    [LIBUSB_TRANSFER_NO_DEVICE] = USB_RET_NODEV,
+    [LIBUSB_TRANSFER_OVERFLOW]  = USB_RET_BABBLE,
+};
+
+static const char *err_names[] = {
+    [-LIBUSB_ERROR_IO]               = "IO",
+    [-LIBUSB_ERROR_INVALID_PARAM]    = "INVALID_PARAM",
+    [-LIBUSB_ERROR_ACCESS]           = "ACCESS",
+    [-LIBUSB_ERROR_NO_DEVICE]        = "NO_DEVICE",
+    [-LIBUSB_ERROR_NOT_FOUND]        = "NOT_FOUND",
+    [-LIBUSB_ERROR_BUSY]             = "BUSY",
+    [-LIBUSB_ERROR_TIMEOUT]          = "TIMEOUT",
+    [-LIBUSB_ERROR_OVERFLOW]         = "OVERFLOW",
+    [-LIBUSB_ERROR_PIPE]             = "PIPE",
+    [-LIBUSB_ERROR_INTERRUPTED]      = "INTERRUPTED",
+    [-LIBUSB_ERROR_NO_MEM]           = "NO_MEM",
+    [-LIBUSB_ERROR_NOT_SUPPORTED]    = "NOT_SUPPORTED",
+    [-LIBUSB_ERROR_OTHER]            = "OTHER",
+};
+
+static libusb_context *ctx;
+static uint32_t loglevel;
+
+#ifndef CONFIG_WIN32
+
+static void usb_host_handle_fd(void *opaque)
+{
+    struct timeval tv = { 0, 0 };
+    libusb_handle_events_timeout(ctx, &tv);
+}
+
+static void usb_host_add_fd(int fd, short events, void *user_data)
+{
+    qemu_set_fd_handler(fd,
+                        (events & POLLIN)  ? usb_host_handle_fd : NULL,
+                        (events & POLLOUT) ? usb_host_handle_fd : NULL,
+                        ctx);
+}
+
+static void usb_host_del_fd(int fd, void *user_data)
+{
+    qemu_set_fd_handler(fd, NULL, NULL, NULL);
+}
+
+#else
+
+static QEMUTimer *poll_timer;
+static uint32_t request_count;
+
+static void usb_host_timer_kick(void)
+{
+    int64_t delay_ns;
+
+    delay_ns = request_count
+        ? (NANOSECONDS_PER_SECOND / 100)  /* 10 ms interval with active req */
+        : (NANOSECONDS_PER_SECOND);       /* 1 sec interval otherwise */
+    timer_mod(poll_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + delay_ns);
+}
+
+static void usb_host_timer(void *opaque)
+{
+    struct timeval tv = { 0, 0 };
+
+    libusb_handle_events_timeout(ctx, &tv);
+    usb_host_timer_kick();
+}
+
+#endif /* !CONFIG_WIN32 */
+
+static int usb_host_init(void)
+{
+#ifndef CONFIG_WIN32
+    const struct libusb_pollfd **poll;
+#endif
+    int rc;
+
+    if (ctx) {
+        return 0;
+    }
+    rc = libusb_init(&ctx);
+    if (rc != 0) {
+        return -1;
+    }
+#if LIBUSB_API_VERSION >= 0x01000106
+    libusb_set_option(ctx, LIBUSB_OPTION_LOG_LEVEL, loglevel);
+#else
+    libusb_set_debug(ctx, loglevel);
+#endif
+#ifdef CONFIG_WIN32
+    poll_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, usb_host_timer, NULL);
+    usb_host_timer_kick();
+#else
+    libusb_set_pollfd_notifiers(ctx, usb_host_add_fd,
+                                usb_host_del_fd,
+                                ctx);
+    poll = libusb_get_pollfds(ctx);
+    if (poll) {
+        int i;
+        for (i = 0; poll[i] != NULL; i++) {
+            usb_host_add_fd(poll[i]->fd, poll[i]->events, ctx);
+        }
+    }
+    free(poll);
+#endif
+    return 0;
+}
+
+static int usb_host_get_port(libusb_device *dev, char *port, size_t len)
+{
+    uint8_t path[7];
+    size_t off;
+    int rc, i;
+
+#if LIBUSB_API_VERSION >= 0x01000102
+    rc = libusb_get_port_numbers(dev, path, 7);
+#else
+    rc = libusb_get_port_path(ctx, dev, path, 7);
+#endif
+    if (rc < 0) {
+        return 0;
+    }
+    off = snprintf(port, len, "%d", path[0]);
+    for (i = 1; i < rc; i++) {
+        off += snprintf(port+off, len-off, ".%d", path[i]);
+    }
+    return off;
+}
+
+static void usb_host_libusb_error(const char *func, int rc)
+{
+    const char *errname;
+
+    if (rc >= 0) {
+        return;
+    }
+
+    if (-rc < ARRAY_SIZE(err_names) && err_names[-rc]) {
+        errname = err_names[-rc];
+    } else {
+        errname = "?";
+    }
+    error_report("%s: %d [%s]", func, rc, errname);
+}
+
+/* ------------------------------------------------------------------------ */
+
+static bool usb_host_use_combining(USBEndpoint *ep)
+{
+    int type;
+
+    if (!ep->pipeline) {
+        return false;
+    }
+    if (ep->pid != USB_TOKEN_IN) {
+        return false;
+    }
+    type = usb_ep_get_type(ep->dev, ep->pid, ep->nr);
+    if (type != USB_ENDPOINT_XFER_BULK) {
+        return false;
+    }
+    return true;
+}
+
+/* ------------------------------------------------------------------------ */
+
+static USBHostRequest *usb_host_req_alloc(USBHostDevice *s, USBPacket *p,
+                                          bool in, size_t bufsize)
+{
+    USBHostRequest *r = g_new0(USBHostRequest, 1);
+
+    r->host = s;
+    r->p = p;
+    r->in = in;
+    r->xfer = libusb_alloc_transfer(0);
+    if (bufsize) {
+        r->buffer = g_malloc(bufsize);
+    }
+    QTAILQ_INSERT_TAIL(&s->requests, r, next);
+#ifdef CONFIG_WIN32
+    request_count++;
+    usb_host_timer_kick();
+#endif
+    return r;
+}
+
+static void usb_host_req_free(USBHostRequest *r)
+{
+#ifdef CONFIG_WIN32
+    request_count--;
+#endif
+    QTAILQ_REMOVE(&r->host->requests, r, next);
+    libusb_free_transfer(r->xfer);
+    g_free(r->buffer);
+    g_free(r);
+}
+
+static USBHostRequest *usb_host_req_find(USBHostDevice *s, USBPacket *p)
+{
+    USBHostRequest *r;
+
+    QTAILQ_FOREACH(r, &s->requests, next) {
+        if (r->p == p) {
+            return r;
+        }
+    }
+    return NULL;
+}
+
+static void LIBUSB_CALL usb_host_req_complete_ctrl(struct libusb_transfer *xfer)
+{
+    USBHostRequest *r = xfer->user_data;
+    USBHostDevice  *s = r->host;
+    bool disconnect = (xfer->status == LIBUSB_TRANSFER_NO_DEVICE);
+
+    if (r->p == NULL) {
+        goto out; /* request was canceled */
+    }
+
+    r->p->status = status_map[xfer->status];
+    r->p->actual_length = xfer->actual_length;
+    if (r->in && xfer->actual_length) {
+        USBDevice *udev = USB_DEVICE(s);
+        struct libusb_config_descriptor *conf = (void *)r->cbuf;
+        memcpy(r->cbuf, r->buffer + 8, xfer->actual_length);
+
+        /* Fix up USB-3 ep0 maxpacket size to allow superspeed connected devices
+         * to work redirected to a not superspeed capable hcd */
+        if (r->usb3ep0quirk && xfer->actual_length >= 18 &&
+            r->cbuf[7] == 9) {
+            r->cbuf[7] = 64;
+        }
+        /*
+         *If this is GET_DESCRIPTOR request for configuration descriptor,
+         * remove 'remote wakeup' flag from it to prevent idle power down
+         * in Windows guest
+         */
+        if (s->suppress_remote_wake &&
+            udev->setup_buf[0] == USB_DIR_IN &&
+            udev->setup_buf[1] == USB_REQ_GET_DESCRIPTOR &&
+            udev->setup_buf[3] == USB_DT_CONFIG && udev->setup_buf[2] == 0 &&
+            xfer->actual_length >
+                offsetof(struct libusb_config_descriptor, bmAttributes) &&
+            (conf->bmAttributes & USB_CFG_ATT_WAKEUP)) {
+                trace_usb_host_remote_wakeup_removed(s->bus_num, s->addr);
+                conf->bmAttributes &= ~USB_CFG_ATT_WAKEUP;
+        }
+    }
+    trace_usb_host_req_complete(s->bus_num, s->addr, r->p,
+                                r->p->status, r->p->actual_length);
+    usb_generic_async_ctrl_complete(USB_DEVICE(s), r->p);
+
+out:
+    usb_host_req_free(r);
+    if (disconnect) {
+        usb_host_nodev(s);
+    }
+}
+
+static void LIBUSB_CALL usb_host_req_complete_data(struct libusb_transfer *xfer)
+{
+    USBHostRequest *r = xfer->user_data;
+    USBHostDevice  *s = r->host;
+    bool disconnect = (xfer->status == LIBUSB_TRANSFER_NO_DEVICE);
+
+    if (r->p == NULL) {
+        goto out; /* request was canceled */
+    }
+
+    r->p->status = status_map[xfer->status];
+    if (r->in && xfer->actual_length) {
+        usb_packet_copy(r->p, r->buffer, xfer->actual_length);
+    }
+    trace_usb_host_req_complete(s->bus_num, s->addr, r->p,
+                                r->p->status, r->p->actual_length);
+    if (usb_host_use_combining(r->p->ep)) {
+        usb_combined_input_packet_complete(USB_DEVICE(s), r->p);
+    } else {
+        usb_packet_complete(USB_DEVICE(s), r->p);
+    }
+
+out:
+    usb_host_req_free(r);
+    if (disconnect) {
+        usb_host_nodev(s);
+    }
+}
+
+static void usb_host_req_abort(USBHostRequest *r)
+{
+    USBHostDevice  *s = r->host;
+    bool inflight = (r->p && r->p->state == USB_PACKET_ASYNC);
+
+    if (inflight) {
+        r->p->status = USB_RET_NODEV;
+        trace_usb_host_req_complete(s->bus_num, s->addr, r->p,
+                                    r->p->status, r->p->actual_length);
+        if (r->p->ep->nr == 0) {
+            usb_generic_async_ctrl_complete(USB_DEVICE(s), r->p);
+        } else {
+            usb_packet_complete(USB_DEVICE(s), r->p);
+        }
+        r->p = NULL;
+
+        libusb_cancel_transfer(r->xfer);
+    }
+}
+
+/* ------------------------------------------------------------------------ */
+
+static void LIBUSB_CALL
+usb_host_req_complete_iso(struct libusb_transfer *transfer)
+{
+    USBHostIsoXfer *xfer = transfer->user_data;
+
+    if (!xfer) {
+        /* USBHostIsoXfer released while inflight */
+        g_free(transfer->buffer);
+        libusb_free_transfer(transfer);
+        return;
+    }
+
+    QTAILQ_REMOVE(&xfer->ring->inflight, xfer, next);
+    if (QTAILQ_EMPTY(&xfer->ring->inflight)) {
+        USBHostDevice *s = xfer->ring->host;
+        trace_usb_host_iso_stop(s->bus_num, s->addr, xfer->ring->ep->nr);
+    }
+    if (xfer->ring->ep->pid == USB_TOKEN_IN) {
+        QTAILQ_INSERT_TAIL(&xfer->ring->copy, xfer, next);
+        usb_wakeup(xfer->ring->ep, 0);
+    } else {
+        QTAILQ_INSERT_TAIL(&xfer->ring->unused, xfer, next);
+    }
+}
+
+static USBHostIsoRing *usb_host_iso_alloc(USBHostDevice *s, USBEndpoint *ep)
+{
+    USBHostIsoRing *ring = g_new0(USBHostIsoRing, 1);
+    USBHostIsoXfer *xfer;
+    /* FIXME: check interval (for now assume one xfer per frame) */
+    int packets = s->iso_urb_frames;
+    int i;
+
+    ring->host = s;
+    ring->ep = ep;
+    QTAILQ_INIT(&ring->unused);
+    QTAILQ_INIT(&ring->inflight);
+    QTAILQ_INIT(&ring->copy);
+    QTAILQ_INSERT_TAIL(&s->isorings, ring, next);
+
+    for (i = 0; i < s->iso_urb_count; i++) {
+        xfer = g_new0(USBHostIsoXfer, 1);
+        xfer->ring = ring;
+        xfer->xfer = libusb_alloc_transfer(packets);
+        xfer->xfer->dev_handle = s->dh;
+        xfer->xfer->type = LIBUSB_TRANSFER_TYPE_ISOCHRONOUS;
+
+        xfer->xfer->endpoint = ring->ep->nr;
+        if (ring->ep->pid == USB_TOKEN_IN) {
+            xfer->xfer->endpoint |= USB_DIR_IN;
+        }
+        xfer->xfer->callback = usb_host_req_complete_iso;
+        xfer->xfer->user_data = xfer;
+
+        xfer->xfer->num_iso_packets = packets;
+        xfer->xfer->length = ring->ep->max_packet_size * packets;
+        xfer->xfer->buffer = g_malloc0(xfer->xfer->length);
+
+        QTAILQ_INSERT_TAIL(&ring->unused, xfer, next);
+    }
+
+    return ring;
+}
+
+static USBHostIsoRing *usb_host_iso_find(USBHostDevice *s, USBEndpoint *ep)
+{
+    USBHostIsoRing *ring;
+
+    QTAILQ_FOREACH(ring, &s->isorings, next) {
+        if (ring->ep == ep) {
+            return ring;
+        }
+    }
+    return NULL;
+}
+
+static void usb_host_iso_reset_xfer(USBHostIsoXfer *xfer)
+{
+    libusb_set_iso_packet_lengths(xfer->xfer,
+                                  xfer->ring->ep->max_packet_size);
+    xfer->packet = 0;
+    xfer->copy_complete = false;
+}
+
+static void usb_host_iso_free_xfer(USBHostIsoXfer *xfer, bool inflight)
+{
+    if (inflight) {
+        xfer->xfer->user_data = NULL;
+    } else {
+        g_free(xfer->xfer->buffer);
+        libusb_free_transfer(xfer->xfer);
+    }
+    g_free(xfer);
+}
+
+static void usb_host_iso_free(USBHostIsoRing *ring)
+{
+    USBHostIsoXfer *xfer;
+
+    while ((xfer = QTAILQ_FIRST(&ring->inflight)) != NULL) {
+        QTAILQ_REMOVE(&ring->inflight, xfer, next);
+        usb_host_iso_free_xfer(xfer, true);
+    }
+    while ((xfer = QTAILQ_FIRST(&ring->unused)) != NULL) {
+        QTAILQ_REMOVE(&ring->unused, xfer, next);
+        usb_host_iso_free_xfer(xfer, false);
+    }
+    while ((xfer = QTAILQ_FIRST(&ring->copy)) != NULL) {
+        QTAILQ_REMOVE(&ring->copy, xfer, next);
+        usb_host_iso_free_xfer(xfer, false);
+    }
+
+    QTAILQ_REMOVE(&ring->host->isorings, ring, next);
+    g_free(ring);
+}
+
+static void usb_host_iso_free_all(USBHostDevice *s)
+{
+    USBHostIsoRing *ring;
+
+    while ((ring = QTAILQ_FIRST(&s->isorings)) != NULL) {
+        usb_host_iso_free(ring);
+    }
+}
+
+static bool usb_host_iso_data_copy(USBHostIsoXfer *xfer, USBPacket *p)
+{
+    unsigned int psize;
+    unsigned char *buf;
+
+    buf = libusb_get_iso_packet_buffer_simple(xfer->xfer, xfer->packet);
+    if (p->pid == USB_TOKEN_OUT) {
+        psize = p->iov.size;
+        if (psize > xfer->ring->ep->max_packet_size) {
+            /* should not happen (guest bug) */
+            psize = xfer->ring->ep->max_packet_size;
+        }
+        xfer->xfer->iso_packet_desc[xfer->packet].length = psize;
+    } else {
+        psize = xfer->xfer->iso_packet_desc[xfer->packet].actual_length;
+        if (psize > p->iov.size) {
+            /* should not happen (guest bug) */
+            psize = p->iov.size;
+        }
+    }
+    usb_packet_copy(p, buf, psize);
+    xfer->packet++;
+    xfer->copy_complete = (xfer->packet == xfer->xfer->num_iso_packets);
+    return xfer->copy_complete;
+}
+
+static void usb_host_iso_data_in(USBHostDevice *s, USBPacket *p)
+{
+    USBHostIsoRing *ring;
+    USBHostIsoXfer *xfer;
+    bool disconnect = false;
+    int rc;
+
+    ring = usb_host_iso_find(s, p->ep);
+    if (ring == NULL) {
+        ring = usb_host_iso_alloc(s, p->ep);
+    }
+
+    /* copy data to guest */
+    xfer = QTAILQ_FIRST(&ring->copy);
+    if (xfer != NULL) {
+        if (usb_host_iso_data_copy(xfer, p)) {
+            QTAILQ_REMOVE(&ring->copy, xfer, next);
+            QTAILQ_INSERT_TAIL(&ring->unused, xfer, next);
+        }
+    }
+
+    /* submit empty bufs to host */
+    while ((xfer = QTAILQ_FIRST(&ring->unused)) != NULL) {
+        QTAILQ_REMOVE(&ring->unused, xfer, next);
+        usb_host_iso_reset_xfer(xfer);
+        rc = libusb_submit_transfer(xfer->xfer);
+        if (rc != 0) {
+            usb_host_libusb_error("libusb_submit_transfer [iso]", rc);
+            QTAILQ_INSERT_TAIL(&ring->unused, xfer, next);
+            if (rc == LIBUSB_ERROR_NO_DEVICE) {
+                disconnect = true;
+            }
+            break;
+        }
+        if (QTAILQ_EMPTY(&ring->inflight)) {
+            trace_usb_host_iso_start(s->bus_num, s->addr, p->ep->nr);
+        }
+        QTAILQ_INSERT_TAIL(&ring->inflight, xfer, next);
+    }
+
+    if (disconnect) {
+        usb_host_nodev(s);
+    }
+}
+
+static void usb_host_iso_data_out(USBHostDevice *s, USBPacket *p)
+{
+    USBHostIsoRing *ring;
+    USBHostIsoXfer *xfer;
+    bool disconnect = false;
+    int rc, filled = 0;
+
+    ring = usb_host_iso_find(s, p->ep);
+    if (ring == NULL) {
+        ring = usb_host_iso_alloc(s, p->ep);
+    }
+
+    /* copy data from guest */
+    xfer = QTAILQ_FIRST(&ring->copy);
+    while (xfer != NULL && xfer->copy_complete) {
+        filled++;
+        xfer = QTAILQ_NEXT(xfer, next);
+    }
+    if (xfer == NULL) {
+        xfer = QTAILQ_FIRST(&ring->unused);
+        if (xfer == NULL) {
+            trace_usb_host_iso_out_of_bufs(s->bus_num, s->addr, p->ep->nr);
+            return;
+        }
+        QTAILQ_REMOVE(&ring->unused, xfer, next);
+        usb_host_iso_reset_xfer(xfer);
+        QTAILQ_INSERT_TAIL(&ring->copy, xfer, next);
+    }
+    usb_host_iso_data_copy(xfer, p);
+
+    if (QTAILQ_EMPTY(&ring->inflight)) {
+        /* wait until half of our buffers are filled
+           before kicking the iso out stream */
+        if (filled*2 < s->iso_urb_count) {
+            return;
+        }
+    }
+
+    /* submit filled bufs to host */
+    while ((xfer = QTAILQ_FIRST(&ring->copy)) != NULL &&
+           xfer->copy_complete) {
+        QTAILQ_REMOVE(&ring->copy, xfer, next);
+        rc = libusb_submit_transfer(xfer->xfer);
+        if (rc != 0) {
+            usb_host_libusb_error("libusb_submit_transfer [iso]", rc);
+            QTAILQ_INSERT_TAIL(&ring->unused, xfer, next);
+            if (rc == LIBUSB_ERROR_NO_DEVICE) {
+                disconnect = true;
+            }
+            break;
+        }
+        if (QTAILQ_EMPTY(&ring->inflight)) {
+            trace_usb_host_iso_start(s->bus_num, s->addr, p->ep->nr);
+        }
+        QTAILQ_INSERT_TAIL(&ring->inflight, xfer, next);
+    }
+
+    if (disconnect) {
+        usb_host_nodev(s);
+    }
+}
+
+/* ------------------------------------------------------------------------ */
+
+static void usb_host_speed_compat(USBHostDevice *s)
+{
+    USBDevice *udev = USB_DEVICE(s);
+    struct libusb_config_descriptor *conf;
+    const struct libusb_interface_descriptor *intf;
+    const struct libusb_endpoint_descriptor *endp;
+#ifdef HAVE_STREAMS
+    struct libusb_ss_endpoint_companion_descriptor *endp_ss_comp;
+#endif
+    bool compat_high = true;
+    bool compat_full = true;
+    uint8_t type;
+    int rc, c, i, a, e;
+
+    for (c = 0;; c++) {
+        rc = libusb_get_config_descriptor(s->dev, c, &conf);
+        if (rc != 0) {
+            break;
+        }
+        for (i = 0; i < conf->bNumInterfaces; i++) {
+            for (a = 0; a < conf->interface[i].num_altsetting; a++) {
+                intf = &conf->interface[i].altsetting[a];
+
+                if (intf->bInterfaceClass == LIBUSB_CLASS_MASS_STORAGE &&
+                    intf->bInterfaceSubClass == 6) { /* SCSI */
+                    udev->flags |= (1 << USB_DEV_FLAG_IS_SCSI_STORAGE);
+                    break;
+                }
+
+                for (e = 0; e < intf->bNumEndpoints; e++) {
+                    endp = &intf->endpoint[e];
+                    type = endp->bmAttributes & 0x3;
+                    switch (type) {
+                    case 0x01: /* ISO */
+                        compat_full = false;
+                        compat_high = false;
+                        break;
+                    case 0x02: /* BULK */
+#ifdef HAVE_STREAMS
+                        rc = libusb_get_ss_endpoint_companion_descriptor
+                            (ctx, endp, &endp_ss_comp);
+                        if (rc == LIBUSB_SUCCESS) {
+                            int streams = endp_ss_comp->bmAttributes & 0x1f;
+                            if (streams) {
+                                compat_full = false;
+                                compat_high = false;
+                            }
+                            libusb_free_ss_endpoint_companion_descriptor
+                                (endp_ss_comp);
+                        }
+#endif
+                        break;
+                    case 0x03: /* INTERRUPT */
+                        if (endp->wMaxPacketSize > 64) {
+                            compat_full = false;
+                        }
+                        if (endp->wMaxPacketSize > 1024) {
+                            compat_high = false;
+                        }
+                        break;
+                    }
+                }
+            }
+        }
+        libusb_free_config_descriptor(conf);
+    }
+
+    udev->speedmask = (1 << udev->speed);
+    if (udev->speed == USB_SPEED_SUPER && compat_high) {
+        udev->speedmask |= USB_SPEED_MASK_HIGH;
+    }
+    if (udev->speed == USB_SPEED_SUPER && compat_full) {
+        udev->speedmask |= USB_SPEED_MASK_FULL;
+    }
+    if (udev->speed == USB_SPEED_HIGH && compat_full) {
+        udev->speedmask |= USB_SPEED_MASK_FULL;
+    }
+}
+
+static void usb_host_ep_update(USBHostDevice *s)
+{
+    static const char *tname[] = {
+        [USB_ENDPOINT_XFER_CONTROL] = "control",
+        [USB_ENDPOINT_XFER_ISOC]    = "isoc",
+        [USB_ENDPOINT_XFER_BULK]    = "bulk",
+        [USB_ENDPOINT_XFER_INT]     = "int",
+    };
+    USBDevice *udev = USB_DEVICE(s);
+    struct libusb_config_descriptor *conf;
+    const struct libusb_interface_descriptor *intf;
+    const struct libusb_endpoint_descriptor *endp;
+#ifdef HAVE_STREAMS
+    struct libusb_ss_endpoint_companion_descriptor *endp_ss_comp;
+#endif
+    uint8_t devep, type;
+    int pid, ep, alt;
+    int rc, i, e;
+
+    usb_ep_reset(udev);
+    rc = libusb_get_active_config_descriptor(s->dev, &conf);
+    if (rc != 0) {
+        return;
+    }
+    trace_usb_host_parse_config(s->bus_num, s->addr,
+                                conf->bConfigurationValue, true);
+
+    for (i = 0; i < conf->bNumInterfaces; i++) {
+        /*
+         * The udev->altsetting array indexes alternate settings
+         * by the interface number. Get the 0th alternate setting
+         * first so that we can grab the interface number, and
+         * then correct the alternate setting value if necessary.
+         */
+        intf = &conf->interface[i].altsetting[0];
+        alt = udev->altsetting[intf->bInterfaceNumber];
+
+        if (alt != 0) {
+            assert(alt < conf->interface[i].num_altsetting);
+            intf = &conf->interface[i].altsetting[alt];
+        }
+
+        trace_usb_host_parse_interface(s->bus_num, s->addr,
+                                       intf->bInterfaceNumber,
+                                       intf->bAlternateSetting, true);
+        for (e = 0; e < intf->bNumEndpoints; e++) {
+            endp = &intf->endpoint[e];
+
+            devep = endp->bEndpointAddress;
+            pid = (devep & USB_DIR_IN) ? USB_TOKEN_IN : USB_TOKEN_OUT;
+            ep = devep & 0xf;
+            type = endp->bmAttributes & 0x3;
+
+            if (ep == 0) {
+                trace_usb_host_parse_error(s->bus_num, s->addr,
+                                           "invalid endpoint address");
+                return;
+            }
+            if (usb_ep_get_type(udev, pid, ep) != USB_ENDPOINT_XFER_INVALID) {
+                trace_usb_host_parse_error(s->bus_num, s->addr,
+                                           "duplicate endpoint address");
+                return;
+            }
+
+            trace_usb_host_parse_endpoint(s->bus_num, s->addr, ep,
+                                          (devep & USB_DIR_IN) ? "in" : "out",
+                                          tname[type], true);
+            usb_ep_set_max_packet_size(udev, pid, ep,
+                                       endp->wMaxPacketSize);
+            usb_ep_set_type(udev, pid, ep, type);
+            usb_ep_set_ifnum(udev, pid, ep, i);
+            usb_ep_set_halted(udev, pid, ep, 0);
+#ifdef HAVE_STREAMS
+            if (type == LIBUSB_TRANSFER_TYPE_BULK &&
+                    libusb_get_ss_endpoint_companion_descriptor(ctx, endp,
+                        &endp_ss_comp) == LIBUSB_SUCCESS) {
+                usb_ep_set_max_streams(udev, pid, ep,
+                                       endp_ss_comp->bmAttributes);
+                libusb_free_ss_endpoint_companion_descriptor(endp_ss_comp);
+            }
+#endif
+        }
+    }
+
+    libusb_free_config_descriptor(conf);
+}
+
+static int usb_host_open(USBHostDevice *s, libusb_device *dev, int hostfd)
+{
+    USBDevice *udev = USB_DEVICE(s);
+    int libusb_speed;
+    int bus_num = 0;
+    int addr = 0;
+    int rc;
+    Error *local_err = NULL;
+
+    if (s->bh_postld_pending) {
+        return -1;
+    }
+    if (s->dh != NULL) {
+        goto fail;
+    }
+
+    if (dev) {
+        bus_num = libusb_get_bus_number(dev);
+        addr = libusb_get_device_address(dev);
+        trace_usb_host_open_started(bus_num, addr);
+
+        rc = libusb_open(dev, &s->dh);
+        if (rc != 0) {
+            goto fail;
+        }
+    } else {
+#if LIBUSB_API_VERSION >= 0x01000107 && !defined(CONFIG_WIN32)
+        trace_usb_host_open_hostfd(hostfd);
+
+        rc = libusb_wrap_sys_device(ctx, hostfd, &s->dh);
+        if (rc != 0) {
+            goto fail;
+        }
+        s->hostfd  = hostfd;
+        dev = libusb_get_device(s->dh);
+        bus_num = libusb_get_bus_number(dev);
+        addr = libusb_get_device_address(dev);
+#else
+        g_assert_not_reached();
+#endif
+    }
+
+    s->dev     = dev;
+    s->bus_num = bus_num;
+    s->addr    = addr;
+
+    usb_host_detach_kernel(s);
+
+    libusb_get_device_descriptor(dev, &s->ddesc);
+    usb_host_get_port(s->dev, s->port, sizeof(s->port));
+
+    usb_ep_init(udev);
+    usb_host_ep_update(s);
+
+    libusb_speed = libusb_get_device_speed(dev);
+#if LIBUSB_API_VERSION >= 0x01000107 && defined(CONFIG_LINUX) && \
+        defined(USBDEVFS_GET_SPEED)
+    if (hostfd && libusb_speed == 0) {
+        /*
+         * Workaround libusb bug: libusb_get_device_speed() does not
+         * work for libusb_wrap_sys_device() devices in v1.0.23.
+         *
+         * Speeds are defined in linux/usb/ch9.h, file not included
+         * due to name conflicts.
+         */
+        int rc = ioctl(hostfd, USBDEVFS_GET_SPEED, NULL);
+        switch (rc) {
+        case 1: /* low */
+            libusb_speed = LIBUSB_SPEED_LOW;
+            break;
+        case 2: /* full */
+            libusb_speed = LIBUSB_SPEED_FULL;
+            break;
+        case 3: /* high */
+        case 4: /* wireless */
+            libusb_speed = LIBUSB_SPEED_HIGH;
+            break;
+        case 5: /* super */
+            libusb_speed = LIBUSB_SPEED_SUPER;
+            break;
+        case 6: /* super plus */
+#ifdef HAVE_SUPER_PLUS
+            libusb_speed = LIBUSB_SPEED_SUPER_PLUS;
+#else
+            libusb_speed = LIBUSB_SPEED_SUPER;
+#endif
+            break;
+        }
+    }
+#endif
+    udev->speed = speed_map[libusb_speed];
+    usb_host_speed_compat(s);
+
+    if (s->ddesc.iProduct) {
+        libusb_get_string_descriptor_ascii(s->dh, s->ddesc.iProduct,
+                                           (unsigned char *)udev->product_desc,
+                                           sizeof(udev->product_desc));
+    } else {
+        snprintf(udev->product_desc, sizeof(udev->product_desc),
+                 "host:%d.%d", bus_num, addr);
+    }
+
+    usb_device_attach(udev, &local_err);
+    if (local_err) {
+        error_report_err(local_err);
+        goto fail;
+    }
+
+    trace_usb_host_open_success(bus_num, addr);
+    return 0;
+
+fail:
+    trace_usb_host_open_failure(bus_num, addr);
+    if (s->dh != NULL) {
+        usb_host_release_interfaces(s);
+        libusb_reset_device(s->dh);
+        usb_host_attach_kernel(s);
+        libusb_close(s->dh);
+        s->dh = NULL;
+        s->dev = NULL;
+    }
+    return -1;
+}
+
+static void usb_host_abort_xfers(USBHostDevice *s)
+{
+    USBHostRequest *r, *rtmp;
+    int limit = 100;
+
+    QTAILQ_FOREACH_SAFE(r, &s->requests, next, rtmp) {
+        usb_host_req_abort(r);
+    }
+
+    while (QTAILQ_FIRST(&s->requests) != NULL) {
+        struct timeval tv;
+        memset(&tv, 0, sizeof(tv));
+        tv.tv_usec = 2500;
+        libusb_handle_events_timeout(ctx, &tv);
+        if (--limit == 0) {
+            /*
+             * Don't wait forever for libusb calling the complete
+             * callback (which will unlink and free the request).
+             *
+             * Leaking memory here, to make sure libusb will not
+             * access memory which we have released already.
+             */
+            QTAILQ_FOREACH_SAFE(r, &s->requests, next, rtmp) {
+                QTAILQ_REMOVE(&s->requests, r, next);
+            }
+            return;
+        }
+    }
+}
+
+static int usb_host_close(USBHostDevice *s)
+{
+    USBDevice *udev = USB_DEVICE(s);
+
+    if (s->dh == NULL) {
+        return -1;
+    }
+
+    trace_usb_host_close(s->bus_num, s->addr);
+
+    usb_host_abort_xfers(s);
+    usb_host_iso_free_all(s);
+
+    if (udev->attached) {
+        usb_device_detach(udev);
+    }
+
+    usb_host_release_interfaces(s);
+    libusb_reset_device(s->dh);
+    usb_host_attach_kernel(s);
+    libusb_close(s->dh);
+    s->dh = NULL;
+    s->dev = NULL;
+
+    if (s->hostfd != -1) {
+        close(s->hostfd);
+        s->hostfd = -1;
+    }
+
+    usb_host_auto_check(NULL);
+    return 0;
+}
+
+static void usb_host_nodev_bh(void *opaque)
+{
+    USBHostDevice *s = opaque;
+    usb_host_close(s);
+}
+
+static void usb_host_nodev(USBHostDevice *s)
+{
+    if (!s->bh_nodev) {
+        s->bh_nodev = qemu_bh_new(usb_host_nodev_bh, s);
+    }
+    qemu_bh_schedule(s->bh_nodev);
+}
+
+static void usb_host_exit_notifier(struct Notifier *n, void *data)
+{
+    USBHostDevice *s = container_of(n, USBHostDevice, exit);
+
+    if (s->dh) {
+        usb_host_abort_xfers(s);
+        usb_host_release_interfaces(s);
+        libusb_reset_device(s->dh);
+        usb_host_attach_kernel(s);
+        libusb_close(s->dh);
+    }
+}
+
+static libusb_device *usb_host_find_ref(int bus, int addr)
+{
+    libusb_device **devs = NULL;
+    libusb_device *ret = NULL;
+    int i, n;
+
+    n = libusb_get_device_list(ctx, &devs);
+    for (i = 0; i < n; i++) {
+        if (libusb_get_bus_number(devs[i]) == bus &&
+            libusb_get_device_address(devs[i]) == addr) {
+            ret = libusb_ref_device(devs[i]);
+            break;
+        }
+    }
+    libusb_free_device_list(devs, 1);
+    return ret;
+}
+
+static void usb_host_realize(USBDevice *udev, Error **errp)
+{
+    USBHostDevice *s = USB_HOST_DEVICE(udev);
+    libusb_device *ldev;
+    int rc;
+
+    if (usb_host_init() != 0) {
+        error_setg(errp, "failed to init libusb");
+        return;
+    }
+    if (s->match.vendor_id > 0xffff) {
+        error_setg(errp, "vendorid out of range");
+        return;
+    }
+    if (s->match.product_id > 0xffff) {
+        error_setg(errp, "productid out of range");
+        return;
+    }
+    if (s->match.addr > 127) {
+        error_setg(errp, "hostaddr out of range");
+        return;
+    }
+
+    loglevel = s->loglevel;
+    udev->flags |= (1 << USB_DEV_FLAG_IS_HOST);
+    udev->auto_attach = 0;
+    QTAILQ_INIT(&s->requests);
+    QTAILQ_INIT(&s->isorings);
+    s->hostfd = -1;
+
+#if LIBUSB_API_VERSION >= 0x01000107 && !defined(CONFIG_WIN32)
+    if (s->hostdevice) {
+        int fd;
+        s->needs_autoscan = false;
+        fd = qemu_open_old(s->hostdevice, O_RDWR);
+        if (fd < 0) {
+            error_setg_errno(errp, errno, "failed to open %s", s->hostdevice);
+            return;
+        }
+        rc = usb_host_open(s, NULL, fd);
+        if (rc < 0) {
+            error_setg(errp, "failed to open host usb device %s", s->hostdevice);
+            return;
+        }
+    } else
+#endif
+    if (s->match.addr && s->match.bus_num &&
+        !s->match.vendor_id &&
+        !s->match.product_id &&
+        !s->match.port) {
+        s->needs_autoscan = false;
+        ldev = usb_host_find_ref(s->match.bus_num,
+                                 s->match.addr);
+        if (!ldev) {
+            error_setg(errp, "failed to find host usb device %d:%d",
+                       s->match.bus_num, s->match.addr);
+            return;
+        }
+        rc = usb_host_open(s, ldev, 0);
+        libusb_unref_device(ldev);
+        if (rc < 0) {
+            error_setg(errp, "failed to open host usb device %d:%d",
+                       s->match.bus_num, s->match.addr);
+            return;
+        }
+    } else {
+        s->needs_autoscan = true;
+        QTAILQ_INSERT_TAIL(&hostdevs, s, next);
+        usb_host_auto_check(NULL);
+    }
+
+    s->exit.notify = usb_host_exit_notifier;
+    qemu_add_exit_notifier(&s->exit);
+}
+
+static void usb_host_instance_init(Object *obj)
+{
+    USBDevice *udev = USB_DEVICE(obj);
+    USBHostDevice *s = USB_HOST_DEVICE(udev);
+
+    device_add_bootindex_property(obj, &s->bootindex,
+                                  "bootindex", NULL,
+                                  &udev->qdev);
+}
+
+static void usb_host_unrealize(USBDevice *udev)
+{
+    USBHostDevice *s = USB_HOST_DEVICE(udev);
+
+    qemu_remove_exit_notifier(&s->exit);
+    if (s->needs_autoscan) {
+        QTAILQ_REMOVE(&hostdevs, s, next);
+    }
+    usb_host_close(s);
+}
+
+static void usb_host_cancel_packet(USBDevice *udev, USBPacket *p)
+{
+    USBHostDevice *s = USB_HOST_DEVICE(udev);
+    USBHostRequest *r;
+
+    if (p->combined) {
+        usb_combined_packet_cancel(udev, p);
+        return;
+    }
+
+    trace_usb_host_req_canceled(s->bus_num, s->addr, p);
+
+    r = usb_host_req_find(s, p);
+    if (r && r->p) {
+        r->p = NULL; /* mark as dead */
+        libusb_cancel_transfer(r->xfer);
+    }
+}
+
+static void usb_host_detach_kernel(USBHostDevice *s)
+{
+    struct libusb_config_descriptor *conf;
+    int rc, i;
+
+    rc = libusb_get_active_config_descriptor(s->dev, &conf);
+    if (rc != 0) {
+        return;
+    }
+    for (i = 0; i < USB_MAX_INTERFACES; i++) {
+        rc = libusb_kernel_driver_active(s->dh, i);
+        usb_host_libusb_error("libusb_kernel_driver_active", rc);
+        if (rc != 1) {
+            if (rc == 0) {
+                s->ifs[i].detached = true;
+            }
+            continue;
+        }
+        trace_usb_host_detach_kernel(s->bus_num, s->addr, i);
+        rc = libusb_detach_kernel_driver(s->dh, i);
+        usb_host_libusb_error("libusb_detach_kernel_driver", rc);
+        s->ifs[i].detached = true;
+    }
+    libusb_free_config_descriptor(conf);
+}
+
+static void usb_host_attach_kernel(USBHostDevice *s)
+{
+    struct libusb_config_descriptor *conf;
+    int rc, i;
+
+    rc = libusb_get_active_config_descriptor(s->dev, &conf);
+    if (rc != 0) {
+        return;
+    }
+    for (i = 0; i < USB_MAX_INTERFACES; i++) {
+        if (!s->ifs[i].detached) {
+            continue;
+        }
+        trace_usb_host_attach_kernel(s->bus_num, s->addr, i);
+        libusb_attach_kernel_driver(s->dh, i);
+        s->ifs[i].detached = false;
+    }
+    libusb_free_config_descriptor(conf);
+}
+
+static int usb_host_claim_interfaces(USBHostDevice *s, int configuration)
+{
+    USBDevice *udev = USB_DEVICE(s);
+    struct libusb_config_descriptor *conf;
+    int rc, i, claimed;
+
+    for (i = 0; i < USB_MAX_INTERFACES; i++) {
+        udev->altsetting[i] = 0;
+    }
+    udev->ninterfaces   = 0;
+    udev->configuration = 0;
+
+    usb_host_detach_kernel(s);
+
+    rc = libusb_get_active_config_descriptor(s->dev, &conf);
+    if (rc != 0) {
+        if (rc == LIBUSB_ERROR_NOT_FOUND) {
+            /* address state - ignore */
+            return USB_RET_SUCCESS;
+        }
+        return USB_RET_STALL;
+    }
+
+    claimed = 0;
+    for (i = 0; i < USB_MAX_INTERFACES; i++) {
+        trace_usb_host_claim_interface(s->bus_num, s->addr, configuration, i);
+        rc = libusb_claim_interface(s->dh, i);
+        if (rc == 0) {
+            s->ifs[i].claimed = true;
+            if (++claimed == conf->bNumInterfaces) {
+                break;
+            }
+        }
+    }
+    if (claimed != conf->bNumInterfaces) {
+        return USB_RET_STALL;
+    }
+
+    udev->ninterfaces   = conf->bNumInterfaces;
+    udev->configuration = configuration;
+
+    libusb_free_config_descriptor(conf);
+    return USB_RET_SUCCESS;
+}
+
+static void usb_host_release_interfaces(USBHostDevice *s)
+{
+    int i, rc;
+
+    for (i = 0; i < USB_MAX_INTERFACES; i++) {
+        if (!s->ifs[i].claimed) {
+            continue;
+        }
+        trace_usb_host_release_interface(s->bus_num, s->addr, i);
+        rc = libusb_release_interface(s->dh, i);
+        usb_host_libusb_error("libusb_release_interface", rc);
+        s->ifs[i].claimed = false;
+    }
+}
+
+static void usb_host_set_address(USBHostDevice *s, int addr)
+{
+    USBDevice *udev = USB_DEVICE(s);
+
+    trace_usb_host_set_address(s->bus_num, s->addr, addr);
+    udev->addr = addr;
+}
+
+static void usb_host_set_config(USBHostDevice *s, int config, USBPacket *p)
+{
+    int rc = 0;
+
+    trace_usb_host_set_config(s->bus_num, s->addr, config);
+
+    usb_host_release_interfaces(s);
+    if (s->ddesc.bNumConfigurations != 1) {
+        rc = libusb_set_configuration(s->dh, config);
+        if (rc != 0) {
+            usb_host_libusb_error("libusb_set_configuration", rc);
+            p->status = USB_RET_STALL;
+            if (rc == LIBUSB_ERROR_NO_DEVICE) {
+                usb_host_nodev(s);
+            }
+            return;
+        }
+    }
+    p->status = usb_host_claim_interfaces(s, config);
+    if (p->status != USB_RET_SUCCESS) {
+        return;
+    }
+    usb_host_ep_update(s);
+}
+
+static void usb_host_set_interface(USBHostDevice *s, int iface, int alt,
+                                   USBPacket *p)
+{
+    USBDevice *udev = USB_DEVICE(s);
+    int rc;
+
+    trace_usb_host_set_interface(s->bus_num, s->addr, iface, alt);
+
+    usb_host_iso_free_all(s);
+
+    if (iface >= USB_MAX_INTERFACES) {
+        p->status = USB_RET_STALL;
+        return;
+    }
+
+    rc = libusb_set_interface_alt_setting(s->dh, iface, alt);
+    if (rc != 0) {
+        usb_host_libusb_error("libusb_set_interface_alt_setting", rc);
+        p->status = USB_RET_STALL;
+        if (rc == LIBUSB_ERROR_NO_DEVICE) {
+            usb_host_nodev(s);
+        }
+        return;
+    }
+
+    udev->altsetting[iface] = alt;
+    usb_host_ep_update(s);
+}
+
+static void usb_host_handle_control(USBDevice *udev, USBPacket *p,
+                                    int request, int value, int index,
+                                    int length, uint8_t *data)
+{
+    USBHostDevice *s = USB_HOST_DEVICE(udev);
+    USBHostRequest *r;
+    int rc;
+
+    trace_usb_host_req_control(s->bus_num, s->addr, p, request, value, index);
+
+    if (s->dh == NULL) {
+        p->status = USB_RET_NODEV;
+        trace_usb_host_req_emulated(s->bus_num, s->addr, p, p->status);
+        return;
+    }
+
+    switch (request) {
+    case DeviceOutRequest | USB_REQ_SET_ADDRESS:
+        usb_host_set_address(s, value);
+        trace_usb_host_req_emulated(s->bus_num, s->addr, p, p->status);
+        return;
+
+    case DeviceOutRequest | USB_REQ_SET_CONFIGURATION:
+        usb_host_set_config(s, value & 0xff, p);
+        trace_usb_host_req_emulated(s->bus_num, s->addr, p, p->status);
+        return;
+
+    case InterfaceOutRequest | USB_REQ_SET_INTERFACE:
+        usb_host_set_interface(s, index, value, p);
+        trace_usb_host_req_emulated(s->bus_num, s->addr, p, p->status);
+        return;
+
+    case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
+        if (value == 0) { /* clear halt */
+            int pid = (index & USB_DIR_IN) ? USB_TOKEN_IN : USB_TOKEN_OUT;
+            libusb_clear_halt(s->dh, index);
+            usb_ep_set_halted(udev, pid, index & 0x0f, 0);
+            trace_usb_host_req_emulated(s->bus_num, s->addr, p, p->status);
+            return;
+        }
+    }
+
+    r = usb_host_req_alloc(s, p, (request >> 8) & USB_DIR_IN, length + 8);
+    r->cbuf = data;
+    r->clen = length;
+    memcpy(r->buffer, udev->setup_buf, 8);
+    if (!r->in) {
+        memcpy(r->buffer + 8, r->cbuf, r->clen);
+    }
+
+    /* Fix up USB-3 ep0 maxpacket size to allow superspeed connected devices
+     * to work redirected to a not superspeed capable hcd */
+    if ((udev->speedmask & USB_SPEED_MASK_SUPER) &&
+        !(udev->port->speedmask & USB_SPEED_MASK_SUPER) &&
+        request == 0x8006 && value == 0x100 && index == 0) {
+        r->usb3ep0quirk = true;
+    }
+
+    libusb_fill_control_transfer(r->xfer, s->dh, r->buffer,
+                                 usb_host_req_complete_ctrl, r,
+                                 CONTROL_TIMEOUT);
+    rc = libusb_submit_transfer(r->xfer);
+    if (rc != 0) {
+        p->status = USB_RET_NODEV;
+        trace_usb_host_req_complete(s->bus_num, s->addr, p,
+                                    p->status, p->actual_length);
+        if (rc == LIBUSB_ERROR_NO_DEVICE) {
+            usb_host_nodev(s);
+        }
+        return;
+    }
+
+    p->status = USB_RET_ASYNC;
+}
+
+static void usb_host_handle_data(USBDevice *udev, USBPacket *p)
+{
+    USBHostDevice *s = USB_HOST_DEVICE(udev);
+    USBHostRequest *r;
+    size_t size;
+    int ep, rc;
+
+    if (usb_host_use_combining(p->ep) && p->state == USB_PACKET_SETUP) {
+        p->status = USB_RET_ADD_TO_QUEUE;
+        return;
+    }
+
+    trace_usb_host_req_data(s->bus_num, s->addr, p,
+                            p->pid == USB_TOKEN_IN,
+                            p->ep->nr, p->iov.size);
+
+    if (s->dh == NULL) {
+        p->status = USB_RET_NODEV;
+        trace_usb_host_req_emulated(s->bus_num, s->addr, p, p->status);
+        return;
+    }
+    if (p->ep->halted) {
+        p->status = USB_RET_STALL;
+        trace_usb_host_req_emulated(s->bus_num, s->addr, p, p->status);
+        return;
+    }
+
+    switch (usb_ep_get_type(udev, p->pid, p->ep->nr)) {
+    case USB_ENDPOINT_XFER_BULK:
+        size = usb_packet_size(p);
+        r = usb_host_req_alloc(s, p, p->pid == USB_TOKEN_IN, size);
+        if (!r->in) {
+            usb_packet_copy(p, r->buffer, size);
+        }
+        ep = p->ep->nr | (r->in ? USB_DIR_IN : 0);
+        if (p->stream) {
+#ifdef HAVE_STREAMS
+            libusb_fill_bulk_stream_transfer(r->xfer, s->dh, ep, p->stream,
+                                             r->buffer, size,
+                                             usb_host_req_complete_data, r,
+                                             BULK_TIMEOUT);
+#else
+            usb_host_req_free(r);
+            p->status = USB_RET_STALL;
+            return;
+#endif
+        } else {
+            libusb_fill_bulk_transfer(r->xfer, s->dh, ep,
+                                      r->buffer, size,
+                                      usb_host_req_complete_data, r,
+                                      BULK_TIMEOUT);
+        }
+        break;
+    case USB_ENDPOINT_XFER_INT:
+        r = usb_host_req_alloc(s, p, p->pid == USB_TOKEN_IN, p->iov.size);
+        if (!r->in) {
+            usb_packet_copy(p, r->buffer, p->iov.size);
+        }
+        ep = p->ep->nr | (r->in ? USB_DIR_IN : 0);
+        libusb_fill_interrupt_transfer(r->xfer, s->dh, ep,
+                                       r->buffer, p->iov.size,
+                                       usb_host_req_complete_data, r,
+                                       INTR_TIMEOUT);
+        break;
+    case USB_ENDPOINT_XFER_ISOC:
+        if (p->pid == USB_TOKEN_IN) {
+            usb_host_iso_data_in(s, p);
+        } else {
+            usb_host_iso_data_out(s, p);
+        }
+        trace_usb_host_req_complete(s->bus_num, s->addr, p,
+                                    p->status, p->actual_length);
+        return;
+    default:
+        p->status = USB_RET_STALL;
+        trace_usb_host_req_complete(s->bus_num, s->addr, p,
+                                    p->status, p->actual_length);
+        return;
+    }
+
+    rc = libusb_submit_transfer(r->xfer);
+    if (rc != 0) {
+        p->status = USB_RET_NODEV;
+        trace_usb_host_req_complete(s->bus_num, s->addr, p,
+                                    p->status, p->actual_length);
+        if (rc == LIBUSB_ERROR_NO_DEVICE) {
+            usb_host_nodev(s);
+        }
+        return;
+    }
+
+    p->status = USB_RET_ASYNC;
+}
+
+static void usb_host_flush_ep_queue(USBDevice *dev, USBEndpoint *ep)
+{
+    if (usb_host_use_combining(ep)) {
+        usb_ep_combine_input_packets(ep);
+    }
+}
+
+static void usb_host_handle_reset(USBDevice *udev)
+{
+    USBHostDevice *s = USB_HOST_DEVICE(udev);
+    int rc;
+
+    if (!s->allow_one_guest_reset && !s->allow_all_guest_resets) {
+        return;
+    }
+    if (!s->allow_all_guest_resets && udev->addr == 0) {
+        return;
+    }
+
+    trace_usb_host_reset(s->bus_num, s->addr);
+
+    rc = libusb_reset_device(s->dh);
+    if (rc != 0) {
+        usb_host_nodev(s);
+    }
+}
+
+static int usb_host_alloc_streams(USBDevice *udev, USBEndpoint **eps,
+                                  int nr_eps, int streams)
+{
+#ifdef HAVE_STREAMS
+    USBHostDevice *s = USB_HOST_DEVICE(udev);
+    unsigned char endpoints[30];
+    int i, rc;
+
+    for (i = 0; i < nr_eps; i++) {
+        endpoints[i] = eps[i]->nr;
+        if (eps[i]->pid == USB_TOKEN_IN) {
+            endpoints[i] |= 0x80;
+        }
+    }
+    rc = libusb_alloc_streams(s->dh, streams, endpoints, nr_eps);
+    if (rc < 0) {
+        usb_host_libusb_error("libusb_alloc_streams", rc);
+    } else if (rc != streams) {
+        error_report("libusb_alloc_streams: got less streams "
+                     "then requested %d < %d", rc, streams);
+    }
+
+    return (rc == streams) ? 0 : -1;
+#else
+    error_report("libusb_alloc_streams: error not implemented");
+    return -1;
+#endif
+}
+
+static void usb_host_free_streams(USBDevice *udev, USBEndpoint **eps,
+                                  int nr_eps)
+{
+#ifdef HAVE_STREAMS
+    USBHostDevice *s = USB_HOST_DEVICE(udev);
+    unsigned char endpoints[30];
+    int i;
+
+    for (i = 0; i < nr_eps; i++) {
+        endpoints[i] = eps[i]->nr;
+        if (eps[i]->pid == USB_TOKEN_IN) {
+            endpoints[i] |= 0x80;
+        }
+    }
+    libusb_free_streams(s->dh, endpoints, nr_eps);
+#endif
+}
+
+/*
+ * This is *NOT* about restoring state.  We have absolutely no idea
+ * what state the host device is in at the moment and whenever it is
+ * still present in the first place.  Attempting to continue where we
+ * left off is impossible.
+ *
+ * What we are going to do here is emulate a surprise removal of
+ * the usb device passed through, then kick host scan so the device
+ * will get re-attached (and re-initialized by the guest) in case it
+ * is still present.
+ *
+ * As the device removal will change the state of other devices (usb
+ * host controller, most likely interrupt controller too) we have to
+ * wait with it until *all* vmstate is loaded.  Thus post_load just
+ * kicks a bottom half which then does the actual work.
+ */
+static void usb_host_post_load_bh(void *opaque)
+{
+    USBHostDevice *dev = opaque;
+    USBDevice *udev = USB_DEVICE(dev);
+
+    if (dev->dh != NULL) {
+        usb_host_close(dev);
+    }
+    if (udev->attached) {
+        usb_device_detach(udev);
+    }
+    dev->bh_postld_pending = false;
+    usb_host_auto_check(NULL);
+}
+
+static int usb_host_post_load(void *opaque, int version_id)
+{
+    USBHostDevice *dev = opaque;
+
+    if (!dev->bh_postld) {
+        dev->bh_postld = qemu_bh_new(usb_host_post_load_bh, dev);
+    }
+    qemu_bh_schedule(dev->bh_postld);
+    dev->bh_postld_pending = true;
+    return 0;
+}
+
+static const VMStateDescription vmstate_usb_host = {
+    .name = "usb-host",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .post_load = usb_host_post_load,
+    .fields = (VMStateField[]) {
+        VMSTATE_USB_DEVICE(parent_obj, USBHostDevice),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static Property usb_host_dev_properties[] = {
+    DEFINE_PROP_UINT32("hostbus",  USBHostDevice, match.bus_num,    0),
+    DEFINE_PROP_UINT32("hostaddr", USBHostDevice, match.addr,       0),
+    DEFINE_PROP_STRING("hostport", USBHostDevice, match.port),
+    DEFINE_PROP_UINT32("vendorid",  USBHostDevice, match.vendor_id,  0),
+    DEFINE_PROP_UINT32("productid", USBHostDevice, match.product_id, 0),
+#if LIBUSB_API_VERSION >= 0x01000107
+    DEFINE_PROP_STRING("hostdevice", USBHostDevice, hostdevice),
+#endif
+    DEFINE_PROP_UINT32("isobufs",  USBHostDevice, iso_urb_count,    4),
+    DEFINE_PROP_UINT32("isobsize", USBHostDevice, iso_urb_frames,   32),
+    DEFINE_PROP_BOOL("guest-reset", USBHostDevice,
+                     allow_one_guest_reset, true),
+    DEFINE_PROP_BOOL("guest-resets-all", USBHostDevice,
+                     allow_all_guest_resets, false),
+    DEFINE_PROP_UINT32("loglevel",  USBHostDevice, loglevel,
+                       LIBUSB_LOG_LEVEL_WARNING),
+    DEFINE_PROP_BIT("pipeline",    USBHostDevice, options,
+                    USB_HOST_OPT_PIPELINE, true),
+    DEFINE_PROP_BOOL("suppress-remote-wake", USBHostDevice,
+                     suppress_remote_wake, true),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void usb_host_class_initfn(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    USBDeviceClass *uc = USB_DEVICE_CLASS(klass);
+
+    uc->realize        = usb_host_realize;
+    uc->product_desc   = "USB Host Device";
+    uc->cancel_packet  = usb_host_cancel_packet;
+    uc->handle_data    = usb_host_handle_data;
+    uc->handle_control = usb_host_handle_control;
+    uc->handle_reset   = usb_host_handle_reset;
+    uc->unrealize      = usb_host_unrealize;
+    uc->flush_ep_queue = usb_host_flush_ep_queue;
+    uc->alloc_streams  = usb_host_alloc_streams;
+    uc->free_streams   = usb_host_free_streams;
+    dc->vmsd = &vmstate_usb_host;
+    device_class_set_props(dc, usb_host_dev_properties);
+    set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
+}
+
+static TypeInfo usb_host_dev_info = {
+    .name          = TYPE_USB_HOST_DEVICE,
+    .parent        = TYPE_USB_DEVICE,
+    .instance_size = sizeof(USBHostDevice),
+    .class_init    = usb_host_class_initfn,
+    .instance_init = usb_host_instance_init,
+};
+module_obj(TYPE_USB_HOST_DEVICE);
+
+static void usb_host_register_types(void)
+{
+    type_register_static(&usb_host_dev_info);
+    monitor_register_hmp("usbhost", true, hmp_info_usbhost);
+}
+
+type_init(usb_host_register_types)
+
+/* ------------------------------------------------------------------------ */
+
+static QEMUTimer *usb_auto_timer;
+static VMChangeStateEntry *usb_vmstate;
+
+static void usb_host_vm_state(void *unused, bool running, RunState state)
+{
+    if (running) {
+        usb_host_auto_check(unused);
+    }
+}
+
+static void usb_host_auto_check(void *unused)
+{
+    struct USBHostDevice *s;
+    struct USBAutoFilter *f;
+    libusb_device **devs = NULL;
+    struct libusb_device_descriptor ddesc;
+    int unconnected = 0;
+    int i, n;
+
+    if (usb_host_init() != 0) {
+        return;
+    }
+
+    if (runstate_is_running()) {
+        n = libusb_get_device_list(ctx, &devs);
+        for (i = 0; i < n; i++) {
+            if (libusb_get_device_descriptor(devs[i], &ddesc) != 0) {
+                continue;
+            }
+            if (ddesc.bDeviceClass == LIBUSB_CLASS_HUB) {
+                continue;
+            }
+            QTAILQ_FOREACH(s, &hostdevs, next) {
+                f = &s->match;
+                if (f->bus_num > 0 &&
+                    f->bus_num != libusb_get_bus_number(devs[i])) {
+                    continue;
+                }
+                if (f->addr > 0 &&
+                    f->addr != libusb_get_device_address(devs[i])) {
+                    continue;
+                }
+                if (f->port != NULL) {
+                    char port[16] = "-";
+                    usb_host_get_port(devs[i], port, sizeof(port));
+                    if (strcmp(f->port, port) != 0) {
+                        continue;
+                    }
+                }
+                if (f->vendor_id > 0 &&
+                    f->vendor_id != ddesc.idVendor) {
+                    continue;
+                }
+                if (f->product_id > 0 &&
+                    f->product_id != ddesc.idProduct) {
+                    continue;
+                }
+
+                /* We got a match */
+                s->seen++;
+                if (s->errcount >= 3) {
+                    continue;
+                }
+                if (s->dh != NULL) {
+                    continue;
+                }
+                if (usb_host_open(s, devs[i], 0) < 0) {
+                    s->errcount++;
+                    continue;
+                }
+                break;
+            }
+        }
+        libusb_free_device_list(devs, 1);
+
+        QTAILQ_FOREACH(s, &hostdevs, next) {
+            if (s->dh == NULL) {
+                unconnected++;
+            }
+            if (s->seen == 0) {
+                if (s->dh) {
+                    usb_host_close(s);
+                }
+                s->errcount = 0;
+            }
+            s->seen = 0;
+        }
+
+#if 0
+        if (unconnected == 0) {
+            /* nothing to watch */
+            if (usb_auto_timer) {
+                timer_del(usb_auto_timer);
+                trace_usb_host_auto_scan_disabled();
+            }
+            return;
+        }
+#endif
+    }
+
+    if (!usb_vmstate) {
+        usb_vmstate = qemu_add_vm_change_state_handler(usb_host_vm_state, NULL);
+    }
+    if (!usb_auto_timer) {
+        usb_auto_timer = timer_new_ms(QEMU_CLOCK_REALTIME, usb_host_auto_check, NULL);
+        if (!usb_auto_timer) {
+            return;
+        }
+        trace_usb_host_auto_scan_enabled();
+    }
+    timer_mod(usb_auto_timer, qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + 2000);
+}
+
+void hmp_info_usbhost(Monitor *mon, const QDict *qdict)
+{
+    libusb_device **devs = NULL;
+    struct libusb_device_descriptor ddesc;
+    char port[16];
+    int i, n;
+
+    if (usb_host_init() != 0) {
+        return;
+    }
+
+    n = libusb_get_device_list(ctx, &devs);
+    for (i = 0; i < n; i++) {
+        if (libusb_get_device_descriptor(devs[i], &ddesc) != 0) {
+            continue;
+        }
+        if (ddesc.bDeviceClass == LIBUSB_CLASS_HUB) {
+            continue;
+        }
+        usb_host_get_port(devs[i], port, sizeof(port));
+        monitor_printf(mon, "  Bus %d, Addr %d, Port %s, Speed %s Mb/s\n",
+                       libusb_get_bus_number(devs[i]),
+                       libusb_get_device_address(devs[i]),
+                       port,
+                       speed_name[libusb_get_device_speed(devs[i])]);
+        monitor_printf(mon, "    Class %02x:", ddesc.bDeviceClass);
+        monitor_printf(mon, " USB device %04x:%04x",
+                       ddesc.idVendor, ddesc.idProduct);
+        if (ddesc.iProduct) {
+            libusb_device_handle *handle;
+            if (libusb_open(devs[i], &handle) == 0) {
+                unsigned char name[64] = "";
+                libusb_get_string_descriptor_ascii(handle,
+                                                   ddesc.iProduct,
+                                                   name, sizeof(name));
+                libusb_close(handle);
+                monitor_printf(mon, ", %s", name);
+            }
+        }
+        monitor_printf(mon, "\n");
+    }
+    libusb_free_device_list(devs, 1);
+}