text: /*
   * 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);
  }
  
  #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
      /* FIXME: add support for Windows. */
  #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);
      return r;
  }
  
  static void usb_host_req_free(USBHostRequest *r)
  {
      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];
                  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.  Attemping to contine 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,
  };
  
  static void usb_host_register_types(void)
  {
      type_register_static(&usb_host_dev_info);
  }
  
  type_init(usb_host_register_types)
  
  /* ------------------------------------------------------------------------ */
  
  static QEMUTimer *usb_auto_timer;
  static VMChangeStateEntry *usb_vmstate;
  
  static void usb_host_vm_state(void *unused, int 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);
  }
  
  /**
   * Check whether USB host device has a USB mass storage SCSI interface
   */
  bool usb_host_dev_is_scsi_storage(USBDevice *ud)
  {
      USBHostDevice *uhd = USB_HOST_DEVICE(ud);
      struct libusb_config_descriptor *conf;
      const struct libusb_interface_descriptor *intf;
      bool is_scsi_storage = false;
      int i;
  
      if (!uhd || libusb_get_active_config_descriptor(uhd->dev, &conf) != 0) {
          return false;
      }
  
      for (i = 0; i < conf->bNumInterfaces; i++) {
          intf = &conf->interface[i].altsetting[ud->altsetting[i]];
          if (intf->bInterfaceClass == LIBUSB_CLASS_MASS_STORAGE &&
              intf->bInterfaceSubClass == 6) {                 /* 6 means SCSI */
              is_scsi_storage = true;
              break;
          }
      }
  
      libusb_free_config_descriptor(conf);
  
      return is_scsi_storage;
  }
  
  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);
  }
  