diff --git a/hw/tusb6010.c b/hw/tusb6010.c
index de6ffc6133..ce7c81f8f2 100644
--- a/hw/tusb6010.c
+++ b/hw/tusb6010.c
@@ -771,13 +771,12 @@ static void tusb6010_reset(DeviceState *dev)
     for (i = 0; i < 15; i++) {
         s->rx_config[i] = s->tx_config[i] = 0;
     }
+    musb_reset(s->musb);
 }
 
 static int tusb6010_init(SysBusDevice *dev)
 {
     TUSBState *s = FROM_SYSBUS(TUSBState, dev);
-    qemu_irq *musb_irqs;
-    int i;
     s->otg_timer = qemu_new_timer_ns(vm_clock, tusb_otg_tick, s);
     s->pwr_timer = qemu_new_timer_ns(vm_clock, tusb_power_tick, s);
     memory_region_init_io(&s->iomem[1], &tusb_async_ops, s, "tusb-async",
@@ -785,12 +784,8 @@ static int tusb6010_init(SysBusDevice *dev)
     sysbus_init_mmio_region(dev, &s->iomem[0]);
     sysbus_init_mmio_region(dev, &s->iomem[1]);
     sysbus_init_irq(dev, &s->irq);
-    qdev_init_gpio_in(&dev->qdev, tusb6010_irq, __musb_irq_max + 1);
-    musb_irqs = g_new0(qemu_irq, __musb_irq_max);
-    for (i = 0; i < __musb_irq_max; i++) {
-        musb_irqs[i] = qdev_get_gpio_in(&dev->qdev, i + 1);
-    }
-    s->musb = musb_init(musb_irqs);
+    qdev_init_gpio_in(&dev->qdev, tusb6010_irq, musb_irq_max + 1);
+    s->musb = musb_init(&dev->qdev, 1);
     return 0;
 }
 
diff --git a/hw/usb-bus.c b/hw/usb-bus.c
index c0bbc7c6b0..93f640d370 100644
--- a/hw/usb-bus.c
+++ b/hw/usb-bus.c
@@ -3,6 +3,7 @@
 #include "qdev.h"
 #include "sysemu.h"
 #include "monitor.h"
+#include "trace.h"
 
 static void usb_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent);
 
@@ -73,9 +74,13 @@ static int usb_qdev_init(DeviceState *qdev, DeviceInfo *base)
     dev->info = info;
     dev->auto_attach = 1;
     QLIST_INIT(&dev->strings);
-    rc = dev->info->init(dev);
-    if (rc == 0 && dev->auto_attach)
+    rc = usb_claim_port(dev);
+    if (rc == 0) {
+        rc = dev->info->init(dev);
+    }
+    if (rc == 0 && dev->auto_attach) {
         rc = usb_device_attach(dev);
+    }
     return rc;
 }
 
@@ -89,6 +94,9 @@ static int usb_qdev_exit(DeviceState *qdev)
     if (dev->info->handle_destroy) {
         dev->info->handle_destroy(dev);
     }
+    if (dev->port) {
+        usb_release_port(dev);
+    }
     return 0;
 }
 
@@ -205,21 +213,13 @@ void usb_unregister_port(USBBus *bus, USBPort *port)
     bus->nfree--;
 }
 
-static int do_attach(USBDevice *dev)
+int usb_claim_port(USBDevice *dev)
 {
     USBBus *bus = usb_bus_from_device(dev);
     USBPort *port;
 
-    if (dev->attached) {
-        error_report("Error: tried to attach usb device %s twice\n",
-                dev->product_desc);
-        return -1;
-    }
-    if (bus->nfree == 0) {
-        error_report("Error: tried to attach usb device %s to a bus with no free ports\n",
-                dev->product_desc);
-        return -1;
-    }
+    assert(dev->port == NULL);
+
     if (dev->port_path) {
         QTAILQ_FOREACH(port, &bus->free, next) {
             if (strcmp(port->path, dev->port_path) == 0) {
@@ -227,68 +227,86 @@ static int do_attach(USBDevice *dev)
             }
         }
         if (port == NULL) {
-            error_report("Error: usb port %s (bus %s) not found\n",
-                    dev->port_path, bus->qbus.name);
+            error_report("Error: usb port %s (bus %s) not found (in use?)\n",
+                         dev->port_path, bus->qbus.name);
             return -1;
         }
     } else {
+        if (bus->nfree == 1 && strcmp(dev->qdev.info->name, "usb-hub") != 0) {
+            /* Create a new hub and chain it on */
+            usb_create_simple(bus, "usb-hub");
+        }
+        if (bus->nfree == 0) {
+            error_report("Error: tried to attach usb device %s to a bus "
+                         "with no free ports\n", dev->product_desc);
+            return -1;
+        }
         port = QTAILQ_FIRST(&bus->free);
     }
-    if (!(port->speedmask & dev->speedmask)) {
-        error_report("Warning: speed mismatch trying to attach usb device %s to bus %s\n",
-                dev->product_desc, bus->qbus.name);
-        return -1;
-    }
+    trace_usb_port_claim(bus->busnr, port->path);
 
-    dev->attached++;
     QTAILQ_REMOVE(&bus->free, port, next);
     bus->nfree--;
 
-    usb_attach(port, dev);
+    dev->port = port;
+    port->dev = dev;
 
     QTAILQ_INSERT_TAIL(&bus->used, port, next);
     bus->nused++;
-
     return 0;
 }
 
+void usb_release_port(USBDevice *dev)
+{
+    USBBus *bus = usb_bus_from_device(dev);
+    USBPort *port = dev->port;
+
+    assert(port != NULL);
+    trace_usb_port_release(bus->busnr, port->path);
+
+    QTAILQ_REMOVE(&bus->used, port, next);
+    bus->nused--;
+
+    dev->port = NULL;
+    port->dev = NULL;
+
+    QTAILQ_INSERT_TAIL(&bus->free, port, next);
+    bus->nfree++;
+}
+
 int usb_device_attach(USBDevice *dev)
 {
     USBBus *bus = usb_bus_from_device(dev);
+    USBPort *port = dev->port;
 
-    if (bus->nfree == 1 && dev->port_path == NULL) {
-        /* Create a new hub and chain it on
-           (unless a physical port location is specified). */
-        usb_create_simple(bus, "usb-hub");
+    assert(port != NULL);
+    assert(!dev->attached);
+    trace_usb_port_attach(bus->busnr, port->path);
+
+    if (!(port->speedmask & dev->speedmask)) {
+        error_report("Warning: speed mismatch trying to attach "
+                     "usb device %s to bus %s\n",
+                     dev->product_desc, bus->qbus.name);
+        return -1;
     }
-    return do_attach(dev);
+
+    dev->attached++;
+    usb_attach(port);
+
+    return 0;
 }
 
 int usb_device_detach(USBDevice *dev)
 {
     USBBus *bus = usb_bus_from_device(dev);
-    USBPort *port;
+    USBPort *port = dev->port;
 
-    if (!dev->attached) {
-        error_report("Error: tried to detach unattached usb device %s\n",
-                dev->product_desc);
-        return -1;
-    }
-    dev->attached--;
-
-    QTAILQ_FOREACH(port, &bus->used, next) {
-        if (port->dev == dev)
-            break;
-    }
     assert(port != NULL);
+    assert(dev->attached);
+    trace_usb_port_detach(bus->busnr, port->path);
 
-    QTAILQ_REMOVE(&bus->used, port, next);
-    bus->nused--;
-
-    usb_attach(port, NULL);
-
-    QTAILQ_INSERT_TAIL(&bus->free, port, next);
-    bus->nfree++;
+    usb_detach(port);
+    dev->attached--;
     return 0;
 }
 
diff --git a/hw/usb-ccid.c b/hw/usb-ccid.c
index c2f9241014..cd349f3f17 100644
--- a/hw/usb-ccid.c
+++ b/hw/usb-ccid.c
@@ -37,6 +37,7 @@
 #include "qemu-common.h"
 #include "qemu-error.h"
 #include "usb.h"
+#include "usb-desc.h"
 #include "monitor.h"
 
 #include "hw/ccid.h"
@@ -306,56 +307,7 @@ typedef struct USBCCIDState {
  *   0dc3:1004 Athena Smartcard Solutions, Inc.
  */
 
-static const uint8_t qemu_ccid_dev_descriptor[] = {
-        0x12,       /*  u8 bLength; */
-        USB_DT_DEVICE, /*  u8 bDescriptorType; Device */
-        0x10, 0x01, /*  u16 bcdUSB; v1.1 */
-
-        0x00,       /*  u8  bDeviceClass; */
-        0x00,       /*  u8  bDeviceSubClass; */
-        0x00,       /*  u8  bDeviceProtocol; [ low/full speeds only ] */
-        0x40,       /*  u8  bMaxPacketSize0; 8 Bytes (valid: 8,16,32,64) */
-
-        /* Vendor and product id are arbitrary.  */
-                    /*  u16 idVendor  */
-        CCID_VENDOR_ID & 0xff, CCID_VENDOR_ID >> 8,
-                    /*  u16 idProduct */
-        CCID_PRODUCT_ID & 0xff, CCID_PRODUCT_ID >> 8,
-                    /*  u16 bcdDevice */
-        CCID_DEVICE_VERSION & 0xff, CCID_DEVICE_VERSION >> 8,
-        0x01,       /*  u8  iManufacturer; */
-        0x02,       /*  u8  iProduct; */
-        0x03,       /*  u8  iSerialNumber; */
-        0x01,       /*  u8  bNumConfigurations; */
-};
-
-static const uint8_t qemu_ccid_config_descriptor[] = {
-
-        /* one configuration */
-        0x09,       /* u8  bLength; */
-        USB_DT_CONFIG, /* u8  bDescriptorType; Configuration */
-        0x5d, 0x00, /* u16 wTotalLength; 9+9+54+7+7+7 */
-        0x01,       /* u8  bNumInterfaces; (1) */
-        0x01,       /* u8  bConfigurationValue; */
-        0x00,       /* u8  iConfiguration; */
-        0xe0,       /* u8  bmAttributes;
-                                 Bit 7: must be set,
-                                     6: Self-powered,
-                                     5: Remote wakeup,
-                                     4..0: resvd */
-        100/2,      /* u8  MaxPower; 50 == 100mA */
-
-        /* one interface */
-        0x09,       /* u8  if_bLength; */
-        USB_DT_INTERFACE, /* u8  if_bDescriptorType; Interface */
-        0x00,       /* u8  if_bInterfaceNumber; */
-        0x00,       /* u8  if_bAlternateSetting; */
-        0x03,       /* u8  if_bNumEndpoints; */
-        0x0b,       /* u8  if_bInterfaceClass; Smart Card Device Class */
-        0x00,       /* u8  if_bInterfaceSubClass; Subclass code */
-        0x00,       /* u8  if_bInterfaceProtocol; Protocol code */
-        0x04,       /* u8  if_iInterface; Index of string descriptor */
-
+static const uint8_t qemu_ccid_descriptor[] = {
         /* Smart Card Device Class Descriptor */
         0x36,       /* u8  bLength; */
         0x21,       /* u8  bDescriptorType; Functional */
@@ -439,38 +391,81 @@ static const uint8_t qemu_ccid_config_descriptor[] = {
                      *                  02h PIN Modification
                      */
         0x01,       /* u8  bMaxCCIDBusySlots; */
+};
 
-        /* Interrupt-IN endpoint */
-        0x07,       /* u8  ep_bLength; */
-                    /* u8  ep_bDescriptorType; Endpoint */
-        USB_DT_ENDPOINT,
-                    /* u8  ep_bEndpointAddress; IN Endpoint 1 */
-        0x80 | CCID_INT_IN_EP,
-        0x03,       /* u8  ep_bmAttributes; Interrupt */
-                    /* u16 ep_wMaxPacketSize; */
-        CCID_MAX_PACKET_SIZE & 0xff, (CCID_MAX_PACKET_SIZE >> 8),
-        0xff,       /* u8  ep_bInterval; */
+enum {
+    STR_MANUFACTURER = 1,
+    STR_PRODUCT,
+    STR_SERIALNUMBER,
+    STR_INTERFACE,
+};
 
-        /* Bulk-In endpoint */
-        0x07,       /* u8  ep_bLength; */
-                    /* u8  ep_bDescriptorType; Endpoint */
-        USB_DT_ENDPOINT,
-                    /* u8  ep_bEndpointAddress; IN Endpoint 2 */
-        0x80 | CCID_BULK_IN_EP,
-        0x02,       /* u8  ep_bmAttributes; Bulk */
-        0x40, 0x00, /* u16 ep_wMaxPacketSize; */
-        0x00,       /* u8  ep_bInterval; */
+static const USBDescStrings desc_strings = {
+    [STR_MANUFACTURER]  = "QEMU " QEMU_VERSION,
+    [STR_PRODUCT]       = "QEMU USB CCID",
+    [STR_SERIALNUMBER]  = "1",
+    [STR_INTERFACE]     = "CCID Interface",
+};
 
-        /* Bulk-Out endpoint */
-        0x07,       /* u8  ep_bLength; */
-                    /* u8  ep_bDescriptorType; Endpoint */
-        USB_DT_ENDPOINT,
-                    /* u8  ep_bEndpointAddress; OUT Endpoint 3 */
-        CCID_BULK_OUT_EP,
-        0x02,       /* u8  ep_bmAttributes; Bulk */
-        0x40, 0x00, /* u16 ep_wMaxPacketSize; */
-        0x00,       /* u8  ep_bInterval; */
+static const USBDescIface desc_iface0 = {
+    .bInterfaceNumber              = 0,
+    .bNumEndpoints                 = 3,
+    .bInterfaceClass               = 0x0b,
+    .bInterfaceSubClass            = 0x00,
+    .bInterfaceProtocol            = 0x00,
+    .iInterface                    = STR_INTERFACE,
+    .ndesc                         = 1,
+    .descs = (USBDescOther[]) {
+        {
+            /* smartcard descriptor */
+            .data = qemu_ccid_descriptor,
+        },
+    },
+    .eps = (USBDescEndpoint[]) {
+        {
+            .bEndpointAddress      = USB_DIR_IN | CCID_INT_IN_EP,
+            .bmAttributes          = USB_ENDPOINT_XFER_INT,
+            .bInterval             = 255,
+            .wMaxPacketSize        = 64,
+        },{
+            .bEndpointAddress      = USB_DIR_IN | CCID_BULK_IN_EP,
+            .bmAttributes          = USB_ENDPOINT_XFER_BULK,
+            .wMaxPacketSize        = 64,
+        },{
+            .bEndpointAddress      = USB_DIR_OUT | CCID_BULK_OUT_EP,
+            .bmAttributes          = USB_ENDPOINT_XFER_BULK,
+            .wMaxPacketSize        = 64,
+        },
+    }
+};
 
+static const USBDescDevice desc_device = {
+    .bcdUSB                        = 0x0110,
+    .bMaxPacketSize0               = 64,
+    .bNumConfigurations            = 1,
+    .confs = (USBDescConfig[]) {
+        {
+            .bNumInterfaces        = 1,
+            .bConfigurationValue   = 1,
+            .bmAttributes          = 0xa0,
+            .bMaxPower             = 50,
+            .nif = 1,
+            .ifs = &desc_iface0,
+        },
+    },
+};
+
+static const USBDesc desc_ccid = {
+    .id = {
+        .idVendor          = CCID_VENDOR_ID,
+        .idProduct         = CCID_PRODUCT_ID,
+        .bcdDevice         = CCID_DEVICE_VERSION,
+        .iManufacturer     = STR_MANUFACTURER,
+        .iProduct          = STR_PRODUCT,
+        .iSerialNumber     = STR_SERIALNUMBER,
+    },
+    .full = &desc_device,
+    .str  = desc_strings,
 };
 
 static bool ccid_has_pending_answers(USBCCIDState *s)
@@ -610,87 +605,12 @@ static int ccid_handle_control(USBDevice *dev, USBPacket *p, int request,
     int ret = 0;
 
     DPRINTF(s, 1, "got control %x, value %x\n", request, value);
+    ret = usb_desc_handle_control(dev, p, request, value, index, length, data);
+    if (ret >= 0) {
+        return ret;
+    }
+
     switch (request) {
-    case DeviceRequest | USB_REQ_GET_STATUS:
-        data[0] = (1 << USB_DEVICE_SELF_POWERED) |
-            (dev->remote_wakeup << USB_DEVICE_REMOTE_WAKEUP);
-        data[1] = 0x00;
-        ret = 2;
-        break;
-    case DeviceOutRequest | USB_REQ_CLEAR_FEATURE:
-        if (value == USB_DEVICE_REMOTE_WAKEUP) {
-            dev->remote_wakeup = 0;
-        } else {
-            goto fail;
-        }
-        ret = 0;
-        break;
-    case DeviceOutRequest | USB_REQ_SET_FEATURE:
-        if (value == USB_DEVICE_REMOTE_WAKEUP) {
-            dev->remote_wakeup = 1;
-        } else {
-            goto fail;
-        }
-        ret = 0;
-        break;
-    case DeviceOutRequest | USB_REQ_SET_ADDRESS:
-        dev->addr = value;
-        ret = 0;
-        break;
-    case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
-        switch (value >> 8) {
-        case USB_DT_DEVICE:
-            memcpy(data, qemu_ccid_dev_descriptor,
-                   sizeof(qemu_ccid_dev_descriptor));
-            ret = sizeof(qemu_ccid_dev_descriptor);
-            break;
-        case USB_DT_CONFIG:
-            memcpy(data, qemu_ccid_config_descriptor,
-                   sizeof(qemu_ccid_config_descriptor));
-            ret = sizeof(qemu_ccid_config_descriptor);
-            break;
-        case USB_DT_STRING:
-            switch (value & 0xff) {
-            case 0:
-                /* language ids */
-                data[0] = 4;
-                data[1] = 3;
-                data[2] = 0x09;
-                data[3] = 0x04;
-                ret = 4;
-                break;
-            case 1:
-                /* vendor description */
-                ret = set_usb_string(data, CCID_VENDOR_DESCRIPTION);
-                break;
-            case 2:
-                /* product description */
-                ret = set_usb_string(data, CCID_PRODUCT_DESCRIPTION);
-                break;
-            case 3:
-                /* serial number */
-                ret = set_usb_string(data, CCID_SERIAL_NUMBER_STRING);
-                break;
-            case 4:
-                /* interface name */
-                ret = set_usb_string(data, CCID_INTERFACE_NAME);
-                break;
-            default:
-                goto fail;
-            }
-            break;
-        default:
-            goto fail;
-        }
-        break;
-    case DeviceRequest | USB_REQ_GET_CONFIGURATION:
-        data[0] = 1;
-        ret = 1;
-        break;
-    case DeviceOutRequest | USB_REQ_SET_CONFIGURATION:
-        /* Only one configuration - we just ignore the request */
-        ret = 0;
-        break;
     case DeviceRequest | USB_REQ_GET_INTERFACE:
         data[0] = 0;
         ret = 1;
@@ -698,9 +618,6 @@ static int ccid_handle_control(USBDevice *dev, USBPacket *p, int request,
     case InterfaceOutRequest | USB_REQ_SET_INTERFACE:
         ret = 0;
         break;
-    case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
-        ret = 0;
-        break;
 
         /* Class specific requests.  */
     case InterfaceOutClass | CCID_CONTROL_ABORT:
@@ -716,7 +633,6 @@ static int ccid_handle_control(USBDevice *dev, USBPacket *p, int request,
         ret = USB_RET_STALL;
         break;
     default:
-fail:
         DPRINTF(s, 1, "got unsupported/bogus control %x, value %x\n",
                 request, value);
         ret = USB_RET_STALL;
@@ -895,6 +811,7 @@ static void ccid_on_slot_change(USBCCIDState *s, bool full)
         s->bmSlotICCState |= SLOT_0_CHANGED_MASK;
     }
     s->notify_slot_change = true;
+    usb_wakeup(&s->dev);
 }
 
 static void ccid_write_data_block_error(
@@ -1075,6 +992,7 @@ static int ccid_handle_data(USBDevice *dev, USBPacket *p)
             break;
         default:
             DPRINTF(s, 1, "Bad endpoint\n");
+            ret = USB_RET_STALL;
             break;
         }
         break;
@@ -1256,6 +1174,7 @@ static int ccid_initfn(USBDevice *dev)
 {
     USBCCIDState *s = DO_UPCAST(USBCCIDState, dev, dev);
 
+    usb_desc_init(dev);
     qbus_create_inplace(&s->bus.qbus, &ccid_bus_info, &dev->qdev, NULL);
     s->bus.qbus.allow_hotplug = 1;
     s->card = NULL;
@@ -1381,6 +1300,7 @@ static struct USBDeviceInfo ccid_info = {
     .qdev.desc      = "CCID Rev 1.1 smartcard reader",
     .qdev.size      = sizeof(USBCCIDState),
     .init           = ccid_initfn,
+    .usb_desc       = &desc_ccid,
     .handle_packet  = usb_generic_handle_packet,
     .handle_reset   = ccid_handle_reset,
     .handle_control = ccid_handle_control,
diff --git a/hw/usb-desc.h b/hw/usb-desc.h
index 9d7ed599ce..5c14e4abdc 100644
--- a/hw/usb-desc.h
+++ b/hw/usb-desc.h
@@ -75,7 +75,7 @@ struct USBDescEndpoint {
 
 struct USBDescOther {
     uint8_t                   length;
-    uint8_t                   *data;
+    const uint8_t             *data;
 };
 
 typedef const char *USBDescStrings[256];
diff --git a/hw/usb-ehci.c b/hw/usb-ehci.c
index 47a7fb9de4..e9e0789795 100644
--- a/hw/usb-ehci.c
+++ b/hw/usb-ehci.c
@@ -149,6 +149,7 @@ typedef enum {
     EST_FETCHENTRY,
     EST_FETCHQH,
     EST_FETCHITD,
+    EST_FETCHSITD,
     EST_ADVANCEQUEUE,
     EST_FETCHQTD,
     EST_EXECUTE,
@@ -646,6 +647,13 @@ static void ehci_trace_itd(EHCIState *s, target_phys_addr_t addr, EHCIitd *itd)
                        get_field(itd->bufptr[0], ITD_BUFPTR_DEVADDR));
 }
 
+static void ehci_trace_sitd(EHCIState *s, target_phys_addr_t addr,
+                            EHCIsitd *sitd)
+{
+    trace_usb_ehci_sitd(addr, sitd->next,
+                        (bool)(sitd->results & SITD_RESULTS_ACTIVE));
+}
+
 /* queue management */
 
 static EHCIQueue *ehci_alloc_queue(EHCIState *ehci, int async)
@@ -849,8 +857,8 @@ static void ehci_reset(void *opaque)
      */
     for(i = 0; i < NB_PORTS; i++) {
         devs[i] = s->ports[i].dev;
-        if (devs[i]) {
-            usb_attach(&s->ports[i], NULL);
+        if (devs[i] && devs[i]->attached) {
+            usb_detach(&s->ports[i]);
         }
     }
 
@@ -870,8 +878,8 @@ static void ehci_reset(void *opaque)
         } else {
             s->portsc[i] = PORTSC_PPOWER;
         }
-        if (devs[i]) {
-            usb_attach(&s->ports[i], devs[i]);
+        if (devs[i] && devs[i]->attached) {
+            usb_attach(&s->ports[i]);
         }
     }
     ehci_queues_rip_all(s);
@@ -937,15 +945,15 @@ static void handle_port_owner_write(EHCIState *s, int port, uint32_t owner)
         return;
     }
 
-    if (dev) {
-        usb_attach(&s->ports[port], NULL);
+    if (dev && dev->attached) {
+        usb_detach(&s->ports[port]);
     }
 
     *portsc &= ~PORTSC_POWNER;
     *portsc |= owner;
 
-    if (dev) {
-        usb_attach(&s->ports[port], dev);
+    if (dev && dev->attached) {
+        usb_attach(&s->ports[port]);
     }
 }
 
@@ -969,8 +977,8 @@ static void handle_port_status_write(EHCIState *s, int port, uint32_t val)
 
     if (!(val & PORTSC_PRESET) &&(*portsc & PORTSC_PRESET)) {
         trace_usb_ehci_port_reset(port, 0);
-        if (dev) {
-            usb_attach(&s->ports[port], dev);
+        if (dev && dev->attached) {
+            usb_attach(&s->ports[port]);
             usb_send_msg(dev, USB_MSG_RESET);
             *portsc &= ~PORTSC_CSC;
         }
@@ -979,7 +987,7 @@ static void handle_port_status_write(EHCIState *s, int port, uint32_t val)
          *  Table 2.16 Set the enable bit(and enable bit change) to indicate
          *  to SW that this port has a high speed device attached
          */
-        if (dev && (dev->speedmask & USB_SPEED_MASK_HIGH)) {
+        if (dev && dev->attached && (dev->speedmask & USB_SPEED_MASK_HIGH)) {
             val |= PORTSC_PED;
         }
     }
@@ -1584,8 +1592,13 @@ static int ehci_state_fetchentry(EHCIState *ehci, int async)
         again = 1;
         break;
 
+    case NLPTR_TYPE_STITD:
+        ehci_set_state(ehci, async, EST_FETCHSITD);
+        again = 1;
+        break;
+
     default:
-        // TODO: handle siTD and FSTN types
+        /* TODO: handle FSTN type */
         fprintf(stderr, "FETCHENTRY: entry at %X is of type %d "
                 "which is not supported yet\n", entry, NLPTR_TYPE_GET(entry));
         return -1;
@@ -1701,6 +1714,30 @@ static int ehci_state_fetchitd(EHCIState *ehci, int async)
     return 1;
 }
 
+static int ehci_state_fetchsitd(EHCIState *ehci, int async)
+{
+    uint32_t entry;
+    EHCIsitd sitd;
+
+    assert(!async);
+    entry = ehci_get_fetch_addr(ehci, async);
+
+    get_dwords(NLPTR_GET(entry), (uint32_t *)&sitd,
+               sizeof(EHCIsitd) >> 2);
+    ehci_trace_sitd(ehci, entry, &sitd);
+
+    if (!(sitd.results & SITD_RESULTS_ACTIVE)) {
+        /* siTD is not active, nothing to do */;
+    } else {
+        /* TODO: split transfers are not implemented */
+        fprintf(stderr, "WARNING: Skipping active siTD\n");
+    }
+
+    ehci_set_fetch_addr(ehci, async, sitd.next);
+    ehci_set_state(ehci, async, EST_FETCHENTRY);
+    return 1;
+}
+
 /* Section 4.10.2 - paragraph 3 */
 static int ehci_state_advqueue(EHCIQueue *q, int async)
 {
@@ -1976,6 +2013,10 @@ static void ehci_advance_state(EHCIState *ehci,
             again = ehci_state_fetchitd(ehci, async);
             break;
 
+        case EST_FETCHSITD:
+            again = ehci_state_fetchsitd(ehci, async);
+            break;
+
         case EST_ADVANCEQUEUE:
             again = ehci_state_advqueue(q, async);
             break;
diff --git a/hw/usb-hub.c b/hw/usb-hub.c
index c49c547d0c..286e3ad85d 100644
--- a/hw/usb-hub.c
+++ b/hw/usb-hub.c
@@ -213,16 +213,6 @@ static void usb_hub_complete(USBPort *port, USBPacket *packet)
     usb_packet_complete(&s->dev, packet);
 }
 
-static void usb_hub_handle_attach(USBDevice *dev)
-{
-    USBHubState *s = DO_UPCAST(USBHubState, dev, dev);
-    int i;
-
-    for (i = 0; i < NUM_PORTS; i++) {
-        usb_port_location(&s->ports[i].port, dev->port, i+1);
-    }
-}
-
 static void usb_hub_handle_reset(USBDevice *dev)
 {
     /* XXX: do it */
@@ -499,6 +489,7 @@ static int usb_hub_initfn(USBDevice *dev)
         usb_register_port(usb_bus_from_device(dev),
                           &port->port, s, i, &usb_hub_port_ops,
                           USB_SPEED_MASK_LOW | USB_SPEED_MASK_FULL);
+        usb_port_location(&port->port, dev->port, i+1);
         port->wPortStatus = PORT_STAT_POWER;
         port->wPortChange = 0;
     }
@@ -537,7 +528,6 @@ static struct USBDeviceInfo hub_info = {
     .usb_desc       = &desc_hub,
     .init           = usb_hub_initfn,
     .handle_packet  = usb_hub_handle_packet,
-    .handle_attach  = usb_hub_handle_attach,
     .handle_reset   = usb_hub_handle_reset,
     .handle_control = usb_hub_handle_control,
     .handle_data    = usb_hub_handle_data,
diff --git a/hw/usb-musb.c b/hw/usb-musb.c
index 799fa6e187..01e2e7c389 100644
--- a/hw/usb-musb.c
+++ b/hw/usb-musb.c
@@ -314,7 +314,7 @@ struct MUSBEndPoint {
 };
 
 struct MUSBState {
-    qemu_irq *irqs;
+    qemu_irq irqs[musb_irq_max];
     USBBus bus;
     USBPort port;
 
@@ -340,14 +340,12 @@ struct MUSBState {
     MUSBEndPoint ep[16];
 };
 
-struct MUSBState *musb_init(qemu_irq *irqs)
+void musb_reset(MUSBState *s)
 {
-    MUSBState *s = g_malloc0(sizeof(*s));
     int i;
 
-    s->irqs = irqs;
-
     s->faddr = 0x00;
+    s->devctl = 0;
     s->power = MGC_M_POWER_HSENAB;
     s->tx_intr = 0x0000;
     s->rx_intr = 0x0000;
@@ -357,6 +355,10 @@ struct MUSBState *musb_init(qemu_irq *irqs)
     s->mask = 0x06;
     s->idx = 0;
 
+    s->setup_len = 0;
+    s->session = 0;
+    memset(s->buf, 0, sizeof(s->buf));
+
     /* TODO: _DW */
     s->ep[0].config = MGC_M_CONFIGDATA_SOFTCONE | MGC_M_CONFIGDATA_DYNFIFO;
     for (i = 0; i < 16; i ++) {
@@ -368,8 +370,20 @@ struct MUSBState *musb_init(qemu_irq *irqs)
         usb_packet_init(&s->ep[i].packey[0].p);
         usb_packet_init(&s->ep[i].packey[1].p);
     }
+}
 
-    usb_bus_new(&s->bus, &musb_bus_ops, NULL /* FIXME */);
+struct MUSBState *musb_init(DeviceState *parent_device, int gpio_base)
+{
+    MUSBState *s = g_malloc0(sizeof(*s));
+    int i;
+
+    for (i = 0; i < musb_irq_max; i++) {
+        s->irqs[i] = qdev_get_gpio_in(parent_device, gpio_base + i);
+    }
+
+    musb_reset(s);
+
+    usb_bus_new(&s->bus, &musb_bus_ops, parent_device);
     usb_register_port(&s->bus, &s->port, s, 0, &musb_port_ops,
                       USB_SPEED_MASK_LOW | USB_SPEED_MASK_FULL);
 
diff --git a/hw/usb-ohci.c b/hw/usb-ohci.c
index d30db3f92f..503ca2d31f 100644
--- a/hw/usb-ohci.c
+++ b/hw/usb-ohci.c
@@ -448,8 +448,8 @@ static void ohci_reset(void *opaque)
       {
         port = &ohci->rhport[i];
         port->ctrl = 0;
-        if (port->port.dev) {
-            usb_attach(&port->port, port->port.dev);
+        if (port->port.dev && port->port.dev->attached) {
+            usb_attach(&port->port);
         }
       }
     if (ohci->async_td) {
diff --git a/hw/usb-uhci.c b/hw/usb-uhci.c
index 6ca7ca81eb..64f7b36c00 100644
--- a/hw/usb-uhci.c
+++ b/hw/usb-uhci.c
@@ -340,8 +340,8 @@ static void uhci_reset(void *opaque)
     for(i = 0; i < NB_PORTS; i++) {
         port = &s->ports[i];
         port->ctrl = 0x0080;
-        if (port->port.dev) {
-            usb_attach(&port->port, port->port.dev);
+        if (port->port.dev && port->port.dev->attached) {
+            usb_attach(&port->port);
         }
     }
 
@@ -446,7 +446,7 @@ static void uhci_ioport_writew(void *opaque, uint32_t addr, uint32_t val)
             for(i = 0; i < NB_PORTS; i++) {
                 port = &s->ports[i];
                 dev = port->port.dev;
-                if (dev) {
+                if (dev && dev->attached) {
                     usb_send_msg(dev, USB_MSG_RESET);
                 }
             }
@@ -486,7 +486,7 @@ static void uhci_ioport_writew(void *opaque, uint32_t addr, uint32_t val)
                 return;
             port = &s->ports[n];
             dev = port->port.dev;
-            if (dev) {
+            if (dev && dev->attached) {
                 /* port reset */
                 if ( (val & UHCI_PORT_RESET) &&
                      !(port->ctrl & UHCI_PORT_RESET) ) {
@@ -660,8 +660,9 @@ static int uhci_broadcast_packet(UHCIState *s, USBPacket *p)
         UHCIPort *port = &s->ports[i];
         USBDevice *dev = port->port.dev;
 
-        if (dev && (port->ctrl & UHCI_PORT_EN))
+        if (dev && dev->attached && (port->ctrl & UHCI_PORT_EN)) {
             ret = usb_handle_packet(dev, p);
+        }
     }
 
     DPRINTF("uhci: packet exit. ret %d len %zd\n", ret, p->iov.size);
diff --git a/hw/usb.c b/hw/usb.c
index 685e775a00..fa90204c5e 100644
--- a/hw/usb.c
+++ b/hw/usb.c
@@ -27,26 +27,23 @@
 #include "usb.h"
 #include "iov.h"
 
-void usb_attach(USBPort *port, USBDevice *dev)
+void usb_attach(USBPort *port)
 {
-    if (dev != NULL) {
-        /* attach */
-        if (port->dev) {
-            usb_attach(port, NULL);
-        }
-        dev->port = port;
-        port->dev = dev;
-        port->ops->attach(port);
-        usb_send_msg(dev, USB_MSG_ATTACH);
-    } else {
-        /* detach */
-        dev = port->dev;
-        assert(dev);
-        port->ops->detach(port);
-        usb_send_msg(dev, USB_MSG_DETACH);
-        dev->port = NULL;
-        port->dev = NULL;
-    }
+    USBDevice *dev = port->dev;
+
+    assert(dev != NULL);
+    assert(dev->attached);
+    port->ops->attach(port);
+    usb_send_msg(dev, USB_MSG_ATTACH);
+}
+
+void usb_detach(USBPort *port)
+{
+    USBDevice *dev = port->dev;
+
+    assert(dev != NULL);
+    port->ops->detach(port);
+    usb_send_msg(dev, USB_MSG_DETACH);
 }
 
 void usb_wakeup(USBDevice *dev)
@@ -338,8 +335,8 @@ void usb_packet_complete(USBDevice *dev, USBPacket *p)
 {
     /* Note: p->owner != dev is possible in case dev is a hub */
     assert(p->owner != NULL);
-    dev->port->ops->complete(dev->port, p);
     p->owner = NULL;
+    dev->port->ops->complete(dev->port, p);
 }
 
 /* Cancel an active packet.  The packed must have been deferred by
diff --git a/hw/usb.h b/hw/usb.h
index d784448290..c08d469496 100644
--- a/hw/usb.h
+++ b/hw/usb.h
@@ -304,7 +304,8 @@ int usb_handle_packet(USBDevice *dev, USBPacket *p);
 void usb_packet_complete(USBDevice *dev, USBPacket *p);
 void usb_cancel_packet(USBPacket * p);
 
-void usb_attach(USBPort *port, USBDevice *dev);
+void usb_attach(USBPort *port);
+void usb_detach(USBPort *port);
 void usb_wakeup(USBDevice *dev);
 int usb_generic_handle_packet(USBDevice *s, USBPacket *p);
 void usb_generic_async_ctrl_complete(USBDevice *s, USBPacket *p);
@@ -337,11 +338,13 @@ enum musb_irq_source_e {
     musb_irq_tx,
     musb_set_vbus,
     musb_set_session,
-    __musb_irq_max,
+    /* Add new interrupts here */
+    musb_irq_max, /* total number of interrupts defined */
 };
 
 typedef struct MUSBState MUSBState;
-MUSBState *musb_init(qemu_irq *irqs);
+MUSBState *musb_init(DeviceState *parent_device, int gpio_base);
+void musb_reset(MUSBState *s);
 uint32_t musb_core_intr_get(MUSBState *s);
 void musb_core_intr_clear(MUSBState *s, uint32_t mask);
 void musb_set_size(MUSBState *s, int epnum, int size, int is_tx);
@@ -378,6 +381,8 @@ int usb_register_companion(const char *masterbus, USBPort *ports[],
                            void *opaque, USBPortOps *ops, int speedmask);
 void usb_port_location(USBPort *downstream, USBPort *upstream, int portnr);
 void usb_unregister_port(USBBus *bus, USBPort *port);
+int usb_claim_port(USBDevice *dev);
+void usb_release_port(USBDevice *dev);
 int usb_device_attach(USBDevice *dev);
 int usb_device_detach(USBDevice *dev);
 int usb_device_delete_addr(int busnr, int addr);
diff --git a/trace-events b/trace-events
index 08ffedfdd1..3fdd60faa4 100644
--- a/trace-events
+++ b/trace-events
@@ -209,6 +209,12 @@ sun4m_iommu_page_get_flags(uint64_t pa, uint64_t iopte, uint32_t ret) "get flags
 sun4m_iommu_translate_pa(uint64_t addr, uint64_t pa, uint32_t iopte) "xlate dva %"PRIx64" => pa %"PRIx64" iopte = %x"
 sun4m_iommu_bad_addr(uint64_t addr) "bad addr %"PRIx64""
 
+# hw/usb-bus.c
+usb_port_claim(int bus, const char *port) "bus %d, port %s"
+usb_port_attach(int bus, const char *port) "bus %d, port %s"
+usb_port_detach(int bus, const char *port) "bus %d, port %s"
+usb_port_release(int bus, const char *port) "bus %d, port %s"
+
 # hw/usb-ehci.c
 usb_ehci_reset(void) "=== RESET ==="
 usb_ehci_mmio_readl(uint32_t addr, const char *str, uint32_t val) "rd mmio %04x [%s] = %x"
@@ -223,6 +229,7 @@ usb_ehci_qtd_ptrs(void *q, uint32_t addr, uint32_t nxt, uint32_t altnext) "q %p
 usb_ehci_qtd_fields(uint32_t addr, int tbytes, int cpage, int cerr, int pid) "QTD @ %08x - tbytes %d, cpage %d, cerr %d, pid %d"
 usb_ehci_qtd_bits(uint32_t addr, int ioc, int active, int halt, int babble, int xacterr) "QTD @ %08x - ioc %d, active %d, halt %d, babble %d, xacterr %d"
 usb_ehci_itd(uint32_t addr, uint32_t nxt, uint32_t mplen, uint32_t mult, uint32_t ep, uint32_t devaddr) "ITD @ %08x: next %08x - mplen %d, mult %d, ep %d, dev %d"
+usb_ehci_sitd(uint32_t addr, uint32_t nxt, uint32_t active) "ITD @ %08x: next %08x - active %d"
 usb_ehci_port_attach(uint32_t port, const char *device) "attach port #%d - %s"
 usb_ehci_port_detach(uint32_t port) "detach port #%d"
 usb_ehci_port_reset(uint32_t port, int enable) "reset port #%d - %d"
@@ -240,6 +247,31 @@ usb_set_config(int addr, int config, int ret) "dev %d, config %d, ret %d"
 usb_clear_device_feature(int addr, int feature, int ret) "dev %d, feature %d, ret %d"
 usb_set_device_feature(int addr, int feature, int ret) "dev %d, feature %d, ret %d"
 
+# usb-linux.c
+usb_host_open_started(int bus, int addr) "dev %d:%d"
+usb_host_open_success(int bus, int addr) "dev %d:%d"
+usb_host_open_failure(int bus, int addr) "dev %d:%d"
+usb_host_disconnect(int bus, int addr) "dev %d:%d"
+usb_host_close(int bus, int addr) "dev %d:%d"
+usb_host_set_address(int bus, int addr, int config) "dev %d:%d, address %d"
+usb_host_set_config(int bus, int addr, int config) "dev %d:%d, config %d"
+usb_host_set_interface(int bus, int addr, int interface, int alt) "dev %d:%d, interface %d, alt %d"
+usb_host_claim_interfaces(int bus, int addr, int config, int nif) "dev %d:%d, config %d, nif %d"
+usb_host_release_interfaces(int bus, int addr) "dev %d:%d"
+usb_host_req_control(int bus, int addr, int req, int value, int index) "dev %d:%d, req 0x%x, value %d, index %d"
+usb_host_req_data(int bus, int addr, int in, int ep, int size) "dev %d:%d, in %d, ep %d, size %d"
+usb_host_req_complete(int bus, int addr, int status) "dev %d:%d, status %d"
+usb_host_urb_submit(int bus, int addr, void *aurb, int length, int more) "dev %d:%d, aurb %p, length %d, more %d"
+usb_host_urb_complete(int bus, int addr, void *aurb, int status, int length, int more) "dev %d:%d, aurb %p, status %d, length %d, more %d"
+usb_host_ep_set_halt(int bus, int addr, int ep) "dev %d:%d, ep %d"
+usb_host_ep_clear_halt(int bus, int addr, int ep) "dev %d:%d, ep %d"
+usb_host_ep_start_iso(int bus, int addr, int ep) "dev %d:%d, ep %d"
+usb_host_ep_stop_iso(int bus, int addr, int ep) "dev %d:%d, ep %d"
+usb_host_reset(int bus, int addr) "dev %d:%d"
+usb_host_auto_scan_enabled(void)
+usb_host_auto_scan_disabled(void)
+usb_host_claim_port(int bus, int hub, int port) "bus %d, hub addr %d, port %d"
+
 # hw/scsi-bus.c
 scsi_req_alloc(int target, int lun, int tag) "target %d lun %d tag %d"
 scsi_req_data(int target, int lun, int tag, int len) "target %d lun %d tag %d len %d"
diff --git a/usb-linux.c b/usb-linux.c
index 2e20f8e935..2075c4c67a 100644
--- a/usb-linux.c
+++ b/usb-linux.c
@@ -34,6 +34,7 @@
 #include "qemu-timer.h"
 #include "monitor.h"
 #include "sysemu.h"
+#include "trace.h"
 
 #include <dirent.h>
 #include <sys/ioctl.h>
@@ -53,7 +54,7 @@ struct usb_ctrltransfer {
     void *data;
 };
 
-typedef int USBScanFunc(void *opaque, int bus_num, int addr, char *port,
+typedef int USBScanFunc(void *opaque, int bus_num, int addr, const char *port,
                         int class_id, int vendor_id, int product_id,
                         const char *product_name, int speed);
 
@@ -114,6 +115,7 @@ struct USBAutoFilter {
 typedef struct USBHostDevice {
     USBDevice dev;
     int       fd;
+    int       hub_fd;
 
     uint8_t   descr[8192];
     int       descr_len;
@@ -123,7 +125,8 @@ typedef struct USBHostDevice {
     uint32_t  iso_urb_count;
     Notifier  exit;
 
-    struct endp_data endp_table[MAX_ENDPOINTS];
+    struct endp_data ep_in[MAX_ENDPOINTS];
+    struct endp_data ep_out[MAX_ENDPOINTS];
     QLIST_HEAD(, AsyncURB) aurbs;
 
     /* Host side address */
@@ -131,6 +134,7 @@ typedef struct USBHostDevice {
     int addr;
     char port[MAX_PORTLEN];
     struct USBAutoFilter match;
+    int seen, errcount;
 
     QTAILQ_ENTRY(USBHostDevice) next;
 } USBHostDevice;
@@ -142,95 +146,107 @@ static int parse_filter(const char *spec, struct USBAutoFilter *f);
 static void usb_host_auto_check(void *unused);
 static int usb_host_read_file(char *line, size_t line_size,
                             const char *device_file, const char *device_name);
+static int usb_linux_update_endp_table(USBHostDevice *s);
 
-static struct endp_data *get_endp(USBHostDevice *s, int ep)
+static struct endp_data *get_endp(USBHostDevice *s, int pid, int ep)
 {
-    return s->endp_table + ep - 1;
+    struct endp_data *eps = pid == USB_TOKEN_IN ? s->ep_in : s->ep_out;
+    assert(pid == USB_TOKEN_IN || pid == USB_TOKEN_OUT);
+    assert(ep > 0 && ep <= MAX_ENDPOINTS);
+    return eps + ep - 1;
 }
 
-static int is_isoc(USBHostDevice *s, int ep)
+static int is_isoc(USBHostDevice *s, int pid, int ep)
 {
-    return get_endp(s, ep)->type == USBDEVFS_URB_TYPE_ISO;
+    return get_endp(s, pid, ep)->type == USBDEVFS_URB_TYPE_ISO;
 }
 
-static int is_valid(USBHostDevice *s, int ep)
+static int is_valid(USBHostDevice *s, int pid, int ep)
 {
-    return get_endp(s, ep)->type != INVALID_EP_TYPE;
+    return get_endp(s, pid, ep)->type != INVALID_EP_TYPE;
 }
 
-static int is_halted(USBHostDevice *s, int ep)
+static int is_halted(USBHostDevice *s, int pid, int ep)
 {
-    return get_endp(s, ep)->halted;
+    return get_endp(s, pid, ep)->halted;
 }
 
-static void clear_halt(USBHostDevice *s, int ep)
+static void clear_halt(USBHostDevice *s, int pid, int ep)
 {
-    get_endp(s, ep)->halted = 0;
+    trace_usb_host_ep_clear_halt(s->bus_num, s->addr, ep);
+    get_endp(s, pid, ep)->halted = 0;
 }
 
-static void set_halt(USBHostDevice *s, int ep)
+static void set_halt(USBHostDevice *s, int pid, int ep)
 {
-    get_endp(s, ep)->halted = 1;
+    if (ep != 0) {
+        trace_usb_host_ep_set_halt(s->bus_num, s->addr, ep);
+        get_endp(s, pid, ep)->halted = 1;
+    }
 }
 
-static int is_iso_started(USBHostDevice *s, int ep)
+static int is_iso_started(USBHostDevice *s, int pid, int ep)
 {
-    return get_endp(s, ep)->iso_started;
+    return get_endp(s, pid, ep)->iso_started;
 }
 
-static void clear_iso_started(USBHostDevice *s, int ep)
+static void clear_iso_started(USBHostDevice *s, int pid, int ep)
 {
-    get_endp(s, ep)->iso_started = 0;
+    trace_usb_host_ep_stop_iso(s->bus_num, s->addr, ep);
+    get_endp(s, pid, ep)->iso_started = 0;
 }
 
-static void set_iso_started(USBHostDevice *s, int ep)
+static void set_iso_started(USBHostDevice *s, int pid, int ep)
 {
-    struct endp_data *e = get_endp(s, ep);
+    struct endp_data *e = get_endp(s, pid, ep);
+
+    trace_usb_host_ep_start_iso(s->bus_num, s->addr, ep);
     if (!e->iso_started) {
         e->iso_started = 1;
         e->inflight = 0;
     }
 }
 
-static int change_iso_inflight(USBHostDevice *s, int ep, int value)
+static int change_iso_inflight(USBHostDevice *s, int pid, int ep, int value)
 {
-    struct endp_data *e = get_endp(s, ep);
+    struct endp_data *e = get_endp(s, pid, ep);
 
     e->inflight += value;
     return e->inflight;
 }
 
-static void set_iso_urb(USBHostDevice *s, int ep, AsyncURB *iso_urb)
+static void set_iso_urb(USBHostDevice *s, int pid, int ep, AsyncURB *iso_urb)
 {
-    get_endp(s, ep)->iso_urb = iso_urb;
+    get_endp(s, pid, ep)->iso_urb = iso_urb;
 }
 
-static AsyncURB *get_iso_urb(USBHostDevice *s, int ep)
+static AsyncURB *get_iso_urb(USBHostDevice *s, int pid, int ep)
 {
-    return get_endp(s, ep)->iso_urb;
+    return get_endp(s, pid, ep)->iso_urb;
 }
 
-static void set_iso_urb_idx(USBHostDevice *s, int ep, int i)
+static void set_iso_urb_idx(USBHostDevice *s, int pid, int ep, int i)
 {
-    get_endp(s, ep)->iso_urb_idx = i;
+    get_endp(s, pid, ep)->iso_urb_idx = i;
 }
 
-static int get_iso_urb_idx(USBHostDevice *s, int ep)
+static int get_iso_urb_idx(USBHostDevice *s, int pid, int ep)
 {
-    return get_endp(s, ep)->iso_urb_idx;
+    return get_endp(s, pid, ep)->iso_urb_idx;
 }
 
-static void set_iso_buffer_used(USBHostDevice *s, int ep, int i)
+static void set_iso_buffer_used(USBHostDevice *s, int pid, int ep, int i)
 {
-    get_endp(s, ep)->iso_buffer_used = i;
+    get_endp(s, pid, ep)->iso_buffer_used = i;
 }
 
-static int get_iso_buffer_used(USBHostDevice *s, int ep)
+static int get_iso_buffer_used(USBHostDevice *s, int pid, int ep)
 {
-    return get_endp(s, ep)->iso_buffer_used;
+    return get_endp(s, pid, ep)->iso_buffer_used;
 }
 
-static void set_max_packet_size(USBHostDevice *s, int ep, uint8_t *descriptor)
+static void set_max_packet_size(USBHostDevice *s, int pid, int ep,
+                                uint8_t *descriptor)
 {
     int raw = descriptor[4] + (descriptor[5] << 8);
     int size, microframes;
@@ -241,12 +257,12 @@ static void set_max_packet_size(USBHostDevice *s, int ep, uint8_t *descriptor)
     case 2:  microframes = 3; break;
     default: microframes = 1; break;
     }
-    get_endp(s, ep)->max_packet_size = size * microframes;
+    get_endp(s, pid, ep)->max_packet_size = size * microframes;
 }
 
-static int get_max_packet_size(USBHostDevice *s, int ep)
+static int get_max_packet_size(USBHostDevice *s, int pid, int ep)
 {
-    return get_endp(s, ep)->max_packet_size;
+    return get_endp(s, pid, ep)->max_packet_size;
 }
 
 /*
@@ -285,8 +301,6 @@ static void async_free(AsyncURB *aurb)
 
 static void do_disconnect(USBHostDevice *s)
 {
-    printf("husb: device %d.%d disconnected\n",
-           s->bus_num, s->addr);
     usb_host_close(s);
     usb_host_auto_check(NULL);
 }
@@ -308,12 +322,15 @@ static void async_complete(void *opaque)
                 }
                 return;
             }
-            if (errno == ENODEV && !s->closing) {
-                do_disconnect(s);
+            if (errno == ENODEV) {
+                if (!s->closing) {
+                    trace_usb_host_disconnect(s->bus_num, s->addr);
+                    do_disconnect(s);
+                }
                 return;
             }
 
-            DPRINTF("husb: async. reap urb failed errno %d\n", errno);
+            perror("USBDEVFS_REAPURBNDELAY");
             return;
         }
 
@@ -324,19 +341,24 @@ static void async_complete(void *opaque)
            anything else (it is handled further in usb_host_handle_iso_data) */
         if (aurb->iso_frame_idx == -1) {
             int inflight;
+            int pid = (aurb->urb.endpoint & USB_DIR_IN) ?
+                USB_TOKEN_IN : USB_TOKEN_OUT;
+            int ep = aurb->urb.endpoint & 0xf;
             if (aurb->urb.status == -EPIPE) {
-                set_halt(s, aurb->urb.endpoint & 0xf);
+                set_halt(s, pid, ep);
             }
             aurb->iso_frame_idx = 0;
             urbs++;
-            inflight = change_iso_inflight(s, aurb->urb.endpoint & 0xf, -1);
-            if (inflight == 0 && is_iso_started(s, aurb->urb.endpoint & 0xf)) {
+            inflight = change_iso_inflight(s, pid, ep, -1);
+            if (inflight == 0 && is_iso_started(s, pid, ep)) {
                 fprintf(stderr, "husb: out of buffers for iso stream\n");
             }
             continue;
         }
 
         p = aurb->packet;
+        trace_usb_host_urb_complete(s->bus_num, s->addr, aurb, aurb->urb.status,
+                                    aurb->urb.actual_length, aurb->more);
 
         if (p) {
             switch (aurb->urb.status) {
@@ -345,7 +367,7 @@ static void async_complete(void *opaque)
                 break;
 
             case -EPIPE:
-                set_halt(s, p->devep);
+                set_halt(s, p->pid, p->devep);
                 p->result = USB_RET_STALL;
                 break;
 
@@ -355,8 +377,10 @@ static void async_complete(void *opaque)
             }
 
             if (aurb->urb.type == USBDEVFS_URB_TYPE_CONTROL) {
+                trace_usb_host_req_complete(s->bus_num, s->addr, p->result);
                 usb_generic_async_ctrl_complete(&s->dev, p);
             } else if (!aurb->more) {
+                trace_usb_host_req_complete(s->bus_num, s->addr, p->result);
                 usb_packet_complete(&s->dev, p);
             }
         }
@@ -394,8 +418,11 @@ static int usb_host_claim_interfaces(USBHostDevice *dev, int configuration)
     int interface, nb_interfaces;
     int ret, i;
 
-    if (configuration == 0) /* address state - ignore */
+    if (configuration == 0) { /* address state - ignore */
+        dev->ninterfaces   = 0;
+        dev->configuration = 0;
         return 1;
+    }
 
     DPRINTF("husb: claiming interfaces. config %d\n", configuration);
 
@@ -418,9 +445,9 @@ static int usb_host_claim_interfaces(USBHostDevice *dev, int configuration)
         }
         config_descr_len = dev->descr[i];
 
-        printf("husb: config #%d need %d\n", dev->descr[i + 5], configuration);
+        DPRINTF("husb: config #%d need %d\n", dev->descr[i + 5], configuration);
 
-        if (configuration < 0 || configuration == dev->descr[i + 5]) {
+        if (configuration == dev->descr[i + 5]) {
             configuration = dev->descr[i + 5];
             break;
         }
@@ -457,17 +484,12 @@ static int usb_host_claim_interfaces(USBHostDevice *dev, int configuration)
         op = "USBDEVFS_CLAIMINTERFACE";
         ret = ioctl(dev->fd, USBDEVFS_CLAIMINTERFACE, &interface);
         if (ret < 0) {
-            if (errno == EBUSY) {
-                printf("husb: update iface. device already grabbed\n");
-            } else {
-                perror("husb: failed to claim interface");
-            }
             goto fail;
         }
     }
 
-    printf("husb: %d interfaces claimed for configuration %d\n",
-           nb_interfaces, configuration);
+    trace_usb_host_claim_interfaces(dev->bus_num, dev->addr,
+                                    nb_interfaces, configuration);
 
     dev->ninterfaces   = nb_interfaces;
     dev->configuration = configuration;
@@ -485,16 +507,15 @@ static int usb_host_release_interfaces(USBHostDevice *s)
 {
     int ret, i;
 
-    DPRINTF("husb: releasing interfaces\n");
+    trace_usb_host_release_interfaces(s->bus_num, s->addr);
 
     for (i = 0; i < s->ninterfaces; i++) {
         ret = ioctl(s->fd, USBDEVFS_RELEASEINTERFACE, &i);
         if (ret < 0) {
-            perror("husb: failed to release interface");
+            perror("USBDEVFS_RELEASEINTERFACE");
             return 0;
         }
     }
-
     return 1;
 }
 
@@ -502,11 +523,12 @@ static void usb_host_handle_reset(USBDevice *dev)
 {
     USBHostDevice *s = DO_UPCAST(USBHostDevice, dev, dev);
 
-    DPRINTF("husb: reset device %u.%u\n", s->bus_num, s->addr);
+    trace_usb_host_reset(s->bus_num, s->addr);
 
     ioctl(s->fd, USBDEVFS_RESET);
 
-    usb_host_claim_interfaces(s, s->configuration);
+    usb_host_claim_interfaces(s, 0);
+    usb_linux_update_endp_table(s);
 }
 
 static void usb_host_handle_destroy(USBDevice *dev)
@@ -514,19 +536,20 @@ static void usb_host_handle_destroy(USBDevice *dev)
     USBHostDevice *s = (USBHostDevice *)dev;
 
     usb_host_close(s);
+    if (s->hub_fd != -1) {
+        close(s->hub_fd);
+    }
     QTAILQ_REMOVE(&hostdevs, s, next);
     qemu_remove_exit_notifier(&s->exit);
 }
 
-static int usb_linux_update_endp_table(USBHostDevice *s);
-
 /* iso data is special, we need to keep enough urbs in flight to make sure
    that the controller never runs out of them, otherwise the device will
    likely suffer a buffer underrun / overrun. */
-static AsyncURB *usb_host_alloc_iso(USBHostDevice *s, uint8_t ep, int in)
+static AsyncURB *usb_host_alloc_iso(USBHostDevice *s, int pid, uint8_t ep)
 {
     AsyncURB *aurb;
-    int i, j, len = get_max_packet_size(s, ep);
+    int i, j, len = get_max_packet_size(s, pid, ep);
 
     aurb = g_malloc0(s->iso_urb_count * sizeof(*aurb));
     for (i = 0; i < s->iso_urb_count; i++) {
@@ -538,23 +561,23 @@ static AsyncURB *usb_host_alloc_iso(USBHostDevice *s, uint8_t ep, int in)
         aurb[i].urb.number_of_packets = ISO_FRAME_DESC_PER_URB;
         for (j = 0 ; j < ISO_FRAME_DESC_PER_URB; j++)
             aurb[i].urb.iso_frame_desc[j].length = len;
-        if (in) {
+        if (pid == USB_TOKEN_IN) {
             aurb[i].urb.endpoint |= 0x80;
             /* Mark as fully consumed (idle) */
             aurb[i].iso_frame_idx = ISO_FRAME_DESC_PER_URB;
         }
     }
-    set_iso_urb(s, ep, aurb);
+    set_iso_urb(s, pid, ep, aurb);
 
     return aurb;
 }
 
-static void usb_host_stop_n_free_iso(USBHostDevice *s, uint8_t ep)
+static void usb_host_stop_n_free_iso(USBHostDevice *s, int pid, uint8_t ep)
 {
     AsyncURB *aurb;
     int i, ret, killed = 0, free = 1;
 
-    aurb = get_iso_urb(s, ep);
+    aurb = get_iso_urb(s, pid, ep);
     if (!aurb) {
         return;
     }
@@ -564,7 +587,7 @@ static void usb_host_stop_n_free_iso(USBHostDevice *s, uint8_t ep)
         if (aurb[i].iso_frame_idx == -1) {
             ret = ioctl(s->fd, USBDEVFS_DISCARDURB, &aurb[i]);
             if (ret < 0) {
-                printf("husb: discard isoc in urb failed errno %d\n", errno);
+                perror("USBDEVFS_DISCARDURB");
                 free = 0;
                 continue;
             }
@@ -585,9 +608,9 @@ static void usb_host_stop_n_free_iso(USBHostDevice *s, uint8_t ep)
         g_free(aurb);
     else
         printf("husb: leaking iso urbs because of discard failure\n");
-    set_iso_urb(s, ep, NULL);
-    set_iso_urb_idx(s, ep, 0);
-    clear_iso_started(s, ep);
+    set_iso_urb(s, pid, ep, NULL);
+    set_iso_urb_idx(s, pid, ep, 0);
+    clear_iso_started(s, pid, ep);
 }
 
 static int urb_status_to_usb_ret(int status)
@@ -606,16 +629,16 @@ static int usb_host_handle_iso_data(USBHostDevice *s, USBPacket *p, int in)
     int i, j, ret, max_packet_size, offset, len = 0;
     uint8_t *buf;
 
-    max_packet_size = get_max_packet_size(s, p->devep);
+    max_packet_size = get_max_packet_size(s, p->pid, p->devep);
     if (max_packet_size == 0)
         return USB_RET_NAK;
 
-    aurb = get_iso_urb(s, p->devep);
+    aurb = get_iso_urb(s, p->pid, p->devep);
     if (!aurb) {
-        aurb = usb_host_alloc_iso(s, p->devep, in);
+        aurb = usb_host_alloc_iso(s, p->pid, p->devep);
     }
 
-    i = get_iso_urb_idx(s, p->devep);
+    i = get_iso_urb_idx(s, p->pid, p->devep);
     j = aurb[i].iso_frame_idx;
     if (j >= 0 && j < ISO_FRAME_DESC_PER_URB) {
         if (in) {
@@ -642,7 +665,7 @@ static int usb_host_handle_iso_data(USBHostDevice *s, USBPacket *p, int in)
             }
         } else {
             len = p->iov.size;
-            offset = (j == 0) ? 0 : get_iso_buffer_used(s, p->devep);
+            offset = (j == 0) ? 0 : get_iso_buffer_used(s, p->pid, p->devep);
 
             /* Check the frame fits */
             if (len > max_packet_size) {
@@ -654,33 +677,33 @@ static int usb_host_handle_iso_data(USBHostDevice *s, USBPacket *p, int in)
             usb_packet_copy(p, aurb[i].urb.buffer + offset, len);
             aurb[i].urb.iso_frame_desc[j].length = len;
             offset += len;
-            set_iso_buffer_used(s, p->devep, offset);
+            set_iso_buffer_used(s, p->pid, p->devep, offset);
 
             /* Start the stream once we have buffered enough data */
-            if (!is_iso_started(s, p->devep) && i == 1 && j == 8) {
-                set_iso_started(s, p->devep);
+            if (!is_iso_started(s, p->pid, p->devep) && i == 1 && j == 8) {
+                set_iso_started(s, p->pid, p->devep);
             }
         }
         aurb[i].iso_frame_idx++;
         if (aurb[i].iso_frame_idx == ISO_FRAME_DESC_PER_URB) {
             i = (i + 1) % s->iso_urb_count;
-            set_iso_urb_idx(s, p->devep, i);
+            set_iso_urb_idx(s, p->pid, p->devep, i);
         }
     } else {
         if (in) {
-            set_iso_started(s, p->devep);
+            set_iso_started(s, p->pid, p->devep);
         } else {
             DPRINTF("hubs: iso out error no free buffer, dropping packet\n");
         }
     }
 
-    if (is_iso_started(s, p->devep)) {
+    if (is_iso_started(s, p->pid, p->devep)) {
         /* (Re)-submit all fully consumed / filled urbs */
         for (i = 0; i < s->iso_urb_count; i++) {
             if (aurb[i].iso_frame_idx == ISO_FRAME_DESC_PER_URB) {
                 ret = ioctl(s->fd, USBDEVFS_SUBMITURB, &aurb[i]);
                 if (ret < 0) {
-                    printf("husb error submitting iso urb %d: %d\n", i, errno);
+                    perror("USBDEVFS_SUBMITURB");
                     if (!in || len == 0) {
                         switch(errno) {
                         case ETIMEDOUT:
@@ -694,7 +717,7 @@ static int usb_host_handle_iso_data(USBHostDevice *s, USBPacket *p, int in)
                     break;
                 }
                 aurb[i].iso_frame_idx = -1;
-                change_iso_inflight(s, p->devep, +1);
+                change_iso_inflight(s, p->pid, p->devep, 1);
             }
         }
     }
@@ -711,7 +734,12 @@ static int usb_host_handle_data(USBDevice *dev, USBPacket *p)
     uint8_t *pbuf;
     uint8_t ep;
 
-    if (!is_valid(s, p->devep)) {
+    trace_usb_host_req_data(s->bus_num, s->addr,
+                            p->pid == USB_TOKEN_IN,
+                            p->devep, p->iov.size);
+
+    if (!is_valid(s, p->pid, p->devep)) {
+        trace_usb_host_req_complete(s->bus_num, s->addr, USB_RET_NAK);
         return USB_RET_NAK;
     }
 
@@ -721,17 +749,18 @@ static int usb_host_handle_data(USBDevice *dev, USBPacket *p)
         ep = p->devep;
     }
 
-    if (is_halted(s, p->devep)) {
-        ret = ioctl(s->fd, USBDEVFS_CLEAR_HALT, &ep);
+    if (is_halted(s, p->pid, p->devep)) {
+        unsigned int arg = ep;
+        ret = ioctl(s->fd, USBDEVFS_CLEAR_HALT, &arg);
         if (ret < 0) {
-            DPRINTF("husb: failed to clear halt. ep 0x%x errno %d\n",
-                   ep, errno);
+            perror("USBDEVFS_CLEAR_HALT");
+            trace_usb_host_req_complete(s->bus_num, s->addr, USB_RET_NAK);
             return USB_RET_NAK;
         }
-        clear_halt(s, p->devep);
+        clear_halt(s, p->pid, p->devep);
     }
 
-    if (is_isoc(s, p->devep)) {
+    if (is_isoc(s, p->pid, p->devep)) {
         return usb_host_handle_iso_data(s, p, p->pid == USB_TOKEN_IN);
     }
 
@@ -767,20 +796,24 @@ static int usb_host_handle_data(USBDevice *dev, USBPacket *p)
             aurb->more         = 1;
         }
 
+        trace_usb_host_urb_submit(s->bus_num, s->addr, aurb,
+                                  urb->buffer_length, aurb->more);
         ret = ioctl(s->fd, USBDEVFS_SUBMITURB, urb);
 
         DPRINTF("husb: data submit: ep 0x%x, len %u, more %d, packet %p, aurb %p\n",
                 urb->endpoint, urb->buffer_length, aurb->more, p, aurb);
 
         if (ret < 0) {
-            DPRINTF("husb: submit failed. errno %d\n", errno);
+            perror("USBDEVFS_SUBMITURB");
             async_free(aurb);
 
             switch(errno) {
             case ETIMEDOUT:
+                trace_usb_host_req_complete(s->bus_num, s->addr, USB_RET_NAK);
                 return USB_RET_NAK;
             case EPIPE:
             default:
+                trace_usb_host_req_complete(s->bus_num, s->addr, USB_RET_STALL);
                 return USB_RET_STALL;
             }
         }
@@ -800,13 +833,15 @@ static int ctrl_error(void)
 
 static int usb_host_set_address(USBHostDevice *s, int addr)
 {
-    DPRINTF("husb: ctrl set addr %u\n", addr);
+    trace_usb_host_set_address(s->bus_num, s->addr, addr);
     s->dev.addr = addr;
     return 0;
 }
 
 static int usb_host_set_config(USBHostDevice *s, int config)
 {
+    trace_usb_host_set_config(s->bus_num, s->addr, config);
+
     usb_host_release_interfaces(s);
 
     int ret = ioctl(s->fd, USBDEVFS_SETCONFIGURATION, &config);
@@ -817,6 +852,7 @@ static int usb_host_set_config(USBHostDevice *s, int config)
         return ctrl_error();
     }
     usb_host_claim_interfaces(s, config);
+    usb_linux_update_endp_table(s);
     return 0;
 }
 
@@ -825,9 +861,14 @@ static int usb_host_set_interface(USBHostDevice *s, int iface, int alt)
     struct usbdevfs_setinterface si;
     int i, ret;
 
+    trace_usb_host_set_interface(s->bus_num, s->addr, iface, alt);
+
     for (i = 1; i <= MAX_ENDPOINTS; i++) {
-        if (is_isoc(s, i)) {
-            usb_host_stop_n_free_iso(s, i);
+        if (is_isoc(s, USB_TOKEN_IN, i)) {
+            usb_host_stop_n_free_iso(s, USB_TOKEN_IN, i);
+        }
+        if (is_isoc(s, USB_TOKEN_OUT, i)) {
+            usb_host_stop_n_free_iso(s, USB_TOKEN_OUT, i);
         }
     }
 
@@ -859,8 +900,7 @@ static int usb_host_handle_control(USBDevice *dev, USBPacket *p,
      */
 
     /* Note request is (bRequestType << 8) | bRequest */
-    DPRINTF("husb: ctrl type 0x%x req 0x%x val 0x%x index %u len %u\n",
-            request >> 8, request & 0xff, value, index, length);
+    trace_usb_host_req_control(s->bus_num, s->addr, request, value, index);
 
     switch (request) {
     case DeviceOutRequest | USB_REQ_SET_ADDRESS:
@@ -900,6 +940,8 @@ static int usb_host_handle_control(USBDevice *dev, USBPacket *p,
 
     urb->usercontext = s;
 
+    trace_usb_host_urb_submit(s->bus_num, s->addr, aurb,
+                              urb->buffer_length, aurb->more);
     ret = ioctl(s->fd, USBDEVFS_SUBMITURB, urb);
 
     DPRINTF("husb: submit ctrl. len %u aurb %p\n", urb->buffer_length, aurb);
@@ -920,51 +962,6 @@ static int usb_host_handle_control(USBDevice *dev, USBPacket *p,
     return USB_RET_ASYNC;
 }
 
-static int usb_linux_get_configuration(USBHostDevice *s)
-{
-    uint8_t configuration;
-    struct usb_ctrltransfer ct;
-    int ret;
-
-    if (usb_fs_type == USB_FS_SYS) {
-        char device_name[32], line[1024];
-        int configuration;
-
-        sprintf(device_name, "%d-%s", s->bus_num, s->port);
-
-        if (!usb_host_read_file(line, sizeof(line), "bConfigurationValue",
-                                device_name)) {
-            goto usbdevfs;
-        }
-        if (sscanf(line, "%d", &configuration) != 1) {
-            goto usbdevfs;
-        }
-        return configuration;
-    }
-
-usbdevfs:
-    ct.bRequestType = USB_DIR_IN;
-    ct.bRequest = USB_REQ_GET_CONFIGURATION;
-    ct.wValue = 0;
-    ct.wIndex = 0;
-    ct.wLength = 1;
-    ct.data = &configuration;
-    ct.timeout = 50;
-
-    ret = ioctl(s->fd, USBDEVFS_CONTROL, &ct);
-    if (ret < 0) {
-        perror("usb_linux_get_configuration");
-        return -1;
-    }
-
-    /* in address state */
-    if (configuration == 0) {
-        return -1;
-    }
-
-    return configuration;
-}
-
 static uint8_t usb_linux_get_alt_setting(USBHostDevice *s,
     uint8_t configuration, uint8_t interface)
 {
@@ -1010,16 +1007,19 @@ usbdevfs:
 static int usb_linux_update_endp_table(USBHostDevice *s)
 {
     uint8_t *descriptors;
-    uint8_t devep, type, configuration, alt_interface;
-    int interface, length, i;
+    uint8_t devep, type, alt_interface;
+    int interface, length, i, ep, pid;
+    struct endp_data *epd;
 
-    for (i = 0; i < MAX_ENDPOINTS; i++)
-        s->endp_table[i].type = INVALID_EP_TYPE;
+    for (i = 0; i < MAX_ENDPOINTS; i++) {
+        s->ep_in[i].type = INVALID_EP_TYPE;
+        s->ep_out[i].type = INVALID_EP_TYPE;
+    }
 
-    i = usb_linux_get_configuration(s);
-    if (i < 0)
-        return 1;
-    configuration = i;
+    if (s->configuration == 0) {
+        /* not configured yet -- leave all endpoints disabled */
+        return 0;
+    }
 
     /* get the desired configuration, interface, and endpoint descriptors
      * from device description */
@@ -1028,8 +1028,9 @@ static int usb_linux_update_endp_table(USBHostDevice *s)
     i = 0;
 
     if (descriptors[i + 1] != USB_DT_CONFIG ||
-        descriptors[i + 5] != configuration) {
-        DPRINTF("invalid descriptor data - configuration\n");
+        descriptors[i + 5] != s->configuration) {
+        fprintf(stderr, "invalid descriptor data - configuration %d\n",
+                s->configuration);
         return 1;
     }
     i += descriptors[i];
@@ -1043,7 +1044,8 @@ static int usb_linux_update_endp_table(USBHostDevice *s)
         }
 
         interface = descriptors[i + 2];
-        alt_interface = usb_linux_get_alt_setting(s, configuration, interface);
+        alt_interface = usb_linux_get_alt_setting(s, s->configuration,
+                                                  interface);
 
         /* the current interface descriptor is the active interface
          * and has endpoints */
@@ -1066,7 +1068,9 @@ static int usb_linux_update_endp_table(USBHostDevice *s)
             }
 
             devep = descriptors[i + 2];
-            if ((devep & 0x0f) == 0) {
+            pid = (devep & USB_DIR_IN) ? USB_TOKEN_IN : USB_TOKEN_OUT;
+            ep = devep & 0xf;
+            if (ep == 0) {
                 fprintf(stderr, "usb-linux: invalid ep descriptor, ep == 0\n");
                 return 1;
             }
@@ -1077,7 +1081,7 @@ static int usb_linux_update_endp_table(USBHostDevice *s)
                 break;
             case 0x01:
                 type = USBDEVFS_URB_TYPE_ISO;
-                set_max_packet_size(s, (devep & 0xf), descriptors + i);
+                set_max_packet_size(s, pid, ep, descriptors + i);
                 break;
             case 0x02:
                 type = USBDEVFS_URB_TYPE_BULK;
@@ -1089,8 +1093,10 @@ static int usb_linux_update_endp_table(USBHostDevice *s)
                 DPRINTF("usb_host: malformed endpoint type\n");
                 type = USBDEVFS_URB_TYPE_BULK;
             }
-            s->endp_table[(devep & 0xf) - 1].type = type;
-            s->endp_table[(devep & 0xf) - 1].halted = 0;
+            epd = get_endp(s, pid, ep);
+            assert(epd->type == INVALID_EP_TYPE);
+            epd->type = type;
+            epd->halted = 0;
 
             i += descriptors[i];
         }
@@ -1135,15 +1141,17 @@ static int usb_linux_full_speed_compat(USBHostDevice *dev)
 }
 
 static int usb_host_open(USBHostDevice *dev, int bus_num,
-                        int addr, char *port, const char *prod_name, int speed)
+                         int addr, const char *port,
+                         const char *prod_name, int speed)
 {
     int fd = -1, ret;
     char buf[1024];
 
+    trace_usb_host_open_started(bus_num, addr);
+
     if (dev->fd != -1) {
         goto fail;
     }
-    printf("husb: open device %d.%d\n", bus_num, addr);
 
     if (!usb_host_device_path) {
         perror("husb: USB Host Device Path not set");
@@ -1182,13 +1190,8 @@ static int usb_host_open(USBHostDevice *dev, int bus_num,
 #endif
 
 
-    /*
-     * Initial configuration is -1 which makes us claim first
-     * available config. We used to start with 1, which does not
-     * always work. I've seen devices where first config starts
-     * with 2.
-     */
-    if (!usb_host_claim_interfaces(dev, -1)) {
+    /* start unconfigured -- we'll wait for the guest to set a configuration */
+    if (!usb_host_claim_interfaces(dev, 0)) {
         goto fail;
     }
 
@@ -1218,7 +1221,7 @@ static int usb_host_open(USBHostDevice *dev, int bus_num,
         dev->dev.speedmask |= USB_SPEED_MASK_FULL;
     }
 
-    printf("husb: grabbed usb device %d.%d\n", bus_num, addr);
+    trace_usb_host_open_success(bus_num, addr);
 
     if (!prod_name || prod_name[0] == '\0') {
         snprintf(dev->dev.product_desc, sizeof(dev->dev.product_desc),
@@ -1239,6 +1242,7 @@ static int usb_host_open(USBHostDevice *dev, int bus_num,
     return 0;
 
 fail:
+    trace_usb_host_open_failure(bus_num, addr);
     if (dev->fd != -1) {
         close(dev->fd);
         dev->fd = -1;
@@ -1254,11 +1258,16 @@ static int usb_host_close(USBHostDevice *dev)
         return -1;
     }
 
+    trace_usb_host_close(dev->bus_num, dev->addr);
+
     qemu_set_fd_handler(dev->fd, NULL, NULL, NULL);
     dev->closing = 1;
     for (i = 1; i <= MAX_ENDPOINTS; i++) {
-        if (is_isoc(dev, i)) {
-            usb_host_stop_n_free_iso(dev, i);
+        if (is_isoc(dev, USB_TOKEN_IN, i)) {
+            usb_host_stop_n_free_iso(dev, USB_TOKEN_IN, i);
+        }
+        if (is_isoc(dev, USB_TOKEN_OUT, i)) {
+            usb_host_stop_n_free_iso(dev, USB_TOKEN_OUT, i);
         }
     }
     async_complete(dev);
@@ -1285,17 +1294,76 @@ static int usb_host_initfn(USBDevice *dev)
 
     dev->auto_attach = 0;
     s->fd = -1;
+    s->hub_fd = -1;
+
     QTAILQ_INSERT_TAIL(&hostdevs, s, next);
     s->exit.notify = usb_host_exit_notifier;
     qemu_add_exit_notifier(&s->exit);
     usb_host_auto_check(NULL);
+
+#ifdef USBDEVFS_CLAIM_PORT
+    if (s->match.bus_num != 0 && s->match.port != NULL) {
+        char *h, hub_name[64], line[1024];
+        int hub_addr, portnr, ret;
+
+        snprintf(hub_name, sizeof(hub_name), "%d-%s",
+                 s->match.bus_num, s->match.port);
+
+        /* try strip off last ".$portnr" to get hub */
+        h = strrchr(hub_name, '.');
+        if (h != NULL) {
+            portnr = atoi(h+1);
+            *h = '\0';
+        } else {
+            /* no dot in there -> it is the root hub */
+            snprintf(hub_name, sizeof(hub_name), "usb%d",
+                     s->match.bus_num);
+            portnr = atoi(s->match.port);
+        }
+
+        if (!usb_host_read_file(line, sizeof(line), "devnum",
+                                hub_name)) {
+            goto out;
+        }
+        if (sscanf(line, "%d", &hub_addr) != 1) {
+            goto out;
+        }
+
+        if (!usb_host_device_path) {
+            goto out;
+        }
+        snprintf(line, sizeof(line), "%s/%03d/%03d",
+                 usb_host_device_path, s->match.bus_num, hub_addr);
+        s->hub_fd = open(line, O_RDWR | O_NONBLOCK);
+        if (s->hub_fd < 0) {
+            goto out;
+        }
+
+        ret = ioctl(s->hub_fd, USBDEVFS_CLAIM_PORT, &portnr);
+        if (ret < 0) {
+            close(s->hub_fd);
+            s->hub_fd = -1;
+            goto out;
+        }
+
+        trace_usb_host_claim_port(s->match.bus_num, hub_addr, portnr);
+    }
+out:
+#endif
+
     return 0;
 }
 
+static const VMStateDescription vmstate_usb_host = {
+    .name = "usb-host",
+    .unmigratable = 1,
+};
+
 static struct USBDeviceInfo usb_host_dev_info = {
     .product_desc   = "USB Host Device",
     .qdev.name      = "usb-host",
     .qdev.size      = sizeof(USBHostDevice),
+    .qdev.vmsd      = &vmstate_usb_host,
     .init           = usb_host_initfn,
     .handle_packet  = usb_generic_handle_packet,
     .cancel_packet  = usb_host_async_cancel,
@@ -1421,7 +1489,8 @@ static int usb_host_scan_dev(void *opaque, USBScanFunc *func)
     FILE *f = NULL;
     char line[1024];
     char buf[1024];
-    int bus_num, addr, speed, device_count, class_id, product_id, vendor_id;
+    int bus_num, addr, speed, device_count;
+    int class_id, product_id, vendor_id, port;
     char product_name[512];
     int ret = 0;
 
@@ -1437,7 +1506,7 @@ static int usb_host_scan_dev(void *opaque, USBScanFunc *func)
     }
 
     device_count = 0;
-    bus_num = addr = class_id = product_id = vendor_id = 0;
+    bus_num = addr = class_id = product_id = vendor_id = port = 0;
     speed = -1; /* Can't get the speed from /[proc|dev]/bus/usb/devices */
     for(;;) {
         if (fgets(line, sizeof(line), f) == NULL) {
@@ -1459,6 +1528,10 @@ static int usb_host_scan_dev(void *opaque, USBScanFunc *func)
                 goto fail;
             }
             bus_num = atoi(buf);
+            if (get_tag_value(buf, sizeof(buf), line, "Port=", " ") < 0) {
+                goto fail;
+            }
+            port = atoi(buf);
             if (get_tag_value(buf, sizeof(buf), line, "Dev#=", " ") < 0) {
                 goto fail;
             }
@@ -1504,7 +1577,12 @@ static int usb_host_scan_dev(void *opaque, USBScanFunc *func)
     }
     if (device_count && (vendor_id || product_id)) {
         /* Add the last device.  */
-        ret = func(opaque, bus_num, addr, 0, class_id, vendor_id,
+        if (port > 0) {
+            snprintf(buf, sizeof(buf), "%d", port);
+        } else {
+            snprintf(buf, sizeof(buf), "?");
+        }
+        ret = func(opaque, bus_num, addr, buf, class_id, vendor_id,
                    product_id, product_name, speed);
     }
  the_end:
@@ -1713,7 +1791,8 @@ static int usb_host_scan(void *opaque, USBScanFunc *func)
 
 static QEMUTimer *usb_auto_timer;
 
-static int usb_host_auto_scan(void *opaque, int bus_num, int addr, char *port,
+static int usb_host_auto_scan(void *opaque, int bus_num,
+                              int addr, const char *port,
                               int class_id, int vendor_id, int product_id,
                               const char *product_name, int speed)
 {
@@ -1745,6 +1824,10 @@ static int usb_host_auto_scan(void *opaque, int bus_num, int addr, char *port,
             continue;
         }
         /* We got a match */
+        s->seen++;
+        if (s->errcount >= 3) {
+            return 0;
+        }
 
         /* Already attached ? */
         if (s->fd != -1) {
@@ -1752,7 +1835,9 @@ static int usb_host_auto_scan(void *opaque, int bus_num, int addr, char *port,
         }
         DPRINTF("husb: auto open: bus_num %d addr %d\n", bus_num, addr);
 
-        usb_host_open(s, bus_num, addr, port, product_name, speed);
+        if (usb_host_open(s, bus_num, addr, port, product_name, speed) < 0) {
+            s->errcount++;
+        }
         break;
     }
 
@@ -1770,12 +1855,17 @@ static void usb_host_auto_check(void *unused)
         if (s->fd == -1) {
             unconnected++;
         }
+        if (s->seen == 0) {
+            s->errcount = 0;
+        }
+        s->seen = 0;
     }
 
     if (unconnected == 0) {
         /* nothing to watch */
         if (usb_auto_timer) {
             qemu_del_timer(usb_auto_timer);
+            trace_usb_host_auto_scan_disabled();
         }
         return;
     }
@@ -1785,6 +1875,7 @@ static void usb_host_auto_check(void *unused)
         if (!usb_auto_timer) {
             return;
         }
+        trace_usb_host_auto_scan_enabled();
     }
     qemu_mod_timer(usb_auto_timer, qemu_get_clock_ms(rt_clock) + 2000);
 }
@@ -1875,7 +1966,8 @@ static const char *usb_class_str(uint8_t class)
     return p->class_name;
 }
 
-static void usb_info_device(Monitor *mon, int bus_num, int addr, char *port,
+static void usb_info_device(Monitor *mon, int bus_num,
+                            int addr, const char *port,
                             int class_id, int vendor_id, int product_id,
                             const char *product_name,
                             int speed)
@@ -1916,7 +2008,7 @@ static void usb_info_device(Monitor *mon, int bus_num, int addr, char *port,
 }
 
 static int usb_host_info_device(void *opaque, int bus_num, int addr,
-                                char *path, int class_id,
+                                const char *path, int class_id,
                                 int vendor_id, int product_id,
                                 const char *product_name,
                                 int speed)