Merge remote-tracking branch 'kraxel/usb.37' into staging

* kraxel/usb.37:
  usb-redir: Improve some debugging messages
  usb-redir: Try to keep our buffer size near the target size
  usb-redir: Pre-fill our isoc input buffer before sending pkts to the host
  usb-redir: Dynamically adjust iso buffering size based on ep interval
  usb-redir: Clear iso / irq error when stopping the stream
  usb: link packets to endpoints not devices
  usb: add max_packet_size to USBEndpoint
  usb/debug: add usb_ep_dump
  usb-desc: USBEndpoint support
  usb: add ifnum to USBEndpoint
  usb: add USBEndpoint
  xhci: Initial xHCI implementation
  usb: add audio device model
  usb-desc: audio endpoint support
  usb: track altsetting in USBDevice
  usb: track configuration and interface count in USBDevice.
  usb-host: rip out legacy procfs support

25 files changed, 3973 insertions, 471 deletions

diff --git a/Makefile.objs b/Makefile.objs
index 4f6d26c917..f94c881667 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -102,7 +102,7 @@ common-obj-y += scsi-disk.o cdrom.o
 common-obj-y += scsi-generic.o scsi-bus.o
 common-obj-y += hid.o
 common-obj-y += usb.o usb-hub.o usb-$(HOST_USB).o usb-hid.o usb-msd.o usb-wacom.o
-common-obj-y += usb-serial.o usb-net.o usb-bus.o usb-desc.o
+common-obj-y += usb-serial.o usb-net.o usb-bus.o usb-desc.o usb-audio.o
 common-obj-$(CONFIG_SSI) += ssi.o
 common-obj-$(CONFIG_SSI_SD) += ssi-sd.o
 common-obj-$(CONFIG_SD) += sd.o
@@ -211,6 +211,7 @@ hw-obj-$(CONFIG_PCKBD) += pckbd.o
 hw-obj-$(CONFIG_USB_UHCI) += usb-uhci.o
 hw-obj-$(CONFIG_USB_OHCI) += usb-ohci.o
 hw-obj-$(CONFIG_USB_EHCI) += usb-ehci.o
+hw-obj-$(CONFIG_USB_XHCI) += usb-xhci.o
 hw-obj-$(CONFIG_FDC) += fdc.o
 hw-obj-$(CONFIG_ACPI) += acpi.o acpi_piix4.o
 hw-obj-$(CONFIG_APM) += pm_smbus.o apm.o
diff --git a/default-configs/pci.mak b/default-configs/pci.mak
index 22bd3502d4..9d3e1dbda1 100644
--- a/default-configs/pci.mak
+++ b/default-configs/pci.mak
@@ -4,6 +4,7 @@ CONFIG_VIRTIO=y
 CONFIG_USB_UHCI=y
 CONFIG_USB_OHCI=y
 CONFIG_USB_EHCI=y
+CONFIG_USB_XHCI=y
 CONFIG_NE2000_PCI=y
 CONFIG_EEPRO100_PCI=y
 CONFIG_PCNET_PCI=y
diff --git a/hw/pci_ids.h b/hw/pci_ids.h
index 83f38934ec..85e5372006 100644
--- a/hw/pci_ids.h
+++ b/hw/pci_ids.h
@@ -120,3 +120,6 @@
 
 #define PCI_VENDOR_ID_XEN               0x5853
 #define PCI_DEVICE_ID_XEN_PLATFORM      0x0001
+
+#define PCI_VENDOR_ID_NEC                0x1033
+#define PCI_DEVICE_ID_NEC_UPD720200      0x0194
diff --git a/hw/usb-audio.c b/hw/usb-audio.c
new file mode 100644
index 0000000000..b22d578910
--- /dev/null
+++ b/hw/usb-audio.c
@@ -0,0 +1,704 @@
+/*
+ * QEMU USB audio device
+ *
+ * written by:
+ *  H. Peter Anvin <hpa@linux.intel.com>
+ *  Gerd Hoffmann <kraxel@redhat.com>
+ *
+ * lousely based on usb net device code which is:
+ *
+ * Copyright (c) 2006 Thomas Sailer
+ * Copyright (c) 2008 Andrzej Zaborowski
+ *
+ * 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-common.h"
+#include "usb.h"
+#include "usb-desc.h"
+#include "hw.h"
+#include "audiodev.h"
+#include "audio/audio.h"
+
+#define USBAUDIO_VENDOR_NUM     0x46f4 /* CRC16() of "QEMU" */
+#define USBAUDIO_PRODUCT_NUM    0x0002
+
+#define DEV_CONFIG_VALUE        1 /* The one and only */
+
+/* Descriptor subtypes for AC interfaces */
+#define DST_AC_HEADER           1
+#define DST_AC_INPUT_TERMINAL   2
+#define DST_AC_OUTPUT_TERMINAL  3
+#define DST_AC_FEATURE_UNIT     6
+/* Descriptor subtypes for AS interfaces */
+#define DST_AS_GENERAL          1
+#define DST_AS_FORMAT_TYPE      2
+/* Descriptor subtypes for endpoints */
+#define DST_EP_GENERAL          1
+
+enum usb_audio_strings {
+    STRING_NULL,
+    STRING_MANUFACTURER,
+    STRING_PRODUCT,
+    STRING_SERIALNUMBER,
+    STRING_CONFIG,
+    STRING_USBAUDIO_CONTROL,
+    STRING_INPUT_TERMINAL,
+    STRING_FEATURE_UNIT,
+    STRING_OUTPUT_TERMINAL,
+    STRING_NULL_STREAM,
+    STRING_REAL_STREAM,
+};
+
+static const USBDescStrings usb_audio_stringtable = {
+    [STRING_MANUFACTURER]       = "QEMU",
+    [STRING_PRODUCT]            = "QEMU USB Audio",
+    [STRING_SERIALNUMBER]       = "1",
+    [STRING_CONFIG]             = "Audio Configuration",
+    [STRING_USBAUDIO_CONTROL]   = "Audio Device",
+    [STRING_INPUT_TERMINAL]     = "Audio Output Pipe",
+    [STRING_FEATURE_UNIT]       = "Audio Output Volume Control",
+    [STRING_OUTPUT_TERMINAL]    = "Audio Output Terminal",
+    [STRING_NULL_STREAM]        = "Audio Output - Disabled",
+    [STRING_REAL_STREAM]        = "Audio Output - 48 kHz Stereo",
+};
+
+#define U16(x) ((x) & 0xff), (((x) >> 8) & 0xff)
+#define U24(x) U16(x), (((x) >> 16) & 0xff)
+#define U32(x) U24(x), (((x) >> 24) & 0xff)
+
+/*
+ * A Basic Audio Device uses these specific values
+ */
+#define USBAUDIO_PACKET_SIZE     192
+#define USBAUDIO_SAMPLE_RATE     48000
+#define USBAUDIO_PACKET_INTERVAL 1
+
+static const USBDescIface desc_iface[] = {
+    {
+        .bInterfaceNumber              = 0,
+        .bNumEndpoints                 = 0,
+        .bInterfaceClass               = USB_CLASS_AUDIO,
+        .bInterfaceSubClass            = USB_SUBCLASS_AUDIO_CONTROL,
+        .bInterfaceProtocol            = 0x04,
+        .iInterface                    = STRING_USBAUDIO_CONTROL,
+        .ndesc                         = 4,
+        .descs = (USBDescOther[]) {
+            {
+                /* Headphone Class-Specific AC Interface Header Descriptor */
+                .data = (uint8_t[]) {
+                    0x09,                       /*  u8  bLength */
+                    USB_DT_CS_INTERFACE,        /*  u8  bDescriptorType */
+                    DST_AC_HEADER,              /*  u8  bDescriptorSubtype */
+                    U16(0x0100),                /* u16  bcdADC */
+                    U16(0x2b),                  /* u16  wTotalLength */
+                    0x01,                       /*  u8  bInCollection */
+                    0x01,                       /*  u8  baInterfaceNr */
+                }
+            },{
+                /* Generic Stereo Input Terminal ID1 Descriptor */
+                .data = (uint8_t[]) {
+                    0x0c,                       /*  u8  bLength */
+                    USB_DT_CS_INTERFACE,        /*  u8  bDescriptorType */
+                    DST_AC_INPUT_TERMINAL,      /*  u8  bDescriptorSubtype */
+                    0x01,                       /*  u8  bTerminalID */
+                    U16(0x0101),                /* u16  wTerminalType */
+                    0x00,                       /*  u8  bAssocTerminal */
+                    0x02,                       /* u16  bNrChannels */
+                    U16(0x0003),                /* u16  wChannelConfig */
+                    0x00,                       /*  u8  iChannelNames */
+                    STRING_INPUT_TERMINAL,      /*  u8  iTerminal */
+                }
+            },{
+                /* Generic Stereo Feature Unit ID2 Descriptor */
+                .data = (uint8_t[]) {
+                    0x0d,                       /*  u8  bLength */
+                    USB_DT_CS_INTERFACE,        /*  u8  bDescriptorType */
+                    DST_AC_FEATURE_UNIT,        /*  u8  bDescriptorSubtype */
+                    0x02,                       /*  u8  bUnitID */
+                    0x01,                       /*  u8  bSourceID */
+                    0x02,                       /*  u8  bControlSize */
+                    U16(0x0001),                /* u16  bmaControls(0) */
+                    U16(0x0002),                /* u16  bmaControls(1) */
+                    U16(0x0002),                /* u16  bmaControls(2) */
+                    STRING_FEATURE_UNIT,        /*  u8  iFeature */
+                }
+            },{
+                /* Headphone Ouptut Terminal ID3 Descriptor */
+                .data = (uint8_t[]) {
+                    0x09,                       /*  u8  bLength */
+                    USB_DT_CS_INTERFACE,        /*  u8  bDescriptorType */
+                    DST_AC_OUTPUT_TERMINAL,     /*  u8  bDescriptorSubtype */
+                    0x03,                       /*  u8  bUnitID */
+                    U16(0x0301),                /* u16  wTerminalType (SPK) */
+                    0x00,                       /*  u8  bAssocTerminal */
+                    0x02,                       /*  u8  bSourceID */
+                    STRING_OUTPUT_TERMINAL,     /*  u8  iTerminal */
+                }
+            }
+        },
+    },{
+        .bInterfaceNumber              = 1,
+        .bAlternateSetting             = 0,
+        .bNumEndpoints                 = 0,
+        .bInterfaceClass               = USB_CLASS_AUDIO,
+        .bInterfaceSubClass            = USB_SUBCLASS_AUDIO_STREAMING,
+        .iInterface                    = STRING_NULL_STREAM,
+    },{
+        .bInterfaceNumber              = 1,
+        .bAlternateSetting             = 1,
+        .bNumEndpoints                 = 1,
+        .bInterfaceClass               = USB_CLASS_AUDIO,
+        .bInterfaceSubClass            = USB_SUBCLASS_AUDIO_STREAMING,
+        .iInterface                    = STRING_REAL_STREAM,
+        .ndesc                         = 2,
+        .descs = (USBDescOther[]) {
+            {
+                /* Headphone Class-specific AS General Interface Descriptor */
+                .data = (uint8_t[]) {
+                    0x07,                       /*  u8  bLength */
+                    USB_DT_CS_INTERFACE,        /*  u8  bDescriptorType */
+                    DST_AS_GENERAL,             /*  u8  bDescriptorSubtype */
+                    0x01,                       /*  u8  bTerminalLink */
+                    0x00,                       /*  u8  bDelay */
+                    0x01, 0x00,                 /* u16  wFormatTag */
+                }
+            },{
+                /* Headphone Type I Format Type Descriptor */
+                .data = (uint8_t[]) {
+                    0x0b,                       /*  u8  bLength */
+                    USB_DT_CS_INTERFACE,        /*  u8  bDescriptorType */
+                    DST_AS_FORMAT_TYPE,         /*  u8  bDescriptorSubtype */
+                    0x01,                       /*  u8  bFormatType */
+                    0x02,                       /*  u8  bNrChannels */
+                    0x02,                       /*  u8  bSubFrameSize */
+                    0x10,                       /*  u8  bBitResolution */
+                    0x01,                       /*  u8  bSamFreqType */
+                    U24(USBAUDIO_SAMPLE_RATE),  /* u24  tSamFreq */
+                }
+            }
+        },
+        .eps = (USBDescEndpoint[]) {
+            {
+                .bEndpointAddress      = USB_DIR_OUT | 0x01,
+                .bmAttributes          = 0x0d,
+                .wMaxPacketSize        = USBAUDIO_PACKET_SIZE,
+                .bInterval             = 1,
+                .is_audio              = 1,
+                /* Stereo Headphone Class-specific
+                   AS Audio Data Endpoint Descriptor */
+                .extra = (uint8_t[]) {
+                    0x07,                       /*  u8  bLength */
+                    USB_DT_CS_ENDPOINT,         /*  u8  bDescriptorType */
+                    DST_EP_GENERAL,             /*  u8  bDescriptorSubtype */
+                    0x00,                       /*  u8  bmAttributes */
+                    0x00,                       /*  u8  bLockDelayUnits */
+                    U16(0x0000),                /* u16  wLockDelay */
+                },
+            },
+        }
+    }
+};
+
+static const USBDescDevice desc_device = {
+    .bcdUSB                        = 0x0200,
+    .bMaxPacketSize0               = 64,
+    .bNumConfigurations            = 1,
+    .confs = (USBDescConfig[]) {
+        {
+            .bNumInterfaces        = 2,
+            .bConfigurationValue   = DEV_CONFIG_VALUE,
+            .iConfiguration        = STRING_CONFIG,
+            .bmAttributes          = 0xc0,
+            .bMaxPower             = 0x32,
+            .nif = ARRAY_SIZE(desc_iface),
+            .ifs = desc_iface,
+        },
+    },
+};
+
+static const USBDesc desc_audio = {
+    .id = {
+        .idVendor          = USBAUDIO_VENDOR_NUM,
+        .idProduct         = USBAUDIO_PRODUCT_NUM,
+        .bcdDevice         = 0,
+        .iManufacturer     = STRING_MANUFACTURER,
+        .iProduct          = STRING_PRODUCT,
+        .iSerialNumber     = STRING_SERIALNUMBER,
+    },
+    .full = &desc_device,
+    .str  = usb_audio_stringtable,
+};
+
+/*
+ * A USB audio device supports an arbitrary number of alternate
+ * interface settings for each interface.  Each corresponds to a block
+ * diagram of parameterized blocks.  This can thus refer to things like
+ * number of channels, data rates, or in fact completely different
+ * block diagrams.  Alternative setting 0 is always the null block diagram,
+ * which is used by a disabled device.
+ */
+enum usb_audio_altset {
+    ALTSET_OFF  = 0x00,         /* No endpoint */
+    ALTSET_ON   = 0x01,         /* Single endpoint */
+};
+
+/*
+ * Class-specific control requests
+ */
+#define CR_SET_CUR      0x01
+#define CR_GET_CUR      0x81
+#define CR_SET_MIN      0x02
+#define CR_GET_MIN      0x82
+#define CR_SET_MAX      0x03
+#define CR_GET_MAX      0x83
+#define CR_SET_RES      0x04
+#define CR_GET_RES      0x84
+#define CR_SET_MEM      0x05
+#define CR_GET_MEM      0x85
+#define CR_GET_STAT     0xff
+
+/*
+ * Feature Unit Control Selectors
+ */
+#define MUTE_CONTROL                    0x01
+#define VOLUME_CONTROL                  0x02
+#define BASS_CONTROL                    0x03
+#define MID_CONTROL                     0x04
+#define TREBLE_CONTROL                  0x05
+#define GRAPHIC_EQUALIZER_CONTROL       0x06
+#define AUTOMATIC_GAIN_CONTROL          0x07
+#define DELAY_CONTROL                   0x08
+#define BASS_BOOST_CONTROL              0x09
+#define LOUDNESS_CONTROL                0x0a
+
+/*
+ * buffering
+ */
+
+struct streambuf {
+    uint8_t *data;
+    uint32_t size;
+    uint32_t prod;
+    uint32_t cons;
+};
+
+static void streambuf_init(struct streambuf *buf, uint32_t size)
+{
+    g_free(buf->data);
+    buf->size = size - (size % USBAUDIO_PACKET_SIZE);
+    buf->data = g_malloc(buf->size);
+    buf->prod = 0;
+    buf->cons = 0;
+}
+
+static void streambuf_fini(struct streambuf *buf)
+{
+    g_free(buf->data);
+    buf->data = NULL;
+}
+
+static int streambuf_put(struct streambuf *buf, USBPacket *p)
+{
+    uint32_t free = buf->size - (buf->prod - buf->cons);
+
+    if (!free) {
+        return 0;
+    }
+    assert(free >= USBAUDIO_PACKET_SIZE);
+    usb_packet_copy(p, buf->data + (buf->prod % buf->size),
+                    USBAUDIO_PACKET_SIZE);
+    buf->prod += USBAUDIO_PACKET_SIZE;
+    return USBAUDIO_PACKET_SIZE;
+}
+
+static uint8_t *streambuf_get(struct streambuf *buf)
+{
+    uint32_t used = buf->prod - buf->cons;
+    uint8_t *data;
+
+    if (!used) {
+        return NULL;
+    }
+    assert(used >= USBAUDIO_PACKET_SIZE);
+    data = buf->data + (buf->cons % buf->size);
+    buf->cons += USBAUDIO_PACKET_SIZE;
+    return data;
+}
+
+typedef struct USBAudioState {
+    /* qemu interfaces */
+    USBDevice dev;
+    QEMUSoundCard card;
+
+    /* state */
+    struct {
+        enum usb_audio_altset altset;
+        struct audsettings as;
+        SWVoiceOut *voice;
+        bool mute;
+        uint8_t vol[2];
+        struct streambuf buf;
+    } out;
+
+    /* properties */
+    uint32_t debug;
+    uint32_t buffer;
+} USBAudioState;
+
+static void output_callback(void *opaque, int avail)
+{
+    USBAudioState *s = opaque;
+    uint8_t *data;
+
+    for (;;) {
+        if (avail < USBAUDIO_PACKET_SIZE) {
+            return;
+        }
+        data = streambuf_get(&s->out.buf);
+        if (NULL == data) {
+            return;
+        }
+        AUD_write(s->out.voice, data, USBAUDIO_PACKET_SIZE);
+        avail -= USBAUDIO_PACKET_SIZE;
+    }
+}
+
+static int usb_audio_set_output_altset(USBAudioState *s, int altset)
+{
+    switch (altset) {
+    case ALTSET_OFF:
+        streambuf_init(&s->out.buf, s->buffer);
+        AUD_set_active_out(s->out.voice, false);
+        break;
+    case ALTSET_ON:
+        AUD_set_active_out(s->out.voice, true);
+        break;
+    default:
+        return -1;
+    }
+
+    if (s->debug) {
+        fprintf(stderr, "usb-audio: set interface %d\n", altset);
+    }
+    s->out.altset = altset;
+    return 0;
+}
+
+/*
+ * Note: we arbitrarily map the volume control range onto -inf..+8 dB
+ */
+#define ATTRIB_ID(cs, attrib, idif)     \
+    (((cs) << 24) | ((attrib) << 16) | (idif))
+
+static int usb_audio_get_control(USBAudioState *s, uint8_t attrib,
+                                 uint16_t cscn, uint16_t idif,
+                                 int length, uint8_t *data)
+{
+    uint8_t cs = cscn >> 8;
+    uint8_t cn = cscn - 1;      /* -1 for the non-present master control */
+    uint32_t aid = ATTRIB_ID(cs, attrib, idif);
+    int ret = USB_RET_STALL;
+
+    switch (aid) {
+    case ATTRIB_ID(MUTE_CONTROL, CR_GET_CUR, 0x0200):
+        data[0] = s->out.mute;
+        ret = 1;
+        break;
+    case ATTRIB_ID(VOLUME_CONTROL, CR_GET_CUR, 0x0200):
+        if (cn < 2) {
+            uint16_t vol = (s->out.vol[cn] * 0x8800 + 127) / 255 + 0x8000;
+            data[0] = vol;
+            data[1] = vol >> 8;
+            ret = 2;
+        }
+        break;
+    case ATTRIB_ID(VOLUME_CONTROL, CR_GET_MIN, 0x0200):
+        if (cn < 2) {
+            data[0] = 0x01;
+            data[1] = 0x80;
+            ret = 2;
+        }
+        break;
+    case ATTRIB_ID(VOLUME_CONTROL, CR_GET_MAX, 0x0200):
+        if (cn < 2) {
+            data[0] = 0x00;
+            data[1] = 0x08;
+            ret = 2;
+        }
+        break;
+    case ATTRIB_ID(VOLUME_CONTROL, CR_GET_RES, 0x0200):
+        if (cn < 2) {
+            data[0] = 0x88;
+            data[1] = 0x00;
+            ret = 2;
+        }
+        break;
+    }
+
+    return ret;
+}
+static int usb_audio_set_control(USBAudioState *s, uint8_t attrib,
+                                 uint16_t cscn, uint16_t idif,
+                                 int length, uint8_t *data)
+{
+    uint8_t cs = cscn >> 8;
+    uint8_t cn = cscn - 1;      /* -1 for the non-present master control */
+    uint32_t aid = ATTRIB_ID(cs, attrib, idif);
+    int ret = USB_RET_STALL;
+    bool set_vol = false;
+
+    switch (aid) {
+    case ATTRIB_ID(MUTE_CONTROL, CR_SET_CUR, 0x0200):
+        s->out.mute = data[0] & 1;
+        set_vol = true;
+        ret = 0;
+        break;
+    case ATTRIB_ID(VOLUME_CONTROL, CR_SET_CUR, 0x0200):
+        if (cn < 2) {
+            uint16_t vol = data[0] + (data[1] << 8);
+
+            if (s->debug) {
+                fprintf(stderr, "usb-audio: vol %04x\n", (uint16_t)vol);
+            }
+
+            vol -= 0x8000;
+            vol = (vol * 255 + 0x4400) / 0x8800;
+            if (vol > 255) {
+                vol = 255;
+            }
+
+            s->out.vol[cn] = vol;
+            set_vol = true;
+            ret = 0;
+        }
+        break;
+    }
+
+    if (set_vol) {
+        if (s->debug) {
+            fprintf(stderr, "usb-audio: mute %d, lvol %3d, rvol %3d\n",
+                    s->out.mute, s->out.vol[0], s->out.vol[1]);
+        }
+        AUD_set_volume_out(s->out.voice, s->out.mute,
+                           s->out.vol[0], s->out.vol[1]);
+    }
+
+    return ret;
+}
+
+static int usb_audio_handle_control(USBDevice *dev, USBPacket *p,
+                                    int request, int value, int index,
+                                    int length, uint8_t *data)
+{
+    USBAudioState *s = DO_UPCAST(USBAudioState, dev, dev);
+    int ret = 0;
+
+    if (s->debug) {
+        fprintf(stderr, "usb-audio: control transaction: "
+                "request 0x%04x value 0x%04x index 0x%04x length 0x%04x\n",
+                request, value, index, length);
+    }
+
+    ret = usb_desc_handle_control(dev, p, request, value, index, length, data);
+    if (ret >= 0) {
+        return ret;
+    }
+
+    switch (request) {
+    case ClassInterfaceRequest | CR_GET_CUR:
+    case ClassInterfaceRequest | CR_GET_MIN:
+    case ClassInterfaceRequest | CR_GET_MAX:
+    case ClassInterfaceRequest | CR_GET_RES:
+        ret = usb_audio_get_control(s, request & 0xff, value, index,
+                                    length, data);
+        if (ret < 0) {
+            if (s->debug) {
+                fprintf(stderr, "usb-audio: fail: get control\n");
+            }
+            goto fail;
+        }
+        break;
+
+    case ClassInterfaceOutRequest | CR_SET_CUR:
+    case ClassInterfaceOutRequest | CR_SET_MIN:
+    case ClassInterfaceOutRequest | CR_SET_MAX:
+    case ClassInterfaceOutRequest | CR_SET_RES:
+        ret = usb_audio_set_control(s, request & 0xff, value, index,
+                                    length, data);
+        if (ret < 0) {
+            if (s->debug) {
+                fprintf(stderr, "usb-audio: fail: set control\n");
+            }
+            goto fail;
+        }
+        break;
+
+    default:
+fail:
+        if (s->debug) {
+            fprintf(stderr, "usb-audio: failed control transaction: "
+                    "request 0x%04x value 0x%04x index 0x%04x length 0x%04x\n",
+                    request, value, index, length);
+        }
+        ret = USB_RET_STALL;
+        break;
+    }
+    return ret;
+}
+
+static void usb_audio_set_interface(USBDevice *dev, int iface,
+                                    int old, int value)
+{
+    USBAudioState *s = DO_UPCAST(USBAudioState, dev, dev);
+
+    if (iface == 1) {
+        usb_audio_set_output_altset(s, value);
+    }
+}
+
+static void usb_audio_handle_reset(USBDevice *dev)
+{
+    USBAudioState *s = DO_UPCAST(USBAudioState, dev, dev);
+
+    if (s->debug) {
+        fprintf(stderr, "usb-audio: reset\n");
+    }
+    usb_audio_set_output_altset(s, ALTSET_OFF);
+}
+
+static int usb_audio_handle_dataout(USBAudioState *s, USBPacket *p)
+{
+    int rc;
+
+    if (s->out.altset == ALTSET_OFF) {
+        return USB_RET_STALL;
+    }
+
+    rc = streambuf_put(&s->out.buf, p);
+    if (rc < p->iov.size && s->debug > 1) {
+        fprintf(stderr, "usb-audio: output overrun (%zd bytes)\n",
+                p->iov.size - rc);
+    }
+
+    return 0;
+}
+
+static int usb_audio_handle_data(USBDevice *dev, USBPacket *p)
+{
+    USBAudioState *s = (USBAudioState *) dev;
+    int ret = 0;
+
+    switch (p->pid) {
+    case USB_TOKEN_OUT:
+        switch (p->devep) {
+        case 1:
+            ret = usb_audio_handle_dataout(s, p);
+            break;
+        default:
+            goto fail;
+        }
+        break;
+
+    default:
+fail:
+        ret = USB_RET_STALL;
+        break;
+    }
+    if (ret == USB_RET_STALL && s->debug) {
+        fprintf(stderr, "usb-audio: failed data transaction: "
+                        "pid 0x%x ep 0x%x len 0x%zx\n",
+                        p->pid, p->devep, p->iov.size);
+    }
+    return ret;
+}
+
+static void usb_audio_handle_destroy(USBDevice *dev)
+{
+    USBAudioState *s = DO_UPCAST(USBAudioState, dev, dev);
+
+    if (s->debug) {
+        fprintf(stderr, "usb-audio: destroy\n");
+    }
+
+    usb_audio_set_output_altset(s, ALTSET_OFF);
+    AUD_close_out(&s->card, s->out.voice);
+    AUD_remove_card(&s->card);
+
+    streambuf_fini(&s->out.buf);
+}
+
+static int usb_audio_initfn(USBDevice *dev)
+{
+    USBAudioState *s = DO_UPCAST(USBAudioState, dev, dev);
+
+    usb_desc_init(dev);
+    s->dev.opaque = s;
+    AUD_register_card("usb-audio", &s->card);
+
+    s->out.altset        = ALTSET_OFF;
+    s->out.mute          = false;
+    s->out.vol[0]        = 240; /* 0 dB */
+    s->out.vol[1]        = 240; /* 0 dB */
+    s->out.as.freq       = USBAUDIO_SAMPLE_RATE;
+    s->out.as.nchannels  = 2;
+    s->out.as.fmt        = AUD_FMT_S16;
+    s->out.as.endianness = 0;
+    streambuf_init(&s->out.buf, s->buffer);
+
+    s->out.voice = AUD_open_out(&s->card, s->out.voice, "usb-audio",
+                                s, output_callback, &s->out.as);
+    AUD_set_volume_out(s->out.voice, s->out.mute, s->out.vol[0], s->out.vol[1]);
+    AUD_set_active_out(s->out.voice, 0);
+    return 0;
+}
+
+static const VMStateDescription vmstate_usb_audio = {
+    .name = "usb-audio",
+    .unmigratable = 1,
+};
+
+static struct USBDeviceInfo usb_audio_info = {
+    .product_desc   = "QEMU USB Audio Interface",
+    .usbdevice_name = "audio",
+    .qdev.name      = "usb-audio",
+    .qdev.size      = sizeof(USBAudioState),
+    .qdev.vmsd      = &vmstate_usb_audio,
+    .usb_desc       = &desc_audio,
+    .init           = usb_audio_initfn,
+    .handle_packet  = usb_generic_handle_packet,
+    .handle_reset   = usb_audio_handle_reset,
+    .handle_control = usb_audio_handle_control,
+    .handle_data    = usb_audio_handle_data,
+    .handle_destroy = usb_audio_handle_destroy,
+    .set_interface  = usb_audio_set_interface,
+    .qdev.props = (Property[]) {
+        DEFINE_PROP_UINT32("debug", USBAudioState, debug, 0),
+        DEFINE_PROP_UINT32("buffer", USBAudioState, buffer,
+                           8 * USBAUDIO_PACKET_SIZE),
+        DEFINE_PROP_END_OF_LIST(),
+    }
+};
+
+static void usb_audio_register_devices(void)
+{
+    usb_qdev_register(&usb_audio_info);
+}
+
+device_init(usb_audio_register_devices)
diff --git a/hw/usb-bt.c b/hw/usb-bt.c
index f30eec1ea2..0c1270be79 100644
--- a/hw/usb-bt.c
+++ b/hw/usb-bt.c
@@ -28,7 +28,6 @@ struct USBBtState {
     USBDevice dev;
     struct HCIInfo *hci;
 
-    int altsetting;
     int config;
 
 #define CFIFO_LEN_MASK	255
@@ -362,7 +361,6 @@ static void usb_bt_handle_reset(USBDevice *dev)
     s->outcmd.len = 0;
     s->outacl.len = 0;
     s->outsco.len = 0;
-    s->altsetting = 0;
 }
 
 static int usb_bt_handle_control(USBDevice *dev, USBPacket *p,
@@ -402,26 +400,6 @@ static int usb_bt_handle_control(USBDevice *dev, USBPacket *p,
     case EndpointOutRequest | USB_REQ_SET_FEATURE:
         goto fail;
         break;
-    case InterfaceRequest | USB_REQ_GET_INTERFACE:
-        if (value != 0 || (index & ~1) || length != 1)
-            goto fail;
-        if (index == 1)
-            data[0] = s->altsetting;
-        else
-            data[0] = 0;
-        ret = 1;
-        break;
-    case InterfaceOutRequest | USB_REQ_SET_INTERFACE:
-        if ((index & ~1) || length != 0 ||
-                        (index == 1 && (value < 0 || value > 4)) ||
-                        (index == 0 && value != 0)) {
-            printf("%s: Wrong SET_INTERFACE request (%i, %i)\n",
-                            __FUNCTION__, index, value);
-            goto fail;
-        }
-        s->altsetting = value;
-        ret = 0;
-        break;
     case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_DEVICE) << 8):
         if (s->config)
             usb_bt_fifo_out_enqueue(s, &s->outcmd, s->hci->cmd_send,
diff --git a/hw/usb-bus.c b/hw/usb-bus.c
index bd4afa7e2b..016a3f2bb4 100644
--- a/hw/usb-bus.c
+++ b/hw/usb-bus.c
@@ -75,6 +75,7 @@ static int usb_qdev_init(DeviceState *qdev, DeviceInfo *base)
     dev->info = info;
     dev->auto_attach = 1;
     QLIST_INIT(&dev->strings);
+    usb_ep_init(dev);
     rc = usb_claim_port(dev);
     if (rc != 0) {
         return rc;
diff --git a/hw/usb-ccid.c b/hw/usb-ccid.c
index cd349f3f17..e9935ad9e6 100644
--- a/hw/usb-ccid.c
+++ b/hw/usb-ccid.c
@@ -611,14 +611,6 @@ static int ccid_handle_control(USBDevice *dev, USBPacket *p, int request,
     }
 
     switch (request) {
-    case DeviceRequest | USB_REQ_GET_INTERFACE:
-        data[0] = 0;
-        ret = 1;
-        break;
-    case InterfaceOutRequest | USB_REQ_SET_INTERFACE:
-        ret = 0;
-        break;
-
         /* Class specific requests.  */
     case InterfaceOutClass | CCID_CONTROL_ABORT:
         DPRINTF(s, 1, "ccid_control abort UNIMPLEMENTED\n");
diff --git a/hw/usb-desc.c b/hw/usb-desc.c
index ae2d384bb3..b3eb97bc6b 100644
--- a/hw/usb-desc.c
+++ b/hw/usb-desc.c
@@ -192,9 +192,10 @@ int usb_desc_iface(const USBDescIface *iface, uint8_t *dest, size_t len)
 
 int usb_desc_endpoint(const USBDescEndpoint *ep, uint8_t *dest, size_t len)
 {
-    uint8_t bLength = 0x07;
+    uint8_t bLength = ep->is_audio ? 0x09 : 0x07;
+    uint8_t extralen = ep->extra ? ep->extra[0] : 0;
 
-    if (len < bLength) {
+    if (len < bLength + extralen) {
         return -1;
     }
 
@@ -205,8 +206,15 @@ int usb_desc_endpoint(const USBDescEndpoint *ep, uint8_t *dest, size_t len)
     dest[0x04] = usb_lo(ep->wMaxPacketSize);
     dest[0x05] = usb_hi(ep->wMaxPacketSize);
     dest[0x06] = ep->bInterval;
+    if (ep->is_audio) {
+        dest[0x07] = ep->bRefresh;
+        dest[0x08] = ep->bSynchAddress;
+    }
+    if (ep->extra) {
+        memcpy(dest + bLength, ep->extra, extralen);
+    }
 
-    return bLength;
+    return bLength + extralen;
 }
 
 int usb_desc_other(const USBDescOther *desc, uint8_t *dest, size_t len)
@@ -223,6 +231,111 @@ int usb_desc_other(const USBDescOther *desc, uint8_t *dest, size_t len)
 
 /* ------------------------------------------------------------------ */
 
+static void usb_desc_ep_init(USBDevice *dev)
+{
+    const USBDescIface *iface;
+    int i, e, pid, ep;
+
+    usb_ep_init(dev);
+    for (i = 0; i < dev->ninterfaces; i++) {
+        iface = dev->ifaces[i];
+        if (iface == NULL) {
+            continue;
+        }
+        for (e = 0; e < iface->bNumEndpoints; e++) {
+            pid = (iface->eps[e].bEndpointAddress & USB_DIR_IN) ?
+                USB_TOKEN_IN : USB_TOKEN_OUT;
+            ep = iface->eps[e].bEndpointAddress & 0x0f;
+            usb_ep_set_type(dev, pid, ep, iface->eps[e].bmAttributes & 0x03);
+            usb_ep_set_ifnum(dev, pid, ep, iface->bInterfaceNumber);
+            usb_ep_set_max_packet_size(dev, pid, ep,
+                                       iface->eps[e].wMaxPacketSize);
+        }
+    }
+}
+
+static const USBDescIface *usb_desc_find_interface(USBDevice *dev,
+                                                   int nif, int alt)
+{
+    const USBDescIface *iface;
+    int g, i;
+
+    if (!dev->config) {
+        return NULL;
+    }
+    for (g = 0; g < dev->config->nif_groups; g++) {
+        for (i = 0; i < dev->config->if_groups[g].nif; i++) {
+            iface = &dev->config->if_groups[g].ifs[i];
+            if (iface->bInterfaceNumber == nif &&
+                iface->bAlternateSetting == alt) {
+                return iface;
+            }
+        }
+    }
+    for (i = 0; i < dev->config->nif; i++) {
+        iface = &dev->config->ifs[i];
+        if (iface->bInterfaceNumber == nif &&
+            iface->bAlternateSetting == alt) {
+            return iface;
+        }
+    }
+    return NULL;
+}
+
+static int usb_desc_set_interface(USBDevice *dev, int index, int value)
+{
+    const USBDescIface *iface;
+    int old;
+
+    iface = usb_desc_find_interface(dev, index, value);
+    if (iface == NULL) {
+        return -1;
+    }
+
+    old = dev->altsetting[index];
+    dev->altsetting[index] = value;
+    dev->ifaces[index] = iface;
+    usb_desc_ep_init(dev);
+
+    if (dev->info->set_interface && old != value) {
+        dev->info->set_interface(dev, index, old, value);
+    }
+    return 0;
+}
+
+static int usb_desc_set_config(USBDevice *dev, int value)
+{
+    int i;
+
+    if (value == 0) {
+        dev->configuration = 0;
+        dev->ninterfaces   = 0;
+        dev->config = NULL;
+    } else {
+        for (i = 0; i < dev->device->bNumConfigurations; i++) {
+            if (dev->device->confs[i].bConfigurationValue == value) {
+                dev->configuration = value;
+                dev->ninterfaces   = dev->device->confs[i].bNumInterfaces;
+                dev->config = dev->device->confs + i;
+                assert(dev->ninterfaces <= USB_MAX_INTERFACES);
+            }
+        }
+        if (i < dev->device->bNumConfigurations) {
+            return -1;
+        }
+    }
+
+    for (i = 0; i < dev->ninterfaces; i++) {
+        usb_desc_set_interface(dev, i, 0);
+    }
+    for (; i < USB_MAX_INTERFACES; i++) {
+        dev->altsetting[i] = 0;
+        dev->ifaces[i] = NULL;
+    }
+
+    return 0;
+}
+
 static void usb_desc_setdefaults(USBDevice *dev)
 {
     const USBDesc *desc = dev->info->usb_desc;
@@ -237,7 +350,7 @@ static void usb_desc_setdefaults(USBDevice *dev)
         dev->device = desc->high;
         break;
     }
-    dev->config = dev->device->confs;
+    usb_desc_set_config(dev, 0);
 }
 
 void usb_desc_init(USBDevice *dev)
@@ -408,7 +521,7 @@ int usb_desc_handle_control(USBDevice *dev, USBPacket *p,
         int request, int value, int index, int length, uint8_t *data)
 {
     const USBDesc *desc = dev->info->usb_desc;
-    int i, ret = -1;
+    int ret = -1;
 
     assert(desc != NULL);
     switch(request) {
@@ -427,12 +540,7 @@ int usb_desc_handle_control(USBDevice *dev, USBPacket *p,
         ret = 1;
         break;
     case DeviceOutRequest | USB_REQ_SET_CONFIGURATION:
-        for (i = 0; i < dev->device->bNumConfigurations; i++) {
-            if (dev->device->confs[i].bConfigurationValue == value) {
-                dev->config = dev->device->confs + i;
-                ret = 0;
-            }
-        }
+        ret = usb_desc_set_config(dev, value);
         trace_usb_set_config(dev->addr, value, ret);
         break;
 
@@ -461,6 +569,19 @@ int usb_desc_handle_control(USBDevice *dev, USBPacket *p,
         }
         trace_usb_set_device_feature(dev->addr, value, ret);
         break;
+
+    case InterfaceRequest | USB_REQ_GET_INTERFACE:
+        if (index < 0 || index >= dev->ninterfaces) {
+            break;
+        }
+        data[0] = dev->altsetting[index];
+        ret = 1;
+        break;
+    case InterfaceOutRequest | USB_REQ_SET_INTERFACE:
+        ret = usb_desc_set_interface(dev, index, value);
+        trace_usb_set_interface(dev->addr, index, value, ret);
+        break;
+
     }
     return ret;
 }
diff --git a/hw/usb-desc.h b/hw/usb-desc.h
index 5c14e4abdc..d6e07ea5d2 100644
--- a/hw/usb-desc.h
+++ b/hw/usb-desc.h
@@ -71,6 +71,11 @@ struct USBDescEndpoint {
     uint8_t                   bmAttributes;
     uint16_t                  wMaxPacketSize;
     uint8_t                   bInterval;
+    uint8_t                   bRefresh;
+    uint8_t                   bSynchAddress;
+
+    uint8_t                   is_audio; /* has bRefresh + bSynchAddress */
+    uint8_t                   *extra;
 };
 
 struct USBDescOther {
diff --git a/hw/usb-ehci.c b/hw/usb-ehci.c
index 7c926c0d47..a3056614a6 100644
--- a/hw/usb-ehci.c
+++ b/hw/usb-ehci.c
@@ -715,7 +715,8 @@ static void ehci_queues_rip_device(EHCIState *ehci, USBDevice *dev)
     EHCIQueue *q, *tmp;
 
     QTAILQ_FOREACH_SAFE(q, &ehci->queues, next, tmp) {
-        if (q->packet.owner != dev) {
+        if (q->packet.owner == NULL ||
+            q->packet.owner->dev != dev) {
             continue;
         }
         ehci_free_queue(q);
diff --git a/hw/usb-hid.c b/hw/usb-hid.c
index a110c74dda..997f8287d8 100644
--- a/hw/usb-hid.c
+++ b/hw/usb-hid.c
@@ -384,13 +384,6 @@ static int usb_hid_handle_control(USBDevice *dev, USBPacket *p,
 
     ret = 0;
     switch (request) {
-    case DeviceRequest | USB_REQ_GET_INTERFACE:
-        data[0] = 0;
-        ret = 1;
-        break;
-    case DeviceOutRequest | USB_REQ_SET_INTERFACE:
-        ret = 0;
-        break;
         /* hid specific requests */
     case InterfaceRequest | USB_REQ_GET_DESCRIPTOR:
         switch (value >> 8) {
diff --git a/hw/usb-hub.c b/hw/usb-hub.c
index e1959372e7..069611bbfb 100644
--- a/hw/usb-hub.c
+++ b/hw/usb-hub.c
@@ -258,13 +258,6 @@ static int usb_hub_handle_control(USBDevice *dev, USBPacket *p,
         }
         ret = 0;
         break;
-    case DeviceRequest | USB_REQ_GET_INTERFACE:
-        data[0] = 0;
-        ret = 1;
-        break;
-    case DeviceOutRequest | USB_REQ_SET_INTERFACE:
-        ret = 0;
-        break;
         /* usb specific requests */
     case GetHubStatus:
         data[0] = 0;
diff --git a/hw/usb-msd.c b/hw/usb-msd.c
index e42729699d..186831d71b 100644
--- a/hw/usb-msd.c
+++ b/hw/usb-msd.c
@@ -306,19 +306,9 @@ static int usb_msd_handle_control(USBDevice *dev, USBPacket *p,
 
     ret = 0;
     switch (request) {
-    case DeviceRequest | USB_REQ_GET_INTERFACE:
-        data[0] = 0;
-        ret = 1;
-        break;
-    case DeviceOutRequest | USB_REQ_SET_INTERFACE:
-        ret = 0;
-        break;
     case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
         ret = 0;
         break;
-    case InterfaceOutRequest | USB_REQ_SET_INTERFACE:
-        ret = 0;
-        break;
         /* Class specific requests.  */
     case ClassInterfaceOutRequest | MassStorageReset:
         /* Reset state ready for the next CBW.  */
diff --git a/hw/usb-musb.c b/hw/usb-musb.c
index 01e2e7c389..4f528d25e5 100644
--- a/hw/usb-musb.c
+++ b/hw/usb-musb.c
@@ -812,7 +812,8 @@ static void musb_async_cancel_device(MUSBState *s, USBDevice *dev)
 
     for (ep = 0; ep < 16; ep++) {
         for (dir = 0; dir < 2; dir++) {
-            if (s->ep[ep].packey[dir].p.owner != dev) {
+            if (s->ep[ep].packey[dir].p.owner == NULL ||
+                s->ep[ep].packey[dir].p.owner->dev != dev) {
                 continue;
             }
             usb_cancel_packet(&s->ep[ep].packey[dir].p);
diff --git a/hw/usb-net.c b/hw/usb-net.c
index f91fa32334..2f527a8ba5 100644
--- a/hw/usb-net.c
+++ b/hw/usb-net.c
@@ -71,9 +71,6 @@ enum usbstring_idx {
 #define USB_CDC_UNION_TYPE		0x06	/* union_desc */
 #define USB_CDC_ETHERNET_TYPE		0x0f	/* ether_desc */
 
-#define USB_DT_CS_INTERFACE		0x24
-#define USB_DT_CS_ENDPOINT		0x25
-
 #define USB_CDC_SEND_ENCAPSULATED_COMMAND	0x00
 #define USB_CDC_GET_ENCAPSULATED_RESPONSE	0x01
 #define USB_CDC_REQ_SET_LINE_CODING		0x20
@@ -1098,17 +1095,6 @@ static int usb_net_handle_control(USBDevice *dev, USBPacket *p,
 #endif
         break;
 
-    case DeviceRequest | USB_REQ_GET_INTERFACE:
-    case InterfaceRequest | USB_REQ_GET_INTERFACE:
-        data[0] = 0;
-        ret = 1;
-        break;
-
-    case DeviceOutRequest | USB_REQ_SET_INTERFACE:
-    case InterfaceOutRequest | USB_REQ_SET_INTERFACE:
-        ret = 0;
-        break;
-
     default:
     fail:
         fprintf(stderr, "usbnet: failed control transaction: "
diff --git a/hw/usb-ohci.c b/hw/usb-ohci.c
index 81488c48e2..69463d2f11 100644
--- a/hw/usb-ohci.c
+++ b/hw/usb-ohci.c
@@ -1707,7 +1707,9 @@ static void ohci_mem_write(void *opaque,
 
 static void ohci_async_cancel_device(OHCIState *ohci, USBDevice *dev)
 {
-    if (ohci->async_td && ohci->usb_packet.owner == dev) {
+    if (ohci->async_td &&
+        ohci->usb_packet.owner != NULL &&
+        ohci->usb_packet.owner->dev == dev) {
         usb_cancel_packet(&ohci->usb_packet);
         ohci->async_td = 0;
     }
diff --git a/hw/usb-serial.c b/hw/usb-serial.c
index 7dbf6dfc6d..e3c82388ac 100644
--- a/hw/usb-serial.c
+++ b/hw/usb-serial.c
@@ -233,13 +233,6 @@ static int usb_serial_handle_control(USBDevice *dev, USBPacket *p,
 
     ret = 0;
     switch (request) {
-    case DeviceRequest | USB_REQ_GET_INTERFACE:
-        data[0] = 0;
-        ret = 1;
-        break;
-    case InterfaceOutRequest | USB_REQ_SET_INTERFACE:
-        ret = 0;
-        break;
     case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
         ret = 0;
         break;
diff --git a/hw/usb-uhci.c b/hw/usb-uhci.c
index f8912e2b0b..25d4e8c15b 100644
--- a/hw/usb-uhci.c
+++ b/hw/usb-uhci.c
@@ -245,7 +245,8 @@ static void uhci_async_cancel_device(UHCIState *s, USBDevice *dev)
     UHCIAsync *curr, *n;
 
     QTAILQ_FOREACH_SAFE(curr, &s->async_pending, next, n) {
-        if (curr->packet.owner != dev) {
+        if (curr->packet.owner == NULL ||
+            curr->packet.owner->dev != dev) {
             continue;
         }
         uhci_async_unlink(s, curr);
diff --git a/hw/usb-wacom.c b/hw/usb-wacom.c
index 25580067f2..61d5b184df 100644
--- a/hw/usb-wacom.c
+++ b/hw/usb-wacom.c
@@ -263,13 +263,6 @@ static int usb_wacom_handle_control(USBDevice *dev, USBPacket *p,
 
     ret = 0;
     switch (request) {
-    case DeviceRequest | USB_REQ_GET_INTERFACE:
-        data[0] = 0;
-        ret = 1;
-        break;
-    case DeviceOutRequest | USB_REQ_SET_INTERFACE:
-        ret = 0;
-        break;
     case WACOM_SET_REPORT:
         if (s->mouse_grabbed) {
             qemu_remove_mouse_event_handler(s->eh_entry);
diff --git a/hw/usb-xhci.c b/hw/usb-xhci.c
new file mode 100644
index 0000000000..28fe9de2a0
--- /dev/null
+++ b/hw/usb-xhci.c
@@ -0,0 +1,2749 @@
+/*
+ * USB xHCI controller emulation
+ *
+ * Copyright (c) 2011 Securiforest
+ * Date: 2011-05-11 ;  Author: Hector Martin <hector@marcansoft.com>
+ * Based on usb-ohci.c, emulates Renesas NEC USB 3.0
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+#include "hw.h"
+#include "qemu-timer.h"
+#include "usb.h"
+#include "pci.h"
+#include "qdev-addr.h"
+#include "msi.h"
+
+//#define DEBUG_XHCI
+//#define DEBUG_DATA
+
+#ifdef DEBUG_XHCI
+#define DPRINTF(...) fprintf(stderr, __VA_ARGS__)
+#else
+#define DPRINTF(...) do {} while (0)
+#endif
+#define FIXME() do { fprintf(stderr, "FIXME %s:%d\n", \
+                             __func__, __LINE__); abort(); } while (0)
+
+#define MAXSLOTS 8
+#define MAXINTRS 1
+
+#define USB2_PORTS 4
+#define USB3_PORTS 4
+
+#define MAXPORTS (USB2_PORTS+USB3_PORTS)
+
+#define TD_QUEUE 24
+#define BG_XFERS 8
+#define BG_PKTS 8
+
+/* Very pessimistic, let's hope it's enough for all cases */
+#define EV_QUEUE (((3*TD_QUEUE)+16)*MAXSLOTS)
+/* Do not deliver ER Full events. NEC's driver does some things not bound
+ * to the specs when it gets them */
+#define ER_FULL_HACK
+
+#define LEN_CAP         0x40
+#define OFF_OPER        LEN_CAP
+#define LEN_OPER        (0x400 + 0x10 * MAXPORTS)
+#define OFF_RUNTIME     ((OFF_OPER + LEN_OPER + 0x20) & ~0x1f)
+#define LEN_RUNTIME     (0x20 + MAXINTRS * 0x20)
+#define OFF_DOORBELL    (OFF_RUNTIME + LEN_RUNTIME)
+#define LEN_DOORBELL    ((MAXSLOTS + 1) * 0x20)
+
+/* must be power of 2 */
+#define LEN_REGS        0x2000
+
+#if (OFF_DOORBELL + LEN_DOORBELL) > LEN_REGS
+# error Increase LEN_REGS
+#endif
+
+#if MAXINTRS > 1
+# error TODO: only one interrupter supported
+#endif
+
+/* bit definitions */
+#define USBCMD_RS       (1<<0)
+#define USBCMD_HCRST    (1<<1)
+#define USBCMD_INTE     (1<<2)
+#define USBCMD_HSEE     (1<<3)
+#define USBCMD_LHCRST   (1<<7)
+#define USBCMD_CSS      (1<<8)
+#define USBCMD_CRS      (1<<9)
+#define USBCMD_EWE      (1<<10)
+#define USBCMD_EU3S     (1<<11)
+
+#define USBSTS_HCH      (1<<0)
+#define USBSTS_HSE      (1<<2)
+#define USBSTS_EINT     (1<<3)
+#define USBSTS_PCD      (1<<4)
+#define USBSTS_SSS      (1<<8)
+#define USBSTS_RSS      (1<<9)
+#define USBSTS_SRE      (1<<10)
+#define USBSTS_CNR      (1<<11)
+#define USBSTS_HCE      (1<<12)
+
+
+#define PORTSC_CCS          (1<<0)
+#define PORTSC_PED          (1<<1)
+#define PORTSC_OCA          (1<<3)
+#define PORTSC_PR           (1<<4)
+#define PORTSC_PLS_SHIFT        5
+#define PORTSC_PLS_MASK     0xf
+#define PORTSC_PP           (1<<9)
+#define PORTSC_SPEED_SHIFT      10
+#define PORTSC_SPEED_MASK   0xf
+#define PORTSC_SPEED_FULL   (1<<10)
+#define PORTSC_SPEED_LOW    (2<<10)
+#define PORTSC_SPEED_HIGH   (3<<10)
+#define PORTSC_SPEED_SUPER  (4<<10)
+#define PORTSC_PIC_SHIFT        14
+#define PORTSC_PIC_MASK     0x3
+#define PORTSC_LWS          (1<<16)
+#define PORTSC_CSC          (1<<17)
+#define PORTSC_PEC          (1<<18)
+#define PORTSC_WRC          (1<<19)
+#define PORTSC_OCC          (1<<20)
+#define PORTSC_PRC          (1<<21)
+#define PORTSC_PLC          (1<<22)
+#define PORTSC_CEC          (1<<23)
+#define PORTSC_CAS          (1<<24)
+#define PORTSC_WCE          (1<<25)
+#define PORTSC_WDE          (1<<26)
+#define PORTSC_WOE          (1<<27)
+#define PORTSC_DR           (1<<30)
+#define PORTSC_WPR          (1<<31)
+
+#define CRCR_RCS        (1<<0)
+#define CRCR_CS         (1<<1)
+#define CRCR_CA         (1<<2)
+#define CRCR_CRR        (1<<3)
+
+#define IMAN_IP         (1<<0)
+#define IMAN_IE         (1<<1)
+
+#define ERDP_EHB        (1<<3)
+
+#define TRB_SIZE 16
+typedef struct XHCITRB {
+    uint64_t parameter;
+    uint32_t status;
+    uint32_t control;
+    target_phys_addr_t addr;
+    bool ccs;
+} XHCITRB;
+
+
+typedef enum TRBType {
+    TRB_RESERVED = 0,
+    TR_NORMAL,
+    TR_SETUP,
+    TR_DATA,
+    TR_STATUS,
+    TR_ISOCH,
+    TR_LINK,
+    TR_EVDATA,
+    TR_NOOP,
+    CR_ENABLE_SLOT,
+    CR_DISABLE_SLOT,
+    CR_ADDRESS_DEVICE,
+    CR_CONFIGURE_ENDPOINT,
+    CR_EVALUATE_CONTEXT,
+    CR_RESET_ENDPOINT,
+    CR_STOP_ENDPOINT,
+    CR_SET_TR_DEQUEUE,
+    CR_RESET_DEVICE,
+    CR_FORCE_EVENT,
+    CR_NEGOTIATE_BW,
+    CR_SET_LATENCY_TOLERANCE,
+    CR_GET_PORT_BANDWIDTH,
+    CR_FORCE_HEADER,
+    CR_NOOP,
+    ER_TRANSFER = 32,
+    ER_COMMAND_COMPLETE,
+    ER_PORT_STATUS_CHANGE,
+    ER_BANDWIDTH_REQUEST,
+    ER_DOORBELL,
+    ER_HOST_CONTROLLER,
+    ER_DEVICE_NOTIFICATION,
+    ER_MFINDEX_WRAP,
+    /* vendor specific bits */
+    CR_VENDOR_VIA_CHALLENGE_RESPONSE = 48,
+    CR_VENDOR_NEC_FIRMWARE_REVISION  = 49,
+    CR_VENDOR_NEC_CHALLENGE_RESPONSE = 50,
+} TRBType;
+
+#define CR_LINK TR_LINK
+
+typedef enum TRBCCode {
+    CC_INVALID = 0,
+    CC_SUCCESS,
+    CC_DATA_BUFFER_ERROR,
+    CC_BABBLE_DETECTED,
+    CC_USB_TRANSACTION_ERROR,
+    CC_TRB_ERROR,
+    CC_STALL_ERROR,
+    CC_RESOURCE_ERROR,
+    CC_BANDWIDTH_ERROR,
+    CC_NO_SLOTS_ERROR,
+    CC_INVALID_STREAM_TYPE_ERROR,
+    CC_SLOT_NOT_ENABLED_ERROR,
+    CC_EP_NOT_ENABLED_ERROR,
+    CC_SHORT_PACKET,
+    CC_RING_UNDERRUN,
+    CC_RING_OVERRUN,
+    CC_VF_ER_FULL,
+    CC_PARAMETER_ERROR,
+    CC_BANDWIDTH_OVERRUN,
+    CC_CONTEXT_STATE_ERROR,
+    CC_NO_PING_RESPONSE_ERROR,
+    CC_EVENT_RING_FULL_ERROR,
+    CC_INCOMPATIBLE_DEVICE_ERROR,
+    CC_MISSED_SERVICE_ERROR,
+    CC_COMMAND_RING_STOPPED,
+    CC_COMMAND_ABORTED,
+    CC_STOPPED,
+    CC_STOPPED_LENGTH_INVALID,
+    CC_MAX_EXIT_LATENCY_TOO_LARGE_ERROR = 29,
+    CC_ISOCH_BUFFER_OVERRUN = 31,
+    CC_EVENT_LOST_ERROR,
+    CC_UNDEFINED_ERROR,
+    CC_INVALID_STREAM_ID_ERROR,
+    CC_SECONDARY_BANDWIDTH_ERROR,
+    CC_SPLIT_TRANSACTION_ERROR
+} TRBCCode;
+
+#define TRB_C               (1<<0)
+#define TRB_TYPE_SHIFT          10
+#define TRB_TYPE_MASK       0x3f
+#define TRB_TYPE(t)         (((t).control >> TRB_TYPE_SHIFT) & TRB_TYPE_MASK)
+
+#define TRB_EV_ED           (1<<2)
+
+#define TRB_TR_ENT          (1<<1)
+#define TRB_TR_ISP          (1<<2)
+#define TRB_TR_NS           (1<<3)
+#define TRB_TR_CH           (1<<4)
+#define TRB_TR_IOC          (1<<5)
+#define TRB_TR_IDT          (1<<6)
+#define TRB_TR_TBC_SHIFT        7
+#define TRB_TR_TBC_MASK     0x3
+#define TRB_TR_BEI          (1<<9)
+#define TRB_TR_TLBPC_SHIFT      16
+#define TRB_TR_TLBPC_MASK   0xf
+#define TRB_TR_FRAMEID_SHIFT    20
+#define TRB_TR_FRAMEID_MASK 0x7ff
+#define TRB_TR_SIA          (1<<31)
+
+#define TRB_TR_DIR          (1<<16)
+
+#define TRB_CR_SLOTID_SHIFT     24
+#define TRB_CR_SLOTID_MASK  0xff
+#define TRB_CR_EPID_SHIFT       16
+#define TRB_CR_EPID_MASK    0x1f
+
+#define TRB_CR_BSR          (1<<9)
+#define TRB_CR_DC           (1<<9)
+
+#define TRB_LK_TC           (1<<1)
+
+#define EP_TYPE_MASK        0x7
+#define EP_TYPE_SHIFT           3
+
+#define EP_STATE_MASK       0x7
+#define EP_DISABLED         (0<<0)
+#define EP_RUNNING          (1<<0)
+#define EP_HALTED           (2<<0)
+#define EP_STOPPED          (3<<0)
+#define EP_ERROR            (4<<0)
+
+#define SLOT_STATE_MASK     0x1f
+#define SLOT_STATE_SHIFT        27
+#define SLOT_STATE(s)       (((s)>>SLOT_STATE_SHIFT)&SLOT_STATE_MASK)
+#define SLOT_ENABLED        0
+#define SLOT_DEFAULT        1
+#define SLOT_ADDRESSED      2
+#define SLOT_CONFIGURED     3
+
+#define SLOT_CONTEXT_ENTRIES_MASK 0x1f
+#define SLOT_CONTEXT_ENTRIES_SHIFT 27
+
+typedef enum EPType {
+    ET_INVALID = 0,
+    ET_ISO_OUT,
+    ET_BULK_OUT,
+    ET_INTR_OUT,
+    ET_CONTROL,
+    ET_ISO_IN,
+    ET_BULK_IN,
+    ET_INTR_IN,
+} EPType;
+
+typedef struct XHCIRing {
+    target_phys_addr_t base;
+    target_phys_addr_t dequeue;
+    bool ccs;
+} XHCIRing;
+
+typedef struct XHCIPort {
+    USBPort port;
+    uint32_t portsc;
+} XHCIPort;
+
+struct XHCIState;
+typedef struct XHCIState XHCIState;
+
+typedef struct XHCITransfer {
+    XHCIState *xhci;
+    USBPacket packet;
+    bool running;
+    bool cancelled;
+    bool complete;
+    bool backgrounded;
+    unsigned int iso_pkts;
+    unsigned int slotid;
+    unsigned int epid;
+    bool in_xfer;
+    bool iso_xfer;
+    bool bg_xfer;
+
+    unsigned int trb_count;
+    unsigned int trb_alloced;
+    XHCITRB *trbs;
+
+    unsigned int data_length;
+    unsigned int data_alloced;
+    uint8_t *data;
+
+    TRBCCode status;
+
+    unsigned int pkts;
+    unsigned int pktsize;
+    unsigned int cur_pkt;
+} XHCITransfer;
+
+typedef struct XHCIEPContext {
+    XHCIRing ring;
+    unsigned int next_xfer;
+    unsigned int comp_xfer;
+    XHCITransfer transfers[TD_QUEUE];
+    bool bg_running;
+    bool bg_updating;
+    unsigned int next_bg;
+    XHCITransfer bg_transfers[BG_XFERS];
+    EPType type;
+    target_phys_addr_t pctx;
+    unsigned int max_psize;
+    bool has_bg;
+    uint32_t state;
+} XHCIEPContext;
+
+typedef struct XHCISlot {
+    bool enabled;
+    target_phys_addr_t ctx;
+    unsigned int port;
+    unsigned int devaddr;
+    XHCIEPContext * eps[31];
+} XHCISlot;
+
+typedef struct XHCIEvent {
+    TRBType type;
+    TRBCCode ccode;
+    uint64_t ptr;
+    uint32_t length;
+    uint32_t flags;
+    uint8_t slotid;
+    uint8_t epid;
+} XHCIEvent;
+
+struct XHCIState {
+    PCIDevice pci_dev;
+    USBBus bus;
+    qemu_irq irq;
+    MemoryRegion mem;
+    const char *name;
+    uint32_t msi;
+    unsigned int devaddr;
+
+    /* Operational Registers */
+    uint32_t usbcmd;
+    uint32_t usbsts;
+    uint32_t dnctrl;
+    uint32_t crcr_low;
+    uint32_t crcr_high;
+    uint32_t dcbaap_low;
+    uint32_t dcbaap_high;
+    uint32_t config;
+
+    XHCIPort ports[MAXPORTS];
+    XHCISlot slots[MAXSLOTS];
+
+    /* Runtime Registers */
+    uint32_t mfindex;
+    /* note: we only support one interrupter */
+    uint32_t iman;
+    uint32_t imod;
+    uint32_t erstsz;
+    uint32_t erstba_low;
+    uint32_t erstba_high;
+    uint32_t erdp_low;
+    uint32_t erdp_high;
+
+    target_phys_addr_t er_start;
+    uint32_t er_size;
+    bool er_pcs;
+    unsigned int er_ep_idx;
+    bool er_full;
+
+    XHCIEvent ev_buffer[EV_QUEUE];
+    unsigned int ev_buffer_put;
+    unsigned int ev_buffer_get;
+
+    XHCIRing cmd_ring;
+};
+
+typedef struct XHCIEvRingSeg {
+    uint32_t addr_low;
+    uint32_t addr_high;
+    uint32_t size;
+    uint32_t rsvd;
+} XHCIEvRingSeg;
+
+static void xhci_kick_ep(XHCIState *xhci, unsigned int slotid,
+                         unsigned int epid);
+
+static inline target_phys_addr_t xhci_addr64(uint32_t low, uint32_t high)
+{
+#if TARGET_PHYS_ADDR_BITS > 32
+    return low | ((target_phys_addr_t)high << 32);
+#else
+    return low;
+#endif
+}
+
+static inline target_phys_addr_t xhci_mask64(uint64_t addr)
+{
+#if TARGET_PHYS_ADDR_BITS > 32
+    return addr;
+#else
+    return addr & 0xffffffff;
+#endif
+}
+
+static void xhci_irq_update(XHCIState *xhci)
+{
+    int level = 0;
+
+    if (xhci->iman & IMAN_IP && xhci->iman & IMAN_IE &&
+        xhci->usbcmd && USBCMD_INTE) {
+        level = 1;
+    }
+
+    DPRINTF("xhci_irq_update(): %d\n", level);
+
+    if (xhci->msi && msi_enabled(&xhci->pci_dev)) {
+        if (level) {
+            DPRINTF("xhci_irq_update(): MSI signal\n");
+            msi_notify(&xhci->pci_dev, 0);
+        }
+    } else {
+        qemu_set_irq(xhci->irq, level);
+    }
+}
+
+static inline int xhci_running(XHCIState *xhci)
+{
+    return !(xhci->usbsts & USBSTS_HCH) && !xhci->er_full;
+}
+
+static void xhci_die(XHCIState *xhci)
+{
+    xhci->usbsts |= USBSTS_HCE;
+    fprintf(stderr, "xhci: asserted controller error\n");
+}
+
+static void xhci_write_event(XHCIState *xhci, XHCIEvent *event)
+{
+    XHCITRB ev_trb;
+    target_phys_addr_t addr;
+
+    ev_trb.parameter = cpu_to_le64(event->ptr);
+    ev_trb.status = cpu_to_le32(event->length | (event->ccode << 24));
+    ev_trb.control = (event->slotid << 24) | (event->epid << 16) |
+                     event->flags | (event->type << TRB_TYPE_SHIFT);
+    if (xhci->er_pcs) {
+        ev_trb.control |= TRB_C;
+    }
+    ev_trb.control = cpu_to_le32(ev_trb.control);
+
+    DPRINTF("xhci_write_event(): [%d] %016"PRIx64" %08x %08x\n",
+            xhci->er_ep_idx, ev_trb.parameter, ev_trb.status, ev_trb.control);
+
+    addr = xhci->er_start + TRB_SIZE*xhci->er_ep_idx;
+    cpu_physical_memory_write(addr, (uint8_t *) &ev_trb, TRB_SIZE);
+
+    xhci->er_ep_idx++;
+    if (xhci->er_ep_idx >= xhci->er_size) {
+        xhci->er_ep_idx = 0;
+        xhci->er_pcs = !xhci->er_pcs;
+    }
+}
+
+static void xhci_events_update(XHCIState *xhci)
+{
+    target_phys_addr_t erdp;
+    unsigned int dp_idx;
+    bool do_irq = 0;
+
+    if (xhci->usbsts & USBSTS_HCH) {
+        return;
+    }
+
+    erdp = xhci_addr64(xhci->erdp_low, xhci->erdp_high);
+    if (erdp < xhci->er_start ||
+        erdp >= (xhci->er_start + TRB_SIZE*xhci->er_size)) {
+        fprintf(stderr, "xhci: ERDP out of bounds: "TARGET_FMT_plx"\n", erdp);
+        fprintf(stderr, "xhci: ER at "TARGET_FMT_plx" len %d\n",
+                xhci->er_start, xhci->er_size);
+        xhci_die(xhci);
+        return;
+    }
+    dp_idx = (erdp - xhci->er_start) / TRB_SIZE;
+    assert(dp_idx < xhci->er_size);
+
+    /* NEC didn't read section 4.9.4 of the spec (v1.0 p139 top Note) and thus
+     * deadlocks when the ER is full. Hack it by holding off events until
+     * the driver decides to free at least half of the ring */
+    if (xhci->er_full) {
+        int er_free = dp_idx - xhci->er_ep_idx;
+        if (er_free <= 0) {
+            er_free += xhci->er_size;
+        }
+        if (er_free < (xhci->er_size/2)) {
+            DPRINTF("xhci_events_update(): event ring still "
+                    "more than half full (hack)\n");
+            return;
+        }
+    }
+
+    while (xhci->ev_buffer_put != xhci->ev_buffer_get) {
+        assert(xhci->er_full);
+        if (((xhci->er_ep_idx+1) % xhci->er_size) == dp_idx) {
+            DPRINTF("xhci_events_update(): event ring full again\n");
+#ifndef ER_FULL_HACK
+            XHCIEvent full = {ER_HOST_CONTROLLER, CC_EVENT_RING_FULL_ERROR};
+            xhci_write_event(xhci, &full);
+#endif
+            do_irq = 1;
+            break;
+        }
+        XHCIEvent *event = &xhci->ev_buffer[xhci->ev_buffer_get];
+        xhci_write_event(xhci, event);
+        xhci->ev_buffer_get++;
+        do_irq = 1;
+        if (xhci->ev_buffer_get == EV_QUEUE) {
+            xhci->ev_buffer_get = 0;
+        }
+    }
+
+    if (do_irq) {
+        xhci->erdp_low |= ERDP_EHB;
+        xhci->iman |= IMAN_IP;
+        xhci->usbsts |= USBSTS_EINT;
+        xhci_irq_update(xhci);
+    }
+
+    if (xhci->er_full && xhci->ev_buffer_put == xhci->ev_buffer_get) {
+        DPRINTF("xhci_events_update(): event ring no longer full\n");
+        xhci->er_full = 0;
+    }
+    return;
+}
+
+static void xhci_event(XHCIState *xhci, XHCIEvent *event)
+{
+    target_phys_addr_t erdp;
+    unsigned int dp_idx;
+
+    if (xhci->er_full) {
+        DPRINTF("xhci_event(): ER full, queueing\n");
+        if (((xhci->ev_buffer_put+1) % EV_QUEUE) == xhci->ev_buffer_get) {
+            fprintf(stderr, "xhci: event queue full, dropping event!\n");
+            return;
+        }
+        xhci->ev_buffer[xhci->ev_buffer_put++] = *event;
+        if (xhci->ev_buffer_put == EV_QUEUE) {
+            xhci->ev_buffer_put = 0;
+        }
+        return;
+    }
+
+    erdp = xhci_addr64(xhci->erdp_low, xhci->erdp_high);
+    if (erdp < xhci->er_start ||
+        erdp >= (xhci->er_start + TRB_SIZE*xhci->er_size)) {
+        fprintf(stderr, "xhci: ERDP out of bounds: "TARGET_FMT_plx"\n", erdp);
+        fprintf(stderr, "xhci: ER at "TARGET_FMT_plx" len %d\n",
+                xhci->er_start, xhci->er_size);
+        xhci_die(xhci);
+        return;
+    }
+
+    dp_idx = (erdp - xhci->er_start) / TRB_SIZE;
+    assert(dp_idx < xhci->er_size);
+
+    if ((xhci->er_ep_idx+1) % xhci->er_size == dp_idx) {
+        DPRINTF("xhci_event(): ER full, queueing\n");
+#ifndef ER_FULL_HACK
+        XHCIEvent full = {ER_HOST_CONTROLLER, CC_EVENT_RING_FULL_ERROR};
+        xhci_write_event(xhci, &full);
+#endif
+        xhci->er_full = 1;
+        if (((xhci->ev_buffer_put+1) % EV_QUEUE) == xhci->ev_buffer_get) {
+            fprintf(stderr, "xhci: event queue full, dropping event!\n");
+            return;
+        }
+        xhci->ev_buffer[xhci->ev_buffer_put++] = *event;
+        if (xhci->ev_buffer_put == EV_QUEUE) {
+            xhci->ev_buffer_put = 0;
+        }
+    } else {
+        xhci_write_event(xhci, event);
+    }
+
+    xhci->erdp_low |= ERDP_EHB;
+    xhci->iman |= IMAN_IP;
+    xhci->usbsts |= USBSTS_EINT;
+
+    xhci_irq_update(xhci);
+}
+
+static void xhci_ring_init(XHCIState *xhci, XHCIRing *ring,
+                           target_phys_addr_t base)
+{
+    ring->base = base;
+    ring->dequeue = base;
+    ring->ccs = 1;
+}
+
+static TRBType xhci_ring_fetch(XHCIState *xhci, XHCIRing *ring, XHCITRB *trb,
+                               target_phys_addr_t *addr)
+{
+    while (1) {
+        TRBType type;
+        cpu_physical_memory_read(ring->dequeue, (uint8_t *) trb, TRB_SIZE);
+        trb->addr = ring->dequeue;
+        trb->ccs = ring->ccs;
+        le64_to_cpus(&trb->parameter);
+        le32_to_cpus(&trb->status);
+        le32_to_cpus(&trb->control);
+
+        DPRINTF("xhci: TRB fetched [" TARGET_FMT_plx "]: "
+                "%016" PRIx64 " %08x %08x\n",
+                ring->dequeue, trb->parameter, trb->status, trb->control);
+
+        if ((trb->control & TRB_C) != ring->ccs) {
+            return 0;
+        }
+
+        type = TRB_TYPE(*trb);
+
+        if (type != TR_LINK) {
+            if (addr) {
+                *addr = ring->dequeue;
+            }
+            ring->dequeue += TRB_SIZE;
+            return type;
+        } else {
+            ring->dequeue = xhci_mask64(trb->parameter);
+            if (trb->control & TRB_LK_TC) {
+                ring->ccs = !ring->ccs;
+            }
+        }
+    }
+}
+
+static int xhci_ring_chain_length(XHCIState *xhci, const XHCIRing *ring)
+{
+    XHCITRB trb;
+    int length = 0;
+    target_phys_addr_t dequeue = ring->dequeue;
+    bool ccs = ring->ccs;
+    /* hack to bundle together the two/three TDs that make a setup transfer */
+    bool control_td_set = 0;
+
+    while (1) {
+        TRBType type;
+        cpu_physical_memory_read(dequeue, (uint8_t *) &trb, TRB_SIZE);
+        le64_to_cpus(&trb.parameter);
+        le32_to_cpus(&trb.status);
+        le32_to_cpus(&trb.control);
+
+        DPRINTF("xhci: TRB peeked [" TARGET_FMT_plx "]: "
+                "%016" PRIx64 " %08x %08x\n",
+                dequeue, trb.parameter, trb.status, trb.control);
+
+        if ((trb.control & TRB_C) != ccs) {
+            return -length;
+        }
+
+        type = TRB_TYPE(trb);
+
+        if (type == TR_LINK) {
+            dequeue = xhci_mask64(trb.parameter);
+            if (trb.control & TRB_LK_TC) {
+                ccs = !ccs;
+            }
+            continue;
+        }
+
+        length += 1;
+        dequeue += TRB_SIZE;
+
+        if (type == TR_SETUP) {
+            control_td_set = 1;
+        } else if (type == TR_STATUS) {
+            control_td_set = 0;
+        }
+
+        if (!control_td_set && !(trb.control & TRB_TR_CH)) {
+            return length;
+        }
+    }
+}
+
+static void xhci_er_reset(XHCIState *xhci)
+{
+    XHCIEvRingSeg seg;
+
+    /* cache the (sole) event ring segment location */
+    if (xhci->erstsz != 1) {
+        fprintf(stderr, "xhci: invalid value for ERSTSZ: %d\n", xhci->erstsz);
+        xhci_die(xhci);
+        return;
+    }
+    target_phys_addr_t erstba = xhci_addr64(xhci->erstba_low, xhci->erstba_high);
+    cpu_physical_memory_read(erstba, (uint8_t *) &seg, sizeof(seg));
+    le32_to_cpus(&seg.addr_low);
+    le32_to_cpus(&seg.addr_high);
+    le32_to_cpus(&seg.size);
+    if (seg.size < 16 || seg.size > 4096) {
+        fprintf(stderr, "xhci: invalid value for segment size: %d\n", seg.size);
+        xhci_die(xhci);
+        return;
+    }
+    xhci->er_start = xhci_addr64(seg.addr_low, seg.addr_high);
+    xhci->er_size = seg.size;
+
+    xhci->er_ep_idx = 0;
+    xhci->er_pcs = 1;
+    xhci->er_full = 0;
+
+    DPRINTF("xhci: event ring:" TARGET_FMT_plx " [%d]\n",
+            xhci->er_start, xhci->er_size);
+}
+
+static void xhci_run(XHCIState *xhci)
+{
+    DPRINTF("xhci_run()\n");
+
+    xhci->usbsts &= ~USBSTS_HCH;
+}
+
+static void xhci_stop(XHCIState *xhci)
+{
+    DPRINTF("xhci_stop()\n");
+    xhci->usbsts |= USBSTS_HCH;
+    xhci->crcr_low &= ~CRCR_CRR;
+}
+
+static void xhci_set_ep_state(XHCIState *xhci, XHCIEPContext *epctx,
+                              uint32_t state)
+{
+    uint32_t ctx[5];
+    if (epctx->state == state) {
+        return;
+    }
+
+    cpu_physical_memory_read(epctx->pctx, (uint8_t *) ctx, sizeof(ctx));
+    ctx[0] &= ~EP_STATE_MASK;
+    ctx[0] |= state;
+    ctx[2] = epctx->ring.dequeue | epctx->ring.ccs;
+    ctx[3] = (epctx->ring.dequeue >> 16) >> 16;
+    DPRINTF("xhci: set epctx: " TARGET_FMT_plx " state=%d dequeue=%08x%08x\n",
+            epctx->pctx, state, ctx[3], ctx[2]);
+    cpu_physical_memory_write(epctx->pctx, (uint8_t *) ctx, sizeof(ctx));
+    epctx->state = state;
+}
+
+static TRBCCode xhci_enable_ep(XHCIState *xhci, unsigned int slotid,
+                               unsigned int epid, target_phys_addr_t pctx,
+                               uint32_t *ctx)
+{
+    XHCISlot *slot;
+    XHCIEPContext *epctx;
+    target_phys_addr_t dequeue;
+    int i;
+
+    assert(slotid >= 1 && slotid <= MAXSLOTS);
+    assert(epid >= 1 && epid <= 31);
+
+    DPRINTF("xhci_enable_ep(%d, %d)\n", slotid, epid);
+
+    slot = &xhci->slots[slotid-1];
+    if (slot->eps[epid-1]) {
+        fprintf(stderr, "xhci: slot %d ep %d already enabled!\n", slotid, epid);
+        return CC_TRB_ERROR;
+    }
+
+    epctx = g_malloc(sizeof(XHCIEPContext));
+    memset(epctx, 0, sizeof(XHCIEPContext));
+
+    slot->eps[epid-1] = epctx;
+
+    dequeue = xhci_addr64(ctx[2] & ~0xf, ctx[3]);
+    xhci_ring_init(xhci, &epctx->ring, dequeue);
+    epctx->ring.ccs = ctx[2] & 1;
+
+    epctx->type = (ctx[1] >> EP_TYPE_SHIFT) & EP_TYPE_MASK;
+    DPRINTF("xhci: endpoint %d.%d type is %d\n", epid/2, epid%2, epctx->type);
+    epctx->pctx = pctx;
+    epctx->max_psize = ctx[1]>>16;
+    epctx->max_psize *= 1+((ctx[1]>>8)&0xff);
+    epctx->has_bg = false;
+    if (epctx->type == ET_ISO_IN) {
+        epctx->has_bg = true;
+    }
+    DPRINTF("xhci: endpoint %d.%d max transaction (burst) size is %d\n",
+            epid/2, epid%2, epctx->max_psize);
+    for (i = 0; i < ARRAY_SIZE(epctx->transfers); i++) {
+        usb_packet_init(&epctx->transfers[i].packet);
+    }
+
+    epctx->state = EP_RUNNING;
+    ctx[0] &= ~EP_STATE_MASK;
+    ctx[0] |= EP_RUNNING;
+
+    return CC_SUCCESS;
+}
+
+static int xhci_ep_nuke_xfers(XHCIState *xhci, unsigned int slotid,
+                               unsigned int epid)
+{
+    XHCISlot *slot;
+    XHCIEPContext *epctx;
+    int i, xferi, killed = 0;
+    assert(slotid >= 1 && slotid <= MAXSLOTS);
+    assert(epid >= 1 && epid <= 31);
+
+    DPRINTF("xhci_ep_nuke_xfers(%d, %d)\n", slotid, epid);
+
+    slot = &xhci->slots[slotid-1];
+
+    if (!slot->eps[epid-1]) {
+        return 0;
+    }
+
+    epctx = slot->eps[epid-1];
+
+    xferi = epctx->next_xfer;
+    for (i = 0; i < TD_QUEUE; i++) {
+        XHCITransfer *t = &epctx->transfers[xferi];
+        if (t->running) {
+            t->cancelled = 1;
+            /* libusb_cancel_transfer(t->usbxfer) */
+            DPRINTF("xhci: cancelling transfer %d, waiting for it to complete...\n", i);
+            killed++;
+        }
+        if (t->backgrounded) {
+            t->backgrounded = 0;
+        }
+        if (t->trbs) {
+            g_free(t->trbs);
+        }
+        if (t->data) {
+            g_free(t->data);
+        }
+
+        t->trbs = NULL;
+        t->data = NULL;
+        t->trb_count = t->trb_alloced = 0;
+        t->data_length = t->data_alloced = 0;
+        xferi = (xferi + 1) % TD_QUEUE;
+    }
+    if (epctx->has_bg) {
+        xferi = epctx->next_bg;
+        for (i = 0; i < BG_XFERS; i++) {
+            XHCITransfer *t = &epctx->bg_transfers[xferi];
+            if (t->running) {
+                t->cancelled = 1;
+                /* libusb_cancel_transfer(t->usbxfer); */
+                DPRINTF("xhci: cancelling bg transfer %d, waiting for it to complete...\n", i);
+                killed++;
+            }
+            if (t->data) {
+                g_free(t->data);
+            }
+
+            t->data = NULL;
+            xferi = (xferi + 1) % BG_XFERS;
+        }
+    }
+    return killed;
+}
+
+static TRBCCode xhci_disable_ep(XHCIState *xhci, unsigned int slotid,
+                               unsigned int epid)
+{
+    XHCISlot *slot;
+    XHCIEPContext *epctx;
+
+    assert(slotid >= 1 && slotid <= MAXSLOTS);
+    assert(epid >= 1 && epid <= 31);
+
+    DPRINTF("xhci_disable_ep(%d, %d)\n", slotid, epid);
+
+    slot = &xhci->slots[slotid-1];
+
+    if (!slot->eps[epid-1]) {
+        DPRINTF("xhci: slot %d ep %d already disabled\n", slotid, epid);
+        return CC_SUCCESS;
+    }
+
+    xhci_ep_nuke_xfers(xhci, slotid, epid);
+
+    epctx = slot->eps[epid-1];
+
+    xhci_set_ep_state(xhci, epctx, EP_DISABLED);
+
+    g_free(epctx);
+    slot->eps[epid-1] = NULL;
+
+    return CC_SUCCESS;
+}
+
+static TRBCCode xhci_stop_ep(XHCIState *xhci, unsigned int slotid,
+                             unsigned int epid)
+{
+    XHCISlot *slot;
+    XHCIEPContext *epctx;
+
+    DPRINTF("xhci_stop_ep(%d, %d)\n", slotid, epid);
+
+    assert(slotid >= 1 && slotid <= MAXSLOTS);
+
+    if (epid < 1 || epid > 31) {
+        fprintf(stderr, "xhci: bad ep %d\n", epid);
+        return CC_TRB_ERROR;
+    }
+
+    slot = &xhci->slots[slotid-1];
+
+    if (!slot->eps[epid-1]) {
+        DPRINTF("xhci: slot %d ep %d not enabled\n", slotid, epid);
+        return CC_EP_NOT_ENABLED_ERROR;
+    }
+
+    if (xhci_ep_nuke_xfers(xhci, slotid, epid) > 0) {
+        fprintf(stderr, "xhci: FIXME: endpoint stopped w/ xfers running, "
+                "data might be lost\n");
+    }
+
+    epctx = slot->eps[epid-1];
+
+    xhci_set_ep_state(xhci, epctx, EP_STOPPED);
+
+    return CC_SUCCESS;
+}
+
+static TRBCCode xhci_reset_ep(XHCIState *xhci, unsigned int slotid,
+                              unsigned int epid)
+{
+    XHCISlot *slot;
+    XHCIEPContext *epctx;
+    USBDevice *dev;
+
+    assert(slotid >= 1 && slotid <= MAXSLOTS);
+
+    DPRINTF("xhci_reset_ep(%d, %d)\n", slotid, epid);
+
+    if (epid < 1 || epid > 31) {
+        fprintf(stderr, "xhci: bad ep %d\n", epid);
+        return CC_TRB_ERROR;
+    }
+
+    slot = &xhci->slots[slotid-1];
+
+    if (!slot->eps[epid-1]) {
+        DPRINTF("xhci: slot %d ep %d not enabled\n", slotid, epid);
+        return CC_EP_NOT_ENABLED_ERROR;
+    }
+
+    epctx = slot->eps[epid-1];
+
+    if (epctx->state != EP_HALTED) {
+        fprintf(stderr, "xhci: reset EP while EP %d not halted (%d)\n",
+                epid, epctx->state);
+        return CC_CONTEXT_STATE_ERROR;
+    }
+
+    if (xhci_ep_nuke_xfers(xhci, slotid, epid) > 0) {
+        fprintf(stderr, "xhci: FIXME: endpoint reset w/ xfers running, "
+                "data might be lost\n");
+    }
+
+    uint8_t ep = epid>>1;
+
+    if (epid & 1) {
+        ep |= 0x80;
+    }
+
+    dev = xhci->ports[xhci->slots[slotid-1].port-1].port.dev;
+    if (!dev) {
+        return CC_USB_TRANSACTION_ERROR;
+    }
+
+    xhci_set_ep_state(xhci, epctx, EP_STOPPED);
+
+    return CC_SUCCESS;
+}
+
+static TRBCCode xhci_set_ep_dequeue(XHCIState *xhci, unsigned int slotid,
+                                    unsigned int epid, uint64_t pdequeue)
+{
+    XHCISlot *slot;
+    XHCIEPContext *epctx;
+    target_phys_addr_t dequeue;
+
+    assert(slotid >= 1 && slotid <= MAXSLOTS);
+
+    if (epid < 1 || epid > 31) {
+        fprintf(stderr, "xhci: bad ep %d\n", epid);
+        return CC_TRB_ERROR;
+    }
+
+    DPRINTF("xhci_set_ep_dequeue(%d, %d, %016"PRIx64")\n", slotid, epid, pdequeue);
+    dequeue = xhci_mask64(pdequeue);
+
+    slot = &xhci->slots[slotid-1];
+
+    if (!slot->eps[epid-1]) {
+        DPRINTF("xhci: slot %d ep %d not enabled\n", slotid, epid);
+        return CC_EP_NOT_ENABLED_ERROR;
+    }
+
+    epctx = slot->eps[epid-1];
+
+
+    if (epctx->state != EP_STOPPED) {
+        fprintf(stderr, "xhci: set EP dequeue pointer while EP %d not stopped\n", epid);
+        return CC_CONTEXT_STATE_ERROR;
+    }
+
+    xhci_ring_init(xhci, &epctx->ring, dequeue & ~0xF);
+    epctx->ring.ccs = dequeue & 1;
+
+    xhci_set_ep_state(xhci, epctx, EP_STOPPED);
+
+    return CC_SUCCESS;
+}
+
+static int xhci_xfer_data(XHCITransfer *xfer, uint8_t *data,
+                          unsigned int length, bool in_xfer, bool out_xfer,
+                          bool report)
+{
+    int i;
+    uint32_t edtla = 0;
+    unsigned int transferred = 0;
+    unsigned int left = length;
+    bool reported = 0;
+    bool shortpkt = 0;
+    XHCIEvent event = {ER_TRANSFER, CC_SUCCESS};
+    XHCIState *xhci = xfer->xhci;
+
+    DPRINTF("xhci_xfer_data(len=%d, in_xfer=%d, out_xfer=%d, report=%d)\n",
+            length, in_xfer, out_xfer, report);
+
+    assert(!(in_xfer && out_xfer));
+
+    for (i = 0; i < xfer->trb_count; i++) {
+        XHCITRB *trb = &xfer->trbs[i];
+        target_phys_addr_t addr;
+        unsigned int chunk = 0;
+
+        switch (TRB_TYPE(*trb)) {
+        case TR_DATA:
+            if ((!(trb->control & TRB_TR_DIR)) != (!in_xfer)) {
+                fprintf(stderr, "xhci: data direction mismatch for TR_DATA\n");
+                xhci_die(xhci);
+                return transferred;
+            }
+            /* fallthrough */
+        case TR_NORMAL:
+        case TR_ISOCH:
+            addr = xhci_mask64(trb->parameter);
+            chunk = trb->status & 0x1ffff;
+            if (chunk > left) {
+                chunk = left;
+                shortpkt = 1;
+            }
+            if (in_xfer || out_xfer) {
+                if (trb->control & TRB_TR_IDT) {
+                    uint64_t idata;
+                    if (chunk > 8 || in_xfer) {
+                        fprintf(stderr, "xhci: invalid immediate data TRB\n");
+                        xhci_die(xhci);
+                        return transferred;
+                    }
+                    idata = le64_to_cpu(trb->parameter);
+                    memcpy(data, &idata, chunk);
+                } else {
+                    DPRINTF("xhci_xfer_data: r/w(%d) %d bytes at "
+                            TARGET_FMT_plx "\n", in_xfer, chunk, addr);
+                    if (in_xfer) {
+                        cpu_physical_memory_write(addr, data, chunk);
+                    } else {
+                        cpu_physical_memory_read(addr, data, chunk);
+                    }
+#ifdef DEBUG_DATA
+                    unsigned int count = chunk;
+                    int i;
+                    if (count > 16) {
+                        count = 16;
+                    }
+                    DPRINTF(" ::");
+                    for (i = 0; i < count; i++) {
+                        DPRINTF(" %02x", data[i]);
+                    }
+                    DPRINTF("\n");
+#endif
+                }
+            }
+            left -= chunk;
+            data += chunk;
+            edtla += chunk;
+            transferred += chunk;
+            break;
+        case TR_STATUS:
+            reported = 0;
+            shortpkt = 0;
+            break;
+        }
+
+        if (report && !reported && (trb->control & TRB_TR_IOC ||
+            (shortpkt && (trb->control & TRB_TR_ISP)))) {
+            event.slotid = xfer->slotid;
+            event.epid = xfer->epid;
+            event.length = (trb->status & 0x1ffff) - chunk;
+            event.flags = 0;
+            event.ptr = trb->addr;
+            if (xfer->status == CC_SUCCESS) {
+                event.ccode = shortpkt ? CC_SHORT_PACKET : CC_SUCCESS;
+            } else {
+                event.ccode = xfer->status;
+            }
+            if (TRB_TYPE(*trb) == TR_EVDATA) {
+                event.ptr = trb->parameter;
+                event.flags |= TRB_EV_ED;
+                event.length = edtla & 0xffffff;
+                DPRINTF("xhci_xfer_data: EDTLA=%d\n", event.length);
+                edtla = 0;
+            }
+            xhci_event(xhci, &event);
+            reported = 1;
+        }
+    }
+    return transferred;
+}
+
+static void xhci_stall_ep(XHCITransfer *xfer)
+{
+    XHCIState *xhci = xfer->xhci;
+    XHCISlot *slot = &xhci->slots[xfer->slotid-1];
+    XHCIEPContext *epctx = slot->eps[xfer->epid-1];
+
+    epctx->ring.dequeue = xfer->trbs[0].addr;
+    epctx->ring.ccs = xfer->trbs[0].ccs;
+    xhci_set_ep_state(xhci, epctx, EP_HALTED);
+    DPRINTF("xhci: stalled slot %d ep %d\n", xfer->slotid, xfer->epid);
+    DPRINTF("xhci: will continue at "TARGET_FMT_plx"\n", epctx->ring.dequeue);
+}
+
+static int xhci_submit(XHCIState *xhci, XHCITransfer *xfer,
+                       XHCIEPContext *epctx);
+
+static void xhci_bg_update(XHCIState *xhci, XHCIEPContext *epctx)
+{
+    if (epctx->bg_updating) {
+        return;
+    }
+    DPRINTF("xhci_bg_update(%p, %p)\n", xhci, epctx);
+    assert(epctx->has_bg);
+    DPRINTF("xhci: fg=%d bg=%d\n", epctx->comp_xfer, epctx->next_bg);
+    epctx->bg_updating = 1;
+    while (epctx->transfers[epctx->comp_xfer].backgrounded &&
+           epctx->bg_transfers[epctx->next_bg].complete) {
+        XHCITransfer *fg = &epctx->transfers[epctx->comp_xfer];
+        XHCITransfer *bg = &epctx->bg_transfers[epctx->next_bg];
+#if 0
+        DPRINTF("xhci: completing fg %d from bg %d.%d (stat: %d)\n",
+                epctx->comp_xfer, epctx->next_bg, bg->cur_pkt,
+                bg->usbxfer->iso_packet_desc[bg->cur_pkt].status
+               );
+#endif
+        assert(epctx->type == ET_ISO_IN);
+        assert(bg->iso_xfer);
+        assert(bg->in_xfer);
+        uint8_t *p = bg->data + bg->cur_pkt * bg->pktsize;
+#if 0
+        int len = bg->usbxfer->iso_packet_desc[bg->cur_pkt].actual_length;
+        fg->status = libusb_to_ccode(bg->usbxfer->iso_packet_desc[bg->cur_pkt].status);
+#else
+        int len = 0;
+        FIXME();
+#endif
+        fg->complete = 1;
+        fg->backgrounded = 0;
+
+        if (fg->status == CC_STALL_ERROR) {
+            xhci_stall_ep(fg);
+        }
+
+        xhci_xfer_data(fg, p, len, 1, 0, 1);
+
+        epctx->comp_xfer++;
+        if (epctx->comp_xfer == TD_QUEUE) {
+            epctx->comp_xfer = 0;
+        }
+        DPRINTF("next fg xfer: %d\n", epctx->comp_xfer);
+        bg->cur_pkt++;
+        if (bg->cur_pkt == bg->pkts) {
+            bg->complete = 0;
+            if (xhci_submit(xhci, bg, epctx) < 0) {
+                fprintf(stderr, "xhci: bg resubmit failed\n");
+            }
+            epctx->next_bg++;
+            if (epctx->next_bg == BG_XFERS) {
+                epctx->next_bg = 0;
+            }
+            DPRINTF("next bg xfer: %d\n", epctx->next_bg);
+
+        xhci_kick_ep(xhci, fg->slotid, fg->epid);
+        }
+    }
+    epctx->bg_updating = 0;
+}
+
+#if 0
+static void xhci_xfer_cb(struct libusb_transfer *transfer)
+{
+    XHCIState *xhci;
+    XHCITransfer *xfer;
+
+    xfer = (XHCITransfer *)transfer->user_data;
+    xhci = xfer->xhci;
+
+    DPRINTF("xhci_xfer_cb(slot=%d, ep=%d, status=%d)\n", xfer->slotid,
+            xfer->epid, transfer->status);
+
+    assert(xfer->slotid >= 1 && xfer->slotid <= MAXSLOTS);
+    assert(xfer->epid >= 1 && xfer->epid <= 31);
+
+    if (xfer->cancelled) {
+        DPRINTF("xhci: transfer cancelled, not reporting anything\n");
+        xfer->running = 0;
+        return;
+    }
+
+    XHCIEPContext *epctx;
+    XHCISlot *slot;
+    slot = &xhci->slots[xfer->slotid-1];
+    assert(slot->eps[xfer->epid-1]);
+    epctx = slot->eps[xfer->epid-1];
+
+    if (xfer->bg_xfer) {
+        DPRINTF("xhci: background transfer, updating\n");
+        xfer->complete = 1;
+        xfer->running = 0;
+        xhci_bg_update(xhci, epctx);
+        return;
+    }
+
+    if (xfer->iso_xfer) {
+        transfer->status = transfer->iso_packet_desc[0].status;
+        transfer->actual_length = transfer->iso_packet_desc[0].actual_length;
+    }
+
+    xfer->status = libusb_to_ccode(transfer->status);
+
+    xfer->complete = 1;
+    xfer->running = 0;
+
+    if (transfer->status == LIBUSB_TRANSFER_STALL)
+        xhci_stall_ep(xhci, epctx, xfer);
+
+    DPRINTF("xhci: transfer actual length = %d\n", transfer->actual_length);
+
+    if (xfer->in_xfer) {
+        if (xfer->epid == 1) {
+            xhci_xfer_data(xhci, xfer, xfer->data + 8,
+                           transfer->actual_length, 1, 0, 1);
+        } else {
+            xhci_xfer_data(xhci, xfer, xfer->data,
+                           transfer->actual_length, 1, 0, 1);
+        }
+    } else {
+        xhci_xfer_data(xhci, xfer, NULL, transfer->actual_length, 0, 0, 1);
+    }
+
+    xhci_kick_ep(xhci, xfer->slotid, xfer->epid);
+}
+
+static int xhci_hle_control(XHCIState *xhci, XHCITransfer *xfer,
+                            uint8_t bmRequestType, uint8_t bRequest,
+                            uint16_t wValue, uint16_t wIndex, uint16_t wLength)
+{
+    uint16_t type_req = (bmRequestType << 8) | bRequest;
+
+    switch (type_req) {
+        case 0x0000 | USB_REQ_SET_CONFIGURATION:
+            DPRINTF("xhci: HLE switch configuration\n");
+            return xhci_switch_config(xhci, xfer->slotid, wValue) == 0;
+        case 0x0100 | USB_REQ_SET_INTERFACE:
+            DPRINTF("xhci: HLE set interface altsetting\n");
+            return xhci_set_iface_alt(xhci, xfer->slotid, wIndex, wValue) == 0;
+        case 0x0200 | USB_REQ_CLEAR_FEATURE:
+            if (wValue == 0) { // endpoint halt
+                DPRINTF("xhci: HLE clear halt\n");
+                return xhci_clear_halt(xhci, xfer->slotid, wIndex);
+            }
+        case 0x0000 | USB_REQ_SET_ADDRESS:
+            fprintf(stderr, "xhci: warn: illegal SET_ADDRESS request\n");
+            return 0;
+        default:
+            return 0;
+    }
+}
+#endif
+
+static int xhci_setup_packet(XHCITransfer *xfer, XHCIPort *port, int ep)
+{
+    usb_packet_setup(&xfer->packet,
+                     xfer->in_xfer ? USB_TOKEN_IN : USB_TOKEN_OUT,
+                     xfer->xhci->slots[xfer->slotid-1].devaddr,
+                     ep & 0x7f);
+    usb_packet_addbuf(&xfer->packet, xfer->data, xfer->data_length);
+    DPRINTF("xhci: setup packet pid 0x%x addr %d ep %d\n",
+            xfer->packet.pid, xfer->packet.devaddr, xfer->packet.devep);
+    return 0;
+}
+
+static int xhci_complete_packet(XHCITransfer *xfer, int ret)
+{
+    if (ret == USB_RET_ASYNC) {
+        xfer->running = 1;
+        xfer->complete = 0;
+        xfer->cancelled = 0;
+        return 0;
+    } else {
+        xfer->running = 0;
+        xfer->complete = 1;
+    }
+
+    if (ret >= 0) {
+        xfer->status = CC_SUCCESS;
+        xhci_xfer_data(xfer, xfer->data, ret, xfer->in_xfer, 0, 1);
+        return 0;
+    }
+
+    /* error */
+    switch (ret) {
+    case USB_RET_NODEV:
+        xfer->status = CC_USB_TRANSACTION_ERROR;
+        xhci_xfer_data(xfer, xfer->data, 0, xfer->in_xfer, 0, 1);
+        xhci_stall_ep(xfer);
+        break;
+    case USB_RET_STALL:
+        xfer->status = CC_STALL_ERROR;
+        xhci_xfer_data(xfer, xfer->data, 0, xfer->in_xfer, 0, 1);
+        xhci_stall_ep(xfer);
+        break;
+    default:
+        fprintf(stderr, "%s: FIXME: ret = %d\n", __FUNCTION__, ret);
+        FIXME();
+    }
+    return 0;
+}
+
+static int xhci_fire_ctl_transfer(XHCIState *xhci, XHCITransfer *xfer)
+{
+    XHCITRB *trb_setup, *trb_status;
+    uint8_t bmRequestType, bRequest;
+    uint16_t wValue, wLength, wIndex;
+    XHCIPort *port;
+    USBDevice *dev;
+    int ret;
+
+    DPRINTF("xhci_fire_ctl_transfer(slot=%d)\n", xfer->slotid);
+
+    trb_setup = &xfer->trbs[0];
+    trb_status = &xfer->trbs[xfer->trb_count-1];
+
+    /* at most one Event Data TRB allowed after STATUS */
+    if (TRB_TYPE(*trb_status) == TR_EVDATA && xfer->trb_count > 2) {
+        trb_status--;
+    }
+
+    /* do some sanity checks */
+    if (TRB_TYPE(*trb_setup) != TR_SETUP) {
+        fprintf(stderr, "xhci: ep0 first TD not SETUP: %d\n",
+                TRB_TYPE(*trb_setup));
+        return -1;
+    }
+    if (TRB_TYPE(*trb_status) != TR_STATUS) {
+        fprintf(stderr, "xhci: ep0 last TD not STATUS: %d\n",
+                TRB_TYPE(*trb_status));
+        return -1;
+    }
+    if (!(trb_setup->control & TRB_TR_IDT)) {
+        fprintf(stderr, "xhci: Setup TRB doesn't have IDT set\n");
+        return -1;
+    }
+    if ((trb_setup->status & 0x1ffff) != 8) {
+        fprintf(stderr, "xhci: Setup TRB has bad length (%d)\n",
+                (trb_setup->status & 0x1ffff));
+        return -1;
+    }
+
+    bmRequestType = trb_setup->parameter;
+    bRequest = trb_setup->parameter >> 8;
+    wValue = trb_setup->parameter >> 16;
+    wIndex = trb_setup->parameter >> 32;
+    wLength = trb_setup->parameter >> 48;
+
+    if (xfer->data && xfer->data_alloced < wLength) {
+        xfer->data_alloced = 0;
+        g_free(xfer->data);
+        xfer->data = NULL;
+    }
+    if (!xfer->data) {
+        DPRINTF("xhci: alloc %d bytes data\n", wLength);
+        xfer->data = g_malloc(wLength+1);
+        xfer->data_alloced = wLength;
+    }
+    xfer->data_length = wLength;
+
+    port = &xhci->ports[xhci->slots[xfer->slotid-1].port-1];
+    dev = port->port.dev;
+    if (!dev) {
+        fprintf(stderr, "xhci: slot %d port %d has no device\n", xfer->slotid,
+                xhci->slots[xfer->slotid-1].port);
+        return -1;
+    }
+
+    xfer->in_xfer = bmRequestType & USB_DIR_IN;
+    xfer->iso_xfer = false;
+
+    xhci_setup_packet(xfer, port, 0);
+    if (!xfer->in_xfer) {
+        xhci_xfer_data(xfer, xfer->data, wLength, 0, 1, 0);
+    }
+    ret = dev->info->handle_control(dev, &xfer->packet,
+                                    (bmRequestType << 8) | bRequest,
+                                    wValue, wIndex, wLength, xfer->data);
+
+    xhci_complete_packet(xfer, ret);
+    if (!xfer->running) {
+        xhci_kick_ep(xhci, xfer->slotid, xfer->epid);
+    }
+    return 0;
+}
+
+static int xhci_submit(XHCIState *xhci, XHCITransfer *xfer, XHCIEPContext *epctx)
+{
+    XHCIPort *port;
+    USBDevice *dev;
+    int ret;
+
+    DPRINTF("xhci_submit(slotid=%d,epid=%d)\n", xfer->slotid, xfer->epid);
+    uint8_t ep = xfer->epid>>1;
+
+    xfer->in_xfer = epctx->type>>2;
+    if (xfer->in_xfer) {
+        ep |= 0x80;
+    }
+
+    if (xfer->data && xfer->data_alloced < xfer->data_length) {
+        xfer->data_alloced = 0;
+        g_free(xfer->data);
+        xfer->data = NULL;
+    }
+    if (!xfer->data && xfer->data_length) {
+        DPRINTF("xhci: alloc %d bytes data\n", xfer->data_length);
+        xfer->data = g_malloc(xfer->data_length);
+        xfer->data_alloced = xfer->data_length;
+    }
+    if (epctx->type == ET_ISO_IN || epctx->type == ET_ISO_OUT) {
+        if (!xfer->bg_xfer) {
+            xfer->pkts = 1;
+        }
+    } else {
+        xfer->pkts = 0;
+    }
+
+    port = &xhci->ports[xhci->slots[xfer->slotid-1].port-1];
+    dev = port->port.dev;
+    if (!dev) {
+        fprintf(stderr, "xhci: slot %d port %d has no device\n", xfer->slotid,
+                xhci->slots[xfer->slotid-1].port);
+        return -1;
+    }
+
+    xhci_setup_packet(xfer, port, ep);
+
+    switch(epctx->type) {
+    case ET_INTR_OUT:
+    case ET_INTR_IN:
+    case ET_BULK_OUT:
+    case ET_BULK_IN:
+        break;
+    case ET_ISO_OUT:
+    case ET_ISO_IN:
+        FIXME();
+        break;
+    default:
+        fprintf(stderr, "xhci: unknown or unhandled EP type %d (ep %02x)\n",
+                epctx->type, ep);
+        return -1;
+    }
+
+    if (!xfer->in_xfer) {
+        xhci_xfer_data(xfer, xfer->data, xfer->data_length, 0, 1, 0);
+    }
+    ret = usb_handle_packet(dev, &xfer->packet);
+
+    xhci_complete_packet(xfer, ret);
+    if (!xfer->running) {
+        xhci_kick_ep(xhci, xfer->slotid, xfer->epid);
+    }
+    return 0;
+}
+
+static int xhci_fire_transfer(XHCIState *xhci, XHCITransfer *xfer, XHCIEPContext *epctx)
+{
+    int i;
+    unsigned int length = 0;
+    XHCITRB *trb;
+
+    DPRINTF("xhci_fire_transfer(slotid=%d,epid=%d)\n", xfer->slotid, xfer->epid);
+
+    for (i = 0; i < xfer->trb_count; i++) {
+        trb = &xfer->trbs[i];
+        if (TRB_TYPE(*trb) == TR_NORMAL || TRB_TYPE(*trb) == TR_ISOCH) {
+            length += trb->status & 0x1ffff;
+        }
+    }
+    DPRINTF("xhci: total TD length=%d\n", length);
+
+    if (!epctx->has_bg) {
+        xfer->data_length = length;
+        xfer->backgrounded = 0;
+        return xhci_submit(xhci, xfer, epctx);
+    } else {
+        if (!epctx->bg_running) {
+            for (i = 0; i < BG_XFERS; i++) {
+                XHCITransfer *t = &epctx->bg_transfers[i];
+                t->xhci = xhci;
+                t->epid = xfer->epid;
+                t->slotid = xfer->slotid;
+                t->pkts = BG_PKTS;
+                t->pktsize = epctx->max_psize;
+                t->data_length = t->pkts * t->pktsize;
+                t->bg_xfer = 1;
+                if (xhci_submit(xhci, t, epctx) < 0) {
+                    fprintf(stderr, "xhci: bg submit failed\n");
+                    return -1;
+                }
+            }
+            epctx->bg_running = 1;
+        }
+        xfer->backgrounded = 1;
+        xhci_bg_update(xhci, epctx);
+        return 0;
+    }
+}
+
+static void xhci_kick_ep(XHCIState *xhci, unsigned int slotid, unsigned int epid)
+{
+    XHCIEPContext *epctx;
+    int length;
+    int i;
+
+    assert(slotid >= 1 && slotid <= MAXSLOTS);
+    assert(epid >= 1 && epid <= 31);
+    DPRINTF("xhci_kick_ep(%d, %d)\n", slotid, epid);
+
+    if (!xhci->slots[slotid-1].enabled) {
+        fprintf(stderr, "xhci: xhci_kick_ep for disabled slot %d\n", slotid);
+        return;
+    }
+    epctx = xhci->slots[slotid-1].eps[epid-1];
+    if (!epctx) {
+        fprintf(stderr, "xhci: xhci_kick_ep for disabled endpoint %d,%d\n",
+                epid, slotid);
+        return;
+    }
+
+    if (epctx->state == EP_HALTED) {
+        DPRINTF("xhci: ep halted, not running schedule\n");
+        return;
+    }
+
+    xhci_set_ep_state(xhci, epctx, EP_RUNNING);
+
+    while (1) {
+        XHCITransfer *xfer = &epctx->transfers[epctx->next_xfer];
+        if (xfer->running || xfer->backgrounded) {
+            DPRINTF("xhci: ep is busy\n");
+            break;
+        }
+        length = xhci_ring_chain_length(xhci, &epctx->ring);
+        if (length < 0) {
+            DPRINTF("xhci: incomplete TD (%d TRBs)\n", -length);
+            break;
+        } else if (length == 0) {
+            break;
+        }
+        DPRINTF("xhci: fetching %d-TRB TD\n", length);
+        if (xfer->trbs && xfer->trb_alloced < length) {
+            xfer->trb_count = 0;
+            xfer->trb_alloced = 0;
+            g_free(xfer->trbs);
+            xfer->trbs = NULL;
+        }
+        if (!xfer->trbs) {
+            xfer->trbs = g_malloc(sizeof(XHCITRB) * length);
+            xfer->trb_alloced = length;
+        }
+        xfer->trb_count = length;
+
+        for (i = 0; i < length; i++) {
+            assert(xhci_ring_fetch(xhci, &epctx->ring, &xfer->trbs[i], NULL));
+        }
+        xfer->xhci = xhci;
+        xfer->epid = epid;
+        xfer->slotid = slotid;
+
+        if (epid == 1) {
+            if (xhci_fire_ctl_transfer(xhci, xfer) >= 0) {
+                epctx->next_xfer = (epctx->next_xfer + 1) % TD_QUEUE;
+            } else {
+                fprintf(stderr, "xhci: error firing CTL transfer\n");
+            }
+        } else {
+            if (xhci_fire_transfer(xhci, xfer, epctx) >= 0) {
+                epctx->next_xfer = (epctx->next_xfer + 1) % TD_QUEUE;
+            } else {
+                fprintf(stderr, "xhci: error firing data transfer\n");
+            }
+        }
+
+        /*
+         * Qemu usb can't handle multiple in-flight xfers.
+         * Also xfers might be finished here already,
+         * possibly with an error.  Stop here for now.
+         */
+        break;
+    }
+}
+
+static TRBCCode xhci_enable_slot(XHCIState *xhci, unsigned int slotid)
+{
+    assert(slotid >= 1 && slotid <= MAXSLOTS);
+    DPRINTF("xhci_enable_slot(%d)\n", slotid);
+    xhci->slots[slotid-1].enabled = 1;
+    xhci->slots[slotid-1].port = 0;
+    memset(xhci->slots[slotid-1].eps, 0, sizeof(XHCIEPContext*)*31);
+
+    return CC_SUCCESS;
+}
+
+static TRBCCode xhci_disable_slot(XHCIState *xhci, unsigned int slotid)
+{
+    int i;
+
+    assert(slotid >= 1 && slotid <= MAXSLOTS);
+    DPRINTF("xhci_disable_slot(%d)\n", slotid);
+
+    for (i = 1; i <= 31; i++) {
+        if (xhci->slots[slotid-1].eps[i-1]) {
+            xhci_disable_ep(xhci, slotid, i);
+        }
+    }
+
+    xhci->slots[slotid-1].enabled = 0;
+    return CC_SUCCESS;
+}
+
+static TRBCCode xhci_address_slot(XHCIState *xhci, unsigned int slotid,
+                                  uint64_t pictx, bool bsr)
+{
+    XHCISlot *slot;
+    USBDevice *dev;
+    target_phys_addr_t ictx, octx, dcbaap;
+    uint64_t poctx;
+    uint32_t ictl_ctx[2];
+    uint32_t slot_ctx[4];
+    uint32_t ep0_ctx[5];
+    unsigned int port;
+    int i;
+    TRBCCode res;
+
+    assert(slotid >= 1 && slotid <= MAXSLOTS);
+    DPRINTF("xhci_address_slot(%d)\n", slotid);
+
+    dcbaap = xhci_addr64(xhci->dcbaap_low, xhci->dcbaap_high);
+    cpu_physical_memory_read(dcbaap + 8*slotid,
+                             (uint8_t *) &poctx, sizeof(poctx));
+    ictx = xhci_mask64(pictx);
+    octx = xhci_mask64(le64_to_cpu(poctx));
+
+    DPRINTF("xhci: input context at "TARGET_FMT_plx"\n", ictx);
+    DPRINTF("xhci: output context at "TARGET_FMT_plx"\n", octx);
+
+    cpu_physical_memory_read(ictx, (uint8_t *) ictl_ctx, sizeof(ictl_ctx));
+
+    if (ictl_ctx[0] != 0x0 || ictl_ctx[1] != 0x3) {
+        fprintf(stderr, "xhci: invalid input context control %08x %08x\n",
+                ictl_ctx[0], ictl_ctx[1]);
+        return CC_TRB_ERROR;
+    }
+
+    cpu_physical_memory_read(ictx+32, (uint8_t *) slot_ctx, sizeof(slot_ctx));
+    cpu_physical_memory_read(ictx+64, (uint8_t *) ep0_ctx, sizeof(ep0_ctx));
+
+    DPRINTF("xhci: input slot context: %08x %08x %08x %08x\n",
+            slot_ctx[0], slot_ctx[1], slot_ctx[2], slot_ctx[3]);
+
+    DPRINTF("xhci: input ep0 context: %08x %08x %08x %08x %08x\n",
+            ep0_ctx[0], ep0_ctx[1], ep0_ctx[2], ep0_ctx[3], ep0_ctx[4]);
+
+    port = (slot_ctx[1]>>16) & 0xFF;
+    dev = xhci->ports[port-1].port.dev;
+
+    if (port < 1 || port > MAXPORTS) {
+        fprintf(stderr, "xhci: bad port %d\n", port);
+        return CC_TRB_ERROR;
+    } else if (!dev) {
+        fprintf(stderr, "xhci: port %d not connected\n", port);
+        return CC_USB_TRANSACTION_ERROR;
+    }
+
+    for (i = 0; i < MAXSLOTS; i++) {
+        if (xhci->slots[i].port == port) {
+            fprintf(stderr, "xhci: port %d already assigned to slot %d\n",
+                    port, i+1);
+            return CC_TRB_ERROR;
+        }
+    }
+
+    slot = &xhci->slots[slotid-1];
+    slot->port = port;
+    slot->ctx = octx;
+
+    if (bsr) {
+        slot_ctx[3] = SLOT_DEFAULT << SLOT_STATE_SHIFT;
+    } else {
+        slot->devaddr = xhci->devaddr++;
+        slot_ctx[3] = (SLOT_ADDRESSED << SLOT_STATE_SHIFT) | slot->devaddr;
+        DPRINTF("xhci: device address is %d\n", slot->devaddr);
+        dev->info->handle_control(dev, NULL,
+                                  DeviceOutRequest | USB_REQ_SET_ADDRESS,
+                                  slot->devaddr, 0, 0, NULL);
+    }
+
+    res = xhci_enable_ep(xhci, slotid, 1, octx+32, ep0_ctx);
+
+    DPRINTF("xhci: output slot context: %08x %08x %08x %08x\n",
+            slot_ctx[0], slot_ctx[1], slot_ctx[2], slot_ctx[3]);
+    DPRINTF("xhci: output ep0 context: %08x %08x %08x %08x %08x\n",
+            ep0_ctx[0], ep0_ctx[1], ep0_ctx[2], ep0_ctx[3], ep0_ctx[4]);
+
+    cpu_physical_memory_write(octx, (uint8_t *) slot_ctx, sizeof(slot_ctx));
+    cpu_physical_memory_write(octx+32, (uint8_t *) ep0_ctx, sizeof(ep0_ctx));
+
+    return res;
+}
+
+
+static TRBCCode xhci_configure_slot(XHCIState *xhci, unsigned int slotid,
+                                  uint64_t pictx, bool dc)
+{
+    target_phys_addr_t ictx, octx;
+    uint32_t ictl_ctx[2];
+    uint32_t slot_ctx[4];
+    uint32_t islot_ctx[4];
+    uint32_t ep_ctx[5];
+    int i;
+    TRBCCode res;
+
+    assert(slotid >= 1 && slotid <= MAXSLOTS);
+    DPRINTF("xhci_configure_slot(%d)\n", slotid);
+
+    ictx = xhci_mask64(pictx);
+    octx = xhci->slots[slotid-1].ctx;
+
+    DPRINTF("xhci: input context at "TARGET_FMT_plx"\n", ictx);
+    DPRINTF("xhci: output context at "TARGET_FMT_plx"\n", octx);
+
+    if (dc) {
+        for (i = 2; i <= 31; i++) {
+            if (xhci->slots[slotid-1].eps[i-1]) {
+                xhci_disable_ep(xhci, slotid, i);
+            }
+        }
+
+        cpu_physical_memory_read(octx, (uint8_t *) slot_ctx, sizeof(slot_ctx));
+        slot_ctx[3] &= ~(SLOT_STATE_MASK << SLOT_STATE_SHIFT);
+        slot_ctx[3] |= SLOT_ADDRESSED << SLOT_STATE_SHIFT;
+        DPRINTF("xhci: output slot context: %08x %08x %08x %08x\n",
+                slot_ctx[0], slot_ctx[1], slot_ctx[2], slot_ctx[3]);
+        cpu_physical_memory_write(octx, (uint8_t *) slot_ctx, sizeof(slot_ctx));
+
+        return CC_SUCCESS;
+    }
+
+    cpu_physical_memory_read(ictx, (uint8_t *) ictl_ctx, sizeof(ictl_ctx));
+
+    if ((ictl_ctx[0] & 0x3) != 0x0 || (ictl_ctx[1] & 0x3) != 0x1) {
+        fprintf(stderr, "xhci: invalid input context control %08x %08x\n",
+                ictl_ctx[0], ictl_ctx[1]);
+        return CC_TRB_ERROR;
+    }
+
+    cpu_physical_memory_read(ictx+32, (uint8_t *) islot_ctx, sizeof(islot_ctx));
+    cpu_physical_memory_read(octx, (uint8_t *) slot_ctx, sizeof(slot_ctx));
+
+    if (SLOT_STATE(slot_ctx[3]) < SLOT_ADDRESSED) {
+        fprintf(stderr, "xhci: invalid slot state %08x\n", slot_ctx[3]);
+        return CC_CONTEXT_STATE_ERROR;
+    }
+
+    for (i = 2; i <= 31; i++) {
+        if (ictl_ctx[0] & (1<<i)) {
+            xhci_disable_ep(xhci, slotid, i);
+        }
+        if (ictl_ctx[1] & (1<<i)) {
+            cpu_physical_memory_read(ictx+32+(32*i),
+                                     (uint8_t *) ep_ctx, sizeof(ep_ctx));
+            DPRINTF("xhci: input ep%d.%d context: %08x %08x %08x %08x %08x\n",
+                    i/2, i%2, ep_ctx[0], ep_ctx[1], ep_ctx[2],
+                    ep_ctx[3], ep_ctx[4]);
+            xhci_disable_ep(xhci, slotid, i);
+            res = xhci_enable_ep(xhci, slotid, i, octx+(32*i), ep_ctx);
+            if (res != CC_SUCCESS) {
+                return res;
+            }
+            DPRINTF("xhci: output ep%d.%d context: %08x %08x %08x %08x %08x\n",
+                    i/2, i%2, ep_ctx[0], ep_ctx[1], ep_ctx[2],
+                    ep_ctx[3], ep_ctx[4]);
+            cpu_physical_memory_write(octx+(32*i),
+                                      (uint8_t *) ep_ctx, sizeof(ep_ctx));
+        }
+    }
+
+    slot_ctx[3] &= ~(SLOT_STATE_MASK << SLOT_STATE_SHIFT);
+    slot_ctx[3] |= SLOT_CONFIGURED << SLOT_STATE_SHIFT;
+    slot_ctx[0] &= ~(SLOT_CONTEXT_ENTRIES_MASK << SLOT_CONTEXT_ENTRIES_SHIFT);
+    slot_ctx[0] |= islot_ctx[0] & (SLOT_CONTEXT_ENTRIES_MASK <<
+                                   SLOT_CONTEXT_ENTRIES_SHIFT);
+    DPRINTF("xhci: output slot context: %08x %08x %08x %08x\n",
+            slot_ctx[0], slot_ctx[1], slot_ctx[2], slot_ctx[3]);
+
+    cpu_physical_memory_write(octx, (uint8_t *) slot_ctx, sizeof(slot_ctx));
+
+    return CC_SUCCESS;
+}
+
+
+static TRBCCode xhci_evaluate_slot(XHCIState *xhci, unsigned int slotid,
+                                   uint64_t pictx)
+{
+    target_phys_addr_t ictx, octx;
+    uint32_t ictl_ctx[2];
+    uint32_t iep0_ctx[5];
+    uint32_t ep0_ctx[5];
+    uint32_t islot_ctx[4];
+    uint32_t slot_ctx[4];
+
+    assert(slotid >= 1 && slotid <= MAXSLOTS);
+    DPRINTF("xhci_evaluate_slot(%d)\n", slotid);
+
+    ictx = xhci_mask64(pictx);
+    octx = xhci->slots[slotid-1].ctx;
+
+    DPRINTF("xhci: input context at "TARGET_FMT_plx"\n", ictx);
+    DPRINTF("xhci: output context at "TARGET_FMT_plx"\n", octx);
+
+    cpu_physical_memory_read(ictx, (uint8_t *) ictl_ctx, sizeof(ictl_ctx));
+
+    if (ictl_ctx[0] != 0x0 || ictl_ctx[1] & ~0x3) {
+        fprintf(stderr, "xhci: invalid input context control %08x %08x\n",
+                ictl_ctx[0], ictl_ctx[1]);
+        return CC_TRB_ERROR;
+    }
+
+    if (ictl_ctx[1] & 0x1) {
+        cpu_physical_memory_read(ictx+32,
+                                 (uint8_t *) islot_ctx, sizeof(islot_ctx));
+
+        DPRINTF("xhci: input slot context: %08x %08x %08x %08x\n",
+                islot_ctx[0], islot_ctx[1], islot_ctx[2], islot_ctx[3]);
+
+        cpu_physical_memory_read(octx, (uint8_t *) slot_ctx, sizeof(slot_ctx));
+
+        slot_ctx[1] &= ~0xFFFF; /* max exit latency */
+        slot_ctx[1] |= islot_ctx[1] & 0xFFFF;
+        slot_ctx[2] &= ~0xFF00000; /* interrupter target */
+        slot_ctx[2] |= islot_ctx[2] & 0xFF000000;
+
+        DPRINTF("xhci: output slot context: %08x %08x %08x %08x\n",
+                slot_ctx[0], slot_ctx[1], slot_ctx[2], slot_ctx[3]);
+
+        cpu_physical_memory_write(octx, (uint8_t *) slot_ctx, sizeof(slot_ctx));
+    }
+
+    if (ictl_ctx[1] & 0x2) {
+        cpu_physical_memory_read(ictx+64,
+                                 (uint8_t *) iep0_ctx, sizeof(iep0_ctx));
+
+        DPRINTF("xhci: input ep0 context: %08x %08x %08x %08x %08x\n",
+                iep0_ctx[0], iep0_ctx[1], iep0_ctx[2],
+                iep0_ctx[3], iep0_ctx[4]);
+
+        cpu_physical_memory_read(octx+32, (uint8_t *) ep0_ctx, sizeof(ep0_ctx));
+
+        ep0_ctx[1] &= ~0xFFFF0000; /* max packet size*/
+        ep0_ctx[1] |= iep0_ctx[1] & 0xFFFF0000;
+
+        DPRINTF("xhci: output ep0 context: %08x %08x %08x %08x %08x\n",
+                ep0_ctx[0], ep0_ctx[1], ep0_ctx[2], ep0_ctx[3], ep0_ctx[4]);
+
+        cpu_physical_memory_write(octx+32,
+                                  (uint8_t *) ep0_ctx, sizeof(ep0_ctx));
+    }
+
+    return CC_SUCCESS;
+}
+
+static TRBCCode xhci_reset_slot(XHCIState *xhci, unsigned int slotid)
+{
+    uint32_t slot_ctx[4];
+    target_phys_addr_t octx;
+    int i;
+
+    assert(slotid >= 1 && slotid <= MAXSLOTS);
+    DPRINTF("xhci_reset_slot(%d)\n", slotid);
+
+    octx = xhci->slots[slotid-1].ctx;
+
+    DPRINTF("xhci: output context at "TARGET_FMT_plx"\n", octx);
+
+    for (i = 2; i <= 31; i++) {
+        if (xhci->slots[slotid-1].eps[i-1]) {
+            xhci_disable_ep(xhci, slotid, i);
+        }
+    }
+
+    cpu_physical_memory_read(octx, (uint8_t *) slot_ctx, sizeof(slot_ctx));
+    slot_ctx[3] &= ~(SLOT_STATE_MASK << SLOT_STATE_SHIFT);
+    slot_ctx[3] |= SLOT_DEFAULT << SLOT_STATE_SHIFT;
+    DPRINTF("xhci: output slot context: %08x %08x %08x %08x\n",
+            slot_ctx[0], slot_ctx[1], slot_ctx[2], slot_ctx[3]);
+    cpu_physical_memory_write(octx, (uint8_t *) slot_ctx, sizeof(slot_ctx));
+
+    return CC_SUCCESS;
+}
+
+static unsigned int xhci_get_slot(XHCIState *xhci, XHCIEvent *event, XHCITRB *trb)
+{
+    unsigned int slotid;
+    slotid = (trb->control >> TRB_CR_SLOTID_SHIFT) & TRB_CR_SLOTID_MASK;
+    if (slotid < 1 || slotid > MAXSLOTS) {
+        fprintf(stderr, "xhci: bad slot id %d\n", slotid);
+        event->ccode = CC_TRB_ERROR;
+        return 0;
+    } else if (!xhci->slots[slotid-1].enabled) {
+        fprintf(stderr, "xhci: slot id %d not enabled\n", slotid);
+        event->ccode = CC_SLOT_NOT_ENABLED_ERROR;
+        return 0;
+    }
+    return slotid;
+}
+
+static TRBCCode xhci_get_port_bandwidth(XHCIState *xhci, uint64_t pctx)
+{
+    target_phys_addr_t ctx;
+    uint8_t bw_ctx[MAXPORTS+1];
+
+    DPRINTF("xhci_get_port_bandwidth()\n");
+
+    ctx = xhci_mask64(pctx);
+
+    DPRINTF("xhci: bandwidth context at "TARGET_FMT_plx"\n", ctx);
+
+    /* TODO: actually implement real values here */
+    bw_ctx[0] = 0;
+    memset(&bw_ctx[1], 80, MAXPORTS); /* 80% */
+    cpu_physical_memory_write(ctx, bw_ctx, sizeof(bw_ctx));
+
+    return CC_SUCCESS;
+}
+
+static uint32_t rotl(uint32_t v, unsigned count)
+{
+    count &= 31;
+    return (v << count) | (v >> (32 - count));
+}
+
+
+static uint32_t xhci_nec_challenge(uint32_t hi, uint32_t lo)
+{
+    uint32_t val;
+    val = rotl(lo - 0x49434878, 32 - ((hi>>8) & 0x1F));
+    val += rotl(lo + 0x49434878, hi & 0x1F);
+    val -= rotl(hi ^ 0x49434878, (lo >> 16) & 0x1F);
+    return ~val;
+}
+
+static void xhci_via_challenge(uint64_t addr)
+{
+    uint32_t buf[8];
+    uint32_t obuf[8];
+    target_phys_addr_t paddr = xhci_mask64(addr);
+
+    cpu_physical_memory_read(paddr, (uint8_t *) &buf, 32);
+
+    memcpy(obuf, buf, sizeof(obuf));
+
+    if ((buf[0] & 0xff) == 2) {
+        obuf[0] = 0x49932000 + 0x54dc200 * buf[2] + 0x7429b578 * buf[3];
+        obuf[0] |=  (buf[2] * buf[3]) & 0xff;
+        obuf[1] = 0x0132bb37 + 0xe89 * buf[2] + 0xf09 * buf[3];
+        obuf[2] = 0x0066c2e9 + 0x2091 * buf[2] + 0x19bd * buf[3];
+        obuf[3] = 0xd5281342 + 0x2cc9691 * buf[2] + 0x2367662 * buf[3];
+        obuf[4] = 0x0123c75c + 0x1595 * buf[2] + 0x19ec * buf[3];
+        obuf[5] = 0x00f695de + 0x26fd * buf[2] + 0x3e9 * buf[3];
+        obuf[6] = obuf[2] ^ obuf[3] ^ 0x29472956;
+        obuf[7] = obuf[2] ^ obuf[3] ^ 0x65866593;
+    }
+
+    cpu_physical_memory_write(paddr, (uint8_t *) &obuf, 32);
+}
+
+static void xhci_process_commands(XHCIState *xhci)
+{
+    XHCITRB trb;
+    TRBType type;
+    XHCIEvent event = {ER_COMMAND_COMPLETE, CC_SUCCESS};
+    target_phys_addr_t addr;
+    unsigned int i, slotid = 0;
+
+    DPRINTF("xhci_process_commands()\n");
+    if (!xhci_running(xhci)) {
+        DPRINTF("xhci_process_commands() called while xHC stopped or paused\n");
+        return;
+    }
+
+    xhci->crcr_low |= CRCR_CRR;
+
+    while ((type = xhci_ring_fetch(xhci, &xhci->cmd_ring, &trb, &addr))) {
+        event.ptr = addr;
+        switch (type) {
+        case CR_ENABLE_SLOT:
+            for (i = 0; i < MAXSLOTS; i++) {
+                if (!xhci->slots[i].enabled) {
+                    break;
+                }
+            }
+            if (i >= MAXSLOTS) {
+                fprintf(stderr, "xhci: no device slots available\n");
+                event.ccode = CC_NO_SLOTS_ERROR;
+            } else {
+                slotid = i+1;
+                event.ccode = xhci_enable_slot(xhci, slotid);
+            }
+            break;
+        case CR_DISABLE_SLOT:
+            slotid = xhci_get_slot(xhci, &event, &trb);
+            if (slotid) {
+                event.ccode = xhci_disable_slot(xhci, slotid);
+            }
+            break;
+        case CR_ADDRESS_DEVICE:
+            slotid = xhci_get_slot(xhci, &event, &trb);
+            if (slotid) {
+                event.ccode = xhci_address_slot(xhci, slotid, trb.parameter,
+                                                trb.control & TRB_CR_BSR);
+            }
+            break;
+        case CR_CONFIGURE_ENDPOINT:
+            slotid = xhci_get_slot(xhci, &event, &trb);
+            if (slotid) {
+                event.ccode = xhci_configure_slot(xhci, slotid, trb.parameter,
+                                                  trb.control & TRB_CR_DC);
+            }
+            break;
+        case CR_EVALUATE_CONTEXT:
+            slotid = xhci_get_slot(xhci, &event, &trb);
+            if (slotid) {
+                event.ccode = xhci_evaluate_slot(xhci, slotid, trb.parameter);
+            }
+            break;
+        case CR_STOP_ENDPOINT:
+            slotid = xhci_get_slot(xhci, &event, &trb);
+            if (slotid) {
+                unsigned int epid = (trb.control >> TRB_CR_EPID_SHIFT)
+                    & TRB_CR_EPID_MASK;
+                event.ccode = xhci_stop_ep(xhci, slotid, epid);
+            }
+            break;
+        case CR_RESET_ENDPOINT:
+            slotid = xhci_get_slot(xhci, &event, &trb);
+            if (slotid) {
+                unsigned int epid = (trb.control >> TRB_CR_EPID_SHIFT)
+                    & TRB_CR_EPID_MASK;
+                event.ccode = xhci_reset_ep(xhci, slotid, epid);
+            }
+            break;
+        case CR_SET_TR_DEQUEUE:
+            slotid = xhci_get_slot(xhci, &event, &trb);
+            if (slotid) {
+                unsigned int epid = (trb.control >> TRB_CR_EPID_SHIFT)
+                    & TRB_CR_EPID_MASK;
+                event.ccode = xhci_set_ep_dequeue(xhci, slotid, epid,
+                                                  trb.parameter);
+            }
+            break;
+        case CR_RESET_DEVICE:
+            slotid = xhci_get_slot(xhci, &event, &trb);
+            if (slotid) {
+                event.ccode = xhci_reset_slot(xhci, slotid);
+            }
+            break;
+        case CR_GET_PORT_BANDWIDTH:
+            event.ccode = xhci_get_port_bandwidth(xhci, trb.parameter);
+            break;
+        case CR_VENDOR_VIA_CHALLENGE_RESPONSE:
+            xhci_via_challenge(trb.parameter);
+            break;
+        case CR_VENDOR_NEC_FIRMWARE_REVISION:
+            event.type = 48; /* NEC reply */
+            event.length = 0x3025;
+            break;
+        case CR_VENDOR_NEC_CHALLENGE_RESPONSE:
+        {
+            uint32_t chi = trb.parameter >> 32;
+            uint32_t clo = trb.parameter;
+            uint32_t val = xhci_nec_challenge(chi, clo);
+            event.length = val & 0xFFFF;
+            event.epid = val >> 16;
+            slotid = val >> 24;
+            event.type = 48; /* NEC reply */
+        }
+        break;
+        default:
+            fprintf(stderr, "xhci: unimplemented command %d\n", type);
+            event.ccode = CC_TRB_ERROR;
+            break;
+        }
+        event.slotid = slotid;
+        xhci_event(xhci, &event);
+    }
+}
+
+static void xhci_update_port(XHCIState *xhci, XHCIPort *port, int is_detach)
+{
+    int nr = port->port.index + 1;
+
+    port->portsc = PORTSC_PP;
+    if (port->port.dev && !is_detach) {
+        port->portsc |= PORTSC_CCS;
+        switch (port->port.dev->speed) {
+        case USB_SPEED_LOW:
+            port->portsc |= PORTSC_SPEED_LOW;
+            break;
+        case USB_SPEED_FULL:
+            port->portsc |= PORTSC_SPEED_FULL;
+            break;
+        case USB_SPEED_HIGH:
+            port->portsc |= PORTSC_SPEED_HIGH;
+            break;
+        }
+    }
+
+    if (xhci_running(xhci)) {
+        port->portsc |= PORTSC_CSC;
+        XHCIEvent ev = { ER_PORT_STATUS_CHANGE, CC_SUCCESS, nr << 24};
+        xhci_event(xhci, &ev);
+        DPRINTF("xhci: port change event for port %d\n", nr);
+    }
+}
+
+static void xhci_reset(void *opaque)
+{
+    XHCIState *xhci = opaque;
+    int i;
+
+    DPRINTF("xhci: full reset\n");
+    if (!(xhci->usbsts & USBSTS_HCH)) {
+        fprintf(stderr, "xhci: reset while running!\n");
+    }
+
+    xhci->usbcmd = 0;
+    xhci->usbsts = USBSTS_HCH;
+    xhci->dnctrl = 0;
+    xhci->crcr_low = 0;
+    xhci->crcr_high = 0;
+    xhci->dcbaap_low = 0;
+    xhci->dcbaap_high = 0;
+    xhci->config = 0;
+    xhci->devaddr = 2;
+
+    for (i = 0; i < MAXSLOTS; i++) {
+        xhci_disable_slot(xhci, i+1);
+    }
+
+    for (i = 0; i < MAXPORTS; i++) {
+        xhci_update_port(xhci, xhci->ports + i, 0);
+    }
+
+    xhci->mfindex = 0;
+    xhci->iman = 0;
+    xhci->imod = 0;
+    xhci->erstsz = 0;
+    xhci->erstba_low = 0;
+    xhci->erstba_high = 0;
+    xhci->erdp_low = 0;
+    xhci->erdp_high = 0;
+
+    xhci->er_ep_idx = 0;
+    xhci->er_pcs = 1;
+    xhci->er_full = 0;
+    xhci->ev_buffer_put = 0;
+    xhci->ev_buffer_get = 0;
+}
+
+static uint32_t xhci_cap_read(XHCIState *xhci, uint32_t reg)
+{
+    DPRINTF("xhci_cap_read(0x%x)\n", reg);
+
+    switch (reg) {
+    case 0x00: /* HCIVERSION, CAPLENGTH */
+        return 0x01000000 | LEN_CAP;
+    case 0x04: /* HCSPARAMS 1 */
+        return (MAXPORTS<<24) | (MAXINTRS<<8) | MAXSLOTS;
+    case 0x08: /* HCSPARAMS 2 */
+        return 0x0000000f;
+    case 0x0c: /* HCSPARAMS 3 */
+        return 0x00000000;
+    case 0x10: /* HCCPARAMS */
+#if TARGET_PHYS_ADDR_BITS > 32
+        return 0x00081001;
+#else
+        return 0x00081000;
+#endif
+    case 0x14: /* DBOFF */
+        return OFF_DOORBELL;
+    case 0x18: /* RTSOFF */
+        return OFF_RUNTIME;
+
+    /* extended capabilities */
+    case 0x20: /* Supported Protocol:00 */
+#if USB3_PORTS > 0
+        return 0x02000402; /* USB 2.0 */
+#else
+        return 0x02000002; /* USB 2.0 */
+#endif
+    case 0x24: /* Supported Protocol:04 */
+        return 0x20425455; /* "USB " */
+    case 0x28: /* Supported Protocol:08 */
+        return 0x00000001 | (USB2_PORTS<<8);
+    case 0x2c: /* Supported Protocol:0c */
+        return 0x00000000; /* reserved */
+#if USB3_PORTS > 0
+    case 0x30: /* Supported Protocol:00 */
+        return 0x03000002; /* USB 3.0 */
+    case 0x34: /* Supported Protocol:04 */
+        return 0x20425455; /* "USB " */
+    case 0x38: /* Supported Protocol:08 */
+        return 0x00000000 | (USB2_PORTS+1) | (USB3_PORTS<<8);
+    case 0x3c: /* Supported Protocol:0c */
+        return 0x00000000; /* reserved */
+#endif
+    default:
+        fprintf(stderr, "xhci_cap_read: reg %d unimplemented\n", reg);
+    }
+    return 0;
+}
+
+static uint32_t xhci_port_read(XHCIState *xhci, uint32_t reg)
+{
+    uint32_t port = reg >> 4;
+    if (port >= MAXPORTS) {
+        fprintf(stderr, "xhci_port_read: port %d out of bounds\n", port);
+        return 0;
+    }
+
+    switch (reg & 0xf) {
+    case 0x00: /* PORTSC */
+        return xhci->ports[port].portsc;
+    case 0x04: /* PORTPMSC */
+    case 0x08: /* PORTLI */
+        return 0;
+    case 0x0c: /* reserved */
+    default:
+        fprintf(stderr, "xhci_port_read (port %d): reg 0x%x unimplemented\n",
+                port, reg);
+        return 0;
+    }
+}
+
+static void xhci_port_write(XHCIState *xhci, uint32_t reg, uint32_t val)
+{
+    uint32_t port = reg >> 4;
+    uint32_t portsc;
+
+    if (port >= MAXPORTS) {
+        fprintf(stderr, "xhci_port_read: port %d out of bounds\n", port);
+        return;
+    }
+
+    switch (reg & 0xf) {
+    case 0x00: /* PORTSC */
+        portsc = xhci->ports[port].portsc;
+        /* write-1-to-clear bits*/
+        portsc &= ~(val & (PORTSC_CSC|PORTSC_PEC|PORTSC_WRC|PORTSC_OCC|
+                           PORTSC_PRC|PORTSC_PLC|PORTSC_CEC));
+        if (val & PORTSC_LWS) {
+            /* overwrite PLS only when LWS=1 */
+            portsc &= ~(PORTSC_PLS_MASK << PORTSC_PLS_SHIFT);
+            portsc |= val & (PORTSC_PLS_MASK << PORTSC_PLS_SHIFT);
+        }
+        /* read/write bits */
+        portsc &= ~(PORTSC_PP|PORTSC_WCE|PORTSC_WDE|PORTSC_WOE);
+        portsc |= (val & (PORTSC_PP|PORTSC_WCE|PORTSC_WDE|PORTSC_WOE));
+        /* write-1-to-start bits */
+        if (val & PORTSC_PR) {
+            DPRINTF("xhci: port %d reset\n", port);
+            if (xhci->ports[port].port.dev) {
+                usb_send_msg(xhci->ports[port].port.dev, USB_MSG_RESET);
+            }
+            portsc |= PORTSC_PRC | PORTSC_PED;
+        }
+        xhci->ports[port].portsc = portsc;
+        break;
+    case 0x04: /* PORTPMSC */
+    case 0x08: /* PORTLI */
+    default:
+        fprintf(stderr, "xhci_port_write (port %d): reg 0x%x unimplemented\n",
+                port, reg);
+    }
+}
+
+static uint32_t xhci_oper_read(XHCIState *xhci, uint32_t reg)
+{
+    DPRINTF("xhci_oper_read(0x%x)\n", reg);
+
+    if (reg >= 0x400) {
+        return xhci_port_read(xhci, reg - 0x400);
+    }
+
+    switch (reg) {
+    case 0x00: /* USBCMD */
+        return xhci->usbcmd;
+    case 0x04: /* USBSTS */
+        return xhci->usbsts;
+    case 0x08: /* PAGESIZE */
+        return 1; /* 4KiB */
+    case 0x14: /* DNCTRL */
+        return xhci->dnctrl;
+    case 0x18: /* CRCR low */
+        return xhci->crcr_low & ~0xe;
+    case 0x1c: /* CRCR high */
+        return xhci->crcr_high;
+    case 0x30: /* DCBAAP low */
+        return xhci->dcbaap_low;
+    case 0x34: /* DCBAAP high */
+        return xhci->dcbaap_high;
+    case 0x38: /* CONFIG */
+        return xhci->config;
+    default:
+        fprintf(stderr, "xhci_oper_read: reg 0x%x unimplemented\n", reg);
+    }
+    return 0;
+}
+
+static void xhci_oper_write(XHCIState *xhci, uint32_t reg, uint32_t val)
+{
+    DPRINTF("xhci_oper_write(0x%x, 0x%08x)\n", reg, val);
+
+    if (reg >= 0x400) {
+        xhci_port_write(xhci, reg - 0x400, val);
+        return;
+    }
+
+    switch (reg) {
+    case 0x00: /* USBCMD */
+        if ((val & USBCMD_RS) && !(xhci->usbcmd & USBCMD_RS)) {
+            xhci_run(xhci);
+        } else if (!(val & USBCMD_RS) && (xhci->usbcmd & USBCMD_RS)) {
+            xhci_stop(xhci);
+        }
+        xhci->usbcmd = val & 0xc0f;
+        if (val & USBCMD_HCRST) {
+            xhci_reset(xhci);
+        }
+        xhci_irq_update(xhci);
+        break;
+
+    case 0x04: /* USBSTS */
+        /* these bits are write-1-to-clear */
+        xhci->usbsts &= ~(val & (USBSTS_HSE|USBSTS_EINT|USBSTS_PCD|USBSTS_SRE));
+        xhci_irq_update(xhci);
+        break;
+
+    case 0x14: /* DNCTRL */
+        xhci->dnctrl = val & 0xffff;
+        break;
+    case 0x18: /* CRCR low */
+        xhci->crcr_low = (val & 0xffffffcf) | (xhci->crcr_low & CRCR_CRR);
+        break;
+    case 0x1c: /* CRCR high */
+        xhci->crcr_high = val;
+        if (xhci->crcr_low & (CRCR_CA|CRCR_CS) && (xhci->crcr_low & CRCR_CRR)) {
+            XHCIEvent event = {ER_COMMAND_COMPLETE, CC_COMMAND_RING_STOPPED};
+            xhci->crcr_low &= ~CRCR_CRR;
+            xhci_event(xhci, &event);
+            DPRINTF("xhci: command ring stopped (CRCR=%08x)\n", xhci->crcr_low);
+        } else {
+            target_phys_addr_t base = xhci_addr64(xhci->crcr_low & ~0x3f, val);
+            xhci_ring_init(xhci, &xhci->cmd_ring, base);
+        }
+        xhci->crcr_low &= ~(CRCR_CA | CRCR_CS);
+        break;
+    case 0x30: /* DCBAAP low */
+        xhci->dcbaap_low = val & 0xffffffc0;
+        break;
+    case 0x34: /* DCBAAP high */
+        xhci->dcbaap_high = val;
+        break;
+    case 0x38: /* CONFIG */
+        xhci->config = val & 0xff;
+        break;
+    default:
+        fprintf(stderr, "xhci_oper_write: reg 0x%x unimplemented\n", reg);
+    }
+}
+
+static uint32_t xhci_runtime_read(XHCIState *xhci, uint32_t reg)
+{
+    DPRINTF("xhci_runtime_read(0x%x)\n", reg);
+
+    switch (reg) {
+    case 0x00: /* MFINDEX */
+        fprintf(stderr, "xhci_runtime_read: MFINDEX not yet implemented\n");
+        return xhci->mfindex;
+    case 0x20: /* IMAN */
+        return xhci->iman;
+    case 0x24: /* IMOD */
+        return xhci->imod;
+    case 0x28: /* ERSTSZ */
+        return xhci->erstsz;
+    case 0x30: /* ERSTBA low */
+        return xhci->erstba_low;
+    case 0x34: /* ERSTBA high */
+        return xhci->erstba_high;
+    case 0x38: /* ERDP low */
+        return xhci->erdp_low;
+    case 0x3c: /* ERDP high */
+        return xhci->erdp_high;
+    default:
+        fprintf(stderr, "xhci_runtime_read: reg 0x%x unimplemented\n", reg);
+    }
+    return 0;
+}
+
+static void xhci_runtime_write(XHCIState *xhci, uint32_t reg, uint32_t val)
+{
+    DPRINTF("xhci_runtime_write(0x%x, 0x%08x)\n", reg, val);
+
+    switch (reg) {
+    case 0x20: /* IMAN */
+        if (val & IMAN_IP) {
+            xhci->iman &= ~IMAN_IP;
+        }
+        xhci->iman &= ~IMAN_IE;
+        xhci->iman |= val & IMAN_IE;
+        xhci_irq_update(xhci);
+        break;
+    case 0x24: /* IMOD */
+        xhci->imod = val;
+        break;
+    case 0x28: /* ERSTSZ */
+        xhci->erstsz = val & 0xffff;
+        break;
+    case 0x30: /* ERSTBA low */
+        /* XXX NEC driver bug: it doesn't align this to 64 bytes
+        xhci->erstba_low = val & 0xffffffc0; */
+        xhci->erstba_low = val & 0xfffffff0;
+        break;
+    case 0x34: /* ERSTBA high */
+        xhci->erstba_high = val;
+        xhci_er_reset(xhci);
+        break;
+    case 0x38: /* ERDP low */
+        if (val & ERDP_EHB) {
+            xhci->erdp_low &= ~ERDP_EHB;
+        }
+        xhci->erdp_low = (val & ~ERDP_EHB) | (xhci->erdp_low & ERDP_EHB);
+        break;
+    case 0x3c: /* ERDP high */
+        xhci->erdp_high = val;
+        xhci_events_update(xhci);
+        break;
+    default:
+        fprintf(stderr, "xhci_oper_write: reg 0x%x unimplemented\n", reg);
+    }
+}
+
+static uint32_t xhci_doorbell_read(XHCIState *xhci, uint32_t reg)
+{
+    DPRINTF("xhci_doorbell_read(0x%x)\n", reg);
+    /* doorbells always read as 0 */
+    return 0;
+}
+
+static void xhci_doorbell_write(XHCIState *xhci, uint32_t reg, uint32_t val)
+{
+    DPRINTF("xhci_doorbell_write(0x%x, 0x%08x)\n", reg, val);
+
+    if (!xhci_running(xhci)) {
+        fprintf(stderr, "xhci: wrote doorbell while xHC stopped or paused\n");
+        return;
+    }
+
+    reg >>= 2;
+
+    if (reg == 0) {
+        if (val == 0) {
+            xhci_process_commands(xhci);
+        } else {
+            fprintf(stderr, "xhci: bad doorbell 0 write: 0x%x\n", val);
+        }
+    } else {
+        if (reg > MAXSLOTS) {
+            fprintf(stderr, "xhci: bad doorbell %d\n", reg);
+        } else if (val > 31) {
+            fprintf(stderr, "xhci: bad doorbell %d write: 0x%x\n", reg, val);
+        } else {
+            xhci_kick_ep(xhci, reg, val);
+        }
+    }
+}
+
+static uint64_t xhci_mem_read(void *ptr, target_phys_addr_t addr,
+                              unsigned size)
+{
+    XHCIState *xhci = ptr;
+
+    /* Only aligned reads are allowed on xHCI */
+    if (addr & 3) {
+        fprintf(stderr, "xhci_mem_read: Mis-aligned read\n");
+        return 0;
+    }
+
+    if (addr < LEN_CAP) {
+        return xhci_cap_read(xhci, addr);
+    } else if (addr >= OFF_OPER && addr < (OFF_OPER + LEN_OPER)) {
+        return xhci_oper_read(xhci, addr - OFF_OPER);
+    } else if (addr >= OFF_RUNTIME && addr < (OFF_RUNTIME + LEN_RUNTIME)) {
+        return xhci_runtime_read(xhci, addr - OFF_RUNTIME);
+    } else if (addr >= OFF_DOORBELL && addr < (OFF_DOORBELL + LEN_DOORBELL)) {
+        return xhci_doorbell_read(xhci, addr - OFF_DOORBELL);
+    } else {
+        fprintf(stderr, "xhci_mem_read: Bad offset %x\n", (int)addr);
+        return 0;
+    }
+}
+
+static void xhci_mem_write(void *ptr, target_phys_addr_t addr,
+                           uint64_t val, unsigned size)
+{
+    XHCIState *xhci = ptr;
+
+    /* Only aligned writes are allowed on xHCI */
+    if (addr & 3) {
+        fprintf(stderr, "xhci_mem_write: Mis-aligned write\n");
+        return;
+    }
+
+    if (addr >= OFF_OPER && addr < (OFF_OPER + LEN_OPER)) {
+        xhci_oper_write(xhci, addr - OFF_OPER, val);
+    } else if (addr >= OFF_RUNTIME && addr < (OFF_RUNTIME + LEN_RUNTIME)) {
+        xhci_runtime_write(xhci, addr - OFF_RUNTIME, val);
+    } else if (addr >= OFF_DOORBELL && addr < (OFF_DOORBELL + LEN_DOORBELL)) {
+        xhci_doorbell_write(xhci, addr - OFF_DOORBELL, val);
+    } else {
+        fprintf(stderr, "xhci_mem_write: Bad offset %x\n", (int)addr);
+    }
+}
+
+static const MemoryRegionOps xhci_mem_ops = {
+    .read = xhci_mem_read,
+    .write = xhci_mem_write,
+    .valid.min_access_size = 4,
+    .valid.max_access_size = 4,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
+static void xhci_attach(USBPort *usbport)
+{
+    XHCIState *xhci = usbport->opaque;
+    XHCIPort *port = &xhci->ports[usbport->index];
+
+    xhci_update_port(xhci, port, 0);
+}
+
+static void xhci_detach(USBPort *usbport)
+{
+    XHCIState *xhci = usbport->opaque;
+    XHCIPort *port = &xhci->ports[usbport->index];
+
+    xhci_update_port(xhci, port, 1);
+}
+
+static void xhci_complete(USBPort *port, USBPacket *packet)
+{
+    XHCITransfer *xfer = container_of(packet, XHCITransfer, packet);
+
+    xhci_complete_packet(xfer, packet->result);
+    xhci_kick_ep(xfer->xhci, xfer->slotid, xfer->epid);
+}
+
+static void xhci_child_detach(USBPort *port, USBDevice *child)
+{
+    FIXME();
+}
+
+static USBPortOps xhci_port_ops = {
+    .attach   = xhci_attach,
+    .detach   = xhci_detach,
+    .complete = xhci_complete,
+    .child_detach = xhci_child_detach,
+};
+
+static USBBusOps xhci_bus_ops = {
+};
+
+static void usb_xhci_init(XHCIState *xhci, DeviceState *dev)
+{
+    int i;
+
+    xhci->usbsts = USBSTS_HCH;
+
+    usb_bus_new(&xhci->bus, &xhci_bus_ops, &xhci->pci_dev.qdev);
+
+    for (i = 0; i < MAXPORTS; i++) {
+        memset(&xhci->ports[i], 0, sizeof(xhci->ports[i]));
+        usb_register_port(&xhci->bus, &xhci->ports[i].port, xhci, i,
+                          &xhci_port_ops, USB_SPEED_MASK_HIGH);
+    }
+    for (i = 0; i < MAXSLOTS; i++) {
+        xhci->slots[i].enabled = 0;
+    }
+
+    qemu_register_reset(xhci_reset, xhci);
+}
+
+static int usb_xhci_initfn(struct PCIDevice *dev)
+{
+    int ret;
+
+    XHCIState *xhci = DO_UPCAST(XHCIState, pci_dev, dev);
+
+    xhci->pci_dev.config[PCI_CLASS_PROG] = 0x30;    /* xHCI */
+    xhci->pci_dev.config[PCI_INTERRUPT_PIN] = 0x01; /* interrupt pin 1 */
+    xhci->pci_dev.config[PCI_CACHE_LINE_SIZE] = 0x10;
+    xhci->pci_dev.config[0x60] = 0x30; /* release number */
+
+    usb_xhci_init(xhci, &dev->qdev);
+
+    xhci->irq = xhci->pci_dev.irq[0];
+
+    memory_region_init_io(&xhci->mem, &xhci_mem_ops, xhci,
+                          "xhci", LEN_REGS);
+    pci_register_bar(&xhci->pci_dev, 0,
+                     PCI_BASE_ADDRESS_SPACE_MEMORY|PCI_BASE_ADDRESS_MEM_TYPE_64,
+                     &xhci->mem);
+
+    ret = pcie_cap_init(&xhci->pci_dev, 0xa0, PCI_EXP_TYPE_ENDPOINT, 0);
+    assert(ret >= 0);
+
+    if (xhci->msi) {
+        ret = msi_init(&xhci->pci_dev, 0x70, 1, true, false);
+        assert(ret >= 0);
+    }
+
+    return 0;
+}
+
+static void xhci_write_config(PCIDevice *dev, uint32_t addr, uint32_t val,
+                              int len)
+{
+    XHCIState *xhci = DO_UPCAST(XHCIState, pci_dev, dev);
+
+    pci_default_write_config(dev, addr, val, len);
+    if (xhci->msi) {
+        msi_write_config(dev, addr, val, len);
+    }
+}
+
+static const VMStateDescription vmstate_xhci = {
+    .name = "xhci",
+    .unmigratable = 1,
+};
+
+static PCIDeviceInfo xhci_info = {
+    .qdev.name    = "nec-usb-xhci",
+    .qdev.alias   = "xhci",
+    .qdev.size    = sizeof(XHCIState),
+    .qdev.vmsd    = &vmstate_xhci,
+    .init         = usb_xhci_initfn,
+    .vendor_id    = PCI_VENDOR_ID_NEC,
+    .device_id    = PCI_DEVICE_ID_NEC_UPD720200,
+    .class_id     = PCI_CLASS_SERIAL_USB,
+    .revision     = 0x03,
+    .is_express   = 1,
+    .config_write = xhci_write_config,
+    .qdev.props   = (Property[]) {
+        DEFINE_PROP_UINT32("msi", XHCIState, msi, 0),
+        DEFINE_PROP_END_OF_LIST(),
+    }
+};
+
+static void xhci_register(void)
+{
+    pci_qdev_register(&xhci_info);
+}
+device_init(xhci_register);
diff --git a/hw/usb.c b/hw/usb.c
index 2216efe077..860538ad3b 100644
--- a/hw/usb.c
+++ b/hw/usb.c
@@ -329,7 +329,7 @@ int usb_handle_packet(USBDevice *dev, USBPacket *p)
     ret = dev->info->handle_packet(dev, p);
     if (ret == USB_RET_ASYNC) {
         if (p->owner == NULL) {
-            p->owner = dev;
+            p->owner = usb_ep_get(dev, p->pid, p->devep);
         } else {
             /* We'll end up here when usb_handle_packet is called
              * recursively due to a hub being in the chain.  Nothing
@@ -357,7 +357,7 @@ void usb_packet_complete(USBDevice *dev, USBPacket *p)
 void usb_cancel_packet(USBPacket * p)
 {
     assert(p->owner != NULL);
-    p->owner->info->cancel_packet(p->owner, p);
+    p->owner->dev->info->cancel_packet(p->owner->dev, p);
     p->owner = NULL;
 }
 
@@ -414,3 +414,124 @@ void usb_packet_cleanup(USBPacket *p)
 {
     qemu_iovec_destroy(&p->iov);
 }
+
+void usb_ep_init(USBDevice *dev)
+{
+    int ep;
+
+    dev->ep_ctl.type = USB_ENDPOINT_XFER_CONTROL;
+    dev->ep_ctl.ifnum = 0;
+    dev->ep_ctl.dev = dev;
+    for (ep = 0; ep < USB_MAX_ENDPOINTS; ep++) {
+        dev->ep_in[ep].type = USB_ENDPOINT_XFER_INVALID;
+        dev->ep_out[ep].type = USB_ENDPOINT_XFER_INVALID;
+        dev->ep_in[ep].ifnum = 0;
+        dev->ep_out[ep].ifnum = 0;
+        dev->ep_in[ep].dev = dev;
+        dev->ep_out[ep].dev = dev;
+    }
+}
+
+void usb_ep_dump(USBDevice *dev)
+{
+    static const char *tname[] = {
+        [USB_ENDPOINT_XFER_CONTROL] = "control",
+        [USB_ENDPOINT_XFER_ISOC]    = "isoc",
+        [USB_ENDPOINT_XFER_BULK]    = "bulk",
+        [USB_ENDPOINT_XFER_INT]     = "int",
+    };
+    int ifnum, ep, first;
+
+    fprintf(stderr, "Device \"%s\", config %d\n",
+            dev->product_desc, dev->configuration);
+    for (ifnum = 0; ifnum < 16; ifnum++) {
+        first = 1;
+        for (ep = 0; ep < USB_MAX_ENDPOINTS; ep++) {
+            if (dev->ep_in[ep].type != USB_ENDPOINT_XFER_INVALID &&
+                dev->ep_in[ep].ifnum == ifnum) {
+                if (first) {
+                    first = 0;
+                    fprintf(stderr, "  Interface %d, alternative %d\n",
+                            ifnum, dev->altsetting[ifnum]);
+                }
+                fprintf(stderr, "    Endpoint %d, IN, %s, %d max\n", ep,
+                        tname[dev->ep_in[ep].type],
+                        dev->ep_in[ep].max_packet_size);
+            }
+            if (dev->ep_out[ep].type != USB_ENDPOINT_XFER_INVALID &&
+                dev->ep_out[ep].ifnum == ifnum) {
+                if (first) {
+                    first = 0;
+                    fprintf(stderr, "  Interface %d, alternative %d\n",
+                            ifnum, dev->altsetting[ifnum]);
+                }
+                fprintf(stderr, "    Endpoint %d, OUT, %s, %d max\n", ep,
+                        tname[dev->ep_out[ep].type],
+                        dev->ep_out[ep].max_packet_size);
+            }
+        }
+    }
+    fprintf(stderr, "--\n");
+}
+
+struct USBEndpoint *usb_ep_get(USBDevice *dev, int pid, int ep)
+{
+    struct USBEndpoint *eps = pid == USB_TOKEN_IN ? dev->ep_in : dev->ep_out;
+    if (ep == 0) {
+        return &dev->ep_ctl;
+    }
+    assert(pid == USB_TOKEN_IN || pid == USB_TOKEN_OUT);
+    assert(ep > 0 && ep <= USB_MAX_ENDPOINTS);
+    return eps + ep - 1;
+}
+
+uint8_t usb_ep_get_type(USBDevice *dev, int pid, int ep)
+{
+    struct USBEndpoint *uep = usb_ep_get(dev, pid, ep);
+    return uep->type;
+}
+
+void usb_ep_set_type(USBDevice *dev, int pid, int ep, uint8_t type)
+{
+    struct USBEndpoint *uep = usb_ep_get(dev, pid, ep);
+    uep->type = type;
+}
+
+uint8_t usb_ep_get_ifnum(USBDevice *dev, int pid, int ep)
+{
+    struct USBEndpoint *uep = usb_ep_get(dev, pid, ep);
+    return uep->ifnum;
+}
+
+void usb_ep_set_ifnum(USBDevice *dev, int pid, int ep, uint8_t ifnum)
+{
+    struct USBEndpoint *uep = usb_ep_get(dev, pid, ep);
+    uep->ifnum = ifnum;
+}
+
+void usb_ep_set_max_packet_size(USBDevice *dev, int pid, int ep,
+                                uint16_t raw)
+{
+    struct USBEndpoint *uep = usb_ep_get(dev, pid, ep);
+    int size, microframes;
+
+    size = raw & 0x7ff;
+    switch ((raw >> 11) & 3) {
+    case 1:
+        microframes = 2;
+        break;
+    case 2:
+        microframes = 3;
+        break;
+    default:
+        microframes = 1;
+        break;
+    }
+    uep->max_packet_size = size * microframes;
+}
+
+int usb_ep_get_max_packet_size(USBDevice *dev, int pid, int ep)
+{
+    struct USBEndpoint *uep = usb_ep_get(dev, pid, ep);
+    return uep->max_packet_size;
+}
diff --git a/hw/usb.h b/hw/usb.h
index 7ea90e4d9c..37f7d96e66 100644
--- a/hw/usb.h
+++ b/hw/usb.h
@@ -79,6 +79,11 @@
 #define USB_CLASS_APP_SPEC		0xfe
 #define USB_CLASS_VENDOR_SPEC		0xff
 
+#define USB_SUBCLASS_UNDEFINED          0
+#define USB_SUBCLASS_AUDIO_CONTROL      1
+#define USB_SUBCLASS_AUDIO_STREAMING    2
+#define USB_SUBCLASS_AUDIO_MIDISTREAMING 3
+
 #define USB_DIR_OUT			0
 #define USB_DIR_IN			0x80
 
@@ -132,11 +137,14 @@
 #define USB_DT_OTHER_SPEED_CONFIG       0x07
 #define USB_DT_DEBUG                    0x0A
 #define USB_DT_INTERFACE_ASSOC          0x0B
+#define USB_DT_CS_INTERFACE             0x24
+#define USB_DT_CS_ENDPOINT              0x25
 
 #define USB_ENDPOINT_XFER_CONTROL	0
 #define USB_ENDPOINT_XFER_ISOC		1
 #define USB_ENDPOINT_XFER_BULK		2
 #define USB_ENDPOINT_XFER_INT		3
+#define USB_ENDPOINT_XFER_INVALID     255
 
 typedef struct USBBus USBBus;
 typedef struct USBBusOps USBBusOps;
@@ -144,6 +152,7 @@ typedef struct USBPort USBPort;
 typedef struct USBDevice USBDevice;
 typedef struct USBDeviceInfo USBDeviceInfo;
 typedef struct USBPacket USBPacket;
+typedef struct USBEndpoint USBEndpoint;
 
 typedef struct USBDesc USBDesc;
 typedef struct USBDescID USBDescID;
@@ -161,6 +170,16 @@ struct USBDescString {
     QLIST_ENTRY(USBDescString) next;
 };
 
+#define USB_MAX_ENDPOINTS  15
+#define USB_MAX_INTERFACES 16
+
+struct USBEndpoint {
+    uint8_t type;
+    uint8_t ifnum;
+    int max_packet_size;
+    USBDevice *dev;
+};
+
 /* definition of a USB device */
 struct USBDevice {
     DeviceState qdev;
@@ -186,9 +205,18 @@ struct USBDevice {
     int32_t setup_len;
     int32_t setup_index;
 
+    USBEndpoint ep_ctl;
+    USBEndpoint ep_in[USB_MAX_ENDPOINTS];
+    USBEndpoint ep_out[USB_MAX_ENDPOINTS];
+
     QLIST_HEAD(, USBDescString) strings;
     const USBDescDevice *device;
+
+    int configuration;
+    int ninterfaces;
+    int altsetting[USB_MAX_INTERFACES];
     const USBDescConfig *config;
+    const USBDescIface  *ifaces[USB_MAX_INTERFACES];
 };
 
 struct USBDeviceInfo {
@@ -241,6 +269,9 @@ struct USBDeviceInfo {
      */
     int (*handle_data)(USBDevice *dev, USBPacket *p);
 
+    void (*set_interface)(USBDevice *dev, int interface,
+                          int alt_old, int alt_new);
+
     const char *product_desc;
     const USBDesc *usb_desc;
 
@@ -288,7 +319,7 @@ struct USBPacket {
     QEMUIOVector iov;
     int result; /* transfer length or USB_RET_* status code */
     /* Internal use by the USB layer.  */
-    USBDevice *owner;
+    USBEndpoint *owner;
 };
 
 void usb_packet_init(USBPacket *p);
@@ -304,6 +335,17 @@ int usb_handle_packet(USBDevice *dev, USBPacket *p);
 void usb_packet_complete(USBDevice *dev, USBPacket *p);
 void usb_cancel_packet(USBPacket * p);
 
+void usb_ep_init(USBDevice *dev);
+void usb_ep_dump(USBDevice *dev);
+struct USBEndpoint *usb_ep_get(USBDevice *dev, int pid, int ep);
+uint8_t usb_ep_get_type(USBDevice *dev, int pid, int ep);
+uint8_t usb_ep_get_ifnum(USBDevice *dev, int pid, int ep);
+void usb_ep_set_type(USBDevice *dev, int pid, int ep, uint8_t type);
+void usb_ep_set_ifnum(USBDevice *dev, int pid, int ep, uint8_t ifnum);
+void usb_ep_set_max_packet_size(USBDevice *dev, int pid, int ep,
+                                uint16_t raw);
+int usb_ep_get_max_packet_size(USBDevice *dev, int pid, int ep);
+
 void usb_attach(USBPort *port);
 void usb_detach(USBPort *port);
 void usb_reset(USBPort *port);
diff --git a/trace-events b/trace-events
index c18435bbe1..834eb7f63d 100644
--- a/trace-events
+++ b/trace-events
@@ -246,6 +246,7 @@ usb_desc_other_speed_config(int addr, int index, int len, int ret) "dev %d query
 usb_desc_string(int addr, int index, int len, int ret) "dev %d query string %d, len %d, ret %d"
 usb_set_addr(int addr) "dev %d"
 usb_set_config(int addr, int config, int ret) "dev %d, config %d, ret %d"
+usb_set_interface(int addr, int iface, int alt, int ret) "dev %d, interface %d, altsetting %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"
 
diff --git a/usb-linux.c b/usb-linux.c
index 749ce71081..56898dd4cd 100644
--- a/usb-linux.c
+++ b/usb-linux.c
@@ -66,27 +66,11 @@ typedef int USBScanFunc(void *opaque, int bus_num, int addr, const char *port,
 #define DPRINTF(...)
 #endif
 
-#define USBDBG_DEVOPENED "husb: opened %s/devices\n"
-
-#define USBPROCBUS_PATH "/proc/bus/usb"
 #define PRODUCT_NAME_SZ 32
-#define MAX_ENDPOINTS 15
 #define MAX_PORTLEN 16
-#define USBDEVBUS_PATH "/dev/bus/usb"
-#define USBSYSBUS_PATH "/sys/bus/usb"
-
-static char *usb_host_device_path;
-
-#define USB_FS_NONE 0
-#define USB_FS_PROC 1
-#define USB_FS_DEV 2
-#define USB_FS_SYS 3
-
-static int usb_fs_type;
 
 /* endpoint association data */
 #define ISO_FRAME_DESC_PER_URB 32
-#define INVALID_EP_TYPE 255
 
 /* devio.c limits single requests to 16k */
 #define MAX_USBFS_BUFFER_SIZE 16384
@@ -94,13 +78,11 @@ static int usb_fs_type;
 typedef struct AsyncURB AsyncURB;
 
 struct endp_data {
-    uint8_t type;
     uint8_t halted;
     uint8_t iso_started;
     AsyncURB *iso_urb;
     int iso_urb_idx;
     int iso_buffer_used;
-    int max_packet_size;
     int inflight;
 };
 
@@ -120,14 +102,12 @@ typedef struct USBHostDevice {
 
     uint8_t   descr[8192];
     int       descr_len;
-    int       configuration;
-    int       ninterfaces;
     int       closing;
     uint32_t  iso_urb_count;
     Notifier  exit;
 
-    struct endp_data ep_in[MAX_ENDPOINTS];
-    struct endp_data ep_out[MAX_ENDPOINTS];
+    struct endp_data ep_in[USB_MAX_ENDPOINTS];
+    struct endp_data ep_out[USB_MAX_ENDPOINTS];
     QLIST_HEAD(, AsyncURB) aurbs;
 
     /* Host side address */
@@ -149,6 +129,19 @@ 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 int usb_host_usbfs_type(USBHostDevice *s, USBPacket *p)
+{
+    static const int usbfs[] = {
+        [USB_ENDPOINT_XFER_CONTROL] = USBDEVFS_URB_TYPE_CONTROL,
+        [USB_ENDPOINT_XFER_ISOC]    = USBDEVFS_URB_TYPE_ISO,
+        [USB_ENDPOINT_XFER_BULK]    = USBDEVFS_URB_TYPE_BULK,
+        [USB_ENDPOINT_XFER_INT]     = USBDEVFS_URB_TYPE_INTERRUPT,
+    };
+    uint8_t type = usb_ep_get_type(&s->dev, p->pid, p->devep);
+    assert(type < ARRAY_SIZE(usbfs));
+    return usbfs[type];
+}
+
 static int usb_host_do_reset(USBHostDevice *dev)
 {
     struct timeval s, e;
@@ -172,18 +165,18 @@ static struct endp_data *get_endp(USBHostDevice *s, int pid, int ep)
 {
     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);
+    assert(ep > 0 && ep <= USB_MAX_ENDPOINTS);
     return eps + ep - 1;
 }
 
 static int is_isoc(USBHostDevice *s, int pid, int ep)
 {
-    return get_endp(s, pid, ep)->type == USBDEVFS_URB_TYPE_ISO;
+    return usb_ep_get_type(&s->dev, pid, ep) == USB_ENDPOINT_XFER_ISOC;
 }
 
 static int is_valid(USBHostDevice *s, int pid, int ep)
 {
-    return get_endp(s, pid, ep)->type != INVALID_EP_TYPE;
+    return usb_ep_get_type(&s->dev, pid, ep) != USB_ENDPOINT_XFER_INVALID;
 }
 
 static int is_halted(USBHostDevice *s, int pid, int ep)
@@ -265,26 +258,6 @@ static int get_iso_buffer_used(USBHostDevice *s, int pid, int ep)
     return get_endp(s, pid, ep)->iso_buffer_used;
 }
 
-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;
-
-    size = raw & 0x7ff;
-    switch ((raw >> 11) & 3) {
-    case 1:  microframes = 2; break;
-    case 2:  microframes = 3; break;
-    default: microframes = 1; break;
-    }
-    get_endp(s, pid, ep)->max_packet_size = size * microframes;
-}
-
-static int get_max_packet_size(USBHostDevice *s, int pid, int ep)
-{
-    return get_endp(s, pid, ep)->max_packet_size;
-}
-
 /*
  * Async URB state.
  * We always allocate iso packet descriptors even for bulk transfers
@@ -431,6 +404,31 @@ static void usb_host_async_cancel(USBDevice *dev, USBPacket *p)
     }
 }
 
+static int usb_host_open_device(int bus, int addr)
+{
+    const char *usbfs = NULL;
+    char filename[32];
+    struct stat st;
+    int fd, rc;
+
+    rc = stat("/dev/bus/usb", &st);
+    if (rc == 0 && S_ISDIR(st.st_mode)) {
+        /* udev-created device nodes available */
+        usbfs = "/dev/bus/usb";
+    } else {
+        /* fallback: usbfs mounted below /proc */
+        usbfs = "/proc/bus/usb";
+    }
+
+    snprintf(filename, sizeof(filename), "%s/%03d/%03d",
+             usbfs, bus, addr);
+    fd = open(filename, O_RDWR | O_NONBLOCK);
+    if (fd < 0) {
+        fprintf(stderr, "husb: open %s: %s\n", filename, strerror(errno));
+    }
+    return fd;
+}
+
 static int usb_host_claim_port(USBHostDevice *s)
 {
 #ifdef USBDEVFS_CLAIM_PORT
@@ -460,12 +458,7 @@ static int usb_host_claim_port(USBHostDevice *s)
         return -1;
     }
 
-    if (!usb_host_device_path) {
-        return -1;
-    }
-    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);
+    s->hub_fd = usb_host_open_device(s->match.bus_num, hub_addr);
     if (s->hub_fd < 0) {
         return -1;
     }
@@ -522,10 +515,6 @@ static int usb_linux_get_num_interfaces(USBHostDevice *s)
     char device_name[64], line[1024];
     int num_interfaces = 0;
 
-    if (usb_fs_type != USB_FS_SYS) {
-        return -1;
-    }
-
     sprintf(device_name, "%d-%s", s->bus_num, s->port);
     if (!usb_host_read_file(line, sizeof(line), "bNumInterfaces",
                             device_name)) {
@@ -544,9 +533,13 @@ static int usb_host_claim_interfaces(USBHostDevice *dev, int configuration)
     int interface, nb_interfaces;
     int ret, i;
 
+    for (i = 0; i < USB_MAX_INTERFACES; i++) {
+        dev->dev.altsetting[i] = 0;
+    }
+
     if (configuration == 0) { /* address state - ignore */
-        dev->ninterfaces   = 0;
-        dev->configuration = 0;
+        dev->dev.ninterfaces   = 0;
+        dev->dev.configuration = 0;
         return 1;
     }
 
@@ -604,8 +597,8 @@ static int usb_host_claim_interfaces(USBHostDevice *dev, int configuration)
     trace_usb_host_claim_interfaces(dev->bus_num, dev->addr,
                                     nb_interfaces, configuration);
 
-    dev->ninterfaces   = nb_interfaces;
-    dev->configuration = configuration;
+    dev->dev.ninterfaces   = nb_interfaces;
+    dev->dev.configuration = configuration;
     return 1;
 
 fail:
@@ -622,7 +615,7 @@ static int usb_host_release_interfaces(USBHostDevice *s)
 
     trace_usb_host_release_interfaces(s->bus_num, s->addr);
 
-    for (i = 0; i < s->ninterfaces; i++) {
+    for (i = 0; i < s->dev.ninterfaces; i++) {
         ret = ioctl(s->fd, USBDEVFS_RELEASEINTERFACE, &i);
         if (ret < 0) {
             perror("USBDEVFS_RELEASEINTERFACE");
@@ -660,7 +653,7 @@ static void usb_host_handle_destroy(USBDevice *dev)
 static AsyncURB *usb_host_alloc_iso(USBHostDevice *s, int pid, uint8_t ep)
 {
     AsyncURB *aurb;
-    int i, j, len = get_max_packet_size(s, pid, ep);
+    int i, j, len = usb_ep_get_max_packet_size(&s->dev, pid, ep);
 
     aurb = g_malloc0(s->iso_urb_count * sizeof(*aurb));
     for (i = 0; i < s->iso_urb_count; i++) {
@@ -740,7 +733,7 @@ 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->pid, p->devep);
+    max_packet_size = usb_ep_get_max_packet_size(&s->dev, p->pid, p->devep);
     if (max_packet_size == 0)
         return USB_RET_NAK;
 
@@ -892,7 +885,7 @@ static int usb_host_handle_data(USBDevice *dev, USBPacket *p)
 
         urb = &aurb->urb;
         urb->endpoint      = ep;
-        urb->type          = USBDEVFS_URB_TYPE_BULK;
+        urb->type          = usb_host_usbfs_type(s, p);
         urb->usercontext   = s;
         urb->buffer        = pbuf;
         urb->buffer_length = prem;
@@ -988,7 +981,7 @@ static int usb_host_set_interface(USBHostDevice *s, int iface, int alt)
 
     trace_usb_host_set_interface(s->bus_num, s->addr, iface, alt);
 
-    for (i = 1; i <= MAX_ENDPOINTS; i++) {
+    for (i = 1; i <= USB_MAX_ENDPOINTS; i++) {
         if (is_isoc(s, USB_TOKEN_IN, i)) {
             usb_host_stop_n_free_iso(s, USB_TOKEN_IN, i);
         }
@@ -997,6 +990,10 @@ static int usb_host_set_interface(USBHostDevice *s, int iface, int alt)
         }
     }
 
+    if (iface >= USB_MAX_INTERFACES) {
+        return USB_RET_STALL;
+    }
+
     si.interface  = iface;
     si.altsetting = alt;
     ret = ioctl(s->fd, USBDEVFS_SETINTERFACE, &si);
@@ -1007,6 +1004,8 @@ static int usb_host_set_interface(USBHostDevice *s, int iface, int alt)
     if (ret < 0) {
         return ctrl_error();
     }
+
+    s->dev.altsetting[iface] = alt;
     usb_linux_update_endp_table(s);
     return 0;
 }
@@ -1090,41 +1089,21 @@ static int usb_host_handle_control(USBDevice *dev, USBPacket *p,
 static uint8_t usb_linux_get_alt_setting(USBHostDevice *s,
     uint8_t configuration, uint8_t interface)
 {
-    uint8_t alt_setting;
-    struct usb_ctrltransfer ct;
-    int ret;
-
-    if (usb_fs_type == USB_FS_SYS) {
-        char device_name[64], line[1024];
-        int alt_setting;
+    char device_name[64], line[1024];
+    int alt_setting;
 
-        sprintf(device_name, "%d-%s:%d.%d", s->bus_num, s->port,
-                (int)configuration, (int)interface);
+    sprintf(device_name, "%d-%s:%d.%d", s->bus_num, s->port,
+            (int)configuration, (int)interface);
 
-        if (!usb_host_read_file(line, sizeof(line), "bAlternateSetting",
-                                device_name)) {
-            goto usbdevfs;
-        }
-        if (sscanf(line, "%d", &alt_setting) != 1) {
-            goto usbdevfs;
-        }
-        return alt_setting;
-    }
-
-usbdevfs:
-    ct.bRequestType = USB_DIR_IN | USB_RECIP_INTERFACE;
-    ct.bRequest = USB_REQ_GET_INTERFACE;
-    ct.wValue = 0;
-    ct.wIndex = interface;
-    ct.wLength = 1;
-    ct.data = &alt_setting;
-    ct.timeout = 50;
-    ret = ioctl(s->fd, USBDEVFS_CONTROL, &ct);
-    if (ret < 0) {
+    if (!usb_host_read_file(line, sizeof(line), "bAlternateSetting",
+                            device_name)) {
+        /* Assume alt 0 on error */
+        return 0;
+    }
+    if (sscanf(line, "%d", &alt_setting) != 1) {
         /* Assume alt 0 on error */
         return 0;
     }
-
     return alt_setting;
 }
 
@@ -1133,15 +1112,13 @@ static int usb_linux_update_endp_table(USBHostDevice *s)
 {
     uint8_t *descriptors;
     uint8_t devep, type, alt_interface;
+    uint16_t raw;
     int interface, length, i, ep, pid;
     struct endp_data *epd;
 
-    for (i = 0; i < MAX_ENDPOINTS; i++) {
-        s->ep_in[i].type = INVALID_EP_TYPE;
-        s->ep_out[i].type = INVALID_EP_TYPE;
-    }
+    usb_ep_init(&s->dev);
 
-    if (s->configuration == 0) {
+    if (s->dev.configuration == 0) {
         /* not configured yet -- leave all endpoints disabled */
         return 0;
     }
@@ -1156,12 +1133,11 @@ static int usb_linux_update_endp_table(USBHostDevice *s)
         if (descriptors[i + 1] != USB_DT_CONFIG) {
             fprintf(stderr, "invalid descriptor data\n");
             return 1;
-        } else if (descriptors[i + 5] != s->configuration) {
-            DPRINTF("not requested configuration %d\n", s->configuration);
+        } else if (descriptors[i + 5] != s->dev.configuration) {
+            DPRINTF("not requested configuration %d\n", s->dev.configuration);
             i += (descriptors[i + 3] << 8) + descriptors[i + 2];
             continue;
         }
-
         i += descriptors[i];
 
         if (descriptors[i + 1] != USB_DT_INTERFACE ||
@@ -1172,7 +1148,7 @@ static int usb_linux_update_endp_table(USBHostDevice *s)
         }
 
         interface = descriptors[i + 2];
-        alt_interface = usb_linux_get_alt_setting(s, s->configuration,
+        alt_interface = usb_linux_get_alt_setting(s, s->dev.configuration,
                                                   interface);
 
         /* the current interface descriptor is the active interface
@@ -1203,32 +1179,23 @@ static int usb_linux_update_endp_table(USBHostDevice *s)
                 return 1;
             }
 
-            switch (descriptors[i + 3] & 0x3) {
-            case 0x00:
-                type = USBDEVFS_URB_TYPE_CONTROL;
-                break;
-            case 0x01:
-                type = USBDEVFS_URB_TYPE_ISO;
-                set_max_packet_size(s, pid, ep, descriptors + i);
-                break;
-            case 0x02:
-                type = USBDEVFS_URB_TYPE_BULK;
-                break;
-            case 0x03:
-                type = USBDEVFS_URB_TYPE_INTERRUPT;
-                break;
-            default:
-                DPRINTF("usb_host: malformed endpoint type\n");
-                type = USBDEVFS_URB_TYPE_BULK;
-            }
+            type = descriptors[i + 3] & 0x3;
+            raw = descriptors[i + 4] + (descriptors[i + 5] << 8);
+            usb_ep_set_max_packet_size(&s->dev, pid, ep, raw);
+            assert(usb_ep_get_type(&s->dev, pid, ep) ==
+                   USB_ENDPOINT_XFER_INVALID);
+            usb_ep_set_type(&s->dev, pid, ep, type);
+            usb_ep_set_ifnum(&s->dev, pid, ep, interface);
+
             epd = get_endp(s, pid, ep);
-            assert(epd->type == INVALID_EP_TYPE);
-            epd->type = type;
             epd->halted = 0;
 
             i += descriptors[i];
         }
     }
+#ifdef DEBUG
+    usb_ep_dump(&s->dev);
+#endif
     return 0;
 }
 
@@ -1273,7 +1240,6 @@ static int usb_host_open(USBHostDevice *dev, int bus_num,
                          const char *prod_name, int speed)
 {
     int fd = -1, ret;
-    char buf[1024];
 
     trace_usb_host_open_started(bus_num, addr);
 
@@ -1281,15 +1247,8 @@ static int usb_host_open(USBHostDevice *dev, int bus_num,
         goto fail;
     }
 
-    if (!usb_host_device_path) {
-        perror("husb: USB Host Device Path not set");
-        goto fail;
-    }
-    snprintf(buf, sizeof(buf), "%s/%03d/%03d", usb_host_device_path,
-             bus_num, addr);
-    fd = open(buf, O_RDWR | O_NONBLOCK);
+    fd = usb_host_open_device(bus_num, addr);
     if (fd < 0) {
-        perror(buf);
         goto fail;
     }
     DPRINTF("husb: opened %s\n", buf);
@@ -1390,7 +1349,7 @@ static int usb_host_close(USBHostDevice *dev)
 
     qemu_set_fd_handler(dev->fd, NULL, NULL, NULL);
     dev->closing = 1;
-    for (i = 1; i <= MAX_ENDPOINTS; i++) {
+    for (i = 1; i <= USB_MAX_ENDPOINTS; i++) {
         if (is_isoc(dev, USB_TOKEN_IN, i)) {
             usb_host_stop_n_free_iso(dev, USB_TOKEN_IN, i);
         }
@@ -1538,149 +1497,6 @@ int usb_host_device_close(const char *devname)
     return -1;
 }
 
-static int get_tag_value(char *buf, int buf_size,
-                         const char *str, const char *tag,
-                         const char *stopchars)
-{
-    const char *p;
-    char *q;
-    p = strstr(str, tag);
-    if (!p) {
-        return -1;
-    }
-    p += strlen(tag);
-    while (qemu_isspace(*p)) {
-        p++;
-    }
-    q = buf;
-    while (*p != '\0' && !strchr(stopchars, *p)) {
-        if ((q - buf) < (buf_size - 1)) {
-            *q++ = *p;
-        }
-        p++;
-    }
-    *q = '\0';
-    return q - buf;
-}
-
-/*
- * Use /proc/bus/usb/devices or /dev/bus/usb/devices file to determine
- * host's USB devices. This is legacy support since many distributions
- * are moving to /sys/bus/usb
- */
-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;
-    int class_id, product_id, vendor_id, port;
-    char product_name[512];
-    int ret = 0;
-
-    if (!usb_host_device_path) {
-        perror("husb: USB Host Device Path not set");
-        goto the_end;
-    }
-    snprintf(line, sizeof(line), "%s/devices", usb_host_device_path);
-    f = fopen(line, "r");
-    if (!f) {
-        perror("husb: cannot open devices file");
-        goto the_end;
-    }
-
-    device_count = 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) {
-            break;
-        }
-        if (strlen(line) > 0) {
-            line[strlen(line) - 1] = '\0';
-        }
-        if (line[0] == 'T' && line[1] == ':') {
-            if (device_count && (vendor_id || product_id)) {
-                /* New device.  Add the previously discovered device.  */
-                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);
-                if (ret) {
-                    goto the_end;
-                }
-            }
-            if (get_tag_value(buf, sizeof(buf), line, "Bus=", " ") < 0) {
-                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;
-            }
-            addr = atoi(buf);
-            if (get_tag_value(buf, sizeof(buf), line, "Spd=", " ") < 0) {
-                goto fail;
-            }
-            if (!strcmp(buf, "5000")) {
-                speed = USB_SPEED_SUPER;
-            } else if (!strcmp(buf, "480")) {
-                speed = USB_SPEED_HIGH;
-            } else if (!strcmp(buf, "1.5")) {
-                speed = USB_SPEED_LOW;
-            } else {
-                speed = USB_SPEED_FULL;
-            }
-            product_name[0] = '\0';
-            class_id = 0xff;
-            device_count++;
-            product_id = 0;
-            vendor_id = 0;
-        } else if (line[0] == 'P' && line[1] == ':') {
-            if (get_tag_value(buf, sizeof(buf), line, "Vendor=", " ") < 0) {
-                goto fail;
-            }
-            vendor_id = strtoul(buf, NULL, 16);
-            if (get_tag_value(buf, sizeof(buf), line, "ProdID=", " ") < 0) {
-                goto fail;
-            }
-            product_id = strtoul(buf, NULL, 16);
-        } else if (line[0] == 'S' && line[1] == ':') {
-            if (get_tag_value(buf, sizeof(buf), line, "Product=", "") < 0) {
-                goto fail;
-            }
-            pstrcpy(product_name, sizeof(product_name), buf);
-        } else if (line[0] == 'D' && line[1] == ':') {
-            if (get_tag_value(buf, sizeof(buf), line, "Cls=", " (") < 0) {
-                goto fail;
-            }
-            class_id = strtoul(buf, NULL, 16);
-        }
-    fail: ;
-    }
-    if (device_count && (vendor_id || product_id)) {
-        /* Add the last device.  */
-        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:
-    if (f) {
-        fclose(f);
-    }
-    return ret;
-}
-
 /*
  * Read sys file-system device file
  *
@@ -1698,7 +1514,7 @@ static int usb_host_read_file(char *line, size_t line_size,
     int ret = 0;
     char filename[PATH_MAX];
 
-    snprintf(filename, PATH_MAX, USBSYSBUS_PATH "/devices/%s/%s", device_name,
+    snprintf(filename, PATH_MAX, "/sys/bus/usb/devices/%s/%s", device_name,
              device_file);
     f = fopen(filename, "r");
     if (f) {
@@ -1716,7 +1532,7 @@ static int usb_host_read_file(char *line, size_t line_size,
  * This code is based on Robert Schiele's original patches posted to
  * the Novell bug-tracker https://bugzilla.novell.com/show_bug.cgi?id=241950
  */
-static int usb_host_scan_sys(void *opaque, USBScanFunc *func)
+static int usb_host_scan(void *opaque, USBScanFunc *func)
 {
     DIR *dir = NULL;
     char line[1024];
@@ -1726,9 +1542,10 @@ static int usb_host_scan_sys(void *opaque, USBScanFunc *func)
     char product_name[512];
     struct dirent *de;
 
-    dir = opendir(USBSYSBUS_PATH "/devices");
+    dir = opendir("/sys/bus/usb/devices");
     if (!dir) {
-        perror("husb: cannot open devices directory");
+        perror("husb: opendir /sys/bus/usb/devices");
+        fprintf(stderr, "husb: please make sure sysfs is mounted at /sys\n");
         goto the_end;
     }
 
@@ -1803,81 +1620,6 @@ static int usb_host_scan_sys(void *opaque, USBScanFunc *func)
     return ret;
 }
 
-/*
- * Determine how to access the host's USB devices and call the
- * specific support function.
- */
-static int usb_host_scan(void *opaque, USBScanFunc *func)
-{
-    Monitor *mon = cur_mon;
-    FILE *f = NULL;
-    DIR *dir = NULL;
-    int ret = 0;
-    const char *fs_type[] = {"unknown", "proc", "dev", "sys"};
-    char devpath[PATH_MAX];
-
-    /* only check the host once */
-    if (!usb_fs_type) {
-        dir = opendir(USBSYSBUS_PATH "/devices");
-        if (dir) {
-            /* devices found in /dev/bus/usb/ (yes - not a mistake!) */
-            strcpy(devpath, USBDEVBUS_PATH);
-            usb_fs_type = USB_FS_SYS;
-            closedir(dir);
-            DPRINTF(USBDBG_DEVOPENED, USBSYSBUS_PATH);
-            goto found_devices;
-        }
-        f = fopen(USBPROCBUS_PATH "/devices", "r");
-        if (f) {
-            /* devices found in /proc/bus/usb/ */
-            strcpy(devpath, USBPROCBUS_PATH);
-            usb_fs_type = USB_FS_PROC;
-            fclose(f);
-            DPRINTF(USBDBG_DEVOPENED, USBPROCBUS_PATH);
-            goto found_devices;
-        }
-        /* try additional methods if an access method hasn't been found yet */
-        f = fopen(USBDEVBUS_PATH "/devices", "r");
-        if (f) {
-            /* devices found in /dev/bus/usb/ */
-            strcpy(devpath, USBDEVBUS_PATH);
-            usb_fs_type = USB_FS_DEV;
-            fclose(f);
-            DPRINTF(USBDBG_DEVOPENED, USBDEVBUS_PATH);
-            goto found_devices;
-        }
-    found_devices:
-        if (!usb_fs_type) {
-            if (mon) {
-                monitor_printf(mon, "husb: unable to access USB devices\n");
-            }
-            return -ENOENT;
-        }
-
-        /* the module setting (used later for opening devices) */
-        usb_host_device_path = g_malloc0(strlen(devpath)+1);
-        strcpy(usb_host_device_path, devpath);
-        if (mon) {
-            monitor_printf(mon, "husb: using %s file-system with %s\n",
-                           fs_type[usb_fs_type], usb_host_device_path);
-        }
-    }
-
-    switch (usb_fs_type) {
-    case USB_FS_PROC:
-    case USB_FS_DEV:
-        ret = usb_host_scan_dev(opaque, func);
-        break;
-    case USB_FS_SYS:
-        ret = usb_host_scan_sys(opaque, func);
-        break;
-    default:
-        ret = -EINVAL;
-        break;
-    }
-    return ret;
-}
-
 static QEMUTimer *usb_auto_timer;
 
 static int usb_host_auto_scan(void *opaque, int bus_num,
diff --git a/usb-redir.c b/usb-redir.c
index 2b53cf30cc..79d29ece1b 100644
--- a/usb-redir.c
+++ b/usb-redir.c
@@ -60,7 +60,11 @@ struct endp_data {
     uint8_t iso_error; /* For reporting iso errors to the HC */
     uint8_t interrupt_started;
     uint8_t interrupt_error;
+    uint8_t bufpq_prefilled;
+    uint8_t bufpq_dropping_packets;
     QTAILQ_HEAD(, buf_packet) bufpq;
+    int bufpq_size;
+    int bufpq_target_size;
 };
 
 struct USBRedirDevice {
@@ -287,21 +291,41 @@ static void usbredir_cancel_packet(USBDevice *udev, USBPacket *p)
     }
 }
 
-static struct buf_packet *bufp_alloc(USBRedirDevice *dev,
+static void bufp_alloc(USBRedirDevice *dev,
     uint8_t *data, int len, int status, uint8_t ep)
 {
-    struct buf_packet *bufp = g_malloc(sizeof(struct buf_packet));
+    struct buf_packet *bufp;
+
+    if (!dev->endpoint[EP2I(ep)].bufpq_dropping_packets &&
+        dev->endpoint[EP2I(ep)].bufpq_size >
+            2 * dev->endpoint[EP2I(ep)].bufpq_target_size) {
+        DPRINTF("bufpq overflow, dropping packets ep %02X\n", ep);
+        dev->endpoint[EP2I(ep)].bufpq_dropping_packets = 1;
+    }
+    /* Since we're interupting the stream anyways, drop enough packets to get
+       back to our target buffer size */
+    if (dev->endpoint[EP2I(ep)].bufpq_dropping_packets) {
+        if (dev->endpoint[EP2I(ep)].bufpq_size >
+                dev->endpoint[EP2I(ep)].bufpq_target_size) {
+            free(data);
+            return;
+        }
+        dev->endpoint[EP2I(ep)].bufpq_dropping_packets = 0;
+    }
+
+    bufp = g_malloc(sizeof(struct buf_packet));
     bufp->data   = data;
     bufp->len    = len;
     bufp->status = status;
     QTAILQ_INSERT_TAIL(&dev->endpoint[EP2I(ep)].bufpq, bufp, next);
-    return bufp;
+    dev->endpoint[EP2I(ep)].bufpq_size++;
 }
 
 static void bufp_free(USBRedirDevice *dev, struct buf_packet *bufp,
     uint8_t ep)
 {
     QTAILQ_REMOVE(&dev->endpoint[EP2I(ep)].bufpq, bufp, next);
+    dev->endpoint[EP2I(ep)].bufpq_size--;
     free(bufp->data);
     g_free(bufp);
 }
@@ -332,35 +356,77 @@ static int usbredir_handle_iso_data(USBRedirDevice *dev, USBPacket *p,
                                      uint8_t ep)
 {
     int status, len;
-
     if (!dev->endpoint[EP2I(ep)].iso_started &&
             !dev->endpoint[EP2I(ep)].iso_error) {
         struct usb_redir_start_iso_stream_header start_iso = {
             .endpoint = ep,
-            /* TODO maybe do something with these depending on ep interval? */
-            .pkts_per_urb = 32,
-            .no_urbs = 3,
         };
+        int pkts_per_sec;
+
+        if (dev->dev.speed == USB_SPEED_HIGH) {
+            pkts_per_sec = 8000 / dev->endpoint[EP2I(ep)].interval;
+        } else {
+            pkts_per_sec = 1000 / dev->endpoint[EP2I(ep)].interval;
+        }
+        /* Testing has shown that we need circa 60 ms buffer */
+        dev->endpoint[EP2I(ep)].bufpq_target_size = (pkts_per_sec * 60) / 1000;
+
+        /* Aim for approx 100 interrupts / second on the client to
+           balance latency and interrupt load */
+        start_iso.pkts_per_urb = pkts_per_sec / 100;
+        if (start_iso.pkts_per_urb < 1) {
+            start_iso.pkts_per_urb = 1;
+        } else if (start_iso.pkts_per_urb > 32) {
+            start_iso.pkts_per_urb = 32;
+        }
+
+        start_iso.no_urbs = (dev->endpoint[EP2I(ep)].bufpq_target_size +
+                             start_iso.pkts_per_urb - 1) /
+                            start_iso.pkts_per_urb;
+        /* Output endpoints pre-fill only 1/2 of the packets, keeping the rest
+           as overflow buffer. Also see the usbredir protocol documentation */
+        if (!(ep & USB_DIR_IN)) {
+            start_iso.no_urbs *= 2;
+        }
+        if (start_iso.no_urbs > 16) {
+            start_iso.no_urbs = 16;
+        }
+
         /* No id, we look at the ep when receiving a status back */
         usbredirparser_send_start_iso_stream(dev->parser, 0, &start_iso);
         usbredirparser_do_write(dev->parser);
-        DPRINTF("iso stream started ep %02X\n", ep);
+        DPRINTF("iso stream started pkts/sec %d pkts/urb %d urbs %d ep %02X\n",
+                pkts_per_sec, start_iso.pkts_per_urb, start_iso.no_urbs, ep);
         dev->endpoint[EP2I(ep)].iso_started = 1;
+        dev->endpoint[EP2I(ep)].bufpq_prefilled = 0;
+        dev->endpoint[EP2I(ep)].bufpq_dropping_packets = 0;
     }
 
     if (ep & USB_DIR_IN) {
         struct buf_packet *isop;
 
+        if (dev->endpoint[EP2I(ep)].iso_started &&
+                !dev->endpoint[EP2I(ep)].bufpq_prefilled) {
+            if (dev->endpoint[EP2I(ep)].bufpq_size <
+                    dev->endpoint[EP2I(ep)].bufpq_target_size) {
+                return usbredir_handle_status(dev, 0, 0);
+            }
+            dev->endpoint[EP2I(ep)].bufpq_prefilled = 1;
+        }
+
         isop = QTAILQ_FIRST(&dev->endpoint[EP2I(ep)].bufpq);
         if (isop == NULL) {
-            DPRINTF2("iso-token-in ep %02X, no isop\n", ep);
+            DPRINTF("iso-token-in ep %02X, no isop, iso_error: %d\n",
+                    ep, dev->endpoint[EP2I(ep)].iso_error);
+            /* Re-fill the buffer */
+            dev->endpoint[EP2I(ep)].bufpq_prefilled = 0;
             /* Check iso_error for stream errors, otherwise its an underrun */
             status = dev->endpoint[EP2I(ep)].iso_error;
             dev->endpoint[EP2I(ep)].iso_error = 0;
             return usbredir_handle_status(dev, status, 0);
         }
-        DPRINTF2("iso-token-in ep %02X status %d len %d\n", ep, isop->status,
-                 isop->len);
+        DPRINTF2("iso-token-in ep %02X status %d len %d queue-size: %d\n", ep,
+                 isop->status, isop->len, dev->endpoint[EP2I(ep)].bufpq_size);
 
         status = isop->status;
         if (status != usb_redir_success) {
@@ -370,7 +436,8 @@ static int usbredir_handle_iso_data(USBRedirDevice *dev, USBPacket *p,
 
         len = isop->len;
         if (len > p->iov.size) {
-            ERROR("received iso data is larger then packet ep %02X\n", ep);
+            ERROR("received iso data is larger then packet ep %02X (%d > %d)\n",
+                  ep, len, (int)p->iov.size);
             bufp_free(dev, isop, ep);
             return USB_RET_NAK;
         }
@@ -410,6 +477,7 @@ static void usbredir_stop_iso_stream(USBRedirDevice *dev, uint8_t ep)
         DPRINTF("iso stream stopped ep %02X\n", ep);
         dev->endpoint[EP2I(ep)].iso_started = 0;
     }
+    dev->endpoint[EP2I(ep)].iso_error = 0;
     usbredir_free_bufpq(dev, ep);
 }
 
@@ -460,6 +528,10 @@ static int usbredir_handle_interrupt_data(USBRedirDevice *dev,
             usbredirparser_do_write(dev->parser);
             DPRINTF("interrupt recv started ep %02X\n", ep);
             dev->endpoint[EP2I(ep)].interrupt_started = 1;
+            /* We don't really want to drop interrupt packets ever, but
+               having some upper limit to how much we buffer is good. */
+            dev->endpoint[EP2I(ep)].bufpq_target_size = 1000;
+            dev->endpoint[EP2I(ep)].bufpq_dropping_packets = 0;
         }
 
         intp = QTAILQ_FIRST(&dev->endpoint[EP2I(ep)].bufpq);
@@ -522,6 +594,7 @@ static void usbredir_stop_interrupt_receiving(USBRedirDevice *dev,
         DPRINTF("interrupt recv stopped ep %02X\n", ep);
         dev->endpoint[EP2I(ep)].interrupt_started = 0;
     }
+    dev->endpoint[EP2I(ep)].interrupt_error = 0;
     usbredir_free_bufpq(dev, ep);
 }
 
@@ -959,9 +1032,24 @@ static void usbredir_ep_info(void *priv,
         dev->endpoint[i].type = ep_info->type[i];
         dev->endpoint[i].interval = ep_info->interval[i];
         dev->endpoint[i].interface = ep_info->interface[i];
-        if (dev->endpoint[i].type != usb_redir_type_invalid) {
+        switch (dev->endpoint[i].type) {
+        case usb_redir_type_invalid:
+            break;
+        case usb_redir_type_iso:
+        case usb_redir_type_interrupt:
+            if (dev->endpoint[i].interval == 0) {
+                ERROR("Received 0 interval for isoc or irq endpoint\n");
+                usbredir_device_disconnect(dev);
+            }
+            /* Fall through */
+        case usb_redir_type_control:
+        case usb_redir_type_bulk:
             DPRINTF("ep: %02X type: %d interface: %d\n", I2EP(i),
                     dev->endpoint[i].type, dev->endpoint[i].interface);
+            break;
+        default:
+            ERROR("Received invalid endpoint type\n");
+            usbredir_device_disconnect(dev);
         }
     }
 }
@@ -1029,7 +1117,7 @@ static void usbredir_iso_stream_status(void *priv, uint32_t id,
     DPRINTF("iso status %d ep %02X id %u\n", iso_stream_status->status,
             ep, id);
 
-    if (!dev->dev.attached) {
+    if (!dev->dev.attached || !dev->endpoint[EP2I(ep)].iso_started) {
         return;
     }
 
@@ -1050,7 +1138,7 @@ static void usbredir_interrupt_receiving_status(void *priv, uint32_t id,
     DPRINTF("interrupt recv status %d ep %02X id %u\n",
             interrupt_receiving_status->status, ep, id);
 
-    if (!dev->dev.attached) {
+    if (!dev->dev.attached || !dev->endpoint[EP2I(ep)].interrupt_started) {
         return;
     }