summary refs log tree commit diff stats
path: root/hw/usb
diff options
context:
space:
mode:
Diffstat (limited to 'hw/usb')
-rw-r--r--hw/usb/Makefile.objs1
-rw-r--r--hw/usb/bus.c13
-rw-r--r--hw/usb/core.c23
-rw-r--r--hw/usb/dev-network.c10
-rw-r--r--hw/usb/dev-storage.c21
-rw-r--r--hw/usb/dev-uas.c779
-rw-r--r--hw/usb/hcd-ehci.c246
-rw-r--r--hw/usb/hcd-ohci.c93
-rw-r--r--hw/usb/hcd-uhci.c21
-rw-r--r--hw/usb/host-linux.c94
-rw-r--r--hw/usb/libhw.c21
-rw-r--r--hw/usb/redirect.c2
12 files changed, 1152 insertions, 172 deletions
diff --git a/hw/usb/Makefile.objs b/hw/usb/Makefile.objs
index 9c7ddf5cb2..4225136d0f 100644
--- a/hw/usb/Makefile.objs
+++ b/hw/usb/Makefile.objs
@@ -11,3 +11,4 @@ common-obj-y += core.o bus.o desc.o dev-hub.o
 common-obj-y += host-$(HOST_USB).o dev-bluetooth.o
 common-obj-y += dev-hid.o dev-storage.o dev-wacom.o
 common-obj-y += dev-serial.o dev-network.o dev-audio.o
+common-obj-y += dev-uas.o
diff --git a/hw/usb/bus.c b/hw/usb/bus.c
index f87cc5f443..b649360dd3 100644
--- a/hw/usb/bus.c
+++ b/hw/usb/bus.c
@@ -37,10 +37,23 @@ static const TypeInfo usb_bus_info = {
 static int next_usb_bus = 0;
 static QTAILQ_HEAD(, USBBus) busses = QTAILQ_HEAD_INITIALIZER(busses);
 
+static int usb_device_post_load(void *opaque, int version_id)
+{
+    USBDevice *dev = opaque;
+
+    if (dev->state == USB_STATE_NOTATTACHED) {
+        dev->attached = 0;
+    } else {
+        dev->attached = 1;
+    }
+    return 0;
+}
+
 const VMStateDescription vmstate_usb_device = {
     .name = "USBDevice",
     .version_id = 1,
     .minimum_version_id = 1,
+    .post_load = usb_device_post_load,
     .fields = (VMStateField []) {
         VMSTATE_UINT8(addr, USBDevice),
         VMSTATE_INT32(state, USBDevice),
diff --git a/hw/usb/core.c b/hw/usb/core.c
index 0e02da7601..01a7622837 100644
--- a/hw/usb/core.c
+++ b/hw/usb/core.c
@@ -522,10 +522,10 @@ void usb_packet_copy(USBPacket *p, void *ptr, size_t bytes)
     switch (p->pid) {
     case USB_TOKEN_SETUP:
     case USB_TOKEN_OUT:
-        iov_to_buf(p->iov.iov, p->iov.niov, ptr, p->result, bytes);
+        iov_to_buf(p->iov.iov, p->iov.niov, p->result, ptr, bytes);
         break;
     case USB_TOKEN_IN:
-        iov_from_buf(p->iov.iov, p->iov.niov, ptr, p->result, bytes);
+        iov_from_buf(p->iov.iov, p->iov.niov, p->result, ptr, bytes);
         break;
     default:
         fprintf(stderr, "%s: invalid pid: %x\n", __func__, p->pid);
@@ -539,7 +539,7 @@ void usb_packet_skip(USBPacket *p, size_t bytes)
     assert(p->result >= 0);
     assert(p->result + bytes <= p->iov.size);
     if (p->pid == USB_TOKEN_IN) {
-        iov_clear(p->iov.iov, p->iov.niov, p->result, bytes);
+        iov_memset(p->iov.iov, p->iov.niov, p->result, 0, bytes);
     }
     p->result += bytes;
 }
@@ -550,7 +550,7 @@ void usb_packet_cleanup(USBPacket *p)
     qemu_iovec_destroy(&p->iov);
 }
 
-void usb_ep_init(USBDevice *dev)
+void usb_ep_reset(USBDevice *dev)
 {
     int ep;
 
@@ -559,7 +559,6 @@ void usb_ep_init(USBDevice *dev)
     dev->ep_ctl.ifnum = 0;
     dev->ep_ctl.dev = dev;
     dev->ep_ctl.pipeline = false;
-    QTAILQ_INIT(&dev->ep_ctl.queue);
     for (ep = 0; ep < USB_MAX_ENDPOINTS; ep++) {
         dev->ep_in[ep].nr = ep + 1;
         dev->ep_out[ep].nr = ep + 1;
@@ -567,12 +566,22 @@ void usb_ep_init(USBDevice *dev)
         dev->ep_out[ep].pid = USB_TOKEN_OUT;
         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].ifnum = USB_INTERFACE_INVALID;
+        dev->ep_out[ep].ifnum = USB_INTERFACE_INVALID;
         dev->ep_in[ep].dev = dev;
         dev->ep_out[ep].dev = dev;
         dev->ep_in[ep].pipeline = false;
         dev->ep_out[ep].pipeline = false;
+    }
+}
+
+void usb_ep_init(USBDevice *dev)
+{
+    int ep;
+
+    usb_ep_reset(dev);
+    QTAILQ_INIT(&dev->ep_ctl.queue);
+    for (ep = 0; ep < USB_MAX_ENDPOINTS; ep++) {
         QTAILQ_INIT(&dev->ep_in[ep].queue);
         QTAILQ_INIT(&dev->ep_out[ep].queue);
     }
diff --git a/hw/usb/dev-network.c b/hw/usb/dev-network.c
index 5d2f0982c9..c84892c98d 100644
--- a/hw/usb/dev-network.c
+++ b/hw/usb/dev-network.c
@@ -1247,7 +1247,7 @@ static int usb_net_handle_data(USBDevice *dev, USBPacket *p)
     return ret;
 }
 
-static ssize_t usbnet_receive(VLANClientState *nc, const uint8_t *buf, size_t size)
+static ssize_t usbnet_receive(NetClientState *nc, const uint8_t *buf, size_t size)
 {
     USBNetState *s = DO_UPCAST(NICState, nc, nc)->opaque;
     struct rndis_packet_msg_type *msg;
@@ -1285,7 +1285,7 @@ static ssize_t usbnet_receive(VLANClientState *nc, const uint8_t *buf, size_t si
     return size;
 }
 
-static int usbnet_can_receive(VLANClientState *nc)
+static int usbnet_can_receive(NetClientState *nc)
 {
     USBNetState *s = DO_UPCAST(NICState, nc, nc)->opaque;
 
@@ -1296,7 +1296,7 @@ static int usbnet_can_receive(VLANClientState *nc)
     return !s->in_len;
 }
 
-static void usbnet_cleanup(VLANClientState *nc)
+static void usbnet_cleanup(NetClientState *nc)
 {
     USBNetState *s = DO_UPCAST(NICState, nc, nc)->opaque;
 
@@ -1309,11 +1309,11 @@ static void usb_net_handle_destroy(USBDevice *dev)
 
     /* TODO: remove the nd_table[] entry */
     rndis_clear_responsequeue(s);
-    qemu_del_vlan_client(&s->nic->nc);
+    qemu_del_net_client(&s->nic->nc);
 }
 
 static NetClientInfo net_usbnet_info = {
-    .type = NET_CLIENT_TYPE_NIC,
+    .type = NET_CLIENT_OPTIONS_KIND_NIC,
     .size = sizeof(NICState),
     .can_receive = usbnet_can_receive,
     .receive = usbnet_receive,
diff --git a/hw/usb/dev-storage.c b/hw/usb/dev-storage.c
index 251e7de1cd..ff48d91049 100644
--- a/hw/usb/dev-storage.c
+++ b/hw/usb/dev-storage.c
@@ -247,6 +247,9 @@ static void usb_msd_command_complete(SCSIRequest *req, uint32_t status, size_t r
                the status read packet.  */
             usb_msd_send_status(s, p);
             s->mode = USB_MSDM_CBW;
+        } else if (s->mode == USB_MSDM_CSW) {
+            usb_msd_send_status(s, p);
+            s->mode = USB_MSDM_CBW;
         } else {
             if (s->data_len) {
                 int len = (p->iov.size - p->result);
@@ -383,6 +386,9 @@ static int usb_msd_handle_data(USBDevice *dev, USBPacket *p)
             assert(le32_to_cpu(s->csw.residue) == 0);
             s->scsi_len = 0;
             s->req = scsi_req_new(s->scsi_dev, tag, 0, cbw.cmd, NULL);
+#ifdef DEBUG_MSD
+            scsi_req_print(s->req);
+#endif
             scsi_req_enqueue(s->req);
             if (s->req && s->req->cmd.xfer != SCSI_XFER_NONE) {
                 scsi_req_continue(s->req);
@@ -410,7 +416,7 @@ static int usb_msd_handle_data(USBDevice *dev, USBPacket *p)
                 }
             }
             if (p->result < p->iov.size) {
-                DPRINTF("Deferring packet %p\n", p);
+                DPRINTF("Deferring packet %p [wait data-out]\n", p);
                 s->packet = p;
                 ret = USB_RET_ASYNC;
             } else {
@@ -445,6 +451,7 @@ static int usb_msd_handle_data(USBDevice *dev, USBPacket *p)
 
             if (s->req) {
                 /* still in flight */
+                DPRINTF("Deferring packet %p [wait status]\n", p);
                 s->packet = p;
                 ret = USB_RET_ASYNC;
             } else {
@@ -471,7 +478,7 @@ static int usb_msd_handle_data(USBDevice *dev, USBPacket *p)
                 }
             }
             if (p->result < p->iov.size) {
-                DPRINTF("Deferring packet %p\n", p);
+                DPRINTF("Deferring packet %p [wait data-in]\n", p);
                 s->packet = p;
                 ret = USB_RET_ASYNC;
             } else {
@@ -532,13 +539,14 @@ static int usb_msd_initfn(USBDevice *dev)
 {
     MSDState *s = DO_UPCAST(MSDState, dev, dev);
     BlockDriverState *bs = s->conf.bs;
-    DriveInfo *dinfo;
 
     if (!bs) {
         error_report("drive property not set");
         return -1;
     }
 
+    blkconf_serial(&s->conf, &s->serial);
+
     /*
      * Hack alert: this pretends to be a block device, but it's really
      * a SCSI bus that can serve only a single device, which it
@@ -551,13 +559,6 @@ static int usb_msd_initfn(USBDevice *dev)
     bdrv_detach_dev(bs, &s->dev.qdev);
     s->conf.bs = NULL;
 
-    if (!s->serial) {
-        /* try to fall back to value set with legacy -drive serial=... */
-        dinfo = drive_get_by_blockdev(bs);
-        if (*dinfo->serial) {
-            s->serial = strdup(dinfo->serial);
-        }
-    }
     if (s->serial) {
         usb_desc_set_string(dev, STR_SERIALNUMBER, s->serial);
     } else {
diff --git a/hw/usb/dev-uas.c b/hw/usb/dev-uas.c
new file mode 100644
index 0000000000..9b02ff48fa
--- /dev/null
+++ b/hw/usb/dev-uas.c
@@ -0,0 +1,779 @@
+/*
+ * UAS (USB Attached SCSI) emulation
+ *
+ * Copyright Red Hat, Inc. 2012
+ *
+ * Author: Gerd Hoffmann <kraxel@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu-common.h"
+#include "qemu-option.h"
+#include "qemu-config.h"
+#include "trace.h"
+
+#include "hw/usb.h"
+#include "hw/usb/desc.h"
+#include "hw/scsi.h"
+#include "hw/scsi-defs.h"
+
+/* --------------------------------------------------------------------- */
+
+#define UAS_UI_COMMAND              0x01
+#define UAS_UI_SENSE                0x03
+#define UAS_UI_RESPONSE             0x04
+#define UAS_UI_TASK_MGMT            0x05
+#define UAS_UI_READ_READY           0x06
+#define UAS_UI_WRITE_READY          0x07
+
+#define UAS_RC_TMF_COMPLETE         0x00
+#define UAS_RC_INVALID_INFO_UNIT    0x02
+#define UAS_RC_TMF_NOT_SUPPORTED    0x04
+#define UAS_RC_TMF_FAILED           0x05
+#define UAS_RC_TMF_SUCCEEDED        0x08
+#define UAS_RC_INCORRECT_LUN        0x09
+#define UAS_RC_OVERLAPPED_TAG       0x0a
+
+#define UAS_TMF_ABORT_TASK          0x01
+#define UAS_TMF_ABORT_TASK_SET      0x02
+#define UAS_TMF_CLEAR_TASK_SET      0x04
+#define UAS_TMF_LOGICAL_UNIT_RESET  0x08
+#define UAS_TMF_I_T_NEXUS_RESET     0x10
+#define UAS_TMF_CLEAR_ACA           0x40
+#define UAS_TMF_QUERY_TASK          0x80
+#define UAS_TMF_QUERY_TASK_SET      0x81
+#define UAS_TMF_QUERY_ASYNC_EVENT   0x82
+
+#define UAS_PIPE_ID_COMMAND         0x01
+#define UAS_PIPE_ID_STATUS          0x02
+#define UAS_PIPE_ID_DATA_IN         0x03
+#define UAS_PIPE_ID_DATA_OUT        0x04
+
+typedef struct {
+    uint8_t    id;
+    uint8_t    reserved;
+    uint16_t   tag;
+} QEMU_PACKED  uas_ui_header;
+
+typedef struct {
+    uint8_t    prio_taskattr;   /* 6:3 priority, 2:0 task attribute   */
+    uint8_t    reserved_1;
+    uint8_t    add_cdb_length;  /* 7:2 additional adb length (dwords) */
+    uint8_t    reserved_2;
+    uint64_t   lun;
+    uint8_t    cdb[16];
+    uint8_t    add_cdb[];
+} QEMU_PACKED  uas_ui_command;
+
+typedef struct {
+    uint16_t   status_qualifier;
+    uint8_t    status;
+    uint8_t    reserved[7];
+    uint16_t   sense_length;
+    uint8_t    sense_data[18];
+} QEMU_PACKED  uas_ui_sense;
+
+typedef struct {
+    uint16_t   add_response_info;
+    uint8_t    response_code;
+} QEMU_PACKED  uas_ui_response;
+
+typedef struct {
+    uint8_t    function;
+    uint8_t    reserved;
+    uint16_t   task_tag;
+    uint64_t   lun;
+} QEMU_PACKED  uas_ui_task_mgmt;
+
+typedef struct {
+    uas_ui_header  hdr;
+    union {
+        uas_ui_command   command;
+        uas_ui_sense     sense;
+        uas_ui_task_mgmt task;
+        uas_ui_response  response;
+    };
+} QEMU_PACKED  uas_ui;
+
+/* --------------------------------------------------------------------- */
+
+typedef struct UASDevice UASDevice;
+typedef struct UASRequest UASRequest;
+typedef struct UASStatus UASStatus;
+
+struct UASDevice {
+    USBDevice                 dev;
+    SCSIBus                   bus;
+    UASRequest                *datain;
+    UASRequest                *dataout;
+    USBPacket                 *status;
+    QEMUBH                    *status_bh;
+    QTAILQ_HEAD(, UASStatus)  results;
+    QTAILQ_HEAD(, UASRequest) requests;
+};
+
+struct UASRequest {
+    uint16_t     tag;
+    uint64_t     lun;
+    UASDevice    *uas;
+    SCSIDevice   *dev;
+    SCSIRequest  *req;
+    USBPacket    *data;
+    bool         data_async;
+    bool         active;
+    bool         complete;
+    uint32_t     buf_off;
+    uint32_t     buf_size;
+    uint32_t     data_off;
+    uint32_t     data_size;
+    QTAILQ_ENTRY(UASRequest)  next;
+};
+
+struct UASStatus {
+    uas_ui                    status;
+    uint32_t                  length;
+    QTAILQ_ENTRY(UASStatus)   next;
+};
+
+/* --------------------------------------------------------------------- */
+
+enum {
+    STR_MANUFACTURER = 1,
+    STR_PRODUCT,
+    STR_SERIALNUMBER,
+    STR_CONFIG_HIGH,
+};
+
+static const USBDescStrings desc_strings = {
+    [STR_MANUFACTURER] = "QEMU",
+    [STR_PRODUCT]      = "USB Attached SCSI HBA",
+    [STR_SERIALNUMBER] = "27842",
+    [STR_CONFIG_HIGH]  = "High speed config (usb 2.0)",
+};
+
+static const USBDescIface desc_iface_high = {
+    .bInterfaceNumber              = 0,
+    .bNumEndpoints                 = 4,
+    .bInterfaceClass               = USB_CLASS_MASS_STORAGE,
+    .bInterfaceSubClass            = 0x06, /* SCSI */
+    .bInterfaceProtocol            = 0x62, /* UAS  */
+    .eps = (USBDescEndpoint[]) {
+        {
+            .bEndpointAddress      = USB_DIR_OUT | UAS_PIPE_ID_COMMAND,
+            .bmAttributes          = USB_ENDPOINT_XFER_BULK,
+            .wMaxPacketSize        = 512,
+            .extra = (uint8_t[]) {
+                0x04,  /*  u8  bLength */
+                0x24,  /*  u8  bDescriptorType */
+                UAS_PIPE_ID_COMMAND,
+                0x00,  /*  u8  bReserved */
+            },
+        },{
+            .bEndpointAddress      = USB_DIR_IN | UAS_PIPE_ID_STATUS,
+            .bmAttributes          = USB_ENDPOINT_XFER_BULK,
+            .wMaxPacketSize        = 512,
+            .extra = (uint8_t[]) {
+                0x04,  /*  u8  bLength */
+                0x24,  /*  u8  bDescriptorType */
+                UAS_PIPE_ID_STATUS,
+                0x00,  /*  u8  bReserved */
+            },
+        },{
+            .bEndpointAddress      = USB_DIR_IN | UAS_PIPE_ID_DATA_IN,
+            .bmAttributes          = USB_ENDPOINT_XFER_BULK,
+            .wMaxPacketSize        = 512,
+            .extra = (uint8_t[]) {
+                0x04,  /*  u8  bLength */
+                0x24,  /*  u8  bDescriptorType */
+                UAS_PIPE_ID_DATA_IN,
+                0x00,  /*  u8  bReserved */
+            },
+        },{
+            .bEndpointAddress      = USB_DIR_OUT | UAS_PIPE_ID_DATA_OUT,
+            .bmAttributes          = USB_ENDPOINT_XFER_BULK,
+            .wMaxPacketSize        = 512,
+            .extra = (uint8_t[]) {
+                0x04,  /*  u8  bLength */
+                0x24,  /*  u8  bDescriptorType */
+                UAS_PIPE_ID_DATA_OUT,
+                0x00,  /*  u8  bReserved */
+            },
+        },
+    }
+};
+
+static const USBDescDevice desc_device_high = {
+    .bcdUSB                        = 0x0200,
+    .bMaxPacketSize0               = 64,
+    .bNumConfigurations            = 1,
+    .confs = (USBDescConfig[]) {
+        {
+            .bNumInterfaces        = 1,
+            .bConfigurationValue   = 1,
+            .iConfiguration        = STR_CONFIG_HIGH,
+            .bmAttributes          = 0xc0,
+            .nif = 1,
+            .ifs = &desc_iface_high,
+        },
+    },
+};
+
+static const USBDesc desc = {
+    .id = {
+        .idVendor          = 0x46f4, /* CRC16() of "QEMU" */
+        .idProduct         = 0x0002,
+        .bcdDevice         = 0,
+        .iManufacturer     = STR_MANUFACTURER,
+        .iProduct          = STR_PRODUCT,
+        .iSerialNumber     = STR_SERIALNUMBER,
+    },
+    .high = &desc_device_high,
+    .str  = desc_strings,
+};
+
+/* --------------------------------------------------------------------- */
+
+static UASStatus *usb_uas_alloc_status(uint8_t id, uint16_t tag)
+{
+    UASStatus *st = g_new0(UASStatus, 1);
+
+    st->status.hdr.id = id;
+    st->status.hdr.tag = cpu_to_be16(tag);
+    st->length = sizeof(uas_ui_header);
+    return st;
+}
+
+static void usb_uas_send_status_bh(void *opaque)
+{
+    UASDevice *uas = opaque;
+    UASStatus *st = QTAILQ_FIRST(&uas->results);
+    USBPacket *p = uas->status;
+
+    assert(p != NULL);
+    assert(st != NULL);
+
+    uas->status = NULL;
+    usb_packet_copy(p, &st->status, st->length);
+    p->result = st->length;
+    QTAILQ_REMOVE(&uas->results, st, next);
+    g_free(st);
+
+    usb_packet_complete(&uas->dev, p);
+}
+
+static void usb_uas_queue_status(UASDevice *uas, UASStatus *st, int length)
+{
+    st->length += length;
+    QTAILQ_INSERT_TAIL(&uas->results, st, next);
+    if (uas->status) {
+        /*
+         * Just schedule bh make sure any in-flight data transaction
+         * is finished before completing (sending) the status packet.
+         */
+        qemu_bh_schedule(uas->status_bh);
+    } else {
+        USBEndpoint *ep = usb_ep_get(&uas->dev, USB_TOKEN_IN,
+                                     UAS_PIPE_ID_STATUS);
+        usb_wakeup(ep);
+    }
+}
+
+static void usb_uas_queue_response(UASDevice *uas, uint16_t tag,
+                                   uint8_t code, uint16_t add_info)
+{
+    UASStatus *st = usb_uas_alloc_status(UAS_UI_RESPONSE, tag);
+
+    trace_usb_uas_response(uas->dev.addr, tag, code);
+    st->status.response.response_code = code;
+    st->status.response.add_response_info = cpu_to_be16(add_info);
+    usb_uas_queue_status(uas, st, sizeof(uas_ui_response));
+}
+
+static void usb_uas_queue_sense(UASRequest *req, uint8_t status)
+{
+    UASStatus *st = usb_uas_alloc_status(UAS_UI_SENSE, req->tag);
+    int len, slen = 0;
+
+    trace_usb_uas_sense(req->uas->dev.addr, req->tag, status);
+    st->status.sense.status = status;
+    st->status.sense.status_qualifier = cpu_to_be16(0);
+    if (status != GOOD) {
+        slen = scsi_req_get_sense(req->req, st->status.sense.sense_data,
+                                  sizeof(st->status.sense.sense_data));
+        st->status.sense.sense_length = cpu_to_be16(slen);
+    }
+    len = sizeof(uas_ui_sense) - sizeof(st->status.sense.sense_data) + slen;
+    usb_uas_queue_status(req->uas, st, len);
+}
+
+static void usb_uas_queue_read_ready(UASRequest *req)
+{
+    UASStatus *st = usb_uas_alloc_status(UAS_UI_READ_READY, req->tag);
+
+    trace_usb_uas_read_ready(req->uas->dev.addr, req->tag);
+    usb_uas_queue_status(req->uas, st, 0);
+}
+
+static void usb_uas_queue_write_ready(UASRequest *req)
+{
+    UASStatus *st = usb_uas_alloc_status(UAS_UI_WRITE_READY, req->tag);
+
+    trace_usb_uas_write_ready(req->uas->dev.addr, req->tag);
+    usb_uas_queue_status(req->uas, st, 0);
+}
+
+/* --------------------------------------------------------------------- */
+
+static int usb_uas_get_lun(uint64_t lun64)
+{
+    return (lun64 >> 48) & 0xff;
+}
+
+static SCSIDevice *usb_uas_get_dev(UASDevice *uas, uint64_t lun64)
+{
+    if ((lun64 >> 56) != 0x00) {
+        return NULL;
+    }
+    return scsi_device_find(&uas->bus, 0, 0, usb_uas_get_lun(lun64));
+}
+
+static void usb_uas_complete_data_packet(UASRequest *req)
+{
+    USBPacket *p;
+
+    if (!req->data_async) {
+        return;
+    }
+    p = req->data;
+    req->data = NULL;
+    req->data_async = false;
+    usb_packet_complete(&req->uas->dev, p);
+}
+
+static void usb_uas_copy_data(UASRequest *req)
+{
+    uint32_t length;
+
+    length = MIN(req->buf_size - req->buf_off,
+                 req->data->iov.size - req->data->result);
+    trace_usb_uas_xfer_data(req->uas->dev.addr, req->tag, length,
+                            req->data->result, req->data->iov.size,
+                            req->buf_off, req->buf_size);
+    usb_packet_copy(req->data, scsi_req_get_buf(req->req) + req->buf_off,
+                    length);
+    req->buf_off += length;
+    req->data_off += length;
+
+    if (req->data->result == req->data->iov.size) {
+        usb_uas_complete_data_packet(req);
+    }
+    if (req->buf_size && req->buf_off == req->buf_size) {
+        req->buf_off = 0;
+        req->buf_size = 0;
+        scsi_req_continue(req->req);
+    }
+}
+
+static void usb_uas_start_next_transfer(UASDevice *uas)
+{
+    UASRequest *req;
+
+    QTAILQ_FOREACH(req, &uas->requests, next) {
+        if (req->active || req->complete) {
+            continue;
+        }
+        if (req->req->cmd.mode == SCSI_XFER_FROM_DEV && uas->datain == NULL) {
+            uas->datain = req;
+            usb_uas_queue_read_ready(req);
+            req->active = true;
+            return;
+        }
+        if (req->req->cmd.mode == SCSI_XFER_TO_DEV && uas->dataout == NULL) {
+            uas->dataout = req;
+            usb_uas_queue_write_ready(req);
+            req->active = true;
+            return;
+        }
+    }
+}
+
+static UASRequest *usb_uas_alloc_request(UASDevice *uas, uas_ui *ui)
+{
+    UASRequest *req;
+
+    req = g_new0(UASRequest, 1);
+    req->uas = uas;
+    req->tag = be16_to_cpu(ui->hdr.tag);
+    req->lun = be64_to_cpu(ui->command.lun);
+    req->dev = usb_uas_get_dev(req->uas, req->lun);
+    return req;
+}
+
+static void usb_uas_scsi_free_request(SCSIBus *bus, void *priv)
+{
+    UASRequest *req = priv;
+    UASDevice *uas = req->uas;
+
+    if (req == uas->datain) {
+        uas->datain = NULL;
+    }
+    if (req == uas->dataout) {
+        uas->dataout = NULL;
+    }
+    QTAILQ_REMOVE(&uas->requests, req, next);
+    g_free(req);
+}
+
+static UASRequest *usb_uas_find_request(UASDevice *uas, uint16_t tag)
+{
+    UASRequest *req;
+
+    QTAILQ_FOREACH(req, &uas->requests, next) {
+        if (req->tag == tag) {
+            return req;
+        }
+    }
+    return NULL;
+}
+
+static void usb_uas_scsi_transfer_data(SCSIRequest *r, uint32_t len)
+{
+    UASRequest *req = r->hba_private;
+
+    trace_usb_uas_scsi_data(req->uas->dev.addr, req->tag, len);
+    req->buf_off = 0;
+    req->buf_size = len;
+    if (req->data) {
+        usb_uas_copy_data(req);
+    } else {
+        usb_uas_start_next_transfer(req->uas);
+    }
+}
+
+static void usb_uas_scsi_command_complete(SCSIRequest *r,
+                                          uint32_t status, size_t resid)
+{
+    UASRequest *req = r->hba_private;
+    UASDevice *uas = req->uas;
+
+    trace_usb_uas_scsi_complete(req->uas->dev.addr, req->tag, status, resid);
+    req->complete = true;
+    if (req->data) {
+        usb_uas_complete_data_packet(req);
+    }
+    usb_uas_queue_sense(req, status);
+    scsi_req_unref(req->req);
+    usb_uas_start_next_transfer(uas);
+}
+
+static void usb_uas_scsi_request_cancelled(SCSIRequest *r)
+{
+    UASRequest *req = r->hba_private;
+
+    /* FIXME: queue notification to status pipe? */
+    scsi_req_unref(req->req);
+}
+
+static const struct SCSIBusInfo usb_uas_scsi_info = {
+    .tcq = true,
+    .max_target = 0,
+    .max_lun = 255,
+
+    .transfer_data = usb_uas_scsi_transfer_data,
+    .complete = usb_uas_scsi_command_complete,
+    .cancel = usb_uas_scsi_request_cancelled,
+    .free_request = usb_uas_scsi_free_request,
+};
+
+/* --------------------------------------------------------------------- */
+
+static void usb_uas_handle_reset(USBDevice *dev)
+{
+    UASDevice *uas = DO_UPCAST(UASDevice, dev, dev);
+    UASRequest *req, *nreq;
+    UASStatus *st, *nst;
+
+    trace_usb_uas_reset(dev->addr);
+    QTAILQ_FOREACH_SAFE(req, &uas->requests, next, nreq) {
+        scsi_req_cancel(req->req);
+    }
+    QTAILQ_FOREACH_SAFE(st, &uas->results, next, nst) {
+        QTAILQ_REMOVE(&uas->results, st, next);
+        g_free(st);
+    }
+}
+
+static int usb_uas_handle_control(USBDevice *dev, USBPacket *p,
+               int request, int value, int index, int length, uint8_t *data)
+{
+    int ret;
+
+    ret = usb_desc_handle_control(dev, p, request, value, index, length, data);
+    if (ret >= 0) {
+        return ret;
+    }
+    fprintf(stderr, "%s: unhandled control request\n", __func__);
+    return USB_RET_STALL;
+}
+
+static void usb_uas_cancel_io(USBDevice *dev, USBPacket *p)
+{
+    UASDevice *uas = DO_UPCAST(UASDevice, dev, dev);
+    UASRequest *req, *nreq;
+
+    if (uas->status == p) {
+        uas->status = NULL;
+        qemu_bh_cancel(uas->status_bh);
+        return;
+    }
+    QTAILQ_FOREACH_SAFE(req, &uas->requests, next, nreq) {
+        if (req->data == p) {
+            req->data = NULL;
+            return;
+        }
+    }
+    assert(!"canceled usb packet not found");
+}
+
+static void usb_uas_command(UASDevice *uas, uas_ui *ui)
+{
+    UASRequest *req;
+    uint32_t len;
+
+    req = usb_uas_find_request(uas, be16_to_cpu(ui->hdr.tag));
+    if (req) {
+        goto overlapped_tag;
+    }
+    req = usb_uas_alloc_request(uas, ui);
+    if (req->dev == NULL) {
+        goto bad_target;
+    }
+
+    trace_usb_uas_command(uas->dev.addr, req->tag,
+                          usb_uas_get_lun(req->lun),
+                          req->lun >> 32, req->lun & 0xffffffff);
+    QTAILQ_INSERT_TAIL(&uas->requests, req, next);
+    req->req = scsi_req_new(req->dev, req->tag,
+                            usb_uas_get_lun(req->lun),
+                            ui->command.cdb, req);
+    len = scsi_req_enqueue(req->req);
+    if (len) {
+        req->data_size = len;
+        scsi_req_continue(req->req);
+    }
+    return;
+
+overlapped_tag:
+    usb_uas_queue_response(uas, req->tag, UAS_RC_OVERLAPPED_TAG, 0);
+    return;
+
+bad_target:
+    /*
+     * FIXME: Seems to upset linux, is this wrong?
+     * NOTE: Happens only with no scsi devices at the bus, not sure
+     *       this is a valid UAS setup in the first place.
+     */
+    usb_uas_queue_response(uas, req->tag, UAS_RC_INVALID_INFO_UNIT, 0);
+    g_free(req);
+    return;
+}
+
+static void usb_uas_task(UASDevice *uas, uas_ui *ui)
+{
+    uint16_t tag = be16_to_cpu(ui->hdr.tag);
+    uint64_t lun64 = be64_to_cpu(ui->task.lun);
+    SCSIDevice *dev = usb_uas_get_dev(uas, lun64);
+    int lun = usb_uas_get_lun(lun64);
+    UASRequest *req;
+    uint16_t task_tag;
+
+    req = usb_uas_find_request(uas, be16_to_cpu(ui->hdr.tag));
+    if (req) {
+        goto overlapped_tag;
+    }
+
+    switch (ui->task.function) {
+    case UAS_TMF_ABORT_TASK:
+        task_tag = be16_to_cpu(ui->task.task_tag);
+        trace_usb_uas_tmf_abort_task(uas->dev.addr, tag, task_tag);
+        if (dev == NULL) {
+            goto bad_target;
+        }
+        if (dev->lun != lun) {
+            goto incorrect_lun;
+        }
+        req = usb_uas_find_request(uas, task_tag);
+        if (req && req->dev == dev) {
+            scsi_req_cancel(req->req);
+        }
+        usb_uas_queue_response(uas, tag, UAS_RC_TMF_COMPLETE, 0);
+        break;
+
+    case UAS_TMF_LOGICAL_UNIT_RESET:
+        trace_usb_uas_tmf_logical_unit_reset(uas->dev.addr, tag, lun);
+        if (dev == NULL) {
+            goto bad_target;
+        }
+        if (dev->lun != lun) {
+            goto incorrect_lun;
+        }
+        qdev_reset_all(&dev->qdev);
+        usb_uas_queue_response(uas, tag, UAS_RC_TMF_COMPLETE, 0);
+        break;
+
+    default:
+        trace_usb_uas_tmf_unsupported(uas->dev.addr, tag, ui->task.function);
+        usb_uas_queue_response(uas, tag, UAS_RC_TMF_NOT_SUPPORTED, 0);
+        break;
+    }
+    return;
+
+overlapped_tag:
+    usb_uas_queue_response(uas, req->tag, UAS_RC_OVERLAPPED_TAG, 0);
+    return;
+
+bad_target:
+    /* FIXME: correct?  [see long comment in usb_uas_command()] */
+    usb_uas_queue_response(uas, tag, UAS_RC_INVALID_INFO_UNIT, 0);
+    return;
+
+incorrect_lun:
+    usb_uas_queue_response(uas, tag, UAS_RC_INCORRECT_LUN, 0);
+    return;
+}
+
+static int usb_uas_handle_data(USBDevice *dev, USBPacket *p)
+{
+    UASDevice *uas = DO_UPCAST(UASDevice, dev, dev);
+    uas_ui ui;
+    UASStatus *st;
+    UASRequest *req;
+    int length, ret = 0;
+
+    switch (p->ep->nr) {
+    case UAS_PIPE_ID_COMMAND:
+        length = MIN(sizeof(ui), p->iov.size);
+        usb_packet_copy(p, &ui, length);
+        switch (ui.hdr.id) {
+        case UAS_UI_COMMAND:
+            usb_uas_command(uas, &ui);
+            ret = length;
+            break;
+        case UAS_UI_TASK_MGMT:
+            usb_uas_task(uas, &ui);
+            ret = length;
+            break;
+        default:
+            fprintf(stderr, "%s: unknown command ui: id 0x%x\n",
+                    __func__, ui.hdr.id);
+            ret = USB_RET_STALL;
+            break;
+        }
+        break;
+    case UAS_PIPE_ID_STATUS:
+        st = QTAILQ_FIRST(&uas->results);
+        if (st == NULL) {
+            assert(uas->status == NULL);
+            uas->status = p;
+            ret = USB_RET_ASYNC;
+            break;
+        }
+        usb_packet_copy(p, &st->status, st->length);
+        ret = st->length;
+        QTAILQ_REMOVE(&uas->results, st, next);
+        g_free(st);
+        break;
+    case UAS_PIPE_ID_DATA_IN:
+    case UAS_PIPE_ID_DATA_OUT:
+        req = (p->ep->nr == UAS_PIPE_ID_DATA_IN) ? uas->datain : uas->dataout;
+        if (req == NULL) {
+            fprintf(stderr, "%s: no inflight request\n", __func__);
+            ret = USB_RET_STALL;
+            break;
+        }
+        scsi_req_ref(req->req);
+        req->data = p;
+        usb_uas_copy_data(req);
+        if (p->result == p->iov.size || req->complete) {
+            req->data = NULL;
+            ret = p->result;
+        } else {
+            req->data_async = true;
+            ret = USB_RET_ASYNC;
+        }
+        scsi_req_unref(req->req);
+        usb_uas_start_next_transfer(uas);
+        break;
+    default:
+        fprintf(stderr, "%s: invalid endpoint %d\n", __func__, p->ep->nr);
+        ret = USB_RET_STALL;
+        break;
+    }
+    return ret;
+}
+
+static void usb_uas_handle_destroy(USBDevice *dev)
+{
+    UASDevice *uas = DO_UPCAST(UASDevice, dev, dev);
+
+    qemu_bh_delete(uas->status_bh);
+}
+
+static int usb_uas_init(USBDevice *dev)
+{
+    UASDevice *uas = DO_UPCAST(UASDevice, dev, dev);
+
+    usb_desc_create_serial(dev);
+    usb_desc_init(dev);
+
+    QTAILQ_INIT(&uas->results);
+    QTAILQ_INIT(&uas->requests);
+    uas->status_bh = qemu_bh_new(usb_uas_send_status_bh, uas);
+
+    scsi_bus_new(&uas->bus, &uas->dev.qdev, &usb_uas_scsi_info);
+
+    return 0;
+}
+
+static const VMStateDescription vmstate_usb_uas = {
+    .name = "usb-uas",
+    .unmigratable = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_USB_DEVICE(dev, UASDevice),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void usb_uas_class_initfn(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    USBDeviceClass *uc = USB_DEVICE_CLASS(klass);
+
+    uc->init           = usb_uas_init;
+    uc->product_desc   = desc_strings[STR_PRODUCT];
+    uc->usb_desc       = &desc;
+    uc->cancel_packet  = usb_uas_cancel_io;
+    uc->handle_attach  = usb_desc_attach;
+    uc->handle_reset   = usb_uas_handle_reset;
+    uc->handle_control = usb_uas_handle_control;
+    uc->handle_data    = usb_uas_handle_data;
+    uc->handle_destroy = usb_uas_handle_destroy;
+    dc->fw_name = "storage";
+    dc->vmsd = &vmstate_usb_uas;
+}
+
+static TypeInfo uas_info = {
+    .name          = "usb-uas",
+    .parent        = TYPE_USB_DEVICE,
+    .instance_size = sizeof(UASDevice),
+    .class_init    = usb_uas_class_initfn,
+};
+
+static void usb_uas_register_types(void)
+{
+    type_register_static(&uas_info);
+}
+
+type_init(usb_uas_register_types)
diff --git a/hw/usb/hcd-ehci.c b/hw/usb/hcd-ehci.c
index 5298204d9d..b043e7c23e 100644
--- a/hw/usb/hcd-ehci.c
+++ b/hw/usb/hcd-ehci.c
@@ -365,6 +365,7 @@ struct EHCIQueue {
     uint32_t seen;
     uint64_t ts;
     int async;
+    int revalidate;
 
     /* cached data from guest - needs to be flushed
      * when guest removes an entry (doorbell, handshake sequence)
@@ -414,16 +415,18 @@ struct EHCIState {
      */
     QEMUTimer *frame_timer;
     QEMUBH *async_bh;
-    int astate;                        // Current state in asynchronous schedule
-    int pstate;                        // Current state in periodic schedule
+    uint32_t astate;         /* Current state in asynchronous schedule */
+    uint32_t pstate;         /* Current state in periodic schedule     */
     USBPort ports[NB_PORTS];
     USBPort *companion_ports[NB_PORTS];
     uint32_t usbsts_pending;
+    uint32_t usbsts_frindex;
     EHCIQueueHead aqueues;
     EHCIQueueHead pqueues;
 
-    uint32_t a_fetch_addr;   // which address to look at next
-    uint32_t p_fetch_addr;   // which address to look at next
+    /* which address to look at next */
+    uint32_t a_fetch_addr;
+    uint32_t p_fetch_addr;
 
     USBPacket ipacket;
     QEMUSGList isgl;
@@ -556,33 +559,45 @@ static inline void ehci_clear_usbsts(EHCIState *s, int mask)
     s->usbsts &= ~mask;
 }
 
-static inline void ehci_set_interrupt(EHCIState *s, int intr)
+/* update irq line */
+static inline void ehci_update_irq(EHCIState *s)
 {
     int level = 0;
 
-    // TODO honour interrupt threshold requests
-
-    ehci_set_usbsts(s, intr);
-
     if ((s->usbsts & USBINTR_MASK) & s->usbintr) {
         level = 1;
     }
 
+    trace_usb_ehci_irq(level, s->frindex, s->usbsts, s->usbintr);
     qemu_set_irq(s->irq, level);
 }
 
-static inline void ehci_record_interrupt(EHCIState *s, int intr)
+/* flag interrupt condition */
+static inline void ehci_raise_irq(EHCIState *s, int intr)
 {
     s->usbsts_pending |= intr;
 }
 
-static inline void ehci_commit_interrupt(EHCIState *s)
+/*
+ * Commit pending interrupts (added via ehci_raise_irq),
+ * at the rate allowed by "Interrupt Threshold Control".
+ */
+static inline void ehci_commit_irq(EHCIState *s)
 {
+    uint32_t itc;
+
     if (!s->usbsts_pending) {
         return;
     }
-    ehci_set_interrupt(s, s->usbsts_pending);
+    if (s->usbsts_frindex > s->frindex) {
+        return;
+    }
+
+    itc = (s->usbcmd >> 16) & 0xff;
+    s->usbsts |= s->usbsts_pending;
     s->usbsts_pending = 0;
+    s->usbsts_frindex = s->frindex + itc;
+    ehci_update_irq(s);
 }
 
 static void ehci_update_halt(EHCIState *s)
@@ -773,7 +788,18 @@ static EHCIQueue *ehci_find_queue_by_qh(EHCIState *ehci, uint32_t addr,
     return NULL;
 }
 
-static void ehci_queues_rip_unused(EHCIState *ehci, int async, int flush)
+static void ehci_queues_tag_unused_async(EHCIState *ehci)
+{
+    EHCIQueue *q;
+
+    QTAILQ_FOREACH(q, &ehci->aqueues, next) {
+        if (!q->seen) {
+            q->revalidate = 1;
+        }
+    }
+}
+
+static void ehci_queues_rip_unused(EHCIState *ehci, int async)
 {
     EHCIQueueHead *head = async ? &ehci->aqueues : &ehci->pqueues;
     uint64_t maxage = FRAME_TIMER_NS * ehci->maxframes * 4;
@@ -785,7 +811,7 @@ static void ehci_queues_rip_unused(EHCIState *ehci, int async, int flush)
             q->ts = ehci->last_run_ns;
             continue;
         }
-        if (!flush && ehci->last_run_ns < q->ts + maxage) {
+        if (ehci->last_run_ns < q->ts + maxage) {
             continue;
         }
         ehci_free_queue(q);
@@ -821,8 +847,9 @@ static void ehci_attach(USBPort *port)
 {
     EHCIState *s = port->opaque;
     uint32_t *portsc = &s->portsc[port->index];
+    const char *owner = (*portsc & PORTSC_POWNER) ? "comp" : "ehci";
 
-    trace_usb_ehci_port_attach(port->index, port->dev->product_desc);
+    trace_usb_ehci_port_attach(port->index, owner, port->dev->product_desc);
 
     if (*portsc & PORTSC_POWNER) {
         USBPort *companion = s->companion_ports[port->index];
@@ -834,15 +861,17 @@ static void ehci_attach(USBPort *port)
     *portsc |= PORTSC_CONNECT;
     *portsc |= PORTSC_CSC;
 
-    ehci_set_interrupt(s, USBSTS_PCD);
+    ehci_raise_irq(s, USBSTS_PCD);
+    ehci_commit_irq(s);
 }
 
 static void ehci_detach(USBPort *port)
 {
     EHCIState *s = port->opaque;
     uint32_t *portsc = &s->portsc[port->index];
+    const char *owner = (*portsc & PORTSC_POWNER) ? "comp" : "ehci";
 
-    trace_usb_ehci_port_detach(port->index);
+    trace_usb_ehci_port_detach(port->index, owner);
 
     if (*portsc & PORTSC_POWNER) {
         USBPort *companion = s->companion_ports[port->index];
@@ -862,7 +891,8 @@ static void ehci_detach(USBPort *port)
     *portsc &= ~(PORTSC_CONNECT|PORTSC_PED);
     *portsc |= PORTSC_CSC;
 
-    ehci_set_interrupt(s, USBSTS_PCD);
+    ehci_raise_irq(s, USBSTS_PCD);
+    ehci_commit_irq(s);
 }
 
 static void ehci_child_detach(USBPort *port, USBDevice *child)
@@ -889,10 +919,11 @@ static void ehci_wakeup(USBPort *port)
         USBPort *companion = s->companion_ports[port->index];
         if (companion->ops->wakeup) {
             companion->ops->wakeup(companion);
-        } else {
-            qemu_bh_schedule(s->async_bh);
         }
+        return;
     }
+
+    qemu_bh_schedule(s->async_bh);
 }
 
 static int ehci_register_companion(USBBus *bus, USBPort *ports[],
@@ -980,6 +1011,8 @@ static void ehci_reset(void *opaque)
 
     s->usbcmd = NB_MAXINTRATE << USBCMD_ITC_SH;
     s->usbsts = USBSTS_HALT;
+    s->usbsts_pending = 0;
+    s->usbsts_frindex = 0;
 
     s->astate = EST_INACTIVE;
     s->pstate = EST_INACTIVE;
@@ -1171,7 +1204,7 @@ static void ehci_mem_writel(void *ptr, target_phys_addr_t addr, uint32_t val)
         val &= USBSTS_RO_MASK;              // bits 6 through 31 are RO
         ehci_clear_usbsts(s, val);          // bits 0 through 5 are R/WC
         val = s->usbsts;
-        ehci_set_interrupt(s, 0);
+        ehci_update_irq(s);
         break;
 
     case USBINTR:
@@ -1242,6 +1275,23 @@ static inline int put_dwords(EHCIState *ehci, uint32_t addr,
     return 1;
 }
 
+/*
+ *  Write the qh back to guest physical memory.  This step isn't
+ *  in the EHCI spec but we need to do it since we don't share
+ *  physical memory with our guest VM.
+ *
+ *  The first three dwords are read-only for the EHCI, so skip them
+ *  when writing back the qh.
+ */
+static void ehci_flush_qh(EHCIQueue *q)
+{
+    uint32_t *qh = (uint32_t *) &q->qh;
+    uint32_t dwords = sizeof(EHCIqh) >> 2;
+    uint32_t addr = NLPTR_GET(q->qhaddr);
+
+    put_dwords(q->ehci, addr + 3 * sizeof(uint32_t), qh + 3, dwords - 3);
+}
+
 // 4.10.2
 
 static int ehci_qh_do_overlay(EHCIQueue *q)
@@ -1289,8 +1339,7 @@ static int ehci_qh_do_overlay(EHCIQueue *q)
     q->qh.bufptr[1] &= ~BUFPTR_CPROGMASK_MASK;
     q->qh.bufptr[2] &= ~BUFPTR_FRAMETAG_MASK;
 
-    put_dwords(q->ehci, NLPTR_GET(q->qhaddr), (uint32_t *) &q->qh,
-               sizeof(EHCIqh) >> 2);
+    ehci_flush_qh(q);
 
     return 0;
 }
@@ -1386,18 +1435,18 @@ static void ehci_execute_complete(EHCIQueue *q)
         case USB_RET_NODEV:
             q->qh.token |= (QTD_TOKEN_HALT | QTD_TOKEN_XACTERR);
             set_field(&q->qh.token, 0, QTD_TOKEN_CERR);
-            ehci_record_interrupt(q->ehci, USBSTS_ERRINT);
+            ehci_raise_irq(q->ehci, USBSTS_ERRINT);
             break;
         case USB_RET_STALL:
             q->qh.token |= QTD_TOKEN_HALT;
-            ehci_record_interrupt(q->ehci, USBSTS_ERRINT);
+            ehci_raise_irq(q->ehci, USBSTS_ERRINT);
             break;
         case USB_RET_NAK:
             set_field(&q->qh.altnext_qtd, 0, QH_ALTNEXT_NAKCNT);
             return; /* We're not done yet with this transaction */
         case USB_RET_BABBLE:
             q->qh.token |= (QTD_TOKEN_HALT | QTD_TOKEN_BABBLE);
-            ehci_record_interrupt(q->ehci, USBSTS_ERRINT);
+            ehci_raise_irq(q->ehci, USBSTS_ERRINT);
             break;
         default:
             /* should not be triggerable */
@@ -1408,7 +1457,7 @@ static void ehci_execute_complete(EHCIQueue *q)
     } else if ((p->usb_status > p->tbytes) && (p->pid == USB_TOKEN_IN)) {
         p->usb_status = USB_RET_BABBLE;
         q->qh.token |= (QTD_TOKEN_HALT | QTD_TOKEN_BABBLE);
-        ehci_record_interrupt(q->ehci, USBSTS_ERRINT);
+        ehci_raise_irq(q->ehci, USBSTS_ERRINT);
     } else {
         // TODO check 4.12 for splits
 
@@ -1422,14 +1471,14 @@ static void ehci_execute_complete(EHCIQueue *q)
         set_field(&q->qh.token, p->tbytes, QTD_TOKEN_TBYTES);
     }
     ehci_finish_transfer(q, p->usb_status);
+    usb_packet_unmap(&p->packet, &p->sgl);
     qemu_sglist_destroy(&p->sgl);
-    usb_packet_unmap(&p->packet);
 
     q->qh.token ^= QTD_TOKEN_DTOGGLE;
     q->qh.token &= ~QTD_TOKEN_ACTIVE;
 
     if (q->qh.token & QTD_TOKEN_IOC) {
-        ehci_record_interrupt(q->ehci, USBSTS_INT);
+        ehci_raise_irq(q->ehci, USBSTS_INT);
     }
 }
 
@@ -1547,7 +1596,7 @@ static int ehci_process_itd(EHCIState *ehci,
                 usb_packet_map(&ehci->ipacket, &ehci->isgl);
                 ret = usb_handle_packet(dev, &ehci->ipacket);
                 assert(ret != USB_RET_ASYNC);
-                usb_packet_unmap(&ehci->ipacket);
+                usb_packet_unmap(&ehci->ipacket, &ehci->isgl);
             } else {
                 DPRINTF("ISOCH: attempt to addess non-iso endpoint\n");
                 ret = USB_RET_NAK;
@@ -1564,12 +1613,12 @@ static int ehci_process_itd(EHCIState *ehci,
                     /* 3.3.2: XACTERR is only allowed on IN transactions */
                     if (dir) {
                         itd->transact[i] |= ITD_XACT_XACTERR;
-                        ehci_record_interrupt(ehci, USBSTS_ERRINT);
+                        ehci_raise_irq(ehci, USBSTS_ERRINT);
                     }
                     break;
                 case USB_RET_BABBLE:
                     itd->transact[i] |= ITD_XACT_BABBLE;
-                    ehci_record_interrupt(ehci, USBSTS_ERRINT);
+                    ehci_raise_irq(ehci, USBSTS_ERRINT);
                     break;
                 case USB_RET_NAK:
                     /* no data for us, so do a zero-length transfer */
@@ -1587,7 +1636,7 @@ static int ehci_process_itd(EHCIState *ehci,
                 }
             }
             if (itd->transact[i] & ITD_XACT_IOC) {
-                ehci_record_interrupt(ehci, USBSTS_INT);
+                ehci_raise_irq(ehci, USBSTS_INT);
             }
             itd->transact[i] &= ~ITD_XACT_ACTIVE;
         }
@@ -1596,23 +1645,6 @@ static int ehci_process_itd(EHCIState *ehci,
 }
 
 
-/*
- *  Write the qh back to guest physical memory.  This step isn't
- *  in the EHCI spec but we need to do it since we don't share
- *  physical memory with our guest VM.
- *
- *  The first three dwords are read-only for the EHCI, so skip them
- *  when writing back the qh.
- */
-static void ehci_flush_qh(EHCIQueue *q)
-{
-    uint32_t *qh = (uint32_t *) &q->qh;
-    uint32_t dwords = sizeof(EHCIqh) >> 2;
-    uint32_t addr = NLPTR_GET(q->qhaddr);
-
-    put_dwords(q->ehci, addr + 3 * sizeof(uint32_t), qh + 3, dwords - 3);
-}
-
 /*  This state is the entry point for asynchronous schedule
  *  processing.  Entry here consitutes a EHCI start event state (4.8.5)
  */
@@ -1628,7 +1660,7 @@ static int ehci_state_waitlisthead(EHCIState *ehci,  int async)
         ehci_set_usbsts(ehci, USBSTS_REC);
     }
 
-    ehci_queues_rip_unused(ehci, async, 0);
+    ehci_queues_rip_unused(ehci, async);
 
     /*  Find the head of the list (4.9.1.1) */
     for(i = 0; i < MAX_QH; i++) {
@@ -1713,6 +1745,7 @@ static EHCIQueue *ehci_state_fetchqh(EHCIState *ehci, int async)
     EHCIPacket *p;
     uint32_t entry, devaddr;
     EHCIQueue *q;
+    EHCIqh qh;
 
     entry = ehci_get_fetch_addr(ehci, async);
     q = ehci_find_queue_by_qh(ehci, entry, async);
@@ -1730,7 +1763,17 @@ static EHCIQueue *ehci_state_fetchqh(EHCIState *ehci, int async)
     }
 
     get_dwords(ehci, NLPTR_GET(q->qhaddr),
-               (uint32_t *) &q->qh, sizeof(EHCIqh) >> 2);
+               (uint32_t *) &qh, sizeof(EHCIqh) >> 2);
+    if (q->revalidate && (q->qh.epchar      != qh.epchar ||
+                          q->qh.epcap       != qh.epcap  ||
+                          q->qh.current_qtd != qh.current_qtd)) {
+        ehci_free_queue(q);
+        q = ehci_alloc_queue(ehci, entry, async);
+        q->seen++;
+        p = NULL;
+    }
+    q->qh = qh;
+    q->revalidate = 0;
     ehci_trace_qh(q, NLPTR_GET(q->qhaddr), &q->qh);
 
     devaddr = get_field(q->qh.epchar, QH_EPCHAR_DEVADDR);
@@ -2067,6 +2110,7 @@ out:
 static int ehci_state_writeback(EHCIQueue *q)
 {
     EHCIPacket *p = QTAILQ_FIRST(&q->packets);
+    uint32_t *qtd, addr;
     int again = 0;
 
     /*  Write back the QTD from the QH area */
@@ -2074,8 +2118,9 @@ static int ehci_state_writeback(EHCIQueue *q)
     assert(p->qtdaddr == q->qtdaddr);
 
     ehci_trace_qtd(q, NLPTR_GET(p->qtdaddr), (EHCIqtd *) &q->qh.next_qtd);
-    put_dwords(q->ehci, NLPTR_GET(p->qtdaddr), (uint32_t *) &q->qh.next_qtd,
-               sizeof(EHCIqtd) >> 2);
+    qtd = (uint32_t *) &q->qh.next_qtd;
+    addr = NLPTR_GET(p->qtdaddr);
+    put_dwords(q->ehci, addr + 2 * sizeof(uint32_t), qtd + 2, 2);
     ehci_free_packet(p);
 
     /*
@@ -2179,8 +2224,6 @@ static void ehci_advance_state(EHCIState *ehci, int async)
         }
     }
     while (again);
-
-    ehci_commit_interrupt(ehci);
 }
 
 static void ehci_advance_async_state(EHCIState *ehci)
@@ -2223,10 +2266,10 @@ static void ehci_advance_async_state(EHCIState *ehci)
          */
         if (ehci->usbcmd & USBCMD_IAAD) {
             /* Remove all unseen qhs from the async qhs queue */
-            ehci_queues_rip_unused(ehci, async, 1);
+            ehci_queues_tag_unused_async(ehci);
             DPRINTF("ASYNC: doorbell request acknowledged\n");
             ehci->usbcmd &= ~USBCMD_IAAD;
-            ehci_set_interrupt(ehci, USBSTS_IAA);
+            ehci_raise_irq(ehci, USBSTS_IAA);
         }
         break;
 
@@ -2276,7 +2319,7 @@ static void ehci_advance_periodic_state(EHCIState *ehci)
         ehci_set_fetch_addr(ehci, async,entry);
         ehci_set_state(ehci, async, EST_FETCHENTRY);
         ehci_advance_state(ehci, async);
-        ehci_queues_rip_unused(ehci, async, 0);
+        ehci_queues_rip_unused(ehci, async);
         break;
 
     default:
@@ -2299,12 +2342,17 @@ static void ehci_update_frindex(EHCIState *ehci, int frames)
         ehci->frindex += 8;
 
         if (ehci->frindex == 0x00002000) {
-            ehci_set_interrupt(ehci, USBSTS_FLR);
+            ehci_raise_irq(ehci, USBSTS_FLR);
         }
 
         if (ehci->frindex == 0x00004000) {
-            ehci_set_interrupt(ehci, USBSTS_FLR);
+            ehci_raise_irq(ehci, USBSTS_FLR);
             ehci->frindex = 0;
+            if (ehci->usbsts_frindex > 0x00004000) {
+                ehci->usbsts_frindex -= 0x00004000;
+            } else {
+                ehci->usbsts_frindex = 0;
+            }
         }
     }
 }
@@ -2312,7 +2360,7 @@ static void ehci_update_frindex(EHCIState *ehci, int frames)
 static void ehci_frame_timer(void *opaque)
 {
     EHCIState *ehci = opaque;
-    int schedules = 0;
+    int need_timer = 0;
     int64_t expire_time, t_now;
     uint64_t ns_elapsed;
     int frames, skipped_frames;
@@ -2323,8 +2371,8 @@ static void ehci_frame_timer(void *opaque)
     frames = ns_elapsed / FRAME_TIMER_NS;
 
     if (ehci_periodic_enabled(ehci) || ehci->pstate != EST_INACTIVE) {
-        schedules++;
-        expire_time = t_now + (get_ticks_per_sec() / FRAME_TIMER_FREQ);
+        need_timer++;
+        ehci->async_stepdown = 0;
 
         if (frames > ehci->maxframes) {
             skipped_frames = frames - ehci->maxframes;
@@ -2343,8 +2391,6 @@ static void ehci_frame_timer(void *opaque)
         if (ehci->async_stepdown < ehci->maxframes / 2) {
             ehci->async_stepdown++;
         }
-        expire_time = t_now + (get_ticks_per_sec()
-                               * ehci->async_stepdown / FRAME_TIMER_FREQ);
         ehci_update_frindex(ehci, frames);
         ehci->last_run_ns += FRAME_TIMER_NS * frames;
     }
@@ -2353,11 +2399,19 @@ static void ehci_frame_timer(void *opaque)
      *  called
      */
     if (ehci_async_enabled(ehci) || ehci->astate != EST_INACTIVE) {
-        schedules++;
-        qemu_bh_schedule(ehci->async_bh);
+        need_timer++;
+        ehci_advance_async_state(ehci);
     }
 
-    if (schedules) {
+    ehci_commit_irq(ehci);
+    if (ehci->usbsts_pending) {
+        need_timer++;
+        ehci->async_stepdown = 0;
+    }
+
+    if (need_timer) {
+        expire_time = t_now + (get_ticks_per_sec()
+                               * (ehci->async_stepdown+1) / FRAME_TIMER_FREQ);
         qemu_mod_timer(ehci->frame_timer, expire_time);
     }
 }
@@ -2390,9 +2444,58 @@ static USBBusOps ehci_bus_ops = {
     .register_companion = ehci_register_companion,
 };
 
+static int usb_ehci_post_load(void *opaque, int version_id)
+{
+    EHCIState *s = opaque;
+    int i;
+
+    for (i = 0; i < NB_PORTS; i++) {
+        USBPort *companion = s->companion_ports[i];
+        if (companion == NULL) {
+            continue;
+        }
+        if (s->portsc[i] & PORTSC_POWNER) {
+            companion->dev = s->ports[i].dev;
+        } else {
+            companion->dev = NULL;
+        }
+    }
+
+    return 0;
+}
+
 static const VMStateDescription vmstate_ehci = {
-    .name = "ehci",
-    .unmigratable = 1,
+    .name        = "ehci",
+    .version_id  = 1,
+    .post_load   = usb_ehci_post_load,
+    .fields      = (VMStateField[]) {
+        VMSTATE_PCI_DEVICE(dev, EHCIState),
+        /* mmio registers */
+        VMSTATE_UINT32(usbcmd, EHCIState),
+        VMSTATE_UINT32(usbsts, EHCIState),
+        VMSTATE_UINT32(usbintr, EHCIState),
+        VMSTATE_UINT32(frindex, EHCIState),
+        VMSTATE_UINT32(ctrldssegment, EHCIState),
+        VMSTATE_UINT32(periodiclistbase, EHCIState),
+        VMSTATE_UINT32(asynclistaddr, EHCIState),
+        VMSTATE_UINT32(configflag, EHCIState),
+        VMSTATE_UINT32(portsc[0], EHCIState),
+        VMSTATE_UINT32(portsc[1], EHCIState),
+        VMSTATE_UINT32(portsc[2], EHCIState),
+        VMSTATE_UINT32(portsc[3], EHCIState),
+        VMSTATE_UINT32(portsc[4], EHCIState),
+        VMSTATE_UINT32(portsc[5], EHCIState),
+        /* frame timer */
+        VMSTATE_TIMER(frame_timer, EHCIState),
+        VMSTATE_UINT64(last_run_ns, EHCIState),
+        VMSTATE_UINT32(async_stepdown, EHCIState),
+        /* schedule state */
+        VMSTATE_UINT32(astate, EHCIState),
+        VMSTATE_UINT32(pstate, EHCIState),
+        VMSTATE_UINT32(a_fetch_addr, EHCIState),
+        VMSTATE_UINT32(p_fetch_addr, EHCIState),
+        VMSTATE_END_OF_LIST()
+    }
 };
 
 static Property ehci_properties[] = {
@@ -2504,6 +2607,7 @@ static int usb_ehci_initfn(PCIDevice *dev)
     s->async_bh = qemu_bh_new(ehci_async_bh, s);
     QTAILQ_INIT(&s->aqueues);
     QTAILQ_INIT(&s->pqueues);
+    usb_packet_init(&s->ipacket);
 
     qemu_register_reset(ehci_reset, s);
 
diff --git a/hw/usb/hcd-ohci.c b/hw/usb/hcd-ohci.c
index 1a1cc88b1f..844e7ed166 100644
--- a/hw/usb/hcd-ohci.c
+++ b/hw/usb/hcd-ohci.c
@@ -31,7 +31,7 @@
 #include "hw/usb.h"
 #include "hw/pci.h"
 #include "hw/sysbus.h"
-#include "hw/qdev-addr.h"
+#include "hw/qdev-dma.h"
 
 //#define DEBUG_OHCI
 /* Dump packet contents.  */
@@ -62,6 +62,7 @@ typedef struct {
     USBBus bus;
     qemu_irq irq;
     MemoryRegion mem;
+    DMAContext *dma;
     int num_ports;
     const char *name;
 
@@ -104,7 +105,7 @@ typedef struct {
     uint32_t htest;
 
     /* SM501 local memory offset */
-    target_phys_addr_t localmem_base;
+    dma_addr_t localmem_base;
 
     /* Active packets.  */
     uint32_t old_ctl;
@@ -482,14 +483,14 @@ static void ohci_reset(void *opaque)
 
 /* Get an array of dwords from main memory */
 static inline int get_dwords(OHCIState *ohci,
-                             uint32_t addr, uint32_t *buf, int num)
+                             dma_addr_t addr, uint32_t *buf, int num)
 {
     int i;
 
     addr += ohci->localmem_base;
 
     for (i = 0; i < num; i++, buf++, addr += sizeof(*buf)) {
-        cpu_physical_memory_read(addr, buf, sizeof(*buf));
+        dma_memory_read(ohci->dma, addr, buf, sizeof(*buf));
         *buf = le32_to_cpu(*buf);
     }
 
@@ -498,7 +499,7 @@ static inline int get_dwords(OHCIState *ohci,
 
 /* Put an array of dwords in to main memory */
 static inline int put_dwords(OHCIState *ohci,
-                             uint32_t addr, uint32_t *buf, int num)
+                             dma_addr_t addr, uint32_t *buf, int num)
 {
     int i;
 
@@ -506,7 +507,7 @@ static inline int put_dwords(OHCIState *ohci,
 
     for (i = 0; i < num; i++, buf++, addr += sizeof(*buf)) {
         uint32_t tmp = cpu_to_le32(*buf);
-        cpu_physical_memory_write(addr, &tmp, sizeof(tmp));
+        dma_memory_write(ohci->dma, addr, &tmp, sizeof(tmp));
     }
 
     return 1;
@@ -514,14 +515,14 @@ static inline int put_dwords(OHCIState *ohci,
 
 /* Get an array of words from main memory */
 static inline int get_words(OHCIState *ohci,
-                            uint32_t addr, uint16_t *buf, int num)
+                            dma_addr_t addr, uint16_t *buf, int num)
 {
     int i;
 
     addr += ohci->localmem_base;
 
     for (i = 0; i < num; i++, buf++, addr += sizeof(*buf)) {
-        cpu_physical_memory_read(addr, buf, sizeof(*buf));
+        dma_memory_read(ohci->dma, addr, buf, sizeof(*buf));
         *buf = le16_to_cpu(*buf);
     }
 
@@ -530,7 +531,7 @@ static inline int get_words(OHCIState *ohci,
 
 /* Put an array of words in to main memory */
 static inline int put_words(OHCIState *ohci,
-                            uint32_t addr, uint16_t *buf, int num)
+                            dma_addr_t addr, uint16_t *buf, int num)
 {
     int i;
 
@@ -538,40 +539,40 @@ static inline int put_words(OHCIState *ohci,
 
     for (i = 0; i < num; i++, buf++, addr += sizeof(*buf)) {
         uint16_t tmp = cpu_to_le16(*buf);
-        cpu_physical_memory_write(addr, &tmp, sizeof(tmp));
+        dma_memory_write(ohci->dma, addr, &tmp, sizeof(tmp));
     }
 
     return 1;
 }
 
 static inline int ohci_read_ed(OHCIState *ohci,
-                               uint32_t addr, struct ohci_ed *ed)
+                               dma_addr_t addr, struct ohci_ed *ed)
 {
     return get_dwords(ohci, addr, (uint32_t *)ed, sizeof(*ed) >> 2);
 }
 
 static inline int ohci_read_td(OHCIState *ohci,
-                               uint32_t addr, struct ohci_td *td)
+                               dma_addr_t addr, struct ohci_td *td)
 {
     return get_dwords(ohci, addr, (uint32_t *)td, sizeof(*td) >> 2);
 }
 
 static inline int ohci_read_iso_td(OHCIState *ohci,
-                                   uint32_t addr, struct ohci_iso_td *td)
+                                   dma_addr_t addr, struct ohci_iso_td *td)
 {
     return (get_dwords(ohci, addr, (uint32_t *)td, 4) &&
             get_words(ohci, addr + 16, td->offset, 8));
 }
 
 static inline int ohci_read_hcca(OHCIState *ohci,
-                                 uint32_t addr, struct ohci_hcca *hcca)
+                                 dma_addr_t addr, struct ohci_hcca *hcca)
 {
-    cpu_physical_memory_read(addr + ohci->localmem_base, hcca, sizeof(*hcca));
+    dma_memory_read(ohci->dma, addr + ohci->localmem_base, hcca, sizeof(*hcca));
     return 1;
 }
 
 static inline int ohci_put_ed(OHCIState *ohci,
-                              uint32_t addr, struct ohci_ed *ed)
+                              dma_addr_t addr, struct ohci_ed *ed)
 {
     /* ed->tail is under control of the HCD.
      * Since just ed->head is changed by HC, just write back this
@@ -583,64 +584,63 @@ static inline int ohci_put_ed(OHCIState *ohci,
 }
 
 static inline int ohci_put_td(OHCIState *ohci,
-                              uint32_t addr, struct ohci_td *td)
+                              dma_addr_t addr, struct ohci_td *td)
 {
     return put_dwords(ohci, addr, (uint32_t *)td, sizeof(*td) >> 2);
 }
 
 static inline int ohci_put_iso_td(OHCIState *ohci,
-                                  uint32_t addr, struct ohci_iso_td *td)
+                                  dma_addr_t addr, struct ohci_iso_td *td)
 {
     return (put_dwords(ohci, addr, (uint32_t *)td, 4) &&
             put_words(ohci, addr + 16, td->offset, 8));
 }
 
 static inline int ohci_put_hcca(OHCIState *ohci,
-                                uint32_t addr, struct ohci_hcca *hcca)
+                                dma_addr_t addr, struct ohci_hcca *hcca)
 {
-    cpu_physical_memory_write(addr + ohci->localmem_base + HCCA_WRITEBACK_OFFSET,
-                              (char *)hcca + HCCA_WRITEBACK_OFFSET,
-                              HCCA_WRITEBACK_SIZE);
+    dma_memory_write(ohci->dma,
+                     addr + ohci->localmem_base + HCCA_WRITEBACK_OFFSET,
+                     (char *)hcca + HCCA_WRITEBACK_OFFSET,
+                     HCCA_WRITEBACK_SIZE);
     return 1;
 }
 
 /* Read/Write the contents of a TD from/to main memory.  */
 static void ohci_copy_td(OHCIState *ohci, struct ohci_td *td,
-                         uint8_t *buf, int len, int write)
+                         uint8_t *buf, int len, DMADirection dir)
 {
-    uint32_t ptr;
-    uint32_t n;
+    dma_addr_t ptr, n;
 
     ptr = td->cbp;
     n = 0x1000 - (ptr & 0xfff);
     if (n > len)
         n = len;
-    cpu_physical_memory_rw(ptr + ohci->localmem_base, buf, n, write);
+    dma_memory_rw(ohci->dma, ptr + ohci->localmem_base, buf, n, dir);
     if (n == len)
         return;
     ptr = td->be & ~0xfffu;
     buf += n;
-    cpu_physical_memory_rw(ptr + ohci->localmem_base, buf, len - n, write);
+    dma_memory_rw(ohci->dma, ptr + ohci->localmem_base, buf, len - n, dir);
 }
 
 /* Read/Write the contents of an ISO TD from/to main memory.  */
 static void ohci_copy_iso_td(OHCIState *ohci,
                              uint32_t start_addr, uint32_t end_addr,
-                             uint8_t *buf, int len, int write)
+                             uint8_t *buf, int len, DMADirection dir)
 {
-    uint32_t ptr;
-    uint32_t n;
+    dma_addr_t ptr, n;
 
     ptr = start_addr;
     n = 0x1000 - (ptr & 0xfff);
     if (n > len)
         n = len;
-    cpu_physical_memory_rw(ptr + ohci->localmem_base, buf, n, write);
+    dma_memory_rw(ohci->dma, ptr + ohci->localmem_base, buf, n, dir);
     if (n == len)
         return;
     ptr = end_addr & ~0xfffu;
     buf += n;
-    cpu_physical_memory_rw(ptr + ohci->localmem_base, buf, len - n, write);
+    dma_memory_rw(ohci->dma, ptr + ohci->localmem_base, buf, len - n, dir);
 }
 
 static void ohci_process_lists(OHCIState *ohci, int completion);
@@ -803,7 +803,8 @@ static int ohci_service_iso_td(OHCIState *ohci, struct ohci_ed *ed,
     }
 
     if (len && dir != OHCI_TD_DIR_IN) {
-        ohci_copy_iso_td(ohci, start_addr, end_addr, ohci->usb_buf, len, 0);
+        ohci_copy_iso_td(ohci, start_addr, end_addr, ohci->usb_buf, len,
+                         DMA_DIRECTION_TO_DEVICE);
     }
 
     if (completion) {
@@ -827,7 +828,8 @@ static int ohci_service_iso_td(OHCIState *ohci, struct ohci_ed *ed,
     /* Writeback */
     if (dir == OHCI_TD_DIR_IN && ret >= 0 && ret <= len) {
         /* IN transfer succeeded */
-        ohci_copy_iso_td(ohci, start_addr, end_addr, ohci->usb_buf, ret, 1);
+        ohci_copy_iso_td(ohci, start_addr, end_addr, ohci->usb_buf, ret,
+                         DMA_DIRECTION_FROM_DEVICE);
         OHCI_SET_BM(iso_td.offset[relative_frame_number], TD_PSW_CC,
                     OHCI_CC_NOERROR);
         OHCI_SET_BM(iso_td.offset[relative_frame_number], TD_PSW_SIZE, ret);
@@ -971,7 +973,8 @@ static int ohci_service_td(OHCIState *ohci, struct ohci_ed *ed)
                 pktlen = len;
             }
             if (!completion) {
-                ohci_copy_td(ohci, &td, ohci->usb_buf, pktlen, 0);
+                ohci_copy_td(ohci, &td, ohci->usb_buf, pktlen,
+                             DMA_DIRECTION_TO_DEVICE);
             }
         }
     }
@@ -1021,7 +1024,8 @@ static int ohci_service_td(OHCIState *ohci, struct ohci_ed *ed)
     }
     if (ret >= 0) {
         if (dir == OHCI_TD_DIR_IN) {
-            ohci_copy_td(ohci, &td, ohci->usb_buf, ret, 1);
+            ohci_copy_td(ohci, &td, ohci->usb_buf, ret,
+                         DMA_DIRECTION_FROM_DEVICE);
 #ifdef DEBUG_PACKET
             DPRINTF("  data:");
             for (i = 0; i < ret; i++)
@@ -1748,11 +1752,14 @@ static USBBusOps ohci_bus_ops = {
 };
 
 static int usb_ohci_init(OHCIState *ohci, DeviceState *dev,
-                         int num_ports, uint32_t localmem_base,
-                         char *masterbus, uint32_t firstport)
+                         int num_ports, dma_addr_t localmem_base,
+                         char *masterbus, uint32_t firstport,
+                         DMAContext *dma)
 {
     int i;
 
+    ohci->dma = dma;
+
     if (usb_frame_time == 0) {
 #ifdef OHCI_TIME_WARP
         usb_frame_time = get_ticks_per_sec();
@@ -1817,7 +1824,8 @@ static int usb_ohci_initfn_pci(struct PCIDevice *dev)
     ohci->pci_dev.config[PCI_INTERRUPT_PIN] = 0x01; /* interrupt pin A */
 
     if (usb_ohci_init(&ohci->state, &dev->qdev, ohci->num_ports, 0,
-                      ohci->masterbus, ohci->firstport) != 0) {
+                      ohci->masterbus, ohci->firstport,
+                      pci_dma_context(dev)) != 0) {
         return -1;
     }
     ohci->state.irq = ohci->pci_dev.irq[0];
@@ -1831,7 +1839,7 @@ typedef struct {
     SysBusDevice busdev;
     OHCIState ohci;
     uint32_t num_ports;
-    target_phys_addr_t dma_offset;
+    dma_addr_t dma_offset;
 } OHCISysBusState;
 
 static int ohci_init_pxa(SysBusDevice *dev)
@@ -1839,7 +1847,8 @@ static int ohci_init_pxa(SysBusDevice *dev)
     OHCISysBusState *s = FROM_SYSBUS(OHCISysBusState, dev);
 
     /* Cannot fail as we pass NULL for masterbus */
-    usb_ohci_init(&s->ohci, &dev->qdev, s->num_ports, s->dma_offset, NULL, 0);
+    usb_ohci_init(&s->ohci, &dev->qdev, s->num_ports, s->dma_offset, NULL, 0,
+                  NULL);
     sysbus_init_irq(dev, &s->ohci.irq);
     sysbus_init_mmio(dev, &s->ohci.mem);
 
@@ -1875,7 +1884,7 @@ static TypeInfo ohci_pci_info = {
 
 static Property ohci_sysbus_properties[] = {
     DEFINE_PROP_UINT32("num-ports", OHCISysBusState, num_ports, 3),
-    DEFINE_PROP_TADDR("dma-offset", OHCISysBusState, dma_offset, 3),
+    DEFINE_PROP_DMAADDR("dma-offset", OHCISysBusState, dma_offset, 3),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/hw/usb/hcd-uhci.c b/hw/usb/hcd-uhci.c
index 9871e24f50..1ace2a41da 100644
--- a/hw/usb/hcd-uhci.c
+++ b/hw/usb/hcd-uhci.c
@@ -292,10 +292,10 @@ static void uhci_async_cancel_device(UHCIState *s, USBDevice *dev)
 
 static void uhci_async_cancel_all(UHCIState *s)
 {
-    UHCIQueue *queue;
+    UHCIQueue *queue, *nq;
     UHCIAsync *curr, *n;
 
-    QTAILQ_FOREACH(queue, &s->queues, next) {
+    QTAILQ_FOREACH_SAFE(queue, &s->queues, next, nq) {
         QTAILQ_FOREACH_SAFE(curr, &queue->asyncs, next, n) {
             uhci_async_unlink(curr);
             uhci_async_cancel(curr);
@@ -388,11 +388,23 @@ static const VMStateDescription vmstate_uhci_port = {
     }
 };
 
+static int uhci_post_load(void *opaque, int version_id)
+{
+    UHCIState *s = opaque;
+
+    if (version_id < 2) {
+        s->expire_time = qemu_get_clock_ns(vm_clock) +
+            (get_ticks_per_sec() / FRAME_TIMER_FREQ);
+    }
+    return 0;
+}
+
 static const VMStateDescription vmstate_uhci = {
     .name = "uhci",
     .version_id = 2,
     .minimum_version_id = 1,
     .minimum_version_id_old = 1,
+    .post_load = uhci_post_load,
     .fields      = (VMStateField []) {
         VMSTATE_PCI_DEVICE(dev, UHCIState),
         VMSTATE_UINT8_EQUAL(num_ports_vmstate, UHCIState),
@@ -871,7 +883,7 @@ static int uhci_handle_td(UHCIState *s, uint32_t addr, UHCI_TD *td,
 
 done:
     len = uhci_complete_td(s, td, async, int_mask);
-    usb_packet_unmap(&async->packet);
+    usb_packet_unmap(&async->packet, &async->sgl);
     uhci_async_free(async);
     return len;
 }
@@ -1257,12 +1269,11 @@ static int usb_uhci_vt82c686b_initfn(PCIDevice *dev)
     return usb_uhci_common_initfn(dev);
 }
 
-static int usb_uhci_exit(PCIDevice *dev)
+static void usb_uhci_exit(PCIDevice *dev)
 {
     UHCIState *s = DO_UPCAST(UHCIState, dev, dev);
 
     memory_region_destroy(&s->io_bar);
-    return 0;
 }
 
 static Property uhci_properties[] = {
diff --git a/hw/usb/host-linux.c b/hw/usb/host-linux.c
index a95b0eda55..d55be878ad 100644
--- a/hw/usb/host-linux.c
+++ b/hw/usb/host-linux.c
@@ -111,6 +111,7 @@ typedef struct USBHostDevice {
     uint32_t  iso_urb_count;
     uint32_t  options;
     Notifier  exit;
+    QEMUBH    *bh;
 
     struct endp_data ep_in[USB_MAX_ENDPOINTS];
     struct endp_data ep_out[USB_MAX_ENDPOINTS];
@@ -212,7 +213,7 @@ static int is_iso_started(USBHostDevice *s, int pid, int ep)
 
 static void clear_iso_started(USBHostDevice *s, int pid, int ep)
 {
-    trace_usb_host_ep_stop_iso(s->bus_num, s->addr, ep);
+    trace_usb_host_iso_stop(s->bus_num, s->addr, ep);
     get_endp(s, pid, ep)->iso_started = 0;
 }
 
@@ -220,7 +221,7 @@ static void set_iso_started(USBHostDevice *s, int pid, int ep)
 {
     struct endp_data *e = get_endp(s, pid, ep);
 
-    trace_usb_host_ep_start_iso(s->bus_num, s->addr, ep);
+    trace_usb_host_iso_start(s->bus_num, s->addr, ep);
     if (!e->iso_started) {
         e->iso_started = 1;
         e->inflight = 0;
@@ -318,7 +319,8 @@ static void async_complete(void *opaque)
         if (r < 0) {
             if (errno == EAGAIN) {
                 if (urbs > 2) {
-                    fprintf(stderr, "husb: %d iso urbs finished at once\n", urbs);
+                    /* indicates possible latency issues */
+                    trace_usb_host_iso_many_urbs(s->bus_num, s->addr, urbs);
                 }
                 return;
             }
@@ -351,7 +353,8 @@ static void async_complete(void *opaque)
             urbs++;
             inflight = change_iso_inflight(s, pid, ep, -1);
             if (inflight == 0 && is_iso_started(s, pid, ep)) {
-                fprintf(stderr, "husb: out of buffers for iso stream\n");
+                /* can be latency issues, or simply end of stream */
+                trace_usb_host_iso_out_of_bufs(s->bus_num, s->addr, ep);
             }
             continue;
         }
@@ -1135,7 +1138,7 @@ static int usb_linux_update_endp_table(USBHostDevice *s)
     USBDescriptor *d;
     bool active = false;
 
-    usb_ep_init(&s->dev);
+    usb_ep_reset(&s->dev);
 
     for (i = 0;; i += d->bLength) {
         if (i+2 >= s->descr_len) {
@@ -1238,7 +1241,7 @@ static int usb_linux_update_endp_table(USBHostDevice *s)
     return 0;
 
 error:
-    usb_ep_init(&s->dev);
+    usb_ep_reset(&s->dev);
     return 1;
 }
 
@@ -1325,6 +1328,7 @@ static int usb_host_open(USBHostDevice *dev, int bus_num,
         goto fail;
     }
 
+    usb_ep_init(&dev->dev);
     ret = usb_linux_update_endp_table(dev);
     if (ret) {
         goto fail;
@@ -1421,6 +1425,43 @@ static void usb_host_exit_notifier(struct Notifier *n, void *data)
     }
 }
 
+/*
+ * This is *NOT* about restoring state.  We have absolutely no idea
+ * what state the host device is in at the moment and whenever it is
+ * still present in the first place.  Attemping to contine where we
+ * left off is impossible.
+ *
+ * What we are going to to to here is emulate a surprise removal of
+ * the usb device passed through, then kick host scan so the device
+ * will get re-attached (and re-initialized by the guest) in case it
+ * is still present.
+ *
+ * As the device removal will change the state of other devices (usb
+ * host controller, most likely interrupt controller too) we have to
+ * wait with it until *all* vmstate is loaded.  Thus post_load just
+ * kicks a bottom half which then does the actual work.
+ */
+static void usb_host_post_load_bh(void *opaque)
+{
+    USBHostDevice *dev = opaque;
+
+    if (dev->fd != -1) {
+        usb_host_close(dev);
+    }
+    if (dev->dev.attached) {
+        usb_device_detach(&dev->dev);
+    }
+    usb_host_auto_check(NULL);
+}
+
+static int usb_host_post_load(void *opaque, int version_id)
+{
+    USBHostDevice *dev = opaque;
+
+    qemu_bh_schedule(dev->bh);
+    return 0;
+}
+
 static int usb_host_initfn(USBDevice *dev)
 {
     USBHostDevice *s = DO_UPCAST(USBHostDevice, dev, dev);
@@ -1432,6 +1473,7 @@ static int usb_host_initfn(USBDevice *dev)
     QTAILQ_INSERT_TAIL(&hostdevs, s, next);
     s->exit.notify = usb_host_exit_notifier;
     qemu_add_exit_notifier(&s->exit);
+    s->bh = qemu_bh_new(usb_host_post_load_bh, s);
     usb_host_auto_check(NULL);
 
     if (s->match.bus_num != 0 && s->match.port != NULL) {
@@ -1443,7 +1485,13 @@ static int usb_host_initfn(USBDevice *dev)
 
 static const VMStateDescription vmstate_usb_host = {
     .name = "usb-host",
-    .unmigratable = 1,
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .post_load = usb_host_post_load,
+    .fields = (VMStateField[]) {
+        VMSTATE_USB_DEVICE(dev, USBHostDevice),
+        VMSTATE_END_OF_LIST()
+    }
 };
 
 static Property usb_host_dev_properties[] = {
@@ -1737,25 +1785,27 @@ static void usb_host_auto_check(void *unused)
     struct USBHostDevice *s;
     int unconnected = 0;
 
-    usb_host_scan(NULL, usb_host_auto_scan);
+    if (runstate_is_running()) {
+        usb_host_scan(NULL, usb_host_auto_scan);
 
-    QTAILQ_FOREACH(s, &hostdevs, next) {
-        if (s->fd == -1) {
-            unconnected++;
-        }
-        if (s->seen == 0) {
-            s->errcount = 0;
+        QTAILQ_FOREACH(s, &hostdevs, next) {
+            if (s->fd == -1) {
+                unconnected++;
+            }
+            if (s->seen == 0) {
+                s->errcount = 0;
+            }
+            s->seen = 0;
         }
-        s->seen = 0;
-    }
 
-    if (unconnected == 0) {
-        /* nothing to watch */
-        if (usb_auto_timer) {
-            qemu_del_timer(usb_auto_timer);
-            trace_usb_host_auto_scan_disabled();
+        if (unconnected == 0) {
+            /* nothing to watch */
+            if (usb_auto_timer) {
+                qemu_del_timer(usb_auto_timer);
+                trace_usb_host_auto_scan_disabled();
+            }
+            return;
         }
-        return;
     }
 
     if (!usb_auto_timer) {
diff --git a/hw/usb/libhw.c b/hw/usb/libhw.c
index 2462351389..c0de30ea88 100644
--- a/hw/usb/libhw.c
+++ b/hw/usb/libhw.c
@@ -26,15 +26,15 @@
 
 int usb_packet_map(USBPacket *p, QEMUSGList *sgl)
 {
-    int is_write = (p->pid == USB_TOKEN_IN);
-    target_phys_addr_t len;
+    DMADirection dir = (p->pid == USB_TOKEN_IN) ?
+        DMA_DIRECTION_FROM_DEVICE : DMA_DIRECTION_TO_DEVICE;
+    dma_addr_t len;
     void *mem;
     int i;
 
     for (i = 0; i < sgl->nsg; i++) {
         len = sgl->sg[i].len;
-        mem = cpu_physical_memory_map(sgl->sg[i].base, &len,
-                                      is_write);
+        mem = dma_memory_map(sgl->dma, sgl->sg[i].base, &len, dir);
         if (!mem) {
             goto err;
         }
@@ -46,18 +46,19 @@ int usb_packet_map(USBPacket *p, QEMUSGList *sgl)
     return 0;
 
 err:
-    usb_packet_unmap(p);
+    usb_packet_unmap(p, sgl);
     return -1;
 }
 
-void usb_packet_unmap(USBPacket *p)
+void usb_packet_unmap(USBPacket *p, QEMUSGList *sgl)
 {
-    int is_write = (p->pid == USB_TOKEN_IN);
+    DMADirection dir = (p->pid == USB_TOKEN_IN) ?
+        DMA_DIRECTION_FROM_DEVICE : DMA_DIRECTION_TO_DEVICE;
     int i;
 
     for (i = 0; i < p->iov.niov; i++) {
-        cpu_physical_memory_unmap(p->iov.iov[i].iov_base,
-                                  p->iov.iov[i].iov_len, is_write,
-                                  p->iov.iov[i].iov_len);
+        dma_memory_unmap(sgl->dma, p->iov.iov[i].iov_base,
+                         p->iov.iov[i].iov_len, dir,
+                         p->iov.iov[i].iov_len);
     }
 }
diff --git a/hw/usb/redirect.c b/hw/usb/redirect.c
index d949f040d5..10b4fbb3a7 100644
--- a/hw/usb/redirect.c
+++ b/hw/usb/redirect.c
@@ -1033,6 +1033,8 @@ static int usbredir_handle_status(USBRedirDevice *dev,
     case usb_redir_inval:
         WARNING("got invalid param error from usb-host?\n");
         return USB_RET_NAK;
+    case usb_redir_babble:
+        return USB_RET_BABBLE;
     case usb_redir_ioerror:
     case usb_redir_timeout:
     default: