[for-2.8,2/2] vhost-vsock: add virtio sockets device

Implement the new virtio sockets device for host<->guest communication
using the Sockets API.  Most of the work is done in a vhost kernel
driver so that virtio-vsock can hook into the AF_VSOCK address family.
The QEMU vhost-vsock device handles configuration and live migration
while the rx/tx happens in the vhost_vsock.ko Linux kernel driver.

The vsock device must be given a CID (host-wide unique address):

  # qemu -device vhost-vsock-pci,id=vhost-vsock-pci0,guest-cid=3 ...

For more information see:
http://qemu-project.org/Features/VirtioVsock

[Endianness fixes and virtio-ccw support by Claudio Imbrenda
<imbrenda@linux.vnet.ibm.com>]

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 configure                         |  10 +
 hw/s390x/virtio-ccw.c             |  54 +++++
 hw/s390x/virtio-ccw.h             |  15 ++
 hw/virtio/Makefile.objs           |   2 +
 hw/virtio/vhost-backend.c         |  17 ++
 hw/virtio/vhost-vsock.c           | 417 ++++++++++++++++++++++++++++++++++++++
 hw/virtio/virtio-pci.c            |  51 +++++
 hw/virtio/virtio-pci.h            |  18 ++
 include/hw/pci/pci.h              |   1 +
 include/hw/virtio/vhost-backend.h |   5 +
 include/hw/virtio/vhost-vsock.h   |  41 ++++
 11 files changed, 631 insertions(+)
 create mode 100644 hw/virtio/vhost-vsock.c
 create mode 100644 include/hw/virtio/vhost-vsock.h

On Tue, Aug 16, 2016 at 01:27:22PM +0100, Stefan Hajnoczi wrote:
> Implement the new virtio sockets device for host<->guest communication
> using the Sockets API.  Most of the work is done in a vhost kernel
> driver so that virtio-vsock can hook into the AF_VSOCK address family.
> The QEMU vhost-vsock device handles configuration and live migration
> while the rx/tx happens in the vhost_vsock.ko Linux kernel driver.
> 
> The vsock device must be given a CID (host-wide unique address):
> 
>   # qemu -device vhost-vsock-pci,id=vhost-vsock-pci0,guest-cid=3 ...
> 
> For more information see:
> http://qemu-project.org/Features/VirtioVsock
> 
> [Endianness fixes and virtio-ccw support by Claudio Imbrenda
> <imbrenda@linux.vnet.ibm.com>]
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

Seems to fail build:

/scm/qemu/hw/s390x/virtio-ccw.c:1664:4: error: ‘VirtioCcwDevice {aka
struct VirtioCcwDevice}’ has no member named ‘bus_id’
     DEFINE_PROP_STRING("devno", VirtioCcwDevice, bus_id),
    ^
/scm/qemu/hw/s390x/virtio-ccw.c:1664:49: error: ‘VirtioCcwDevice {aka
struct VirtioCcwDevice}’ has no member named ‘bus_id’
     DEFINE_PROP_STRING("devno", VirtioCcwDevice, bus_id),



> ---
>  configure                         |  10 +
>  hw/s390x/virtio-ccw.c             |  54 +++++
>  hw/s390x/virtio-ccw.h             |  15 ++
>  hw/virtio/Makefile.objs           |   2 +
>  hw/virtio/vhost-backend.c         |  17 ++
>  hw/virtio/vhost-vsock.c           | 417 ++++++++++++++++++++++++++++++++++++++
>  hw/virtio/virtio-pci.c            |  51 +++++
>  hw/virtio/virtio-pci.h            |  18 ++
>  include/hw/pci/pci.h              |   1 +
>  include/hw/virtio/vhost-backend.h |   5 +
>  include/hw/virtio/vhost-vsock.h   |  41 ++++
>  11 files changed, 631 insertions(+)
>  create mode 100644 hw/virtio/vhost-vsock.c
>  create mode 100644 include/hw/virtio/vhost-vsock.h
> 
> diff --git a/configure b/configure
> index 4b808f9..a71ad4c 100755
> --- a/configure
> +++ b/configure
> @@ -229,6 +229,7 @@ xfs=""
>  
>  vhost_net="no"
>  vhost_scsi="no"
> +vhost_vsock="no"
>  kvm="no"
>  rdma=""
>  gprof="no"
> @@ -674,6 +675,7 @@ Haiku)
>    kvm="yes"
>    vhost_net="yes"
>    vhost_scsi="yes"
> +  vhost_vsock="yes"
>    QEMU_INCLUDES="-I\$(SRC_PATH)/linux-headers -I$(pwd)/linux-headers $QEMU_INCLUDES"
>  ;;
>  esac
> @@ -1017,6 +1019,10 @@ for opt do
>    ;;
>    --enable-vhost-scsi) vhost_scsi="yes"
>    ;;
> +  --disable-vhost-vsock) vhost_vsock="no"
> +  ;;
> +  --enable-vhost-vsock) vhost_vsock="yes"
> +  ;;
>    --disable-opengl) opengl="no"
>    ;;
>    --enable-opengl) opengl="yes"
> @@ -4871,6 +4877,7 @@ echo "uuid support      $uuid"
>  echo "libcap-ng support $cap_ng"
>  echo "vhost-net support $vhost_net"
>  echo "vhost-scsi support $vhost_scsi"
> +echo "vhost-vsock support $vhost_vsock"
>  echo "Trace backends    $trace_backends"
>  if have_backend "simple"; then
>  echo "Trace output file $trace_file-<pid>"
> @@ -5252,6 +5259,9 @@ fi
>  if test "$vhost_net" = "yes" ; then
>    echo "CONFIG_VHOST_NET_USED=y" >> $config_host_mak
>  fi
> +if test "$vhost_vsock" = "yes" ; then
> +  echo "CONFIG_VHOST_VSOCK=y" >> $config_host_mak
> +fi
>  if test "$blobs" = "yes" ; then
>    echo "INSTALL_BLOBS=yes" >> $config_host_mak
>  fi
> diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
> index a554a24..bd5475a 100644
> --- a/hw/s390x/virtio-ccw.c
> +++ b/hw/s390x/virtio-ccw.c
> @@ -1658,6 +1658,57 @@ static const TypeInfo virtio_ccw_9p_info = {
>  };
>  #endif
>  
> +#ifdef CONFIG_VHOST_VSOCK
> +
> +static Property vhost_vsock_ccw_properties[] = {
> +    DEFINE_PROP_STRING("devno", VirtioCcwDevice, bus_id),
> +    DEFINE_PROP_UINT32("max_revision", VirtioCcwDevice, max_rev,
> +                       VIRTIO_CCW_MAX_REV),
> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
> +static void vhost_vsock_ccw_realize(VirtioCcwDevice *ccw_dev, Error **errp)
> +{
> +    VHostVSockCCWState *dev = VHOST_VSOCK_CCW(ccw_dev);
> +    DeviceState *vdev = DEVICE(&dev->vdev);
> +    Error *err = NULL;
> +
> +    qdev_set_parent_bus(vdev, BUS(&ccw_dev->bus));
> +    object_property_set_bool(OBJECT(vdev), true, "realized", &err);
> +    if (err) {
> +        error_propagate(errp, err);
> +    }
> +}
> +
> +static void vhost_vsock_ccw_class_init(ObjectClass *klass, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +    VirtIOCCWDeviceClass *k = VIRTIO_CCW_DEVICE_CLASS(klass);
> +
> +    k->realize = vhost_vsock_ccw_realize;
> +    k->exit = virtio_ccw_exit;
> +    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
> +    dc->props = vhost_vsock_ccw_properties;
> +    dc->reset = virtio_ccw_reset;
> +}
> +
> +static void vhost_vsock_ccw_instance_init(Object *obj)
> +{
> +    VHostVSockCCWState *dev = VHOST_VSOCK_CCW(obj);
> +
> +    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
> +                                TYPE_VHOST_VSOCK);
> +}
> +
> +static const TypeInfo vhost_vsock_ccw_info = {
> +    .name          = TYPE_VHOST_VSOCK_CCW,
> +    .parent        = TYPE_VIRTIO_CCW_DEVICE,
> +    .instance_size = sizeof(VHostVSockCCWState),
> +    .instance_init = vhost_vsock_ccw_instance_init,
> +    .class_init    = vhost_vsock_ccw_class_init,
> +};
> +#endif
> +
>  static void virtio_ccw_register(void)
>  {
>      type_register_static(&virtio_ccw_bus_info);
> @@ -1674,6 +1725,9 @@ static void virtio_ccw_register(void)
>  #ifdef CONFIG_VIRTFS
>      type_register_static(&virtio_ccw_9p_info);
>  #endif
> +#ifdef CONFIG_VHOST_VSOCK
> +    type_register_static(&vhost_vsock_ccw_info);
> +#endif
>  }
>  
>  type_init(virtio_ccw_register)
> diff --git a/hw/s390x/virtio-ccw.h b/hw/s390x/virtio-ccw.h
> index 1c6bc86..904e357 100644
> --- a/hw/s390x/virtio-ccw.h
> +++ b/hw/s390x/virtio-ccw.h
> @@ -23,6 +23,9 @@
>  #include "hw/virtio/virtio-balloon.h"
>  #include "hw/virtio/virtio-rng.h"
>  #include "hw/virtio/virtio-bus.h"
> +#ifdef CONFIG_VHOST_VSOCK
> +#include "hw/virtio/vhost-vsock.h"
> +#endif /* CONFIG_VHOST_VSOCK */
>  
>  #include "hw/s390x/s390_flic.h"
>  #include "hw/s390x/css.h"
> @@ -197,4 +200,16 @@ typedef struct V9fsCCWState {
>  
>  #endif /* CONFIG_VIRTFS */
>  
> +#ifdef CONFIG_VHOST_VSOCK
> +#define TYPE_VHOST_VSOCK_CCW "vhost-vsock-ccw"
> +#define VHOST_VSOCK_CCW(obj) \
> +    OBJECT_CHECK(VHostVSockCCWState, (obj), TYPE_VHOST_VSOCK_CCW)
> +
> +typedef struct VHostVSockCCWState {
> +    VirtioCcwDevice parent_obj;
> +    VHostVSock vdev;
> +} VHostVSockCCWState;
> +
> +#endif /* CONFIG_VHOST_VSOCK */
> +
>  #endif
> diff --git a/hw/virtio/Makefile.objs b/hw/virtio/Makefile.objs
> index 3e2b175..e716308 100644
> --- a/hw/virtio/Makefile.objs
> +++ b/hw/virtio/Makefile.objs
> @@ -5,3 +5,5 @@ common-obj-y += virtio-mmio.o
>  
>  obj-y += virtio.o virtio-balloon.o 
>  obj-$(CONFIG_LINUX) += vhost.o vhost-backend.o vhost-user.o
> +
> +obj-$(CONFIG_VHOST_VSOCK) += vhost-vsock.o
> diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c
> index 7681f15..272a5ec 100644
> --- a/hw/virtio/vhost-backend.c
> +++ b/hw/virtio/vhost-backend.c
> @@ -172,6 +172,19 @@ static int vhost_kernel_get_vq_index(struct vhost_dev *dev, int idx)
>      return idx - dev->vq_index;
>  }
>  
> +#ifdef CONFIG_VHOST_VSOCK
> +static int vhost_kernel_vsock_set_guest_cid(struct vhost_dev *dev,
> +                                            uint64_t guest_cid)
> +{
> +    return vhost_kernel_call(dev, VHOST_VSOCK_SET_GUEST_CID, &guest_cid);
> +}
> +
> +static int vhost_kernel_vsock_set_running(struct vhost_dev *dev, int start)
> +{
> +    return vhost_kernel_call(dev, VHOST_VSOCK_SET_RUNNING, &start);
> +}
> +#endif /* CONFIG_VHOST_VSOCK */
> +
>  static const VhostOps kernel_ops = {
>          .backend_type = VHOST_BACKEND_TYPE_KERNEL,
>          .vhost_backend_init = vhost_kernel_init,
> @@ -197,6 +210,10 @@ static const VhostOps kernel_ops = {
>          .vhost_set_owner = vhost_kernel_set_owner,
>          .vhost_reset_device = vhost_kernel_reset_device,
>          .vhost_get_vq_index = vhost_kernel_get_vq_index,
> +#ifdef CONFIG_VHOST_VSOCK
> +        .vhost_vsock_set_guest_cid = vhost_kernel_vsock_set_guest_cid,
> +        .vhost_vsock_set_running = vhost_kernel_vsock_set_running,
> +#endif /* CONFIG_VHOST_VSOCK */
>  };
>  
>  int vhost_set_backend_type(struct vhost_dev *dev, VhostBackendType backend_type)
> diff --git a/hw/virtio/vhost-vsock.c b/hw/virtio/vhost-vsock.c
> new file mode 100644
> index 0000000..bde2456
> --- /dev/null
> +++ b/hw/virtio/vhost-vsock.c
> @@ -0,0 +1,417 @@
> +/*
> + * Virtio vsock device
> + *
> + * Copyright 2015 Red Hat, Inc.
> + *
> + * Authors:
> + *  Stefan Hajnoczi <stefanha@redhat.com>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or
> + * (at your option) any later version.  See the COPYING file in the
> + * top-level directory.
> + */
> +
> +#include <sys/ioctl.h>
> +#include "qemu/osdep.h"
> +#include "standard-headers/linux/virtio_vsock.h"
> +#include "qapi/error.h"
> +#include "hw/virtio/virtio-bus.h"
> +#include "hw/virtio/virtio-access.h"
> +#include "migration/migration.h"
> +#include "qemu/error-report.h"
> +#include "hw/virtio/vhost-vsock.h"
> +#include "qemu/iov.h"
> +#include "monitor/monitor.h"
> +
> +enum {
> +    VHOST_VSOCK_SAVEVM_VERSION = 0,
> +
> +    VHOST_VSOCK_QUEUE_SIZE = 128,
> +};
> +
> +static void vhost_vsock_get_config(VirtIODevice *vdev, uint8_t *config)
> +{
> +    VHostVSock *vsock = VHOST_VSOCK(vdev);
> +    struct virtio_vsock_config vsockcfg = {};
> +
> +    virtio_stq_p(vdev, &vsockcfg.guest_cid, vsock->conf.guest_cid);
> +    memcpy(config, &vsockcfg, sizeof(vsockcfg));
> +}
> +
> +static int vhost_vsock_set_guest_cid(VHostVSock *vsock)
> +{
> +    const VhostOps *vhost_ops = vsock->vhost_dev.vhost_ops;
> +    int ret;
> +
> +    if (!vhost_ops->vhost_vsock_set_guest_cid) {
> +        return -ENOSYS;
> +    }
> +
> +    ret = vhost_ops->vhost_vsock_set_guest_cid(&vsock->vhost_dev,
> +                                               vsock->conf.guest_cid);
> +    if (ret < 0) {
> +        return -errno;
> +    }
> +    return 0;
> +}
> +
> +static int vhost_vsock_set_running(VHostVSock *vsock, int start)
> +{
> +    const VhostOps *vhost_ops = vsock->vhost_dev.vhost_ops;
> +    int ret;
> +
> +    if (!vhost_ops->vhost_vsock_set_running) {
> +        return -ENOSYS;
> +    }
> +
> +    ret = vhost_ops->vhost_vsock_set_running(&vsock->vhost_dev, start);
> +    if (ret < 0) {
> +        return -errno;
> +    }
> +    return 0;
> +}
> +
> +static void vhost_vsock_start(VirtIODevice *vdev)
> +{
> +    VHostVSock *vsock = VHOST_VSOCK(vdev);
> +    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
> +    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
> +    int ret;
> +    int i;
> +
> +    if (!k->set_guest_notifiers) {
> +        error_report("binding does not support guest notifiers");
> +        return;
> +    }
> +
> +    ret = vhost_dev_enable_notifiers(&vsock->vhost_dev, vdev);
> +    if (ret < 0) {
> +        error_report("Error enabling host notifiers: %d", -ret);
> +        return;
> +    }
> +
> +    ret = k->set_guest_notifiers(qbus->parent, vsock->vhost_dev.nvqs, true);
> +    if (ret < 0) {
> +        error_report("Error binding guest notifier: %d", -ret);
> +        goto err_host_notifiers;
> +    }
> +
> +    vsock->vhost_dev.acked_features = vdev->guest_features;
> +    ret = vhost_dev_start(&vsock->vhost_dev, vdev);
> +    if (ret < 0) {
> +        error_report("Error starting vhost: %d", -ret);
> +        goto err_guest_notifiers;
> +    }
> +
> +    ret = vhost_vsock_set_running(vsock, 1);
> +    if (ret < 0) {
> +        error_report("Error starting vhost vsock: %d", -ret);
> +        goto err_dev_start;
> +    }
> +
> +    /* guest_notifier_mask/pending not used yet, so just unmask
> +     * everything here.  virtio-pci will do the right thing by
> +     * enabling/disabling irqfd.
> +     */
> +    for (i = 0; i < vsock->vhost_dev.nvqs; i++) {
> +        vhost_virtqueue_mask(&vsock->vhost_dev, vdev, i, false);
> +    }
> +
> +    return;
> +
> +err_dev_start:
> +    vhost_dev_stop(&vsock->vhost_dev, vdev);
> +err_guest_notifiers:
> +    k->set_guest_notifiers(qbus->parent, vsock->vhost_dev.nvqs, false);
> +err_host_notifiers:
> +    vhost_dev_disable_notifiers(&vsock->vhost_dev, vdev);
> +}
> +
> +static void vhost_vsock_stop(VirtIODevice *vdev)
> +{
> +    VHostVSock *vsock = VHOST_VSOCK(vdev);
> +    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
> +    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
> +    int ret;
> +
> +    if (!k->set_guest_notifiers) {
> +        return;
> +    }
> +
> +    ret = vhost_vsock_set_running(vsock, 0);
> +    if (ret < 0) {
> +        error_report("vhost vsock set running failed: %d", ret);
> +        return;
> +    }
> +
> +    vhost_dev_stop(&vsock->vhost_dev, vdev);
> +
> +    ret = k->set_guest_notifiers(qbus->parent, vsock->vhost_dev.nvqs, false);
> +    if (ret < 0) {
> +        error_report("vhost guest notifier cleanup failed: %d", ret);
> +        return;
> +    }
> +
> +    vhost_dev_disable_notifiers(&vsock->vhost_dev, vdev);
> +}
> +
> +static void vhost_vsock_set_status(VirtIODevice *vdev, uint8_t status)
> +{
> +    VHostVSock *vsock = VHOST_VSOCK(vdev);
> +    bool should_start = status & VIRTIO_CONFIG_S_DRIVER_OK;
> +
> +    if (!vdev->vm_running) {
> +        should_start = false;
> +    }
> +
> +    if (vsock->vhost_dev.started == should_start) {
> +        return;
> +    }
> +
> +    if (should_start) {
> +        vhost_vsock_start(vdev);
> +    } else {
> +        vhost_vsock_stop(vdev);
> +    }
> +}
> +
> +static uint64_t vhost_vsock_get_features(VirtIODevice *vdev,
> +                                         uint64_t requested_features,
> +                                         Error **errp)
> +{
> +    /* No feature bits used yet */
> +    return requested_features;
> +}
> +
> +static void vhost_vsock_handle_output(VirtIODevice *vdev, VirtQueue *vq)
> +{
> +    /* Do nothing */
> +}
> +
> +static void vhost_vsock_guest_notifier_mask(VirtIODevice *vdev, int idx,
> +                                            bool mask)
> +{
> +    VHostVSock *vsock = VHOST_VSOCK(vdev);
> +
> +    vhost_virtqueue_mask(&vsock->vhost_dev, vdev, idx, mask);
> +}
> +
> +static bool vhost_vsock_guest_notifier_pending(VirtIODevice *vdev, int idx)
> +{
> +    VHostVSock *vsock = VHOST_VSOCK(vdev);
> +
> +    return vhost_virtqueue_pending(&vsock->vhost_dev, idx);
> +}
> +
> +static void vhost_vsock_send_transport_reset(VHostVSock *vsock)
> +{
> +    VirtQueueElement *elem;
> +    VirtQueue *vq = vsock->event_vq;
> +    struct virtio_vsock_event event = {
> +        .id = cpu_to_le32(VIRTIO_VSOCK_EVENT_TRANSPORT_RESET),
> +    };
> +
> +    elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
> +    if (!elem) {
> +        error_report("vhost-vsock missed transport reset event");
> +        return;
> +    }
> +
> +    if (elem->out_num) {
> +        error_report("invalid vhost-vsock event virtqueue element with "
> +                     "out buffers");
> +        goto out;
> +    }
> +
> +    if (iov_from_buf(elem->in_sg, elem->in_num, 0,
> +                     &event, sizeof(event)) != sizeof(event)) {
> +        error_report("vhost-vsock event virtqueue element is too short");
> +        goto out;
> +    }
> +
> +    virtqueue_push(vq, elem, sizeof(event));
> +    virtio_notify(VIRTIO_DEVICE(vsock), vq);
> +
> +out:
> +    g_free(elem);
> +}
> +
> +static void vhost_vsock_save(QEMUFile *f, void *opaque, size_t size)
> +{
> +    VHostVSock *vsock = opaque;
> +    VirtIODevice *vdev = VIRTIO_DEVICE(vsock);
> +
> +    /* At this point, backend must be stopped, otherwise
> +     * it might keep writing to memory. */
> +    assert(!vsock->vhost_dev.started);
> +    virtio_save(vdev, f);
> +}
> +
> +static void vhost_vsock_post_load_timer_cleanup(VHostVSock *vsock)
> +{
> +    if (!vsock->post_load_timer) {
> +        return;
> +    }
> +
> +    timer_del(vsock->post_load_timer);
> +    timer_free(vsock->post_load_timer);
> +    vsock->post_load_timer = NULL;
> +}
> +
> +static void vhost_vsock_post_load_timer_cb(void *opaque)
> +{
> +    VHostVSock *vsock = opaque;
> +
> +    vhost_vsock_post_load_timer_cleanup(vsock);
> +    vhost_vsock_send_transport_reset(vsock);
> +}
> +
> +static int vhost_vsock_load(QEMUFile *f, void *opaque, size_t size)
> +{
> +    VHostVSock *vsock = opaque;
> +    VirtIODevice *vdev = VIRTIO_DEVICE(vsock);
> +    int ret;
> +
> +    ret = virtio_load(vdev, f, VHOST_VSOCK_SAVEVM_VERSION);
> +    if (ret) {
> +        return ret;
> +    }
> +
> +    if (virtio_queue_get_addr(vdev, 2)) {
> +        /* Defer transport reset event to a vm clock timer so that virtqueue
> +         * changes happen after migration has completed.
> +         */
> +        assert(!vsock->post_load_timer);
> +        vsock->post_load_timer =
> +            timer_new_ns(QEMU_CLOCK_VIRTUAL,
> +                         vhost_vsock_post_load_timer_cb,
> +                         vsock);
> +        timer_mod(vsock->post_load_timer, 1);
> +    }
> +
> +    return 0;
> +}
> +
> +VMSTATE_VIRTIO_DEVICE(vhost_vsock, VHOST_VSOCK_SAVEVM_VERSION,
> +                      vhost_vsock_load, vhost_vsock_save);
> +
> +static void vhost_vsock_device_realize(DeviceState *dev, Error **errp)
> +{
> +    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> +    VHostVSock *vsock = VHOST_VSOCK(dev);
> +    int vhostfd;
> +    int ret;
> +
> +    /* Refuse to use reserved CID numbers */
> +    if (vsock->conf.guest_cid <= 2) {
> +        error_setg(errp, "guest-cid property must be greater than 2");
> +        return;
> +    }
> +
> +    if (vsock->conf.guest_cid > UINT32_MAX) {
> +        error_setg(errp, "guest-cid property must be a 32-bit number");
> +        return;
> +    }
> +
> +    if (vsock->conf.vhostfd) {
> +        vhostfd = monitor_fd_param(cur_mon, vsock->conf.vhostfd, errp);
> +        if (vhostfd == -1) {
> +            error_prepend(errp, "vhost-vsock: unable to parse vhostfd: ");
> +            return;
> +        }
> +    } else {
> +        vhostfd = open("/dev/vhost-vsock", O_RDWR);
> +        if (vhostfd < 0) {
> +            error_setg_errno(errp, -errno,
> +                             "vhost-vsock: failed to open vhost device");
> +            return;
> +        }
> +    }
> +
> +    virtio_init(vdev, "vhost-vsock", VIRTIO_ID_VSOCK,
> +                sizeof(struct virtio_vsock_config));
> +
> +    /* Receive and transmit queues belong to vhost */
> +    virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE, vhost_vsock_handle_output);
> +    virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE, vhost_vsock_handle_output);
> +
> +    /* The event queue belongs to QEMU */
> +    vsock->event_vq = virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE,
> +                                       vhost_vsock_handle_output);
> +
> +    vsock->vhost_dev.nvqs = ARRAY_SIZE(vsock->vhost_vqs);
> +    vsock->vhost_dev.vqs = vsock->vhost_vqs;
> +    ret = vhost_dev_init(&vsock->vhost_dev, (void *)(uintptr_t)vhostfd,
> +                         VHOST_BACKEND_TYPE_KERNEL, 0);
> +    if (ret < 0) {
> +        error_setg_errno(errp, -ret, "vhost-vsock: vhost_dev_init failed");
> +        goto err_virtio;
> +    }
> +
> +    ret = vhost_vsock_set_guest_cid(vsock);
> +    if (ret < 0) {
> +        error_setg_errno(errp, -ret, "vhost-vsock: unable to set guest cid");
> +        goto err_vhost_dev;
> +    }
> +
> +    vsock->post_load_timer = NULL;
> +    return;
> +
> +err_vhost_dev:
> +    vhost_dev_cleanup(&vsock->vhost_dev);
> +err_virtio:
> +    virtio_cleanup(vdev);
> +    close(vhostfd);
> +    return;
> +}
> +
> +static void vhost_vsock_device_unrealize(DeviceState *dev, Error **errp)
> +{
> +    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> +    VHostVSock *vsock = VHOST_VSOCK(dev);
> +
> +    vhost_vsock_post_load_timer_cleanup(vsock);
> +
> +    /* This will stop vhost backend if appropriate. */
> +    vhost_vsock_set_status(vdev, 0);
> +
> +    vhost_dev_cleanup(&vsock->vhost_dev);
> +    virtio_cleanup(vdev);
> +}
> +
> +static Property vhost_vsock_properties[] = {
> +    DEFINE_PROP_UINT64("guest-cid", VHostVSock, conf.guest_cid, 0),
> +    DEFINE_PROP_STRING("vhostfd", VHostVSock, conf.vhostfd),
> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
> +static void vhost_vsock_class_init(ObjectClass *klass, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +    VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
> +
> +    dc->props = vhost_vsock_properties;
> +    dc->vmsd = &vmstate_virtio_vhost_vsock;
> +    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
> +    vdc->realize = vhost_vsock_device_realize;
> +    vdc->unrealize = vhost_vsock_device_unrealize;
> +    vdc->get_features = vhost_vsock_get_features;
> +    vdc->get_config = vhost_vsock_get_config;
> +    vdc->set_status = vhost_vsock_set_status;
> +    vdc->guest_notifier_mask = vhost_vsock_guest_notifier_mask;
> +    vdc->guest_notifier_pending = vhost_vsock_guest_notifier_pending;
> +}
> +
> +static const TypeInfo vhost_vsock_info = {
> +    .name = TYPE_VHOST_VSOCK,
> +    .parent = TYPE_VIRTIO_DEVICE,
> +    .instance_size = sizeof(VHostVSock),
> +    .class_init = vhost_vsock_class_init,
> +};
> +
> +static void vhost_vsock_register_types(void)
> +{
> +    type_register_static(&vhost_vsock_info);
> +}
> +
> +type_init(vhost_vsock_register_types)
> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> index 755f921..ac42c54 100644
> --- a/hw/virtio/virtio-pci.c
> +++ b/hw/virtio/virtio-pci.c
> @@ -2055,6 +2055,54 @@ static const TypeInfo vhost_scsi_pci_info = {
>  };
>  #endif
>  
> +/* vhost-vsock-pci */
> +
> +#ifdef CONFIG_VHOST_VSOCK
> +static Property vhost_vsock_pci_properties[] = {
> +    DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, 3),
> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
> +static void vhost_vsock_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
> +{
> +    VHostVSockPCI *dev = VHOST_VSOCK_PCI(vpci_dev);
> +    DeviceState *vdev = DEVICE(&dev->vdev);
> +
> +    qdev_set_parent_bus(vdev, BUS(&vpci_dev->bus));
> +    object_property_set_bool(OBJECT(vdev), true, "realized", errp);
> +}
> +
> +static void vhost_vsock_pci_class_init(ObjectClass *klass, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +    VirtioPCIClass *k = VIRTIO_PCI_CLASS(klass);
> +    PCIDeviceClass *pcidev_k = PCI_DEVICE_CLASS(klass);
> +    k->realize = vhost_vsock_pci_realize;
> +    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
> +    dc->props = vhost_vsock_pci_properties;
> +    pcidev_k->vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET;
> +    pcidev_k->device_id = PCI_DEVICE_ID_VIRTIO_VSOCK;
> +    pcidev_k->revision = 0x00;
> +    pcidev_k->class_id = PCI_CLASS_COMMUNICATION_OTHER;
> +}
> +
> +static void vhost_vsock_pci_instance_init(Object *obj)
> +{
> +    VHostVSockPCI *dev = VHOST_VSOCK_PCI(obj);
> +
> +    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
> +                                TYPE_VHOST_VSOCK);
> +}
> +
> +static const TypeInfo vhost_vsock_pci_info = {
> +    .name          = TYPE_VHOST_VSOCK_PCI,
> +    .parent        = TYPE_VIRTIO_PCI,
> +    .instance_size = sizeof(VHostVSockPCI),
> +    .instance_init = vhost_vsock_pci_instance_init,
> +    .class_init    = vhost_vsock_pci_class_init,
> +};
> +#endif
> +
>  /* virtio-balloon-pci */
>  
>  static Property virtio_balloon_pci_properties[] = {
> @@ -2485,6 +2533,9 @@ static void virtio_pci_register_types(void)
>  #ifdef CONFIG_VHOST_SCSI
>      type_register_static(&vhost_scsi_pci_info);
>  #endif
> +#ifdef CONFIG_VHOST_VSOCK
> +    type_register_static(&vhost_vsock_pci_info);
> +#endif
>  }
>  
>  type_init(virtio_pci_register_types)
> diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h
> index 25fbf8a..efd27f7 100644
> --- a/hw/virtio/virtio-pci.h
> +++ b/hw/virtio/virtio-pci.h
> @@ -31,6 +31,9 @@
>  #ifdef CONFIG_VHOST_SCSI
>  #include "hw/virtio/vhost-scsi.h"
>  #endif
> +#ifdef CONFIG_VHOST_VSOCK
> +#include "hw/virtio/vhost-vsock.h"
> +#endif
>  
>  typedef struct VirtIOPCIProxy VirtIOPCIProxy;
>  typedef struct VirtIOBlkPCI VirtIOBlkPCI;
> @@ -44,6 +47,7 @@ typedef struct VirtIOInputPCI VirtIOInputPCI;
>  typedef struct VirtIOInputHIDPCI VirtIOInputHIDPCI;
>  typedef struct VirtIOInputHostPCI VirtIOInputHostPCI;
>  typedef struct VirtIOGPUPCI VirtIOGPUPCI;
> +typedef struct VHostVSockPCI VHostVSockPCI;
>  
>  /* virtio-pci-bus */
>  
> @@ -324,6 +328,20 @@ struct VirtIOGPUPCI {
>      VirtIOGPU vdev;
>  };
>  
> +#ifdef CONFIG_VHOST_VSOCK
> +/*
> + * vhost-vsock-pci: This extends VirtioPCIProxy.
> + */
> +#define TYPE_VHOST_VSOCK_PCI "vhost-vsock-pci"
> +#define VHOST_VSOCK_PCI(obj) \
> +        OBJECT_CHECK(VHostVSockPCI, (obj), TYPE_VHOST_VSOCK_PCI)
> +
> +struct VHostVSockPCI {
> +    VirtIOPCIProxy parent_obj;
> +    VHostVSock vdev;
> +};
> +#endif
> +
>  /* Virtio ABI version, if we increment this, we break the guest driver. */
>  #define VIRTIO_PCI_ABI_VERSION          0
>  
> diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
> index 929ec2f..e8b83bb 100644
> --- a/include/hw/pci/pci.h
> +++ b/include/hw/pci/pci.h
> @@ -79,6 +79,7 @@
>  #define PCI_DEVICE_ID_VIRTIO_SCSI        0x1004
>  #define PCI_DEVICE_ID_VIRTIO_RNG         0x1005
>  #define PCI_DEVICE_ID_VIRTIO_9P          0x1009
> +#define PCI_DEVICE_ID_VIRTIO_VSOCK       0x1012
>  
>  #define PCI_VENDOR_ID_REDHAT             0x1b36
>  #define PCI_DEVICE_ID_REDHAT_BRIDGE      0x0001
> diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h
> index cf7f0b5..6e90703 100644
> --- a/include/hw/virtio/vhost-backend.h
> +++ b/include/hw/virtio/vhost-backend.h
> @@ -73,6 +73,9 @@ typedef int (*vhost_migration_done_op)(struct vhost_dev *dev,
>  typedef bool (*vhost_backend_can_merge_op)(struct vhost_dev *dev,
>                                             uint64_t start1, uint64_t size1,
>                                             uint64_t start2, uint64_t size2);
> +typedef int (*vhost_vsock_set_guest_cid_op)(struct vhost_dev *dev,
> +                                            uint64_t guest_cid);
> +typedef int (*vhost_vsock_set_running_op)(struct vhost_dev *dev, int start);
>  
>  typedef struct VhostOps {
>      VhostBackendType backend_type;
> @@ -102,6 +105,8 @@ typedef struct VhostOps {
>      vhost_requires_shm_log_op vhost_requires_shm_log;
>      vhost_migration_done_op vhost_migration_done;
>      vhost_backend_can_merge_op vhost_backend_can_merge;
> +    vhost_vsock_set_guest_cid_op vhost_vsock_set_guest_cid;
> +    vhost_vsock_set_running_op vhost_vsock_set_running;
>  } VhostOps;
>  
>  extern const VhostOps user_ops;
> diff --git a/include/hw/virtio/vhost-vsock.h b/include/hw/virtio/vhost-vsock.h
> new file mode 100644
> index 0000000..7b9205f
> --- /dev/null
> +++ b/include/hw/virtio/vhost-vsock.h
> @@ -0,0 +1,41 @@
> +/*
> + * Vhost vsock virtio device
> + *
> + * Copyright 2015 Red Hat, Inc.
> + *
> + * Authors:
> + *  Stefan Hajnoczi <stefanha@redhat.com>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or
> + * (at your option) any later version.  See the COPYING file in the
> + * top-level directory.
> + */
> +
> +#ifndef _QEMU_VHOST_VSOCK_H
> +#define _QEMU_VHOST_VSOCK_H
> +
> +#include "hw/virtio/virtio.h"
> +#include "hw/virtio/vhost.h"
> +
> +#define TYPE_VHOST_VSOCK "vhost-vsock-device"
> +#define VHOST_VSOCK(obj) \
> +        OBJECT_CHECK(VHostVSock, (obj), TYPE_VHOST_VSOCK)
> +
> +typedef struct {
> +    uint64_t guest_cid;
> +    char *vhostfd;
> +} VHostVSockConf;
> +
> +typedef struct {
> +    /*< private >*/
> +    VirtIODevice parent;
> +    VHostVSockConf conf;
> +    struct vhost_virtqueue vhost_vqs[2];
> +    struct vhost_dev vhost_dev;
> +    VirtQueue *event_vq;
> +    QEMUTimer *post_load_timer;
> +
> +    /*< public >*/
> +} VHostVSock;
> +
> +#endif /* _QEMU_VHOST_VSOCK_H */
> -- 
> 2.7.4