Re: [Qemu-block] [Qemu-devel] [PATCH 1/1 V2] Add vhost-pci-blk driver

[Dongli Zhang]

It looks the kernel space vhost-blk can only process raw image.

How about to verify that only raw image is used in the drive command line when
vhost-blk-pci is paired with it?

Otherwise, vhost-blk-pci might be working with qcow2 image without any warning
on qemu side.

Dongli Zhang

On 11/06/2018 04:56 AM, Vitaly Mayatskikh wrote:
> This driver uses the kernel-mode acceleration for virtio-blk and
> allows to get a near bare metal disk performance inside a VM.
> 
> Signed-off-by: Vitaly Mayatskikh <address@hidden>
> ---
>  configure                     |  10 +
>  default-configs/virtio.mak    |   1 +
>  hw/block/Makefile.objs        |   1 +
>  hw/block/vhost-blk.c          | 429 ++++++++++++++++++++++++++++++++++
>  hw/virtio/virtio-pci.c        |  60 +++++
>  hw/virtio/virtio-pci.h        |  19 ++
>  include/hw/virtio/vhost-blk.h |  43 ++++
>  7 files changed, 563 insertions(+)
>  create mode 100644 hw/block/vhost-blk.c
>  create mode 100644 include/hw/virtio/vhost-blk.h
> 
> diff --git a/configure b/configure
> index 46ae1e8c76..787bc780da 100755
> --- a/configure
> +++ b/configure
> @@ -371,6 +371,7 @@ vhost_crypto="no"
>  vhost_scsi="no"
>  vhost_vsock="no"
>  vhost_user=""
> +vhost_blk=""
>  kvm="no"
>  hax="no"
>  hvf="no"
> @@ -869,6 +870,7 @@ Linux)
>    vhost_crypto="yes"
>    vhost_scsi="yes"
>    vhost_vsock="yes"
> +  vhost_blk="yes"
>    QEMU_INCLUDES="-I\$(SRC_PATH)/linux-headers -I$(pwd)/linux-headers 
> $QEMU_INCLUDES"
>    supported_os="yes"
>    libudev="yes"
> @@ -1263,6 +1265,10 @@ for opt do
>    ;;
>    --enable-vhost-vsock) vhost_vsock="yes"
>    ;;
> +  --disable-vhost-blk) vhost_blk="no"
> +  ;;
> +  --enable-vhost-blk) vhost_blk="yes"
> +  ;;
>    --disable-opengl) opengl="no"
>    ;;
>    --enable-opengl) opengl="yes"
> @@ -6000,6 +6006,7 @@ echo "vhost-crypto support $vhost_crypto"
>  echo "vhost-scsi support $vhost_scsi"
>  echo "vhost-vsock support $vhost_vsock"
>  echo "vhost-user support $vhost_user"
> +echo "vhost-blk support $vhost_blk"
>  echo "Trace backends    $trace_backends"
>  if have_backend "simple"; then
>  echo "Trace output file $trace_file-<pid>"
> @@ -6461,6 +6468,9 @@ fi
>  if test "$vhost_user" = "yes" ; then
>    echo "CONFIG_VHOST_USER=y" >> $config_host_mak
>  fi
> +if test "$vhost_blk" = "yes" ; then
> +  echo "CONFIG_VHOST_BLK=y" >> $config_host_mak
> +fi
>  if test "$blobs" = "yes" ; then
>    echo "INSTALL_BLOBS=yes" >> $config_host_mak
>  fi
> diff --git a/default-configs/virtio.mak b/default-configs/virtio.mak
> index 1304849018..765c0a2a04 100644
> --- a/default-configs/virtio.mak
> +++ b/default-configs/virtio.mak
> @@ -1,5 +1,6 @@
>  CONFIG_VHOST_USER_SCSI=$(call land,$(CONFIG_VHOST_USER),$(CONFIG_LINUX))
>  CONFIG_VHOST_USER_BLK=$(call land,$(CONFIG_VHOST_USER),$(CONFIG_LINUX))
> +CONFIG_VHOST_BLK=$(CONFIG_LINUX)
>  CONFIG_VIRTIO=y
>  CONFIG_VIRTIO_9P=y
>  CONFIG_VIRTIO_BALLOON=y
> diff --git a/hw/block/Makefile.objs b/hw/block/Makefile.objs
> index 53ce5751ae..857ce823fc 100644
> --- a/hw/block/Makefile.objs
> +++ b/hw/block/Makefile.objs
> @@ -14,3 +14,4 @@ obj-$(CONFIG_SH4) += tc58128.o
>  obj-$(CONFIG_VIRTIO_BLK) += virtio-blk.o
>  obj-$(CONFIG_VIRTIO_BLK) += dataplane/
>  obj-$(CONFIG_VHOST_USER_BLK) += vhost-user-blk.o
> +obj-$(CONFIG_VHOST_BLK) += vhost-blk.o
> diff --git a/hw/block/vhost-blk.c b/hw/block/vhost-blk.c
> new file mode 100644
> index 0000000000..4ca8040ee7
> --- /dev/null
> +++ b/hw/block/vhost-blk.c
> @@ -0,0 +1,429 @@
> +/*
> + * vhost-blk host device
> + *
> + * Copyright(C) 2018 IBM Corporation
> + *
> + * Authors:
> + *  Vitaly Mayatskikh <address@hidden>
> + *
> + * Largely based on the "vhost-user-blk.c" implemented by:
> + * Changpeng Liu <address@hidden>
> + *
> + * This work is licensed under the terms of the GNU LGPL, version 2 or later.
> + * See the COPYING.LIB file in the top-level directory.
> + *
> + */
> +
> +#include "qemu/osdep.h"
> +#include "qapi/error.h"
> +#include "qemu/error-report.h"
> +#include "qemu/cutils.h"
> +#include "qom/object.h"
> +#include "hw/qdev-core.h"
> +#include "hw/virtio/vhost.h"
> +#include "hw/virtio/vhost-blk.h"
> +#include "hw/virtio/virtio.h"
> +#include "hw/virtio/virtio-bus.h"
> +#include "hw/virtio/virtio-access.h"
> +#include <sys/ioctl.h>
> +#include <linux/fs.h>
> +
> +static const int feature_bits[] = {
> +    VIRTIO_BLK_F_SIZE_MAX,
> +    VIRTIO_BLK_F_SEG_MAX,
> +    VIRTIO_BLK_F_BLK_SIZE,
> +    VIRTIO_BLK_F_TOPOLOGY,
> +    VIRTIO_BLK_F_MQ,
> +    VIRTIO_BLK_F_RO,
> +    VIRTIO_BLK_F_FLUSH,
> +    VIRTIO_BLK_F_CONFIG_WCE,
> +    VIRTIO_F_VERSION_1,
> +    VIRTIO_RING_F_INDIRECT_DESC,
> +    VIRTIO_RING_F_EVENT_IDX,
> +    VIRTIO_F_NOTIFY_ON_EMPTY,
> +    VHOST_INVALID_FEATURE_BIT
> +};
> +
> +static void vhost_blk_get_config(VirtIODevice *vdev, uint8_t *config)
> +{
> +    VHostBlk *s = VHOST_BLK(vdev);
> +    memcpy(config, &s->blkcfg, sizeof(struct virtio_blk_config));
> +}
> +
> +static void vhost_blk_set_config(VirtIODevice *vdev, const uint8_t *config)
> +{
> +    VHostBlk *s = VHOST_BLK(vdev);
> +    struct virtio_blk_config *blkcfg = (struct virtio_blk_config *)config;
> +    int ret;
> +
> +    if (blkcfg->wce == s->blkcfg.wce) {
> +        return;
> +    }
> +
> +    ret = vhost_dev_set_config(&s->dev, &blkcfg->wce,
> +                               offsetof(struct virtio_blk_config, wce),
> +                               sizeof(blkcfg->wce),
> +                               VHOST_SET_CONFIG_TYPE_MASTER);
> +    if (ret) {
> +        error_report("set device config space failed");
> +        return;
> +    }
> +
> +    s->blkcfg.wce = blkcfg->wce;
> +}
> +
> +static int vhost_blk_handle_config_change(struct vhost_dev *dev)
> +{
> +    int ret;
> +    struct virtio_blk_config blkcfg;
> +    VHostBlk *s = VHOST_BLK(dev->vdev);
> +
> +    ret = vhost_dev_get_config(dev, (uint8_t *)&blkcfg,
> +                               sizeof(struct virtio_blk_config));
> +    if (ret < 0) {
> +        error_report("get config space failed");
> +        return -1;
> +    }
> +
> +    /* valid for resize only */
> +    if (blkcfg.capacity != s->blkcfg.capacity) {
> +        s->blkcfg.capacity = blkcfg.capacity;
> +        memcpy(dev->vdev->config, &s->blkcfg, sizeof(struct 
> virtio_blk_config));
> +        virtio_notify_config(dev->vdev);
> +    }
> +
> +    return 0;
> +}
> +
> +const VhostDevConfigOps vhost_blk_ops = {
> +    .vhost_dev_config_notifier = vhost_blk_handle_config_change,
> +};
> +
> +static void vhost_blk_start(VirtIODevice *vdev)
> +{
> +    VHostBlk *s = VHOST_BLK(vdev);
> +    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
> +    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
> +    int i, ret;
> +
> +    if (!k->set_guest_notifiers) {
> +        error_report("binding does not support guest notifiers");
> +        return;
> +    }
> +
> +    ret = vhost_dev_enable_notifiers(&s->dev, vdev);
> +    if (ret < 0) {
> +        error_report("Error enabling host notifiers: %d", -ret);
> +        return;
> +    }
> +
> +    ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true);
> +    if (ret < 0) {
> +        error_report("Error binding guest notifier: %d", -ret);
> +        goto err_host_notifiers;
> +    }
> +
> +    s->dev.acked_features = vdev->guest_features;
> +
> +    ret = vhost_dev_start(&s->dev, vdev);
> +    if (ret < 0) {
> +        error_report("Error starting vhost: %d", -ret);
> +        goto err_guest_notifiers;
> +    }
> +    /* 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 < s->dev.nvqs; i++) {
> +        vhost_virtqueue_mask(&s->dev, vdev, i, false);
> +    }
> +
> +    s->bs_fd = open(blk_bs(s->blk)->filename, O_RDWR);
> +    if (s->bs_fd < 0) {
> +        error_report("Error opening backing store: %d", -errno);
> +        goto err_ioctl;
> +    }
> +    ret = ioctl(s->vhostfd, _IOW(0xaf, 0x50, int), &s->bs_fd);
> +    if (ret < 0) {
> +        error_report("Error setting up backend: %d", -errno);
> +        goto err_ioctl;
> +    }
> +
> +    return;
> +
> +err_ioctl:
> +    if (s->bs_fd > 0) {
> +        close(s->bs_fd);
> +    }
> +    vhost_dev_stop(&s->dev, vdev);
> +err_guest_notifiers:
> +    k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
> +err_host_notifiers:
> +    vhost_dev_disable_notifiers(&s->dev, vdev);
> +}
> +
> +static void vhost_blk_stop(VirtIODevice *vdev)
> +{
> +    VHostBlk *s = VHOST_BLK(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;
> +    }
> +
> +    vhost_dev_stop(&s->dev, vdev);
> +
> +    ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
> +    if (ret < 0) {
> +        error_report("vhost guest notifier cleanup failed: %d", ret);
> +        return;
> +    }
> +
> +    vhost_dev_disable_notifiers(&s->dev, vdev);
> +    close(s->bs_fd);
> +}
> +
> +static void vhost_blk_set_status(VirtIODevice *vdev, uint8_t status)
> +{
> +    VHostBlk *s = VHOST_BLK(vdev);
> +    bool should_start = status & VIRTIO_CONFIG_S_DRIVER_OK;
> +
> +    if (!vdev->vm_running) {
> +        should_start = false;
> +    }
> +
> +    if (s->dev.started == should_start) {
> +        return;
> +    }
> +
> +    if (should_start) {
> +        vhost_blk_start(vdev);
> +    } else {
> +        vhost_blk_stop(vdev);
> +    }
> +
> +}
> +
> +static uint64_t vhost_blk_get_features(VirtIODevice *vdev,
> +                                       uint64_t features,
> +                                       Error **errp)
> +{
> +    VHostBlk *s = VHOST_BLK(vdev);
> +
> +    /* Turn on pre-defined features */
> +    virtio_add_feature(&features, VIRTIO_BLK_F_SIZE_MAX);
> +    virtio_add_feature(&features, VIRTIO_BLK_F_SEG_MAX);
> +    virtio_add_feature(&features, VIRTIO_BLK_F_TOPOLOGY);
> +    virtio_add_feature(&features, VIRTIO_BLK_F_BLK_SIZE);
> +    virtio_add_feature(&features, VIRTIO_BLK_F_FLUSH);
> +    virtio_add_feature(&features, VIRTIO_BLK_F_RO);
> +
> +    if (s->config_wce) {
> +        virtio_add_feature(&features, VIRTIO_BLK_F_CONFIG_WCE);
> +    }
> +    if (s->num_queues > 1) {
> +        virtio_add_feature(&features, VIRTIO_BLK_F_MQ);
> +    }
> +
> +    return vhost_get_features(&s->dev, feature_bits, features);
> +}
> +
> +static void vhost_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
> +{
> +}
> +
> +static int vhost_blk_cfg_init(VHostBlk *s)
> +{
> +    int ret;
> +    uint64_t size64;
> +    int size32;
> +    int blksize;
> +    int fd = -1;
> +    struct stat st;
> +    char *filename = blk_bs(s->blk)->filename;
> +
> +    fd = open(filename, O_RDWR);
> +    if (fd < 0) {
> +        error_report("Can't open device %s: %d", filename, errno);
> +        goto out;
> +    }
> +
> +    ret = fstat(fd, &st);
> +    if (ret != 0) {
> +        error_report("Can't fstat backend drive %s: %d", filename, errno);
> +        goto out;
> +    }
> +    if (S_ISBLK(st.st_mode)) {
> +        ret = ioctl(fd, BLKGETSIZE64, &size64);
> +        if (ret != 0 && (errno == ENOTTY)) {
> +            ret = ioctl(fd, BLKGETSIZE, &size32);
> +            size64 = size32;
> +        }
> +        if (ret != 0) {
> +            error_report("Can't get drive size: %d", errno);
> +            goto out;
> +        }
> +        ret = ioctl(fd, BLKSSZGET, &blksize);
> +        if (ret != 0) {
> +            error_report("Can't get logical sector size, assuming 512: %d",
> +                         errno);
> +            blksize = 512;
> +        }
> +    } else {
> +        size64 = st.st_size;
> +        blksize = st.st_blksize;
> +    }
> +
> +    s->blkcfg.capacity = size64 / 512;
> +    s->blkcfg.blk_size = blksize;
> +    s->blkcfg.physical_block_exp = 0;
> +    s->blkcfg.num_queues = s->num_queues;
> +    /* TODO query actual block device */
> +    s->blkcfg.size_max = 8192;
> +    s->blkcfg.seg_max = 8192 / 512;
> +    s->blkcfg.min_io_size = 512;
> +    s->blkcfg.opt_io_size = 8192;
> +
> +out:
> +    if (fd > 0) {
> +        close(fd);
> +    }
> +    return ret;
> +}
> +
> +static void vhost_blk_device_realize(DeviceState *dev, Error **errp)
> +{
> +    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> +    VHostBlk *s = VHOST_BLK(vdev);
> +    int i, ret;
> +
> +    if (!s->blk) {
> +        error_setg(errp, "drive property not set");
> +        return;
> +    }
> +    if (!blk_is_inserted(s->blk)) {
> +        error_setg(errp, "Device needs media, but drive is empty");
> +        return;
> +    }
> +
> +    if (!s->num_queues || s->num_queues > VIRTIO_QUEUE_MAX) {
> +        error_setg(errp, "vhost-blk: invalid number of IO queues");
> +        return;
> +    }
> +
> +    if (!s->queue_size) {
> +        error_setg(errp, "vhost-blk: queue size must be non-zero");
> +        return;
> +    }
> +
> +    virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK,
> +                sizeof(struct virtio_blk_config));
> +
> +    s->dev.max_queues = s->num_queues;
> +    s->dev.nvqs = s->num_queues;
> +    s->dev.vqs = g_new(struct vhost_virtqueue, s->dev.nvqs);
> +    s->dev.vq_index = 0;
> +    s->dev.backend_features = 0;
> +
> +    vhost_dev_set_config_notifier(&s->dev, &vhost_blk_ops);
> +
> +    for (i = 0; i < s->dev.max_queues; i++) {
> +        virtio_add_queue(vdev, s->queue_size,
> +                         vhost_blk_handle_output);
> +    }
> +
> +    s->vhostfd = open("/dev/vhost-blk", O_RDWR);
> +    if (s->vhostfd < 0) {
> +        error_setg_errno(errp, -errno,
> +                        "vhost-blk: failed to open vhost device");
> +        goto virtio_err;
> +    }
> +
> +    ret = vhost_dev_init(&s->dev, (void *)(uintptr_t)s->vhostfd,
> +                         VHOST_BACKEND_TYPE_KERNEL, 0);
> +    if (ret < 0) {
> +        error_setg(errp, "vhost-blk: vhost initialization failed: %s",
> +                   strerror(-ret));
> +        goto virtio_err;
> +    }
> +
> +    vhost_blk_cfg_init(s);
> +    blk_iostatus_enable(s->blk);
> +    return;
> +
> +virtio_err:
> +    g_free(s->dev.vqs);
> +    virtio_cleanup(vdev);
> +    close(s->vhostfd);
> +}
> +
> +static void vhost_blk_device_unrealize(DeviceState *dev, Error **errp)
> +{
> +    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> +    VHostBlk *s = VHOST_BLK(dev);
> +
> +    vhost_blk_set_status(vdev, 0);
> +    close(s->vhostfd);
> +    vhost_dev_cleanup(&s->dev);
> +    g_free(s->dev.vqs);
> +    virtio_cleanup(vdev);
> +}
> +
> +static void vhost_blk_instance_init(Object *obj)
> +{
> +    VHostBlk *s = VHOST_BLK(obj);
> +
> +    device_add_bootindex_property(obj, &s->bootindex, "bootindex",
> +                                  "/address@hidden,0", DEVICE(obj), NULL);
> +}
> +
> +static const VMStateDescription vmstate_vhost_blk = {
> +    .name = "vhost-blk",
> +    .minimum_version_id = 1,
> +    .version_id = 1,
> +    .fields = (VMStateField[]) {
> +        VMSTATE_VIRTIO_DEVICE,
> +        VMSTATE_END_OF_LIST()
> +    },
> +};
> +
> +static Property vhost_blk_properties[] = {
> +    DEFINE_PROP_DRIVE("drive", VHostBlk, blk),
> +    DEFINE_PROP_UINT16("num-queues", VHostBlk, num_queues, 1),
> +    DEFINE_PROP_UINT32("queue-size", VHostBlk, queue_size, 128),
> +    DEFINE_PROP_BIT("config-wce", VHostBlk, config_wce, 0, true),
> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
> +static void vhost_blk_class_init(ObjectClass *klass, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +    VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
> +
> +    dc->props = vhost_blk_properties;
> +    dc->vmsd = &vmstate_vhost_blk;
> +    set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
> +    vdc->realize = vhost_blk_device_realize;
> +    vdc->unrealize = vhost_blk_device_unrealize;
> +    vdc->get_config = vhost_blk_get_config;
> +    vdc->set_config = vhost_blk_set_config;
> +    vdc->get_features = vhost_blk_get_features;
> +    vdc->set_status = vhost_blk_set_status;
> +}
> +
> +static const TypeInfo vhost_blk_info = {
> +    .name = TYPE_VHOST_BLK,
> +    .parent = TYPE_VIRTIO_DEVICE,
> +    .instance_size = sizeof(VHostBlk),
> +    .instance_init = vhost_blk_instance_init,
> +    .class_init = vhost_blk_class_init,
> +};
> +
> +static void virtio_register_types(void)
> +{
> +    type_register_static(&vhost_blk_info);
> +}
> +
> +type_init(virtio_register_types)
> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> index a954799267..ec00b54424 100644
> --- a/hw/virtio/virtio-pci.c
> +++ b/hw/virtio/virtio-pci.c
> @@ -2060,6 +2060,63 @@ static const TypeInfo vhost_user_blk_pci_info = {
>  };
>  #endif
>  
> +#ifdef CONFIG_VHOST_BLK
> +/* vhost-blk */
> +
> +static Property vhost_blk_pci_properties[] = {
> +    DEFINE_PROP_UINT32("class", VirtIOPCIProxy, class_code, 0),
> +    DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors,
> +                       DEV_NVECTORS_UNSPECIFIED),
> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
> +static void vhost_blk_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
> +{
> +    VHostBlkPCI *dev = VHOST_BLK_PCI(vpci_dev);
> +    DeviceState *vdev = DEVICE(&dev->vdev);
> +
> +    if (vpci_dev->nvectors == DEV_NVECTORS_UNSPECIFIED) {
> +        vpci_dev->nvectors = dev->vdev.num_queues + 1;
> +    }
> +
> +    qdev_set_parent_bus(vdev, BUS(&vpci_dev->bus));
> +    object_property_set_bool(OBJECT(vdev), true, "realized", errp);
> +}
> +
> +static void vhost_blk_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);
> +
> +    set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
> +    dc->props = vhost_blk_pci_properties;
> +    k->realize = vhost_blk_pci_realize;
> +    pcidev_k->vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET;
> +    pcidev_k->device_id = PCI_DEVICE_ID_VIRTIO_BLOCK;
> +    pcidev_k->revision = VIRTIO_PCI_ABI_VERSION;
> +    pcidev_k->class_id = PCI_CLASS_STORAGE_SCSI;
> +}
> +
> +static void vhost_blk_pci_instance_init(Object *obj)
> +{
> +    VHostBlkPCI *dev = VHOST_BLK_PCI(obj);
> +
> +    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
> +                                TYPE_VHOST_BLK);
> +    object_property_add_alias(obj, "bootindex", OBJECT(&dev->vdev),
> +                              "bootindex", &error_abort);
> +}
> +
> +static const TypeInfo vhost_blk_pci_info = {
> +    .name           = TYPE_VHOST_BLK_PCI,
> +    .parent         = TYPE_VIRTIO_PCI,
> +    .instance_size  = sizeof(VHostBlkPCI),
> +    .instance_init  = vhost_blk_pci_instance_init,
> +    .class_init     = vhost_blk_pci_class_init,
> +};
> +#endif
> +
>  /* virtio-scsi-pci */
>  
>  static Property virtio_scsi_pci_properties[] = {
> @@ -2723,6 +2780,9 @@ static void virtio_pci_register_types(void)
>  #ifdef CONFIG_VHOST_VSOCK
>      type_register_static(&vhost_vsock_pci_info);
>  #endif
> +#ifdef CONFIG_VHOST_BLK
> +    type_register_static(&vhost_blk_pci_info);
> +#endif
>  }
>  
>  type_init(virtio_pci_register_types)
> diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h
> index 813082b0d7..4cca04a45a 100644
> --- a/hw/virtio/virtio-pci.h
> +++ b/hw/virtio/virtio-pci.h
> @@ -31,6 +31,10 @@
>  #include "hw/virtio/vhost-user-blk.h"
>  #endif
>  
> +#ifdef CONFIG_VHOST_BLK
> +#include "hw/virtio/vhost-blk.h"
> +#endif
> +
>  #ifdef CONFIG_VIRTFS
>  #include "hw/9pfs/virtio-9p.h"
>  #endif
> @@ -50,6 +54,7 @@ typedef struct VirtIONetPCI VirtIONetPCI;
>  typedef struct VHostSCSIPCI VHostSCSIPCI;
>  typedef struct VHostUserSCSIPCI VHostUserSCSIPCI;
>  typedef struct VHostUserBlkPCI VHostUserBlkPCI;
> +typedef struct VHostBlkPCI VHostBlkPCI;
>  typedef struct VirtIORngPCI VirtIORngPCI;
>  typedef struct VirtIOInputPCI VirtIOInputPCI;
>  typedef struct VirtIOInputHIDPCI VirtIOInputHIDPCI;
> @@ -262,6 +267,20 @@ struct VHostUserBlkPCI {
>  };
>  #endif
>  
> +#ifdef CONFIG_VHOST_BLK
> +/*
> + * vhost-blk-pci: This extends VirtioPCIProxy.
> + */
> +#define TYPE_VHOST_BLK_PCI "vhost-blk-pci"
> +#define VHOST_BLK_PCI(obj) \
> +        OBJECT_CHECK(VHostBlkPCI, (obj), TYPE_VHOST_BLK_PCI)
> +
> +struct VHostBlkPCI {
> +    VirtIOPCIProxy parent_obj;
> +    VHostBlk vdev;
> +};
> +#endif
> +
>  /*
>   * virtio-blk-pci: This extends VirtioPCIProxy.
>   */
> diff --git a/include/hw/virtio/vhost-blk.h b/include/hw/virtio/vhost-blk.h
> new file mode 100644
> index 0000000000..6dc5d9634a
> --- /dev/null
> +++ b/include/hw/virtio/vhost-blk.h
> @@ -0,0 +1,43 @@
> +/*
> + * vhost-blk host device
> + * Copyright(C) 2018 IBM Corporation.
> + *
> + * Authors:
> + *  Vitaly Mayatskikh <address@hidden>
> + *
> + * Based on vhost-user-blk.h, Copyright Intel, Corp. 2017
> + *
> + * This work is licensed under the terms of the GNU LGPL, version 2 or later.
> + * See the COPYING.LIB file in the top-level directory.
> + *
> + */
> +
> +#ifndef VHOST_BLK_H
> +#define VHOST_BLK_H
> +
> +#include "standard-headers/linux/virtio_blk.h"
> +#include "qemu-common.h"
> +#include "hw/qdev.h"
> +#include "hw/block/block.h"
> +#include "hw/virtio/vhost.h"
> +#include "sysemu/block-backend.h"
> +
> +#define TYPE_VHOST_BLK "vhost-blk"
> +#define VHOST_BLK(obj) \
> +        OBJECT_CHECK(VHostBlk, (obj), TYPE_VHOST_BLK)
> +
> +typedef struct VHostBlk {
> +    VirtIODevice parent_obj;
> +    BlockConf conf;
> +    BlockBackend *blk;
> +    int32_t bootindex;
> +    struct virtio_blk_config blkcfg;
> +    uint16_t num_queues;
> +    uint32_t queue_size;
> +    uint32_t config_wce;
> +    int vhostfd;
> +    int bs_fd;
> +    struct vhost_dev dev;
> +} VHostBlk;
> +
> +#endif
>