[RFC] vhost-vdpa-net: add vhost-vdpa-net host device support

["Longpeng(Mike)" via <qemu-devel@nongnu.org>]

From: Longpeng <longpeng2@huawei.com>

Hi guys,

This patch introduces vhost-vdpa-net device, which is inspired
by vhost-user-blk and the proposal of vhost-vdpa-blk device [1].

I've tested this patch on Huawei's offload card:
./x86_64-softmmu/qemu-system-x86_64 \
    -device vhost-vdpa-net-pci,vdpa-dev=/dev/vhost-vdpa-0

For virtio hardware offloading, the most important requirement for us
is to support live migration between offloading cards from different
vendors, the combination of netdev and virtio-net seems too heavy, we
prefer a lightweight way.

Maybe we could support both in the future ? Such as:

* Lightweight
 Net: vhost-vdpa-net
 Storage: vhost-vdpa-blk

* Heavy but more powerful
 Net: netdev + virtio-net + vhost-vdpa
 Storage: bdrv + virtio-blk + vhost-vdpa

[1] https://www.mail-archive.com/qemu-devel@nongnu.org/msg797569.html

Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
---
 hw/net/meson.build                 |   1 +
 hw/net/vhost-vdpa-net.c            | 338 +++++++++++++++++++++++++++++++++++++
 hw/virtio/Kconfig                  |   5 +
 hw/virtio/meson.build              |   1 +
 hw/virtio/vhost-vdpa-net-pci.c     | 118 +++++++++++++
 include/hw/virtio/vhost-vdpa-net.h |  31 ++++
 include/net/vhost-vdpa.h           |   2 +
 net/vhost-vdpa.c                   |   2 +-
 8 files changed, 497 insertions(+), 1 deletion(-)
 create mode 100644 hw/net/vhost-vdpa-net.c
 create mode 100644 hw/virtio/vhost-vdpa-net-pci.c
 create mode 100644 include/hw/virtio/vhost-vdpa-net.h

diff --git a/hw/net/meson.build b/hw/net/meson.build
index bdf71f1..139ebc4 100644
--- a/hw/net/meson.build
+++ b/hw/net/meson.build
@@ -44,6 +44,7 @@ specific_ss.add(when: 'CONFIG_XILINX_ETHLITE', if_true: files('xilinx_ethlite.c'
 
 softmmu_ss.add(when: 'CONFIG_VIRTIO_NET', if_true: files('net_rx_pkt.c'))
 specific_ss.add(when: 'CONFIG_VIRTIO_NET', if_true: files('virtio-net.c'))
+specific_ss.add(when: 'CONFIG_VHOST_VDPA_NET', if_true: files('vhost-vdpa-net.c'))
 
 softmmu_ss.add(when: ['CONFIG_VIRTIO_NET', 'CONFIG_VHOST_NET'], if_true: files('vhost_net.c'), if_false: files('vhost_net-stub.c'))
 softmmu_ss.add(when: 'CONFIG_ALL', if_true: files('vhost_net-stub.c'))
diff --git a/hw/net/vhost-vdpa-net.c b/hw/net/vhost-vdpa-net.c
new file mode 100644
index 0000000..48b99f9
--- /dev/null
+++ b/hw/net/vhost-vdpa-net.c
@@ -0,0 +1,338 @@
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "qemu/error-report.h"
+#include "qemu/cutils.h"
+#include "hw/qdev-core.h"
+#include "hw/qdev-properties.h"
+#include "hw/qdev-properties-system.h"
+#include "hw/virtio/vhost.h"
+#include "hw/virtio/vhost-vdpa-net.h"
+#include "hw/virtio/virtio.h"
+#include "hw/virtio/virtio-bus.h"
+#include "hw/virtio/virtio-access.h"
+#include "sysemu/sysemu.h"
+#include "sysemu/runstate.h"
+#include "net/vhost-vdpa.h"
+
+static void vhost_vdpa_net_get_config(VirtIODevice *vdev, uint8_t *config)
+{
+    VHostVdpaNet *s = VHOST_VDPA_NET(vdev);
+
+    memcpy(config, &s->netcfg, sizeof(struct virtio_net_config));
+}
+
+static void vhost_vdpa_net_set_config(VirtIODevice *vdev, const uint8_t *config)
+{
+    VHostVdpaNet *s = VHOST_VDPA_NET(vdev);
+    struct virtio_net_config *netcfg = (struct virtio_net_config *)config;
+    int ret;
+
+    ret = vhost_dev_set_config(&s->dev, (uint8_t *)netcfg, 0, sizeof(*netcfg),
+                               VHOST_SET_CONFIG_TYPE_MASTER);
+    if (ret) {
+        error_report("set device config space failed");
+        return;
+    }
+}
+
+static uint64_t vhost_vdpa_net_get_features(VirtIODevice *vdev,
+                                            uint64_t features,
+                                            Error **errp)
+{
+    VHostVdpaNet *s = VHOST_VDPA_NET(vdev);
+
+    virtio_add_feature(&features, VIRTIO_NET_F_CSUM);
+    virtio_add_feature(&features, VIRTIO_NET_F_GUEST_CSUM);
+    virtio_add_feature(&features, VIRTIO_NET_F_MAC);
+    virtio_add_feature(&features, VIRTIO_NET_F_GSO);
+    virtio_add_feature(&features, VIRTIO_NET_F_GUEST_TSO4);
+    virtio_add_feature(&features, VIRTIO_NET_F_GUEST_TSO6);
+    virtio_add_feature(&features, VIRTIO_NET_F_GUEST_ECN);
+    virtio_add_feature(&features, VIRTIO_NET_F_GUEST_UFO);
+    virtio_add_feature(&features, VIRTIO_NET_F_GUEST_ANNOUNCE);
+    virtio_add_feature(&features, VIRTIO_NET_F_HOST_TSO4);
+    virtio_add_feature(&features, VIRTIO_NET_F_HOST_TSO6);
+    virtio_add_feature(&features, VIRTIO_NET_F_HOST_ECN);
+    virtio_add_feature(&features, VIRTIO_NET_F_HOST_UFO);
+    virtio_add_feature(&features, VIRTIO_NET_F_MRG_RXBUF);
+    virtio_add_feature(&features, VIRTIO_NET_F_STATUS);
+    virtio_add_feature(&features, VIRTIO_NET_F_CTRL_VQ);
+    virtio_add_feature(&features, VIRTIO_NET_F_CTRL_RX);
+    virtio_add_feature(&features, VIRTIO_NET_F_CTRL_VLAN);
+    virtio_add_feature(&features, VIRTIO_NET_F_CTRL_RX_EXTRA);
+    virtio_add_feature(&features, VIRTIO_NET_F_CTRL_MAC_ADDR);
+    virtio_add_feature(&features, VIRTIO_NET_F_MQ);
+
+    return vhost_get_features(&s->dev, vdpa_feature_bits, features);
+}
+
+static int vhost_vdpa_net_start(VirtIODevice *vdev, Error **errp)
+{
+    VHostVdpaNet *s = VHOST_VDPA_NET(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_setg(errp, "binding does not support guest notifiers");
+        return -ENOSYS;
+    }
+
+    ret = vhost_dev_enable_notifiers(&s->dev, vdev);
+    if (ret < 0) {
+        error_setg_errno(errp, -ret, "Error enabling host notifiers");
+        return ret;
+    }
+
+    ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true);
+    if (ret < 0) {
+        error_setg_errno(errp, -ret, "Error binding guest notifier");
+        goto err_host_notifiers;
+    }
+
+    s->dev.acked_features = vdev->guest_features;
+
+    ret = vhost_dev_start(&s->dev, vdev);
+    if (ret < 0) {
+        error_setg_errno(errp, -ret, "Error starting vhost");
+        goto err_guest_notifiers;
+    }
+    s->started = true;
+
+    /* 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);
+    }
+
+    return ret;
+
+err_guest_notifiers:
+    k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
+err_host_notifiers:
+    vhost_dev_disable_notifiers(&s->dev, vdev);
+    return ret;
+}
+
+static void vhost_vdpa_net_handle_output(VirtIODevice *vdev, VirtQueue *vq)
+{
+    VHostVdpaNet *s = VHOST_VDPA_NET(vdev);
+    Error *local_err = NULL;
+    int i, ret;
+
+    if (!vdev->start_on_kick) {
+        return;
+    }
+
+    if (s->dev.started) {
+        return;
+    }
+
+    /* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start
+     * vhost here instead of waiting for .set_status().
+     */
+    ret = vhost_vdpa_net_start(vdev, &local_err);
+    if (ret < 0) {
+        error_reportf_err(local_err, "vhost-vdpa-net: start failed: ");
+        return;
+    }
+
+    /* Kick right away to begin processing requests already in vring */
+    for (i = 0; i < s->dev.nvqs; i++) {
+        VirtQueue *kick_vq = virtio_get_queue(vdev, i);
+
+        if (!virtio_queue_get_desc_addr(vdev, i)) {
+            continue;
+        }
+        event_notifier_set(virtio_queue_get_host_notifier(kick_vq));
+    }
+}
+
+static void vhost_vdpa_net_stop(VirtIODevice *vdev)
+{
+    VHostVdpaNet *s = VHOST_VDPA_NET(vdev);
+    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
+    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
+    int ret;
+
+    if (!s->started) {
+        return;
+    }
+    s->started = false;
+
+    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);
+}
+
+static void vhost_vdpa_net_set_status(VirtIODevice *vdev, uint8_t status)
+{
+    VHostVdpaNet *s = VHOST_VDPA_NET(vdev);
+    bool should_start = virtio_device_started(vdev, status);
+    Error *local_err = NULL;
+    int ret;
+
+    if (!vdev->vm_running) {
+        should_start = false;
+    }
+
+    if (s->started == should_start) {
+        return;
+    }
+
+    if (should_start) {
+        ret = vhost_vdpa_net_start(vdev, &local_err);
+        if (ret < 0) {
+            error_reportf_err(local_err, "vhost-vdpa-net: start failed: ");
+        }
+    } else {
+        vhost_vdpa_net_stop(vdev);
+    }
+}
+
+static void vhost_vdpa_net_unrealize(VHostVdpaNet *s)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(s);
+    int i;
+
+    for (i = 0; i < s->queue_pairs * 2; i++) {
+        virtio_delete_queue(s->virtqs[i]);
+    }
+    /* ctrl vq */
+    virtio_delete_queue(s->virtqs[i]);
+
+    g_free(s->virtqs);
+    virtio_cleanup(vdev);
+}
+
+static void vhost_vdpa_net_device_realize(DeviceState *dev, Error **errp)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VHostVdpaNet *s = VHOST_VDPA_NET(vdev);
+    int i, ret;
+
+    s->vdpa.device_fd = qemu_open_old(s->vdpa_dev, O_RDWR);
+    if (s->vdpa.device_fd == -1) {
+        error_setg(errp, "vhost-vdpa-net: open %s failed: %s",
+                   s->vdpa_dev, strerror(errno));
+        return;
+    }
+
+    virtio_init(vdev, "virtio-net", VIRTIO_ID_NET,
+                sizeof(struct virtio_net_config));
+
+    s->dev.nvqs = s->queue_pairs * 2 + 1;
+    s->dev.vqs = g_new0(struct vhost_virtqueue, s->dev.nvqs);
+    s->dev.vq_index = 0;
+    s->dev.vq_index_end = s->dev.nvqs;
+    s->dev.backend_features = 0;
+    s->started = false;
+
+    s->virtqs = g_new0(VirtQueue *, s->dev.nvqs);
+    for (i = 0; i < s->dev.nvqs; i++) {
+        s->virtqs[i] = virtio_add_queue(vdev, s->queue_size,
+                                        vhost_vdpa_net_handle_output);
+    }
+
+    ret = vhost_dev_init(&s->dev, &s->vdpa, VHOST_BACKEND_TYPE_VDPA, 0, NULL);
+    if (ret < 0) {
+        error_setg(errp, "vhost-vdpa-net: vhost initialization failed: %s",
+                   strerror(-ret));
+        goto init_err;
+    }
+
+    ret = vhost_dev_get_config(&s->dev, (uint8_t *)&s->netcfg,
+                               sizeof(struct virtio_net_config), NULL);
+    if (ret < 0) {
+        error_setg(errp, "vhost-vdpa-net: get network config failed");
+        goto config_err;
+    }
+
+    return;
+config_err:
+    vhost_dev_cleanup(&s->dev);
+init_err:
+    vhost_vdpa_net_unrealize(s);
+    close(s->vdpa.device_fd);
+}
+
+static void vhost_vdpa_net_device_unrealize(DeviceState *dev)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VHostVdpaNet *s = VHOST_VDPA_NET(vdev);
+
+    virtio_set_status(vdev, 0);
+    vhost_dev_cleanup(&s->dev);
+    vhost_vdpa_net_unrealize(s);
+    close(s->vdpa.device_fd);
+}
+
+static const VMStateDescription vmstate_vhost_vdpa_net = {
+    .name = "vhost-vdpa-net",
+    .minimum_version_id = 1,
+    .version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_VIRTIO_DEVICE,
+        VMSTATE_END_OF_LIST()
+    },
+};
+
+static void vhost_vdpa_net_instance_init(Object *obj)
+{
+    VHostVdpaNet *s = VHOST_VDPA_NET(obj);
+
+    device_add_bootindex_property(obj, &s->bootindex, "bootindex",
+                                  "/ethernet-phy@0,0", DEVICE(obj));
+}
+
+static Property vhost_vdpa_net_properties[] = {
+    DEFINE_PROP_STRING("vdpa-dev", VHostVdpaNet, vdpa_dev),
+    DEFINE_PROP_UINT16("queue-pairs", VHostVdpaNet, queue_pairs,
+                       VHOST_VDPA_NET_AUTO_QUEUE_PAIRS),
+    DEFINE_PROP_UINT32("queue-size", VHostVdpaNet, queue_size,
+                       VHOST_VDPA_NET_QUEUE_DEFAULT_SIZE),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void vhost_vdpa_net_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
+
+    device_class_set_props(dc, vhost_vdpa_net_properties);
+    dc->vmsd = &vmstate_vhost_vdpa_net;
+    set_bit(DEVICE_CATEGORY_NETWORK, dc->categories);
+    vdc->realize = vhost_vdpa_net_device_realize;
+    vdc->unrealize = vhost_vdpa_net_device_unrealize;
+    vdc->get_config = vhost_vdpa_net_get_config;
+    vdc->set_config = vhost_vdpa_net_set_config;
+    vdc->get_features = vhost_vdpa_net_get_features;
+    vdc->set_status = vhost_vdpa_net_set_status;
+}
+
+static const TypeInfo vhost_vdpa_net_info = {
+    .name = TYPE_VHOST_VDPA_NET,
+    .parent = TYPE_VIRTIO_DEVICE,
+    .instance_size = sizeof(VHostVdpaNet),
+    .instance_init = vhost_vdpa_net_instance_init,
+    .class_init = vhost_vdpa_net_class_init,
+};
+
+static void virtio_register_types(void)
+{
+    type_register_static(&vhost_vdpa_net_info);
+}
+
+type_init(virtio_register_types)
diff --git a/hw/virtio/Kconfig b/hw/virtio/Kconfig
index c144d42..50dba2e 100644
--- a/hw/virtio/Kconfig
+++ b/hw/virtio/Kconfig
@@ -68,3 +68,8 @@ config VHOST_USER_RNG
     bool
     default y
     depends on VIRTIO && VHOST_USER
+
+config VHOST_VDPA_NET
+    bool
+    default y if VIRTIO_PCI
+    depends on VIRTIO && VHOST_VDPA && LINUX
diff --git a/hw/virtio/meson.build b/hw/virtio/meson.build
index 521f7d6..3089222 100644
--- a/hw/virtio/meson.build
+++ b/hw/virtio/meson.build
@@ -34,6 +34,7 @@ virtio_pci_ss = ss.source_set()
 virtio_pci_ss.add(when: 'CONFIG_VHOST_VSOCK', if_true: files('vhost-vsock-pci.c'))
 virtio_pci_ss.add(when: 'CONFIG_VHOST_USER_VSOCK', if_true: files('vhost-user-vsock-pci.c'))
 virtio_pci_ss.add(when: 'CONFIG_VHOST_USER_BLK', if_true: files('vhost-user-blk-pci.c'))
+virtio_pci_ss.add(when: 'CONFIG_VHOST_VDPA_NET', if_true: files('vhost-vdpa-net-pci.c'))
 virtio_pci_ss.add(when: 'CONFIG_VHOST_USER_INPUT', if_true: files('vhost-user-input-pci.c'))
 virtio_pci_ss.add(when: 'CONFIG_VHOST_USER_SCSI', if_true: files('vhost-user-scsi-pci.c'))
 virtio_pci_ss.add(when: 'CONFIG_VHOST_SCSI', if_true: files('vhost-scsi-pci.c'))
diff --git a/hw/virtio/vhost-vdpa-net-pci.c b/hw/virtio/vhost-vdpa-net-pci.c
new file mode 100644
index 0000000..84199a8
--- /dev/null
+++ b/hw/virtio/vhost-vdpa-net-pci.c
@@ -0,0 +1,118 @@
+#include "qemu/osdep.h"
+#include "standard-headers/linux/virtio_pci.h"
+#include "hw/virtio/virtio.h"
+#include "hw/virtio/vhost-vdpa-net.h"
+#include "hw/pci/pci.h"
+#include "hw/qdev-properties.h"
+#include "qapi/error.h"
+#include "qemu/error-report.h"
+#include "qemu/module.h"
+#include "virtio-pci.h"
+#include "qom/object.h"
+#include "net/vhost-vdpa.h"
+
+typedef struct VHostVdpaNetPCI VHostVdpaNetPCI;
+
+#define TYPE_VHOST_VDPA_NET_PCI "vhost-vdpa-net-pci-base"
+DECLARE_INSTANCE_CHECKER(VHostVdpaNetPCI, VHOST_VDPA_NET_PCI,
+                         TYPE_VHOST_VDPA_NET_PCI)
+
+struct VHostVdpaNetPCI {
+    VirtIOPCIProxy parent_obj;
+    VHostVdpaNet vdev;
+};
+
+static Property vhost_vdpa_net_pci_properties[] = {
+    DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors,
+                       DEV_NVECTORS_UNSPECIFIED),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static int vhost_vdpa_net_get_queue_pairs(VHostVdpaNetPCI *dev, Error **errp)
+{
+    int device_fd, queue_pairs;
+    int has_cvq;
+
+    device_fd = qemu_open_old(dev->vdev.vdpa_dev, O_RDWR);
+    if (device_fd == -1) {
+        error_setg(errp, "vhost-vdpa-net: open %s failed: %s",
+                   dev->vdev.vdpa_dev, strerror(errno));
+        return -1;
+    }
+
+    queue_pairs = vhost_vdpa_get_max_queue_pairs(device_fd, &has_cvq, errp);
+    if (queue_pairs < 0) {
+        error_setg(errp, "vhost-vdpa-net: get queue pairs failed: %s",
+                   strerror(errno));
+        goto out;
+    }
+
+    if (!has_cvq) {
+        error_setg(errp, "vhost-vdpa-net: not support ctrl vq");
+    }
+
+out:
+    close(device_fd);
+    return queue_pairs;
+}
+
+static void vhost_vdpa_net_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
+{
+    VHostVdpaNetPCI *dev = VHOST_VDPA_NET_PCI(vpci_dev);
+    DeviceState *vdev = DEVICE(&dev->vdev);
+
+    if (dev->vdev.queue_pairs == VHOST_VDPA_NET_AUTO_QUEUE_PAIRS) {
+        dev->vdev.queue_pairs = vhost_vdpa_net_get_queue_pairs(dev, errp);
+        if (*errp) {
+            return;
+        }
+    }
+
+    if (vpci_dev->nvectors == DEV_NVECTORS_UNSPECIFIED) {
+        vpci_dev->nvectors = dev->vdev.queue_pairs * 2 + 1;
+    }
+
+    qdev_realize(vdev, BUS(&vpci_dev->bus), errp);
+}
+
+static void vhost_vdpa_net_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_NETWORK, dc->categories);
+    device_class_set_props(dc, vhost_vdpa_net_pci_properties);
+    k->realize = vhost_vdpa_net_pci_realize;
+    pcidev_k->vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET;
+    pcidev_k->device_id = PCI_DEVICE_ID_VIRTIO_NET;
+    pcidev_k->revision = VIRTIO_PCI_ABI_VERSION;
+    pcidev_k->class_id = PCI_CLASS_NETWORK_ETHERNET;
+}
+
+static void vhost_vdpa_net_pci_instance_init(Object *obj)
+{
+    VHostVdpaNetPCI *dev = VHOST_VDPA_NET_PCI(obj);
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VHOST_VDPA_NET);
+    object_property_add_alias(obj, "bootindex", OBJECT(&dev->vdev),
+                              "bootindex");
+}
+
+static const VirtioPCIDeviceTypeInfo vhost_vdpa_net_pci_info = {
+    .base_name               = TYPE_VHOST_VDPA_NET_PCI,
+    .generic_name            = "vhost-vdpa-net-pci",
+    .transitional_name       = "vhost-vdpa-net-pci-transitional",
+    .non_transitional_name   = "vhost-vdpa-net-pci-non-transitional",
+    .instance_size  = sizeof(VHostVdpaNetPCI),
+    .instance_init  = vhost_vdpa_net_pci_instance_init,
+    .class_init     = vhost_vdpa_net_pci_class_init,
+};
+
+static void vhost_vdpa_net_pci_register(void)
+{
+    virtio_pci_types_register(&vhost_vdpa_net_pci_info);
+}
+
+type_init(vhost_vdpa_net_pci_register)
diff --git a/include/hw/virtio/vhost-vdpa-net.h b/include/hw/virtio/vhost-vdpa-net.h
new file mode 100644
index 0000000..63bf3a6
--- /dev/null
+++ b/include/hw/virtio/vhost-vdpa-net.h
@@ -0,0 +1,31 @@
+#ifndef VHOST_VDPA_NET_H
+#define VHOST_VDPA_NET_H
+
+#include "standard-headers/linux/virtio_blk.h"
+#include "hw/block/block.h"
+#include "chardev/char-fe.h"
+#include "hw/virtio/vhost.h"
+#include "hw/virtio/vhost-vdpa.h"
+#include "hw/virtio/virtio-net.h"
+#include "qom/object.h"
+
+#define TYPE_VHOST_VDPA_NET "vhost-vdpa-net"
+OBJECT_DECLARE_SIMPLE_TYPE(VHostVdpaNet, VHOST_VDPA_NET)
+
+struct VHostVdpaNet {
+    VirtIODevice parent_obj;
+    int32_t bootindex;
+    struct virtio_net_config netcfg;
+    uint16_t queue_pairs;
+    uint32_t queue_size;
+    struct vhost_dev dev;
+    VirtQueue **virtqs;
+    struct vhost_vdpa vdpa;
+    char *vdpa_dev;
+    bool started;
+};
+
+#define VHOST_VDPA_NET_AUTO_QUEUE_PAIRS     UINT16_MAX
+#define VHOST_VDPA_NET_QUEUE_DEFAULT_SIZE   256
+
+#endif
diff --git a/include/net/vhost-vdpa.h b/include/net/vhost-vdpa.h
index b81f9a6..f029972 100644
--- a/include/net/vhost-vdpa.h
+++ b/include/net/vhost-vdpa.h
@@ -18,4 +18,6 @@ struct vhost_net *vhost_vdpa_get_vhost_net(NetClientState *nc);
 
 extern const int vdpa_feature_bits[];
 
+int vhost_vdpa_get_max_queue_pairs(int fd, int *has_cvq, Error **errp);
+
 #endif /* VHOST_VDPA_H */
diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
index 25dd6dd..8ee6ba5 100644
--- a/net/vhost-vdpa.c
+++ b/net/vhost-vdpa.c
@@ -219,7 +219,7 @@ static NetClientState *net_vhost_vdpa_init(NetClientState *peer,
     return nc;
 }
 
-static int vhost_vdpa_get_max_queue_pairs(int fd, int *has_cvq, Error **errp)
+int vhost_vdpa_get_max_queue_pairs(int fd, int *has_cvq, Error **errp)
 {
     unsigned long config_size = offsetof(struct vhost_vdpa_config, buf);
     g_autofree struct vhost_vdpa_config *config = NULL;
-- 
1.8.3.1