[v1,09/10] vhost-vdpa: introduce vhost-vdpa backend

diff --git a/configure b/configure
index 23b5e93752..53679ee57f 100755
--- a/configure
+++ b/configure
@@ -1557,6 +1557,10 @@  for opt do
   ;;
   --enable-vhost-user) vhost_user="yes"
   ;;
+  --disable-vhost-vdpa) vhost_vdpa="no"
+  ;;
+  --enable-vhost-vdpa) vhost_vdpa="yes"
+  ;;
   --disable-vhost-kernel) vhost_kernel="no"
   ;;
   --enable-vhost-kernel) vhost_kernel="yes"
@@ -1846,6 +1850,7 @@  disabled with --disable-FEATURE, default is enabled if available:
   vhost-crypto    vhost-user-crypto backend support
   vhost-kernel    vhost kernel backend support
   vhost-user      vhost-user backend support
+  vhost-vdpa      vhost-vdpa kernel backend support
   spice           spice
   rbd             rados block device (rbd)
   libiscsi        iscsi support
@@ -2336,6 +2341,10 @@  test "$vhost_user" = "" && vhost_user=yes
 if test "$vhost_user" = "yes" && test "$mingw32" = "yes"; then
   error_exit "vhost-user isn't available on win32"
 fi
+test "$vhost_vdpa" = "" && vhost_vdpa=$linux
+if test "$vhost_vdpa" = "yes" && test "$linux" != "yes"; then
+  error_exit "vhost-vdpa is only available on Linux"
+fi
 test "$vhost_kernel" = "" && vhost_kernel=$linux
 if test "$vhost_kernel" = "yes" && test "$linux" != "yes"; then
   error_exit "vhost-kernel is only available on Linux"
@@ -2364,6 +2373,11 @@  test "$vhost_user_fs" = "" && vhost_user_fs=$vhost_user
 if test "$vhost_user_fs" = "yes" && test "$vhost_user" = "no"; then
   error_exit "--enable-vhost-user-fs requires --enable-vhost-user"
 fi
+#vhost-vdpa backends
+test "$vhost_net_vdpa" = "" && vhost_net_vdpa=$vhost_vdpa
+if test "$vhost_net_vdpa" = "yes" && test "$vhost_vdpa" = "no"; then
+  error_exit "--enable-vhost-net-vdpa requires --enable-vhost-vdpa"
+fi
 
 # OR the vhost-kernel and vhost-user values for simplicity
 if test "$vhost_net" = ""; then
@@ -6673,6 +6687,7 @@  echo "vhost-scsi support $vhost_scsi"
 echo "vhost-vsock support $vhost_vsock"
 echo "vhost-user support $vhost_user"
 echo "vhost-user-fs support $vhost_user_fs"
+echo "vhost-vdpa support $vhost_vdpa"
 echo "Trace backends    $trace_backends"
 if have_backend "simple"; then
 echo "Trace output file $trace_file-<pid>"
@@ -7170,6 +7185,9 @@  fi
 if test "$vhost_net_user" = "yes" ; then
   echo "CONFIG_VHOST_NET_USER=y" >> $config_host_mak
 fi
+if test "$vhost_net_vdpa" = "yes" ; then
+  echo "CONFIG_VHOST_NET_VDPA=y" >> $config_host_mak
+fi
 if test "$vhost_crypto" = "yes" ; then
   echo "CONFIG_VHOST_CRYPTO=y" >> $config_host_mak
 fi
@@ -7182,6 +7200,9 @@  fi
 if test "$vhost_user" = "yes" ; then
   echo "CONFIG_VHOST_USER=y" >> $config_host_mak
 fi
+if test "$vhost_vdpa" = "yes" ; then
+  echo "CONFIG_VHOST_VDPA=y" >> $config_host_mak
+fi
 if test "$vhost_user_fs" = "yes" ; then
   echo "CONFIG_VHOST_USER_FS=y" >> $config_host_mak
 fi
diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index 04cc3db264..cc259e571d 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -17,8 +17,10 @@ 
 #include "net/net.h"
 #include "net/tap.h"
 #include "net/vhost-user.h"
+#include "net/vhost-vdpa.h"
 
 #include "standard-headers/linux/vhost_types.h"
+#include "linux-headers/linux/vhost.h"
 #include "hw/virtio/virtio-net.h"
 #include "net/vhost_net.h"
 #include "qemu/error-report.h"
@@ -33,12 +35,6 @@ 
 #include "hw/virtio/vhost.h"
 #include "hw/virtio/virtio-bus.h"
 
-struct vhost_net {
-    struct vhost_dev dev;
-    struct vhost_virtqueue vqs[2];
-    int backend;
-    NetClientState *nc;
-};
 
 /* Features supported by host kernel. */
 static const int kernel_feature_bits[] = {
@@ -84,7 +80,6 @@  static const int user_feature_bits[] = {
 
     VHOST_INVALID_FEATURE_BIT
 };
-
 static const int *vhost_net_get_feature_bits(struct vhost_net *net)
 {
     const int *feature_bits = 0;
@@ -96,6 +91,9 @@  static const int *vhost_net_get_feature_bits(struct vhost_net *net)
     case NET_CLIENT_DRIVER_VHOST_USER:
         feature_bits = user_feature_bits;
         break;
+    case NET_CLIENT_DRIVER_VHOST_VDPA:
+        feature_bits = vdpa_feature_bits;
+        break;
     default:
         error_report("Feature bits not defined for this type: %d",
                 net->nc->info->type);
@@ -348,6 +346,7 @@  int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
     }
 
     for (i = 0; i < total_queues; i++) {
+
         peer = qemu_get_peer(ncs, i);
         r = vhost_net_start_one(get_vhost_net(peer), dev);
 
@@ -444,6 +443,12 @@  VHostNetState *get_vhost_net(NetClientState *nc)
         vhost_net = vhost_user_get_vhost_net(nc);
         assert(vhost_net);
         break;
+#endif
+#ifdef CONFIG_VHOST_NET_VDPA
+    case NET_CLIENT_DRIVER_VHOST_VDPA:
+        vhost_net = vhost_vdpa_get_vhost_net(nc);
+        assert(vhost_net);
+        break;
 #endif
     default:
         break;
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index a46e3b37a7..8c85e2e1e1 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -42,6 +42,7 @@ 
 #include "trace.h"
 #include "monitor/qdev.h"
 #include "hw/pci/pci.h"
+#include "hw/virtio/vhost.h"
 
 #define VIRTIO_NET_VM_VERSION    11
 
@@ -131,6 +132,8 @@  static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
 {
     VirtIONet *n = VIRTIO_NET(vdev);
     struct virtio_net_config netcfg;
+    int ret = 0;
+    memset(&netcfg, 0 , sizeof(struct virtio_net_config));
 
     virtio_stw_p(vdev, &netcfg.status, n->status);
     virtio_stw_p(vdev, &netcfg.max_virtqueue_pairs, n->max_queues);
@@ -139,13 +142,21 @@  static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
     virtio_stl_p(vdev, &netcfg.speed, n->net_conf.speed);
     netcfg.duplex = n->net_conf.duplex;
     memcpy(config, &netcfg, n->config_size);
+    NetClientState *nc = qemu_get_queue(n->nic);
+    if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
+        ret = vhost_net_get_config(get_vhost_net(nc->peer), (uint8_t *)&netcfg,
+                             n->config_size);
+        if (ret != -1) {
+            memcpy(config, &netcfg, n->config_size);
+        }
+    }
 }
 
 static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
 {
     VirtIONet *n = VIRTIO_NET(vdev);
+    NetClientState *nc = qemu_get_queue(n->nic);
     struct virtio_net_config netcfg = {};
-
     memcpy(&netcfg, config, n->config_size);
 
     if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR) &&
@@ -154,6 +165,11 @@  static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
         memcpy(n->mac, netcfg.mac, ETH_ALEN);
         qemu_format_nic_info_str(qemu_get_queue(n->nic), n->mac);
     }
+    if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
+        vhost_net_set_config(get_vhost_net(nc->peer), (uint8_t *)&netcfg,
+                               0, n->config_size,
+                               VHOST_SET_CONFIG_TYPE_MASTER);
+      }
 }
 
 static bool virtio_net_started(VirtIONet *n, uint8_t status)
@@ -2958,7 +2974,6 @@  static void virtio_net_device_realize(DeviceState *dev, Error **errp)
     } else if (n->net_conf.speed >= 0) {
         n->host_features |= (1ULL << VIRTIO_NET_F_SPEED_DUPLEX);
     }
-
     if (n->failover) {
         n->primary_listener.should_be_hidden =
             virtio_net_primary_should_be_hidden;
diff --git a/hw/virtio/Makefile.objs b/hw/virtio/Makefile.objs
index 4e4d39a0a4..6b1b1a5fce 100644
--- a/hw/virtio/Makefile.objs
+++ b/hw/virtio/Makefile.objs
@@ -5,6 +5,7 @@  obj-y += virtio.o
 obj-$(CONFIG_VHOST) += vhost.o vhost-backend.o
 common-obj-$(call lnot,$(CONFIG_VHOST)) += vhost-stub.o
 obj-$(CONFIG_VHOST_USER) += vhost-user.o
+obj-$(CONFIG_VHOST_VDPA) += vhost-vdpa.o
 
 common-obj-$(CONFIG_VIRTIO_RNG) += virtio-rng.o
 common-obj-$(CONFIG_VIRTIO_PCI) += virtio-pci.o
diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c
index 660e9e8588..84e5b1a833 100644
--- a/hw/virtio/vhost-backend.c
+++ b/hw/virtio/vhost-backend.c
@@ -14,7 +14,7 @@ 
 #include "qemu/error-report.h"
 #include "qemu/main-loop.h"
 #include "standard-headers/linux/vhost_types.h"
-
+#include "hw/virtio/vhost-vdpa.h"
 #ifdef CONFIG_VHOST_KERNEL
 #include <linux/vhost.h>
 #include <sys/ioctl.h>
@@ -22,10 +22,19 @@ 
 static int vhost_kernel_call(struct vhost_dev *dev, unsigned long int request,
                              void *arg)
 {
-    int fd = (uintptr_t) dev->opaque;
-
-    assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_KERNEL);
+    int fd = -1;
+    switch (dev->vhost_ops->backend_type) {
+    case VHOST_BACKEND_TYPE_KERNEL:
+        fd  = (uintptr_t)dev->opaque;
+        break;
+    case VHOST_BACKEND_TYPE_VDPA:
+        fd = ((struct vhost_vdpa *)dev->opaque)->device_fd;
+        break;
+    default:
+        g_assert_not_reached();
+    }
 
+    assert(fd != -1);
     return ioctl(fd, request, arg);
 }
 
@@ -285,6 +294,11 @@  int vhost_set_backend_type(struct vhost_dev *dev, VhostBackendType backend_type)
     case VHOST_BACKEND_TYPE_USER:
         dev->vhost_ops = &user_ops;
         break;
+#endif
+#ifdef CONFIG_VHOST_VDPA
+    case VHOST_BACKEND_TYPE_VDPA:
+        dev->vhost_ops = &vdpa_ops;
+        break;
 #endif
     default:
         error_report("Unknown vhost backend type");
diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
new file mode 100644
index 0000000000..1724d404ce
--- /dev/null
+++ b/hw/virtio/vhost-vdpa.c
@@ -0,0 +1,406 @@ 
+/*
+ * vhost-vdpa
+ *
+ *  Copyright(c) 2017-2018 Intel Corporation.
+ *  Copyright(c) 2020 Red Hat, Inc.
+ *
+ * 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/osdep.h"
+#include <linux/vhost.h>
+#include <linux/vfio.h>
+#include <sys/eventfd.h>
+#include <sys/ioctl.h>
+#include "hw/virtio/vhost.h"
+#include "hw/virtio/vhost-backend.h"
+#include "hw/virtio/virtio-net.h"
+#include "hw/virtio/vhost-vdpa.h"
+#include "qemu/main-loop.h"
+#include <linux/kvm.h>
+#include "sysemu/kvm.h"
+
+
+static bool vhost_vdpa_listener_skipped_section(MemoryRegionSection *section)
+{
+    return (!memory_region_is_ram(section->mr) &&
+            !memory_region_is_iommu(section->mr)) ||
+           /*
+            * Sizing an enabled 64-bit BAR can cause spurious mappings to
+            * addresses in the upper part of the 64-bit address space.  These
+            * are never accessed by the CPU and beyond the address width of
+            * some IOMMU hardware.  TODO: VDPA should tell us the IOMMU width.
+            */
+           section->offset_within_address_space & (1ULL << 63);
+}
+
+static int vhost_vdpa_dma_map(struct vhost_vdpa *v, hwaddr iova, hwaddr size,
+                              void *vaddr, bool readonly)
+{
+    struct vhost_msg_v2 msg;
+    int fd = v->device_fd;
+    int ret = 0;
+
+    msg.type =  v->msg_type;
+    msg.iotlb.iova = iova;
+    msg.iotlb.size = size;
+    msg.iotlb.uaddr = (uint64_t)vaddr;
+    msg.iotlb.perm = readonly ? VHOST_ACCESS_RO : VHOST_ACCESS_RW;
+    msg.iotlb.type = VHOST_IOTLB_UPDATE;
+
+    if (write(fd, &msg, sizeof(msg)) != sizeof(msg)) {
+        error_report("failed to write, fd=%d, errno=%d (%s)",
+            fd, errno, strerror(errno));
+        return -EIO ;
+    }
+
+    return ret;
+}
+
+static int vhost_vdpa_dma_unmap(struct vhost_vdpa *v, hwaddr iova,
+                                hwaddr size)
+{
+    struct vhost_msg_v2 msg;
+    int fd = v->device_fd;
+    int ret = 0;
+
+    msg.type =  v->msg_type;
+    msg.iotlb.iova = iova;
+    msg.iotlb.size = size;
+    msg.iotlb.type = VHOST_IOTLB_INVALIDATE;
+
+    if (write(fd, &msg, sizeof(msg)) != sizeof(msg)) {
+        error_report("failed to write, fd=%d, errno=%d (%s)",
+            fd, errno, strerror(errno));
+        return -EIO ;
+    }
+
+    return ret;
+}
+
+static void vhost_vdpa_listener_region_add(MemoryListener *listener,
+                                           MemoryRegionSection *section)
+{
+    struct vhost_vdpa *v = container_of(listener, struct vhost_vdpa, listener);
+    hwaddr iova;
+    Int128 llend, llsize;
+    void *vaddr;
+    int ret;
+
+    if (vhost_vdpa_listener_skipped_section(section)) {
+        return;
+    }
+
+    if (unlikely((section->offset_within_address_space & ~TARGET_PAGE_MASK) !=
+                 (section->offset_within_region & ~TARGET_PAGE_MASK))) {
+        error_report("%s received unaligned region", __func__);
+        return;
+    }
+
+    iova = TARGET_PAGE_ALIGN(section->offset_within_address_space);
+    llend = int128_make64(section->offset_within_address_space);
+    llend = int128_add(llend, section->size);
+    llend = int128_and(llend, int128_exts64(TARGET_PAGE_MASK));
+
+    if (int128_ge(int128_make64(iova), llend)) {
+        return;
+    }
+
+    memory_region_ref(section->mr);
+
+    /* Here we assume that memory_region_is_ram(section->mr)==true */
+
+    vaddr = memory_region_get_ram_ptr(section->mr) +
+            section->offset_within_region +
+            (iova - section->offset_within_address_space);
+
+    llsize = int128_sub(llend, int128_make64(iova));
+
+    ret = vhost_vdpa_dma_map(v, iova, int128_get64(llsize),
+                             vaddr, section->readonly);
+    if (ret) {
+        error_report("vhost vdpa map fail!");
+        if (memory_region_is_ram_device(section->mr)) {
+            /* Allow unexpected mappings not to be fatal for RAM devices */
+            error_report("map ram fail!");
+          return ;
+        }
+        goto fail;
+    }
+
+    return;
+
+fail:
+    if (memory_region_is_ram_device(section->mr)) {
+        error_report("failed to vdpa_dma_map. pci p2p may not work");
+        return;
+
+    }
+    /*
+     * On the initfn path, store the first error in the container so we
+     * can gracefully fail.  Runtime, there's not much we can do other
+     * than throw a hardware error.
+     */
+    error_report("vhost-vdpa: DMA mapping failed, unable to continue");
+    return;
+
+}
+
+static void vhost_vdpa_listener_region_del(MemoryListener *listener,
+                                           MemoryRegionSection *section)
+{
+    struct vhost_vdpa *v = container_of(listener, struct vhost_vdpa, listener);
+    hwaddr iova;
+    Int128 llend, llsize;
+    int ret;
+    bool try_unmap = true;
+
+    if (vhost_vdpa_listener_skipped_section(section)) {
+        return;
+    }
+
+    if (unlikely((section->offset_within_address_space & ~TARGET_PAGE_MASK) !=
+                 (section->offset_within_region & ~TARGET_PAGE_MASK))) {
+        error_report("%s received unaligned region", __func__);
+        return;
+    }
+
+    iova = TARGET_PAGE_ALIGN(section->offset_within_address_space);
+    llend = int128_make64(section->offset_within_address_space);
+    llend = int128_add(llend, section->size);
+    llend = int128_and(llend, int128_exts64(TARGET_PAGE_MASK));
+
+    if (int128_ge(int128_make64(iova), llend)) {
+        return;
+    }
+
+    llsize = int128_sub(llend, int128_make64(iova));
+
+    if (try_unmap) {
+        ret = vhost_vdpa_dma_unmap(v, iova, int128_get64(llsize));
+        if (ret) {
+            error_report("vhost_vdpa dma unmap error!");
+        }
+    }
+
+    memory_region_unref(section->mr);
+}
+/*
+ * IOTLB API is used by vhost-vpda which requires incremental updating
+ * of the mapping. So we can not use generic vhost memory listener which
+ * depends on the addnop().
+ */
+static const MemoryListener vhost_vdpa_memory_listener = {
+    .region_add = vhost_vdpa_listener_region_add,
+    .region_del = vhost_vdpa_listener_region_del,
+};
+
+static int vhost_vdpa_call(struct vhost_dev *dev, unsigned long int request,
+                             void *arg)
+{
+    struct vhost_vdpa *v = dev->opaque;
+    int fd = v->device_fd;
+
+    assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA);
+
+    return ioctl(fd, request, arg);
+}
+
+static void vhost_vdpa_add_status(struct vhost_dev *dev, uint8_t status)
+{
+    uint8_t s;
+
+    if (vhost_vdpa_call(dev, VHOST_VDPA_GET_STATUS, &s)) {
+        return;
+    }
+
+    s |= status;
+
+    vhost_vdpa_call(dev, VHOST_VDPA_SET_STATUS, &s);
+}
+
+static int vhost_vdpa_init(struct vhost_dev *dev, void *opaque)
+{
+    struct vhost_vdpa *v;
+    uint64_t features;
+    assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA);
+
+    v = opaque;
+    dev->opaque =  opaque ;
+    vhost_vdpa_call(dev, VHOST_GET_FEATURES, &features);
+    dev->backend_features = features;
+    v->listener = vhost_vdpa_memory_listener;
+    v->msg_type = VHOST_IOTLB_MSG_V2;
+
+    vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
+                               VIRTIO_CONFIG_S_DRIVER);
+
+    return 0;
+}
+
+static int vhost_vdpa_cleanup(struct vhost_dev *dev)
+{
+    struct vhost_vdpa *v;
+    assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA);
+    v = dev->opaque;
+    memory_listener_unregister(&v->listener);
+
+    dev->opaque = NULL;
+    return 0;
+}
+
+static int vhost_vdpa_memslots_limit(struct vhost_dev *dev)
+{
+    return INT_MAX;
+}
+
+static int vhost_vdpa_set_mem_table(struct vhost_dev *dev,
+                                    struct vhost_memory *mem)
+{
+
+    if (mem->padding) {
+        return -1;
+    }
+
+    return 0;
+}
+
+static int vhost_vdpa_set_features(struct vhost_dev *dev,
+                                   uint64_t features)
+{
+    int ret;
+    ret = vhost_vdpa_call(dev, VHOST_SET_FEATURES, &features);
+    uint8_t status = 0;
+    if (ret) {
+        return ret;
+    }
+    vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_FEATURES_OK);
+    vhost_vdpa_call(dev, VHOST_VDPA_GET_STATUS, &status);
+
+    return !(status & VIRTIO_CONFIG_S_FEATURES_OK);
+}
+
+int vhost_vdpa_get_device_id(struct vhost_dev *dev,
+                                   uint32_t *device_id)
+{
+    return vhost_vdpa_call(dev, VHOST_VDPA_GET_DEVICE_ID, device_id);
+}
+
+static int vhost_vdpa_reset_device(struct vhost_dev *dev)
+{
+    uint8_t status = 0;
+
+    return vhost_vdpa_call(dev, VHOST_VDPA_SET_STATUS, &status);
+}
+
+static int vhost_vdpa_get_vq_index(struct vhost_dev *dev, int idx)
+{
+    assert(idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs);
+
+    return idx - dev->vq_index;
+}
+
+static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev)
+{
+    int i;
+    for (i = 0; i < dev->nvqs; ++i) {
+        struct vhost_vring_state state = {
+            .index = dev->vq_index + i,
+            .num = 1,
+        };
+        vhost_vdpa_call(dev, VHOST_VDPA_SET_VRING_ENABLE, &state);
+    }
+    return 0;
+}
+
+static int vhost_vdpa_set_config(struct vhost_dev *dev, const uint8_t *data,
+                                   uint32_t offset, uint32_t size,
+                                   uint32_t flags)
+{
+    struct vhost_vdpa_config *config;
+    int ret;
+    unsigned long config_size = offsetof(struct vhost_vdpa_config, buf);
+    config = g_malloc(size + config_size);
+    if (config == NULL) {
+        return -1;
+    }
+    config->off = offset;
+    config->len = size;
+    memcpy(config->buf, data, size);
+    ret = vhost_vdpa_call(dev, VHOST_VDPA_SET_CONFIG, config);
+    g_free(config);
+    return ret;
+}
+
+static int vhost_vdpa_get_config(struct vhost_dev *dev, uint8_t *config,
+                                   uint32_t config_len)
+{
+    struct vhost_vdpa_config *v_config;
+    unsigned long config_size = offsetof(struct vhost_vdpa_config, buf);
+    int ret;
+
+    v_config = g_malloc(config_len + config_size);
+    if (v_config == NULL) {
+        return -1;
+    }
+    v_config->len = config_len;
+    v_config->off = 0;
+    ret = vhost_vdpa_call(dev, VHOST_VDPA_GET_CONFIG, v_config);
+    memcpy(config, v_config->buf, config_len);
+    g_free(v_config);
+    return ret;
+ }
+
+static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
+{
+    struct vhost_vdpa *v = dev->opaque;
+    if (started) {
+        uint8_t status = 0;
+        memory_listener_register(&v->listener, &address_space_memory);
+        vhost_vdpa_set_vring_ready(dev);
+        vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
+        vhost_vdpa_call(dev, VHOST_VDPA_GET_STATUS, &status);
+
+        return !(status & VIRTIO_CONFIG_S_DRIVER_OK);
+    } else {
+        vhost_vdpa_reset_device(dev);
+        vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
+                                   VIRTIO_CONFIG_S_DRIVER);
+        memory_listener_unregister(&v->listener);
+
+        return 0;
+    }
+}
+
+const VhostOps vdpa_ops = {
+        .backend_type = VHOST_BACKEND_TYPE_VDPA,
+        .vhost_backend_init = vhost_vdpa_init,
+        .vhost_backend_cleanup = vhost_vdpa_cleanup,
+        .vhost_set_log_base = vhost_kernel_set_log_base,
+        .vhost_set_vring_addr = vhost_kernel_set_vring_addr,
+        .vhost_set_vring_num = vhost_kernel_set_vring_num,
+        .vhost_set_vring_base = vhost_kernel_set_vring_base,
+        .vhost_get_vring_base = vhost_kernel_get_vring_base,
+        .vhost_set_vring_kick = vhost_kernel_set_vring_kick,
+        .vhost_set_vring_call = vhost_kernel_set_vring_call,
+        .vhost_get_features = vhost_kernel_get_features,
+        .vhost_set_owner = vhost_kernel_set_owner,
+        .vhost_set_vring_endian = NULL,
+        .vhost_backend_memslots_limit = vhost_vdpa_memslots_limit,
+        .vhost_set_mem_table = vhost_vdpa_set_mem_table,
+        .vhost_set_features = vhost_vdpa_set_features,
+        .vhost_reset_device = vhost_vdpa_reset_device,
+        .vhost_get_vq_index = vhost_vdpa_get_vq_index,
+        .vhost_get_config  = vhost_vdpa_get_config,
+        .vhost_set_config = vhost_vdpa_set_config,
+        .vhost_requires_shm_log = NULL,
+        .vhost_migration_done = NULL,
+        .vhost_backend_can_merge = NULL,
+        .vhost_net_set_mtu = NULL,
+        .vhost_set_iotlb_callback = NULL,
+        .vhost_send_device_iotlb_msg = NULL,
+        .vhost_dev_start = vhost_vdpa_dev_start,
+        .vhost_get_device_id = vhost_vdpa_get_device_id,
+};
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index bfd7f9ce1f..a75be7216b 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -744,19 +744,34 @@  static void vhost_iommu_region_del(MemoryListener *listener,
     }
 }
 
+static void vhost_virtqueue_get_addr(struct vhost_dev *dev,
+                                    struct vhost_vring_addr *addr,
+                                    struct vhost_virtqueue *vq)
+{
+    /*vDPA need to use the IOVA here to set to hardware*/
+    if (dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA) {
+        addr->desc_user_addr = (uint64_t)(unsigned long)vq->desc_phys;
+        addr->avail_user_addr = (uint64_t)(unsigned long)vq->avail_phys;
+        addr->used_user_addr = (uint64_t)(unsigned long)vq->used_phys;
+    } else {
+        addr->desc_user_addr = (uint64_t)(unsigned long)vq->desc;
+        addr->avail_user_addr = (uint64_t)(unsigned long)vq->avail;
+        addr->used_user_addr = (uint64_t)(unsigned long)vq->used;
+    }
+}
 
 static int vhost_virtqueue_set_addr(struct vhost_dev *dev,
                                     struct vhost_virtqueue *vq,
                                     unsigned idx, bool enable_log)
 {
-    struct vhost_vring_addr addr = {
-        .index = idx,
-        .desc_user_addr = (uint64_t)(unsigned long)vq->desc,
-        .avail_user_addr = (uint64_t)(unsigned long)vq->avail,
-        .used_user_addr = (uint64_t)(unsigned long)vq->used,
-        .log_guest_addr = vq->used_phys,
-        .flags = enable_log ? (1 << VHOST_VRING_F_LOG) : 0,
-    };
+    struct vhost_vring_addr addr;
+    memset(&addr, 0, sizeof(struct vhost_vring_addr));
+
+    vhost_virtqueue_get_addr(dev, &addr, vq);
+    addr.index = idx;
+    addr .log_guest_addr = vq->used_phys;
+    addr .flags = enable_log ? (1 << VHOST_VRING_F_LOG) : 0;
+
     int r = dev->vhost_ops->vhost_set_vring_addr(dev, &addr);
     if (r < 0) {
         VHOST_OPS_DEBUG("vhost_set_vring_addr failed");
@@ -774,7 +789,9 @@  static int vhost_dev_set_features(struct vhost_dev *dev,
         features |= 0x1ULL << VHOST_F_LOG_ALL;
     }
     if (!vhost_dev_has_iommu(dev)) {
-        features &= ~(0x1ULL << VIRTIO_F_IOMMU_PLATFORM);
+        if (dev->vhost_ops->backend_type != VHOST_BACKEND_TYPE_VDPA) {
+            features &= ~(0x1ULL << VIRTIO_F_IOMMU_PLATFORM);
+        }
     }
     r = dev->vhost_ops->vhost_set_features(dev, features);
     if (r < 0) {
@@ -1667,7 +1684,8 @@  int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev)
         goto fail_log;
     }
 
-    if (vhost_dev_has_iommu(hdev)) {
+    if (vhost_dev_has_iommu(hdev) &&
+        hdev->vhost_ops->vhost_set_iotlb_callback) {
         hdev->vhost_ops->vhost_set_iotlb_callback(hdev, true);
 
         /* Update used ring information for IOTLB to work correctly,
@@ -1713,7 +1731,9 @@  void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
     }
 
     if (vhost_dev_has_iommu(hdev)) {
-        hdev->vhost_ops->vhost_set_iotlb_callback(hdev, false);
+        if (hdev->vhost_ops->vhost_set_iotlb_callback) {
+            hdev->vhost_ops->vhost_set_iotlb_callback(hdev, false);
+        }
         memory_listener_unregister(&hdev->iommu_listener);
     }
     vhost_log_put(hdev, true);
diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h
index c1384bd2c7..c418c2fa0e 100644
--- a/include/hw/virtio/vhost-backend.h
+++ b/include/hw/virtio/vhost-backend.h
@@ -17,7 +17,8 @@  typedef enum VhostBackendType {
     VHOST_BACKEND_TYPE_NONE = 0,
     VHOST_BACKEND_TYPE_KERNEL = 1,
     VHOST_BACKEND_TYPE_USER = 2,
-    VHOST_BACKEND_TYPE_MAX = 3,
+    VHOST_BACKEND_TYPE_VDPA = 3,
+    VHOST_BACKEND_TYPE_MAX = 4,
 } VhostBackendType;
 
 typedef enum VhostSetConfigType {
@@ -113,6 +114,7 @@  typedef int (*vhost_set_inflight_fd_op)(struct vhost_dev *dev,
                                         struct vhost_inflight *inflight);
 
 typedef int (*vhost_dev_start_op)(struct vhost_dev *dev, bool started);
+typedef int (*vhost_get_device_id_op)(struct vhost_dev *dev, uint32_t *dev_id);
 typedef struct VhostOps {
     VhostBackendType backend_type;
     vhost_backend_init vhost_backend_init;
@@ -154,9 +156,11 @@  typedef struct VhostOps {
     vhost_get_inflight_fd_op vhost_get_inflight_fd;
     vhost_set_inflight_fd_op vhost_set_inflight_fd;
     vhost_dev_start_op vhost_dev_start;
+    vhost_get_device_id_op vhost_get_device_id;
 } VhostOps;
 
 extern const VhostOps user_ops;
+extern const VhostOps vdpa_ops;
 
 int vhost_set_backend_type(struct vhost_dev *dev,
                            VhostBackendType backend_type);
diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h
new file mode 100644
index 0000000000..6455663388
--- /dev/null
+++ b/include/hw/virtio/vhost-vdpa.h
@@ -0,0 +1,26 @@ 
+/*
+ * vhost-vdpa.h
+ *
+ * Copyright(c) 2017-2018 Intel Corporation.
+ * Copyright(c) 2020 Red Hat, Inc.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef HW_VIRTIO_VHOST_VDPA_H
+#define HW_VIRTIO_VHOST_VDPA_H
+
+#include "hw/virtio/virtio.h"
+
+typedef struct vhost_vdpa {
+    int device_fd;
+    uint32_t msg_type;
+    MemoryListener listener;
+} VhostVDPA;
+
+extern AddressSpace address_space_memory;
+extern int vhost_vdpa_get_device_id(struct vhost_dev *dev,
+                                   uint32_t *device_id);
+#endif
diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index 59ea53f8c2..f69b5e4a02 100644
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -92,6 +92,12 @@  struct vhost_dev {
     const VhostDevConfigOps *config_ops;
 };
 
+struct vhost_net {
+    struct vhost_dev dev;
+    struct vhost_virtqueue vqs[2];
+    int backend;
+    NetClientState *nc;
+};
 
 int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
                    VhostBackendType backend_type,
diff --git a/qemu-options.hx b/qemu-options.hx
index 292d4e7c0c..d7d0daaa0e 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -2409,6 +2409,10 @@  DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
 #ifdef CONFIG_POSIX
     "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n"
     "                configure a vhost-user network, backed by a chardev 'dev'\n"
+#endif
+#ifdef __linux__
+    "-netdev vhost-vdpa,id=str,vhostdev=/path/to/dev\n"
+    "                configure a vhost-vdpa network,Establish a vhost-vdpa netdev\n"
 #endif
     "-netdev hubport,id=str,hubid=n[,netdev=nd]\n"
     "                configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL)
@@ -2888,6 +2892,14 @@  SRST
              -netdev type=vhost-user,id=net0,chardev=chr0 \
              -device virtio-net-pci,netdev=net0
 
+``-netdev vhost-vdpa,vhostdev=/path/to/dev``
+    Establish a vhost-vdpa netdev.
+
+    vDPA device is a device that uses a datapath which complies with
+    the virtio specifications with a vendor specific control path.
+    vDPA devices can be both physically located on the hardware or
+    emulated by software.
+
 ``-netdev hubport,id=id,hubid=hubid[,netdev=nd]``
     Create a hub port on the emulated hub with ID hubid.