diff mbox

[6/6] Add new vhost-user netdev backend

Message ID 1386635110-31990-7-git-send-email-a.motakis@virtualopensystems.com
State New
Headers show

Commit Message

Antonios Motakis Dec. 10, 2013, 12:25 a.m. UTC
Add a new QEMU netdev backend that is intended to invoke vhost_net
with the vhost-user backend. Also decouple virtio-net from the tap
backend.

Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
---
 hw/net/vhost_net.c       | 66 ++++++++++++++++++++++++++-------
 hw/net/virtio-net.c      | 42 +++++++++------------
 hw/virtio/vhost.c        |  1 -
 include/net/vhost-user.h | 17 +++++++++
 include/net/vhost_net.h  |  1 +
 net/Makefile.objs        |  2 +-
 net/clients.h            |  3 ++
 net/hub.c                |  1 +
 net/net.c                |  2 +
 net/vhost-user.c         | 95 ++++++++++++++++++++++++++++++++++++++++++++++++
 qapi-schema.json         | 18 ++++++++-
 11 files changed, 205 insertions(+), 43 deletions(-)
 create mode 100644 include/net/vhost-user.h
 create mode 100644 net/vhost-user.c

Comments

Eric Blake Dec. 10, 2013, 10:29 p.m. UTC | #1
On 12/09/2013 05:25 PM, Antonios Motakis wrote:
> Add a new QEMU netdev backend that is intended to invoke vhost_net
> with the vhost-user backend. Also decouple virtio-net from the tap
> backend.
> 
> Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
> Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
> ---

> +++ b/include/net/vhost-user.h
> @@ -0,0 +1,17 @@
> +/*
> + * vhost-user.h
> + *
> + * Copyright (c) 2013 Virtual Open Systems Sarl.
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2.  See
> + * the COPYING file in the top-level directory.

Can you please use GPLv2+ (that is, add the "or later" clause)?  Yes, we
already have GPLv2-only files, but I'd like to avoid adding even more of
them.

> +++ b/net/vhost-user.c
> @@ -0,0 +1,95 @@
> +/*
> + * vhost-user.c
> + *
> + * Copyright (c) 2013 Virtual Open Systems Sarl.
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2.  See
> + * the COPYING file in the top-level directory.

Same question applies to all new files added throughout this series.

> +++ b/qapi-schema.json
> @@ -3009,11 +3009,24 @@
>      'hubid':     'int32' } }
>  
>  ##
> +# @NetdevVhostUserOptions
> +#
> +# Vhost-user network backend
> +#
> +# @file: control socket path

What does it mean when 'file' is not present?  Is there a default value?
 Normally, we mark '#optional' in the docs for an optional argument.

> +#
> +# Since 2.0
> +##
> +{ 'type': 'NetdevVhostUserOptions',
> +  'data': {
> +    '*file': 'str' } }

Or is file always present, in which case this should be 'file' instead
of '*file'?

> +
> +##
>  # @NetClientOptions
>  #
>  # A discriminated record of network device traits.
>  #
> -# Since 1.2
> +# Since 2.0

Wrong.  NetClientOptions has existed since 1.2; but some of the branches
of the union are newer.  The way we have documented that elsewhere looks
more like:

# A discriminated record of network device traits.
# @vde: traits for VDE
# @dump: traits when using the device to dump all traffic
# @bridge: traits for a bridge device
# @hubport: traits for a hub port
# @vhost-user: traits for a vhost-user (since 2.0)
#
# Since 1.2

>  ##
>  { 'union': 'NetClientOptions',
>    'data': {
> @@ -3025,7 +3038,8 @@
>      'vde':      'NetdevVdeOptions',
>      'dump':     'NetdevDumpOptions',
>      'bridge':   'NetdevBridgeOptions',
> -    'hubport':  'NetdevHubPortOptions' } }
> +    'hubport':  'NetdevHubPortOptions',
> +    'vhost-user': 'NetdevVhostUserOptions' } }
>  
>  ##
>  # @NetLegacy
>
Antonios Motakis Dec. 11, 2013, 11:41 a.m. UTC | #2
On Tue, Dec 10, 2013 at 11:29 PM, Eric Blake <eblake@redhat.com> wrote:

> On 12/09/2013 05:25 PM, Antonios Motakis wrote:
> > Add a new QEMU netdev backend that is intended to invoke vhost_net
> > with the vhost-user backend. Also decouple virtio-net from the tap
> > backend.
> >
> > Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
> > Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
> > ---
>
> > +++ b/include/net/vhost-user.h
> > @@ -0,0 +1,17 @@
> > +/*
> > + * vhost-user.h
> > + *
> > + * Copyright (c) 2013 Virtual Open Systems Sarl.
> > + *
> > + * This work is licensed under the terms of the GNU GPL, version 2.  See
> > + * the COPYING file in the top-level directory.
>
> Can you please use GPLv2+ (that is, add the "or later" clause)?  Yes, we
> already have GPLv2-only files, but I'd like to avoid adding even more of
> them.
>
> > +++ b/net/vhost-user.c
> > @@ -0,0 +1,95 @@
> > +/*
> > + * vhost-user.c
> > + *
> > + * Copyright (c) 2013 Virtual Open Systems Sarl.
> > + *
> > + * This work is licensed under the terms of the GNU GPL, version 2.  See
> > + * the COPYING file in the top-level directory.
>
> Same question applies to all new files added throughout this series.
>
> > +++ b/qapi-schema.json
> > @@ -3009,11 +3009,24 @@
> >      'hubid':     'int32' } }
> >
> >  ##
> > +# @NetdevVhostUserOptions
> > +#
> > +# Vhost-user network backend
> > +#
> > +# @file: control socket path
>
> What does it mean when 'file' is not present?  Is there a default value?
>  Normally, we mark '#optional' in the docs for an optional argument.
>
> > +#
> > +# Since 2.0
> > +##
> > +{ 'type': 'NetdevVhostUserOptions',
> > +  'data': {
> > +    '*file': 'str' } }
>
> Or is file always present, in which case this should be 'file' instead
> of '*file'?
>

File should always be present, so we will change it to file without the
asterisk.


>
> > +
> > +##
> >  # @NetClientOptions
> >  #
> >  # A discriminated record of network device traits.
> >  #
> > -# Since 1.2
> > +# Since 2.0
>
> Wrong.  NetClientOptions has existed since 1.2; but some of the branches
> of the union are newer.  The way we have documented that elsewhere looks
> more like:
>
> # A discriminated record of network device traits.
> # @vde: traits for VDE
> # @dump: traits when using the device to dump all traffic
> # @bridge: traits for a bridge device
> # @hubport: traits for a hub port
> # @vhost-user: traits for a vhost-user (since 2.0)
> #
> # Since 1.2
>
>
Thanks for your feedback, we will take it into account for the next version
of the series.

Antonios

 >  ##
> >  { 'union': 'NetClientOptions',
> >    'data': {
> > @@ -3025,7 +3038,8 @@
> >      'vde':      'NetdevVdeOptions',
> >      'dump':     'NetdevDumpOptions',
> >      'bridge':   'NetdevBridgeOptions',
> > -    'hubport':  'NetdevHubPortOptions' } }
> > +    'hubport':  'NetdevHubPortOptions',
> > +    'vhost-user': 'NetdevVhostUserOptions' } }
> >
> >  ##
> >  # @NetLegacy
> >
>
> --
> Eric Blake   eblake redhat com    +1-919-301-3266
> Libvirt virtualization library http://libvirt.org
>
>
diff mbox

Patch

diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index 5fc2900..cf960bb 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -15,6 +15,7 @@ 
 
 #include "net/net.h"
 #include "net/tap.h"
+#include "net/vhost-user.h"
 
 #include "hw/virtio/virtio-net.h"
 #include "net/vhost_net.h"
@@ -173,15 +174,20 @@  static int vhost_net_start_one(struct vhost_net *net,
         goto fail_start;
     }
 
-    net->nc->info->poll(net->nc, false);
-    qemu_set_fd_handler(net->backend, NULL, NULL, NULL);
-    file.fd = net->backend;
-    for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
-        const VhostOps *vhost_ops = net->dev.vhost_ops;
-        r = vhost_ops->vhost_call(&net->dev, VHOST_NET_SET_BACKEND, &file);
-        if (r < 0) {
-            r = -errno;
-            goto fail;
+    if (net->nc->info->poll) {
+        net->nc->info->poll(net->nc, false);
+    }
+
+    if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP) {
+        qemu_set_fd_handler(net->backend, NULL, NULL, NULL);
+        file.fd = net->backend;
+        for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
+            const VhostOps *vhost_ops = net->dev.vhost_ops;
+            r = vhost_ops->vhost_call(&net->dev, VHOST_NET_SET_BACKEND, &file);
+            if (r < 0) {
+                r = -errno;
+                goto fail;
+            }
         }
     }
     return 0;
@@ -192,7 +198,9 @@  fail:
         int r = vhost_ops->vhost_call(&net->dev, VHOST_NET_SET_BACKEND, &file);
         assert(r >= 0);
     }
-    net->nc->info->poll(net->nc, true);
+    if (net->nc->info->poll) {
+        net->nc->info->poll(net->nc, true);
+    }
     vhost_dev_stop(&net->dev, dev);
 fail_start:
     vhost_dev_disable_notifiers(&net->dev, dev);
@@ -214,7 +222,9 @@  static void vhost_net_stop_one(struct vhost_net *net,
         int r = vhost_ops->vhost_call(&net->dev, VHOST_NET_SET_BACKEND, &file);
         assert(r >= 0);
     }
-    net->nc->info->poll(net->nc, true);
+    if (net->nc->info->poll) {
+        net->nc->info->poll(net->nc, true);
+    }
     vhost_dev_stop(&net->dev, dev);
     vhost_dev_disable_notifiers(&net->dev, dev);
 }
@@ -234,7 +244,7 @@  int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
     }
 
     for (i = 0; i < total_queues; i++) {
-        r = vhost_net_start_one(tap_get_vhost_net(ncs[i].peer), dev, i * 2);
+        r = vhost_net_start_one(get_vhost_net(ncs[i].peer), dev, i * 2);
 
         if (r < 0) {
             goto err;
@@ -251,7 +261,7 @@  int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
 
 err:
     while (--i >= 0) {
-        vhost_net_stop_one(tap_get_vhost_net(ncs[i].peer), dev);
+        vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
     }
     return r;
 }
@@ -272,7 +282,7 @@  void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
     assert(r >= 0);
 
     for (i = 0; i < total_queues; i++) {
-        vhost_net_stop_one(tap_get_vhost_net(ncs[i].peer), dev);
+        vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
     }
 }
 
@@ -292,6 +302,29 @@  void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
 {
     vhost_virtqueue_mask(&net->dev, dev, idx, mask);
 }
+
+VHostNetState *get_vhost_net(NetClientState *nc)
+{
+    VHostNetState * vhost_net = 0;
+
+    if (!nc) {
+        return 0;
+    }
+
+    switch(nc->info->type) {
+    case NET_CLIENT_OPTIONS_KIND_TAP:
+        vhost_net = tap_get_vhost_net(nc);
+        break;
+    case NET_CLIENT_OPTIONS_KIND_VHOST_USER:
+        vhost_net = vhost_user_get_vhost_net(nc);
+        break;
+    default:
+        break;
+    }
+
+    return vhost_net;
+}
+
 #else
 struct vhost_net *vhost_net_init(VhostNetOptions *options)
 {
@@ -337,4 +370,9 @@  void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
                               int idx, bool mask)
 {
 }
+
+VHostNetState *get_vhost_net(NetClientState *nc)
+{
+    return 0;
+}
 #endif
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 90eca9a..668d547 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -105,14 +105,7 @@  static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
     NetClientState *nc = qemu_get_queue(n->nic);
     int queues = n->multiqueue ? n->max_queues : 1;
 
-    if (!nc->peer) {
-        return;
-    }
-    if (nc->peer->info->type != NET_CLIENT_OPTIONS_KIND_TAP) {
-        return;
-    }
-
-    if (!tap_get_vhost_net(nc->peer)) {
+    if (!get_vhost_net(nc->peer)) {
         return;
     }
 
@@ -122,7 +115,7 @@  static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
     }
     if (!n->vhost_started) {
         int r;
-        if (!vhost_net_query(tap_get_vhost_net(nc->peer), vdev)) {
+        if (!vhost_net_query(get_vhost_net(nc->peer), vdev)) {
             return;
         }
         n->vhost_started = 1;
@@ -325,11 +318,16 @@  static void peer_test_vnet_hdr(VirtIONet *n)
         return;
     }
 
-    if (nc->peer->info->type != NET_CLIENT_OPTIONS_KIND_TAP) {
-        return;
+    switch (nc->peer->info->type) {
+    case NET_CLIENT_OPTIONS_KIND_TAP:
+        n->has_vnet_hdr = tap_has_vnet_hdr(nc->peer);
+        break;
+    case NET_CLIENT_OPTIONS_KIND_VHOST_USER:
+        n->has_vnet_hdr = 0;
+        break;
+    default:
+        break;
     }
-
-    n->has_vnet_hdr = tap_has_vnet_hdr(nc->peer);
 }
 
 static int peer_has_vnet_hdr(VirtIONet *n)
@@ -437,13 +435,10 @@  static uint32_t virtio_net_get_features(VirtIODevice *vdev, uint32_t features)
         features &= ~(0x1 << VIRTIO_NET_F_HOST_UFO);
     }
 
-    if (!nc->peer || nc->peer->info->type != NET_CLIENT_OPTIONS_KIND_TAP) {
+    if (!get_vhost_net(nc->peer)) {
         return features;
     }
-    if (!tap_get_vhost_net(nc->peer)) {
-        return features;
-    }
-    return vhost_net_get_features(tap_get_vhost_net(nc->peer), features);
+    return vhost_net_get_features(get_vhost_net(nc->peer), features);
 }
 
 static uint32_t virtio_net_bad_features(VirtIODevice *vdev)
@@ -507,13 +502,10 @@  static void virtio_net_set_features(VirtIODevice *vdev, uint32_t features)
     for (i = 0;  i < n->max_queues; i++) {
         NetClientState *nc = qemu_get_subqueue(n->nic, i);
 
-        if (!nc->peer || nc->peer->info->type != NET_CLIENT_OPTIONS_KIND_TAP) {
-            continue;
-        }
-        if (!tap_get_vhost_net(nc->peer)) {
+        if (!get_vhost_net(nc->peer)) {
             continue;
         }
-        vhost_net_ack_features(tap_get_vhost_net(nc->peer), features);
+        vhost_net_ack_features(get_vhost_net(nc->peer), features);
     }
 }
 
@@ -1438,7 +1430,7 @@  static bool virtio_net_guest_notifier_pending(VirtIODevice *vdev, int idx)
     VirtIONet *n = VIRTIO_NET(vdev);
     NetClientState *nc = qemu_get_subqueue(n->nic, vq2q(idx));
     assert(n->vhost_started);
-    return vhost_net_virtqueue_pending(tap_get_vhost_net(nc->peer), idx);
+    return vhost_net_virtqueue_pending(get_vhost_net(nc->peer), idx);
 }
 
 static void virtio_net_guest_notifier_mask(VirtIODevice *vdev, int idx,
@@ -1447,7 +1439,7 @@  static void virtio_net_guest_notifier_mask(VirtIODevice *vdev, int idx,
     VirtIONet *n = VIRTIO_NET(vdev);
     NetClientState *nc = qemu_get_subqueue(n->nic, vq2q(idx));
     assert(n->vhost_started);
-    vhost_net_virtqueue_mask(tap_get_vhost_net(nc->peer),
+    vhost_net_virtqueue_mask(get_vhost_net(nc->peer),
                              vdev, idx, mask);
 }
 
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index a1137e1..fe622fb 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -14,7 +14,6 @@ 
  */
 
 #include "hw/virtio/vhost.h"
-#include "hw/virtio/vhost-backend.h"
 #include "hw/hw.h"
 #include "qemu/atomic.h"
 #include "qemu/range.h"
diff --git a/include/net/vhost-user.h b/include/net/vhost-user.h
new file mode 100644
index 0000000..2d83202
--- /dev/null
+++ b/include/net/vhost-user.h
@@ -0,0 +1,17 @@ 
+/*
+ * vhost-user.h
+ *
+ * Copyright (c) 2013 Virtual Open Systems Sarl.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef VHOST_USER_H_
+#define VHOST_USER_H_
+
+struct vhost_net;
+struct vhost_net *vhost_user_get_vhost_net(NetClientState *nc);
+
+#endif /* VHOST_USER_H_ */
diff --git a/include/net/vhost_net.h b/include/net/vhost_net.h
index 1169562..abd3d0b 100644
--- a/include/net/vhost_net.h
+++ b/include/net/vhost_net.h
@@ -31,4 +31,5 @@  void vhost_net_ack_features(VHostNetState *net, unsigned features);
 bool vhost_net_virtqueue_pending(VHostNetState *net, int n);
 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
                               int idx, bool mask);
+VHostNetState *get_vhost_net(NetClientState *nc);
 #endif
diff --git a/net/Makefile.objs b/net/Makefile.objs
index 4854a14..fc5b547 100644
--- a/net/Makefile.objs
+++ b/net/Makefile.objs
@@ -2,7 +2,7 @@  common-obj-y = net.o queue.o checksum.o util.o hub.o
 common-obj-y += socket.o
 common-obj-y += dump.o
 common-obj-y += eth.o
-common-obj-$(CONFIG_POSIX) += tap.o
+common-obj-$(CONFIG_POSIX) += tap.o vhost-user.o
 common-obj-$(CONFIG_LINUX) += tap-linux.o
 common-obj-$(CONFIG_WIN32) += tap-win32.o
 common-obj-$(CONFIG_BSD) += tap-bsd.o
diff --git a/net/clients.h b/net/clients.h
index 7793294..3978f90 100644
--- a/net/clients.h
+++ b/net/clients.h
@@ -52,4 +52,7 @@  int net_init_vde(const NetClientOptions *opts, const char *name,
                  NetClientState *peer);
 #endif
 
+int net_init_vhost_user(const NetClientOptions *opts, const char *name,
+                  NetClientState *peer);
+
 #endif /* QEMU_NET_CLIENTS_H */
diff --git a/net/hub.c b/net/hub.c
index 33a99c9..7e0f2d6 100644
--- a/net/hub.c
+++ b/net/hub.c
@@ -322,6 +322,7 @@  void net_hub_check_clients(void)
             case NET_CLIENT_OPTIONS_KIND_TAP:
             case NET_CLIENT_OPTIONS_KIND_SOCKET:
             case NET_CLIENT_OPTIONS_KIND_VDE:
+            case NET_CLIENT_OPTIONS_KIND_VHOST_USER:
                 has_host_dev = 1;
                 break;
             default:
diff --git a/net/net.c b/net/net.c
index 0a88e68..d91add9 100644
--- a/net/net.c
+++ b/net/net.c
@@ -731,6 +731,7 @@  static int (* const net_client_init_fun[NET_CLIENT_OPTIONS_KIND_MAX])(
         [NET_CLIENT_OPTIONS_KIND_BRIDGE]    = net_init_bridge,
 #endif
         [NET_CLIENT_OPTIONS_KIND_HUBPORT]   = net_init_hubport,
+        [NET_CLIENT_OPTIONS_KIND_VHOST_USER]= net_init_vhost_user,
 };
 
 
@@ -761,6 +762,7 @@  static int net_client_init1(const void *object, int is_netdev, Error **errp)
         case NET_CLIENT_OPTIONS_KIND_BRIDGE:
 #endif
         case NET_CLIENT_OPTIONS_KIND_HUBPORT:
+        case NET_CLIENT_OPTIONS_KIND_VHOST_USER:
             break;
 
         default:
diff --git a/net/vhost-user.c b/net/vhost-user.c
new file mode 100644
index 0000000..2f3b90a
--- /dev/null
+++ b/net/vhost-user.c
@@ -0,0 +1,95 @@ 
+/*
+ * vhost-user.c
+ *
+ * Copyright (c) 2013 Virtual Open Systems Sarl.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#include "clients.h"
+#include "net/vhost_net.h"
+#include "net/vhost-user.h"
+#include "qemu/error-report.h"
+
+typedef struct VhostUserState {
+    NetClientState nc;
+    VHostNetState *vhost_net;
+} VhostUserState;
+
+VHostNetState *vhost_user_get_vhost_net(NetClientState *nc)
+{
+    VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
+    assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
+    return s->vhost_net;
+}
+
+static void vhost_user_cleanup(NetClientState *nc)
+{
+    VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
+
+    if (s->vhost_net) {
+        vhost_net_cleanup(s->vhost_net);
+        s->vhost_net = NULL;
+    }
+
+    qemu_purge_queued_packets(nc);
+}
+
+static NetClientInfo net_vhost_user_info = {
+        .type = NET_CLIENT_OPTIONS_KIND_VHOST_USER,
+        .size = sizeof(VhostUserState),
+        .cleanup = vhost_user_cleanup,
+};
+
+static int net_vhost_user_init(NetClientState *peer, const char *device,
+                          const char *name, const char *filename)
+{
+    NetClientState *nc;
+    VhostUserState *s;
+    VhostNetOptions options;
+
+    nc = qemu_new_net_client(&net_vhost_user_info, peer, device, name);
+
+    snprintf(nc->info_str, sizeof(nc->info_str), "vhost-user to %s", filename);
+
+    s = DO_UPCAST(VhostUserState, nc, nc);
+
+    options.backend_type = VHOST_BACKEND_TYPE_USER;
+    options.net_backend = &s->nc;
+    options.devpath = filename;
+    options.devfd = -1;
+    options.force = 0;
+
+    s->vhost_net = vhost_net_init(&options);
+
+    if (!s->vhost_net) {
+        error_report("vhost-net requested but could not be initialized");
+        return -1;
+    }
+
+    /* We don't provide a receive callback */
+    s->nc.receive_disabled = 0;
+
+    return 0;
+}
+
+int net_init_vhost_user(const NetClientOptions *opts, const char *name,
+                   NetClientState *peer)
+{
+    const char *file;
+    const NetdevVhostUserOptions *vhost_user;
+
+    assert(opts->kind == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
+    vhost_user = opts->vhost_user;
+
+    if (vhost_user->has_file) {
+        file = vhost_user->file;
+    } else {
+        fprintf(stderr, "file has to be specified");
+        return -1;
+    }
+
+    return net_vhost_user_init(peer, "vhost_user", name, file);
+}
diff --git a/qapi-schema.json b/qapi-schema.json
index 8630eb5..a9ef934 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -3009,11 +3009,24 @@ 
     'hubid':     'int32' } }
 
 ##
+# @NetdevVhostUserOptions
+#
+# Vhost-user network backend
+#
+# @file: control socket path
+#
+# Since 2.0
+##
+{ 'type': 'NetdevVhostUserOptions',
+  'data': {
+    '*file': 'str' } }
+
+##
 # @NetClientOptions
 #
 # A discriminated record of network device traits.
 #
-# Since 1.2
+# Since 2.0
 ##
 { 'union': 'NetClientOptions',
   'data': {
@@ -3025,7 +3038,8 @@ 
     'vde':      'NetdevVdeOptions',
     'dump':     'NetdevDumpOptions',
     'bridge':   'NetdevBridgeOptions',
-    'hubport':  'NetdevHubPortOptions' } }
+    'hubport':  'NetdevHubPortOptions',
+    'vhost-user': 'NetdevVhostUserOptions' } }
 
 ##
 # @NetLegacy