diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
index 39f5a8823a68ac0b5b1b4cf5c7839fbf071ca307..30cb196261e9af329b899b3f587c3e081d171bae 100644
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@@ -4975,6 +4975,9 @@ qemu-kvm -net nic,model=? /dev/null
<model type='virtio'/>
<backend tap='/dev/net/tun' vhost='/dev/vhost-net'/>
<driver name='vhost' txmode='iothread' ioeventfd='on' event_idx='off' queues='5'/>
+ <tune>
+ <sndbuf>1600</sndbuf>
+ </tune>
</interface>
</devices>
...
@@ -4985,7 +4988,12 @@ qemu-kvm -net nic,model=? /dev/null
device path (/dev/vhost-net) for devices with virtio model.
The tap attribute overrides the tun/tap device path (default:
/dev/net/tun) for network and bridge interfaces. This does not work
- in session mode.
+ in session mode. Since 1.2.9
+
+
+ For tap devices there is also sndbuf element which can
+ adjust the size of send buffer in the host. Since
+ 0.8.8