The network XML is updated in the following ways:
1) The <forward> element can now contain a list of forward interfaces:
<forward .... >
<interface dev='eth10'/>
<interface dev='eth11'/>
<interface dev='eth12'/>
<interface dev='eth13'/>
</forward>
The first of these takes the place of the dev attribute that is
normally in <forward> - when defining a network you can specify
either one, and on output both will be present. If you specify
both on input, they must match.
2) In addition to forward modes of 'nat' and 'route', these new modes
are supported:
private, passthrough, vepa - when this network is referenced by a
domain's interface, it will have the same effect as if the
interface had been defined as type='direct', e.g.:
<interface type='direct'>
<source mode='${mode}' dev='${dev}>
...
</interface>
where ${mode} is one of the three new modes, and ${dev} is an interface
selected from the list given in <forward>.
bridge - if a <forward> dev (or multiple devs) is defined, and
forward mode is 'bridge' this is just like the modes 'private',
'passthrough', and 'vepa' above. If there is no forward dev
specified but a bridge name is given (e.g. "<bridge
name='br0'/>"), then guest interfaces using this network will use
libvirt's "host bridge" mode, equivalent to this:
<interface type='bridge'>
<source bridge='${bridge-name}'/>
...
</interface>
3) A network can have multiple <portgroup> elements, which may be
selected by the guest interface definition (by adding
"portgroup='${name}'" in the <source> element along with the
network name). Currently a portgroup can only contain a
virtportprofile, but the intent is that other configuration items
may be put there int the future (e.g. bandwidth config). When
building a guest's interface, if the <interface> XML itself has no
virtportprofile, and if the requested network has a portgroup with
a name matching the name given in the <interface> (or if one of the
network's portgroups is marked with the "default='yes'" attribute),
the virtportprofile from that portgroup will be used by the
interface.
4) A network can have a virtportprofile defined at the top level,
which will be used by a guest interface when connecting in one of
the 'direct' modes if the guest interface XML itself hasn't
specified any virtportprofile, and if there are also no matching
portgroups on the network.
