[libvirt] Supporting vhost-net and macvtap in libvirt for QEMU

Vivek Kashyap kashyapv at us.ibm.com
Thu Jan 28 16:12:30 UTC 2010

On Wed, 27 Jan 2010, Daniel P. Berrange wrote:

>> The above is not in the domain xml but was proposed in the bridge xml.
>> The advantage of using the bridge concept is that it appears the same
>> for macvlan and the virtual Linux host bridge. The 'macvlan' interface
>> itself can support 'bridge' mode in addition to the 'vepa' mode.
>> Therefore, one is creating the bridge, attaching it to the physical
>> device. This device is the one which provides the 'uplink' i.e. is
>> either the sr-iov card or is the device associated with the macvlan driver.
>> The domain xml can now point to the above bridge.  For the interfaces it
>> creates it can associate target names.
> The main issue with this, is that when using VEPA/macvlan there's
> no actual host device being created as there is when using the
> linux software bridge. The <interface> descriptions here are mapped
> straight into the  /etc/sysconfig/networking-scripts/ifcfg-XXX files
> that trigger creation & setup of the physical, bridge, bonding & vlan
> interfaces. Since there is no actual bridge interface, there's no
> ifcfg-XXX to map onto in the VEPA case.

ok, thanks for this clarification. We can use the similar setup using a
different construct - maybe physical or direct.

> Daniel
> -- 
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Vivek Kashyap
Linux Technology Center, IBM

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