[libvirt] [PATCH v5] ESX: Add routines to interface driver

[Matthias Bolte]

2012/8/7 Laine Stump <laine at laine.org>:
> On 08/06/2012 03:18 PM, Ata Bohra wrote:
>> But re-thinking the whole design in light of the explanation provided by
>> you, libvirt interfaces are actually mapping physical interfaces to virtual
>> network. Further, hostVirtualSwitch behaves like switch which defines ports
>> where we can plug VM virtual ethernet cards. It seems likely that we still
>> want to have ability of configuring ESXi virtual interfaces
>> (hostVirtualNics) so not sure if listing physical Nics is completly right to
>> get an 100% operational ESX host.
>
> After reading Matthias' explanation, I was left wondering exactly what is
> the purpose of a hostVirtualNic. Is it used to give the hypervisor a
> connection to the hostVirtualSwitch?

That its exact purpose. The hypervisor uses a HostVirtualNic to
connect through a HostVirtualSwitch and PhysicalNic to the network in
order to access network-based storage via NFS or iSCSI. This network
connection is also used for migration.

> If so, that's something that's implied
> in libvirt's networks when they have an IP address defined - the presence of
> an IP address for the network is really indicating that there's a connection
> up to the host's (aka hypervisor) IP stack. (this is a legacy of the design
> of Linux host bridges - I think of there being an "implied port" on the
> bridge that is connected to the host kernel if the bridge has an IP
> address.)

This sounds like a promising idea that might allow to expose a
HostVirtualNic as part of a libvirt network.

-- 
Matthias Bolte
http://photron.blogspot.com