Re: [dpdk-dev] [PATCH 2/2] virtio: allow running w/o vlan filtering

[Stephen Hemminger <stephen@networkplumber.org>]

On Fri, 6 Mar 2015 03:39:47 +0000
"Ouyang, Changchun" <changchun.ouyang@intel.com> wrote:

> 
> 
> > -----Original Message-----
> > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Stephen
> > Hemminger
> > Sent: Friday, March 6, 2015 8:45 AM
> > To: dev@dpdk.org
> > Subject: [dpdk-dev] [PATCH 2/2] virtio: allow running w/o vlan filtering
> > 
> > Vlan filtering is an option, and not a requirement.
> > If host does not support filtering then it can be done in software.
> > 
> 
> The question is that guest only send command, no real action to do the vlan filter. 
> So if both host and guest have no real action for vlan filter, who will do it? 
> 
> Thanks
> Changchun
> 
> 

The virtio driver has features.
Guest can not send commands to host where feature bit not enabled.
Application can call filter_set and check if filter worked or not.

Our code already had to do MAC and VLAN validation of incoming packets
therefore if hardware can't do vlan match, there is no problem.
I would expect other applications would do the same thing.

Failing during configuration is bad. DPDK API should never force
application to play "guess the working configuration" with the device
driver or do string match on "which device is this anyway"