[Intel-wired-lan] vlan packet handling in ixgbevf driver when in promiscuous mode

[Chris Friesen <chris.friesen@windriver.com>]

On 06/04/2015 09:54 AM, Rose, Gregory V wrote:
>> -----Original Message----- From: Chris Friesen
>> [mailto:chris.friesen at windriver.com] Sent: Monday, June 01, 2015 5:02 PM
>> To: Rose, Gregory V; intel-wired-lan at lists.osuosl.org Subject: Re:
>> [Intel-wired-lan] vlan packet handling in ixgbevf driver when in
>> promiscuous mode
>>
>> Could you elaborate?
>>
>> The use-case here is for NFV/SDN type stuff, where we want to be able to
>> run a router or something similar in the guest--so it needs to be able to
>> receive packets from all VLANs.
>>
>> From what I see if you enable promiscuous mode on the PF then the VFs get
>> packets from all VLANs.

> If you have a working configuration then that's fine.  I was merely pointing
> out that promiscuous mode, as the semantics are commonly applied to word in a
> networking context, is not supported for virtual functions on the 82599
> controller.  There are configurations you can apply to suit your own purposes
> and we would like to support that for you if we can.

Well, it's "working" but it means we have to patch the ixgbevf driver, which is 
a bit of a pain.

I'd like to see something like what Alexander Duyck suggested where the stock 
ixgbevf driver would only strip the VLAN tags off for packets where the VLAN 
matches the port VLAN ID and let all the other VLAN tags through.  (If the guest 
interface is in promiscuous mode.)

Arguably if the guest interface is not in promiscuous mode then I think we 
should be dropping packets from all VLANs other than what the guest has 
explicitly registered for (or that the PF has assigned to the VF.  It makes no 
sense to me that we would let them all through but strip off the VLAN header.

Chris