From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jesse Gross Subject: Re: [net-next 02/10] ixgbevf: Fix broken trunk vlan Date: Tue, 27 Sep 2011 09:49:06 -0700 Message-ID: References: <1316855863-6091-1-git-send-email-jeffrey.t.kirsher@intel.com> <1316855863-6091-3-git-send-email-jeffrey.t.kirsher@intel.com> <43F901BD926A4E43B106BF17856F0755019C519319@orsmsx508.amr.corp.intel.com> <43F901BD926A4E43B106BF17856F0755019C5E5B68@orsmsx508.amr.corp.intel.com> <43F901BD926A4E43B106BF17856F0755019C5E5E44@orsmsx508.amr.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: "Kirsher, Jeffrey T" , "davem@davemloft.net" , "netdev@vger.kernel.org" , "gospo@redhat.com" , Jiri Pirko To: "Rose, Gregory V" Return-path: Received: from mail-vx0-f174.google.com ([209.85.220.174]:49949 "EHLO mail-vx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751542Ab1I0Qt1 convert rfc822-to-8bit (ORCPT ); Tue, 27 Sep 2011 12:49:27 -0400 Received: by vcbfk10 with SMTP id fk10so3846203vcb.19 for ; Tue, 27 Sep 2011 09:49:26 -0700 (PDT) In-Reply-To: <43F901BD926A4E43B106BF17856F0755019C5E5E44@orsmsx508.amr.corp.intel.com> Sender: netdev-owner@vger.kernel.org List-ID: On Tue, Sep 27, 2011 at 9:39 AM, Rose, Gregory V wrote: >> -----Original Message----- >> From: Jesse Gross [mailto:jesse@nicira.com] >> Sent: Monday, September 26, 2011 5:54 PM >> To: Rose, Gregory V >> Cc: Kirsher, Jeffrey T; davem@davemloft.net; netdev@vger.kernel.org; >> gospo@redhat.com; Jiri Pirko >> Subject: Re: [net-next 02/10] ixgbevf: Fix broken trunk vlan >> >> >> OK, maybe due to hardware limitations what I'm looking for just real= ly >> isn't possible. > > From what I can tell that is the case. > >> =C2=A0However, what I'm trying to emphasize is that vconfig >> is not the only way that vlans can be consumed by the network stack >> and active_vlans is just an indication of whether a vlan filter was >> set, nothing more (perhaps I should have picked a better name when I >> originally designed this stuff). > > Understood. =C2=A0The VF is incapable of receiving VLAN traffic unles= s a filter has been set. =C2=A0It doesn't do promiscuous mode and any p= ath that doesn't actually end up setting a VLAN filter won't receive an= y VLAN traffic. > >> =C2=A0In particular, it is not intended to >> determine whether a tag should be stripped off or not because >> non-vconfig users don't necessarily know which vlans they care about >> (think tcpdump or trunking over a bridge). =C2=A0A major goal of the >> existing vlan infrastructure is to avoid having drivers make >> assumptions about the consumer of the tag and instead just hand all >> information over to the network stack so it can behave in a consiste= nt >> manner. =C2=A0That's why I was looking for alternate ways to get thi= s >> information without depending on active_vlans as this driver behaves >> quite a bit differently from others, include the ixgbe PF driver. > > There are only two paths for the ixgbevf driver to receive VLAN traff= ic. =C2=A0Either a VLAN filter has been set, which will result in a bit= tag in active_vlans being set or the system administrator in the host = VMM has put the VF device in trunk VLAN mode using the 'ip link set vf ' path. =C2=A0There is no other way for it to receive= VLAN traffic, so I think we're fine. =C2=A0And keep in mind, once the = system admin has put the VF device in trunk vlan mode, the VF is no lon= ger allowed, as a policy implemented in the PF driver, to set any other= VLAN filters. =C2=A0Even if it did, it wouldn't work due to the operat= ional characteristics of the VF device HW. > > The methods by which the ixgbe driver, as a fully featured Physical F= unction device, are quite a bit more varied. =C2=A0I believe you're thi= nking of the VF device as a typical Ethernet device and that is just no= t the case. Yes, I think you're right. Thanks for the explanation.