From mboxrd@z Thu Jan 1 00:00:00 1970 From: Subject: Re: [PATCH net-next] net: Add phys_port identifier to struct net_device and export it to sysfs Date: Tue, 2 Jul 2013 07:40:40 -0700 Message-ID: <20130702144018.GA11970@fedora18-dev.oslab.blr.amer.dell.com> References: <20130617181004.GA1364@fedora-17-guest.dell.com> <51BF59D8.10806@gmail.com> <1371656194.1956.25.camel@bwh-desktop.uk.level5networks.com> <1371670481.1956.105.camel@bwh-desktop.uk.level5networks.com> <51C4892B.8000806@gmail.com> <51CDBAE9.1020807@gmail.com> <1372439353.1937.21.camel@bwh-desktop.uk.level5networks.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Cc: , , To: Return-path: Received: from ausxippc101.us.dell.com ([143.166.85.207]:36449 "EHLO ausxippc101.us.dell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752165Ab3GBOo5 convert rfc822-to-8bit (ORCPT ); Tue, 2 Jul 2013 10:44:57 -0400 In-Reply-To: <1372439353.1937.21.camel@bwh-desktop.uk.level5networks.com> Sender: netdev-owner@vger.kernel.org List-ID: On Fri, Jun 28, 2013 at 10:39:13PM +0530, Ben Hutchings wrote: > > On Fri, 2013-06-28 at 09:33 -0700, John Fastabend wrote: [...] > > > John, I think it will be useful in the SRIOV scenario also when more > > than one VF from two NICs are assigned to the guest. phys_port would be > > helpful in choosing the correct slave interfaces when host details are > > not available. > > > > OK. But I'm not sure why you would assign two VFs from the same NIC > > to a guest? This doesn't seem like a good configuration for failover > > because if one VF fails it seems likely both will fail. Maybe there > > are some benefits for load balancing? Or my assumption both VFs will > > fail is wrong. > > I believe Narendra is trying to provide hints to the guest that would > allow it to avoid such broken bonding configurations. But it is > certainly a good question why there would be two VFs assigned in the > first place. > > I could imagine passing through two VFs for the same physical port that > have been assigned to different VLANs. But then you wouldn't want to > bond two devices that are on different VLANs, whether or not they're > using the same port! I was thinking of the following scenario in the guest. bond0 = NIC1 VF0 + NIC2 VF0 bond1 = NIC1 VF1 + NIC2 VF1 bond0 and bond1 are on different VLANs. The phys_port identifier hint would be helpful to the guest in selecting the correct slaves for the above configuration. Sorry if I missed any detail here. > > > Anyways it does seem useful in the partitioning case with multiple > > physical functions. Yes, I agree. > > I was thinking it could also help to support the hybrid guest networking > mode. In this mode, the guest gets a PV (e.g. virtio_net) device and a > VF bridged to the same physical port, and the VF can be removed before > the guest is migrated (and maybe reinserted if there's a VF available on > the new host) without a major disruption to the guest. In that case the > guest *should* bond together the two net devices that have the same > physical port ID but different drivers. This would require the physical > port ID to be propagated through macvtap/macvlan and virtio. > > Ben. > > -- > Ben Hutchings, Staff Engineer, Solarflare > Not speaking for my employer; that's the marketing department's job. > They asked us to note that Solarflare product names are trademarked. > > -- > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- With regards, Narendra K Linux Engineering Dell Inc.