From: <Narendra_K@Dell.com>
To: <bhutchings@solarflare.com>
Cc: <john.fastabend@gmail.com>, <netdev@vger.kernel.org>,
<john.r.fastabend@intel.com>
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 [thread overview]
Message-ID: <20130702144018.GA11970@fedora18-dev.oslab.blr.amer.dell.com> (raw)
In-Reply-To: <1372439353.1937.21.camel@bwh-desktop.uk.level5networks.com>
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.
next prev parent reply other threads:[~2013-07-02 14:44 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-17 18:10 [PATCH net-next] net: Add phys_port identifier to struct net_device and export it to sysfs Narendra_K
2013-06-17 18:47 ` John Fastabend
2013-06-19 14:29 ` Narendra_K
2013-06-19 15:36 ` Ben Hutchings
2013-06-19 18:53 ` Narendra_K
2013-06-19 19:34 ` Ben Hutchings
2013-06-19 21:37 ` Praveen_Paladugu
2013-06-21 17:11 ` John Fastabend
2013-06-25 17:33 ` Narendra_K
2013-06-28 16:33 ` John Fastabend
2013-06-28 17:09 ` Ben Hutchings
2013-07-02 14:40 ` Narendra_K [this message]
2013-07-11 20:39 ` Jiri Pirko
2013-07-15 15:34 ` Narendra_K
2013-07-21 5:55 ` Or Gerlitz
2013-07-21 7:24 ` Jiri Pirko
2013-07-21 11:14 ` Or Gerlitz
2013-07-21 14:48 ` Ben Hutchings
2013-07-21 20:29 ` Or Gerlitz
2013-07-21 20:50 ` Ben Hutchings
2013-07-22 11:46 ` Narendra_K
2013-07-22 11:49 ` Jiri Pirko
2013-07-22 15:48 ` Or Gerlitz
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