From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: [virtio-dev] Re: [Qemu-devel] [PATCH] qemu: Introduce
	VIRTIO_NET_F_STANDBY feature bit to virtio_net
Date: Tue, 26 Jun 2018 20:50:20 +0300
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Cc: Alexander Duyck <alexander.h.duyck@intel.com>,
	virtio-dev@lists.oasis-open.org, Jiri Pirko <jiri@resnulli.us>,
	konrad.wilk@oracle.com, Jakub Kicinski <kubakici@wp.pl>,
	"Samudrala, Sridhar" <sridhar.samudrala@intel.com>,
	qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org,
	Siwei Liu <loseweigh@gmail.com>,
	Venu Busireddy <venu.busireddy@oracle.com>,
	Netdev <netdev@vger.kernel.org>, boris.ostrovsky@oracle.com,
	aaron.f.brown@intel.com, Joao Martins <joao.m.martins@oracle.com>
To: Cornelia Huck <cohuck@redhat.com>
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On Tue, Jun 26, 2018 at 05:08:13PM +0200, Cornelia Huck wrote:
> On Fri, 22 Jun 2018 17:05:04 -0700
> Siwei Liu <loseweigh@gmail.com> wrote:
> 
> > On Fri, Jun 22, 2018 at 3:33 PM, Michael S. Tsirkin <mst@redhat.com> wrote:
> > > I suspect the diveregence will be lost on most users though
> > > simply because they don't even care about vfio. They just
> > > want things to go fast.  
> > 
> > Like Jason said, VF isn't faster than virtio-net in all cases. It
> > depends on the workload and performance metrics: throughput, latency,
> > or packet per second.
> 
> So, will it be guest/admin-controllable then where the traffic flows
> through? Just because we do have a vf available after negotiation of
> the feature bit, it does not necessarily mean we want to use it? Do we
> (the guest) even want to make it visible in that case?

I think these ideas belong to what Alex Duyck wanted to do:
some kind of advanced device that isn't tied to
any network interfaces and allows workload and performance
specific tuning.

Way out of scope for a simple failover, and more importantly,
no one is looking at even enumerating the problems involved,
much less solving them.

-- 
MST