Subject: Re: [virtio-dev] Re: [Qemu-devel] [PATCH] qemu: Introduce VIRTIO_NET_F_STANDBY feature bit to virtio_net

From: "Michael S. Tsirkin" <[email-masked]>
Date: Tue, 26 Jun 2018 20:50:20 +0300

On Tue, Jun 26, 2018 at 05:08:13PM +0200, Cornelia Huck wrote:
> On Fri, 22 Jun 2018 17:05:04 -0700
> Siwei Liu <[email-masked]> wrote:
> 
> > On Fri, Jun 22, 2018 at 3:33 PM, Michael S. Tsirkin <[email-masked]> 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