From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stephen Hemminger <stephen@networkplumber.org>
Subject: Re: [RFC PATCH net-next v6 4/4] netvsc: refactor notifier/event
	handling code to use the bypass framework
Date: Tue, 10 Apr 2018 14:26:08 -0700
Message-ID: <20180410142608.50f15b45__28609.4832387336$1523395474$gmane$org@xeon-e3>
References: <1523386790-12396-1-git-send-email-sridhar.samudrala@intel.com>
	<1523386790-12396-5-git-send-email-sridhar.samudrala@intel.com>
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To: Sridhar Samudrala <sridhar.samudrala@intel.com>
Cc: alexander.h.duyck@intel.com, virtio-dev@lists.oasis-open.org, jiri@resnulli.us, mst@redhat.com, kubakici@wp.pl, netdev@vger.kernel.org, virtualization@lists.linux-foundation.org, loseweigh@gmail.com, davem@davemloft.net
List-Id: virtualization@lists.linuxfoundation.org

On Tue, 10 Apr 2018 11:59:50 -0700
Sridhar Samudrala <sridhar.samudrala@intel.com> wrote:

> Use the registration/notification framework supported by the generic
> bypass infrastructure.
> 
> Signed-off-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
> ---

Thanks for doing this.  Your current version has couple show stopper
issues.

First, the slave device is instantly taking over the slave.
This doesn't allow udev/systemd to do its device rename of the slave
device. Netvsc uses a delayed work to workaround this.

Secondly, the select queue needs to call queue selection in VF.
The bonding/teaming logic doesn't work well for UDP flows.
Commit b3bf5666a510 ("hv_netvsc: defer queue selection to VF")
fixed this performance problem.

Lastly, more indirection is bad in current climate.

I am not completely adverse to this but it needs to be fast, simple
and completely transparent.