netdev - Re: [RFC PATCH net-next v6 4/4] netvsc: refactor notifier/event handling code to use the bypass framework

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 11 Apr 2018 09:50:20 +0200
From:   Jiri Pirko <jiri@...nulli.us>
To:     "Michael S. Tsirkin" <mst@...hat.com>
Cc:     Stephen Hemminger <stephen@...workplumber.org>,
        Sridhar Samudrala <sridhar.samudrala@...el.com>,
        davem@...emloft.net, netdev@...r.kernel.org,
        virtualization@...ts.linux-foundation.org,
        virtio-dev@...ts.oasis-open.org, jesse.brandeburg@...el.com,
        alexander.h.duyck@...el.com, kubakici@...pl, jasowang@...hat.com,
        loseweigh@...il.com
Subject: Re: [RFC PATCH net-next v6 4/4] netvsc: refactor notifier/event
 handling code to use the bypass framework

Wed, Apr 11, 2018 at 01:28:51AM CEST, mst@...hat.com wrote:
>On Tue, Apr 10, 2018 at 02:26:08PM -0700, Stephen Hemminger wrote:
>> On Tue, 10 Apr 2018 11:59:50 -0700
>> Sridhar Samudrala <sridhar.samudrala@...el.com> wrote:
>> 
>> > Use the registration/notification framework supported by the generic
>> > bypass infrastructure.
>> > 
>> > Signed-off-by: Sridhar Samudrala <sridhar.samudrala@...el.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.
>
>Interesting. Does this mean udev must act within a specific time window
>then?

Yeah. That is scarry. Also, wrong.


>
>> 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.