netdev - Re: [RFC PATCH] virtio_net: Extend virtio to use VF datapath when available

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]

Message-ID: <20171219114627.76dac732@xeon-e3>
Date:   Tue, 19 Dec 2017 11:46:27 -0800
From:   Stephen Hemminger <stephen@...workplumber.org>
To:     "Samudrala, Sridhar" <sridhar.samudrala@...el.com>
Cc:     David Miller <davem@...emloft.net>, mst@...hat.com,
        netdev@...r.kernel.org, virtualization@...ts.linux-foundation.org,
        alexander.duyck@...il.com, jesse.brandeburg@...el.com
Subject: Re: [RFC PATCH] virtio_net: Extend virtio to use VF datapath when
 available

On Tue, 19 Dec 2017 11:42:33 -0800
"Samudrala, Sridhar" <sridhar.samudrala@...el.com> wrote:

> On 12/19/2017 10:41 AM, Stephen Hemminger wrote:
> > On Tue, 19 Dec 2017 13:21:17 -0500 (EST)
> > David Miller <davem@...emloft.net> wrote:
> >  
> >> From: Stephen Hemminger <stephen@...workplumber.org>
> >> Date: Tue, 19 Dec 2017 09:55:48 -0800
> >>  
> >>> could be 10ms, just enough to let udev do its renaming  
> >> Please, move to some kind of notification or event based handling of
> >> this problem.
> >>
> >> No delay is safe, what if userspace gets swapped out or whatever
> >> else might make userspace stall unexpectedly?
> >>  
> > The plan is to remove the delay and do the naming in the kernel.
> > This was suggested by Lennart since udev is only doing naming policy
> > because kernel names were not repeatable.
> >
> > This makes the VF show up as "ethN_vf" on Hyper-V which is user friendly.
> >
> > Patch is pending.  
> Do we really need to delay the setup until the name is changed?
> Can't we call dev_set_mtu() and dev_open() until dev_change_name() is done?
> 
> Thanks
> Sridhar

You can call dev_set_mtu, but when dev_open is done the device name
can not be changed by userspace.