netdev - Re: [patch net-next v2 8/9] switchdev: introduce Netlink API

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: <20140922221727.GA4708@casper.infradead.org>
Date:	Mon, 22 Sep 2014 23:17:27 +0100
From:	Thomas Graf <tgraf@...g.ch>
To:	Tom Herbert <therbert@...gle.com>
Cc:	Alexei Starovoitov <alexei.starovoitov@...il.com>,
	Jiri Pirko <jiri@...nulli.us>,
	John Fastabend <john.r.fastabend@...el.com>,
	Jamal Hadi Salim <jhs@...atatu.com>,
	"netdev@...r.kernel.org" <netdev@...r.kernel.org>,
	"David S. Miller" <davem@...emloft.net>,
	Neil Horman <nhorman@...driver.com>,
	Andy Gospodarek <andy@...yhouse.net>,
	Daniel Borkmann <dborkman@...hat.com>,
	Or Gerlitz <ogerlitz@...lanox.com>,
	Jesse Gross <jesse@...ira.com>,
	Pravin Shelar <pshelar@...ira.com>,
	Andy Zhou <azhou@...ira.com>,
	Ben Hutchings <ben@...adent.org.uk>,
	Stephen Hemminger <stephen@...workplumber.org>,
	Jeff Kirsher <jeffrey.t.kirsher@...el.com>,
	Vladislav Yasevich <vyasevic@...hat.com>,
	Cong Wang <xiyou.wangcong@...il.com>,
	Eric Dumazet <edumazet@...gle.com>,
	Scott Feldman <sfeldma@...ulusnetworks.com>,
	Florian Fainelli <f.fainelli@...il.com>,
	Roopa Prabhu <roopa@...ulusnetworks.com>,
	John Linville <linville@...driver.com>,
	"dev@...nvswitch.org" <dev@...nvswitch.org>,
	Jason Wang <jasowang@...hat.com>,
	"Eric W. Biederman" <ebiederm@...ssion.com>,
	Nicolas Dichtel <nicolas.dichtel@...nd.com>,
	ryazanov.s.a@...il.com, Lennert Buytenhek <buytenh@...tstofly.org>,
	aviadr@...lanox.com, Felix Fietkau <nbd@...nwrt.org>,
	Neil Jerram <Neil.Jerram@...aswitch.com>, ronye@...lanox.com,
	simon.horman@...ronome.com,
	Alexander Duyck <alexander.h.duyck@...el.com>
Subject: Re: [patch net-next v2 8/9] switchdev: introduce Netlink API

On 09/22/14 at 08:10am, Tom Herbert wrote:
> Thomas, can you (or someone else) quantify what the host case is. I
> suppose there may be merit in using a switch on NIC for kernel bypass
> scenarios, but I'm still having a hard time understanding how this
> could be integrated into the host stack with benefits that outweigh

Personally my primary interest is on lxc and vm based workloads w/
end to end encryption, encap, distributed L3 and NAT, and policy
enforcement including service graphs which imply both east-west
and north-south traffic patterns on a host. The usual I guess ;-)

> complexity. The history of stateful offloads in NICs is not great, and
> encapsulation (stuffing a few bytes of header into a packet) is in
> itself not nearly an expensive enough operation to warrant offloading

No argument here. The direct benchmark comparisons I've measured showed
only around 2% improvement.

What makes stateful offload interesting to me is that the final
desintation of a packet is known at RX and can be redirected to a
queue or VF. This allows to build packet batches on shared pages
while preserving the securiy model.

Will the gains outweigh complexity? I hope so but I don't know for
sure. If you have insights, let me know. What I know for sure is that
I don't want to rely on a kernel bypass for the above.

> to the NIC. Personally, I wish if NIC vendors are going to focus on
> stateful offload I rather see it be for encryption which I believe
> currently does warrant offload at 40G and higher speeds.

Agreed. I would like to be see a focus on both.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html