From mboxrd@z Thu Jan  1 00:00:00 1970
From: Sagi Grimberg <sagig@dev.mellanox.co.il>
Subject: Re: [PATCH 09/14] target/configfs: Expose protection device attributes
Date: Sun, 12 Jan 2014 14:18:15 +0200
Message-ID: <52D28807.2000004@dev.mellanox.co.il>
References: <1389212157-14540-1-git-send-email-nab@daterainc.com>	<1389212157-14540-10-git-send-email-nab@daterainc.com> <yq161prr1p8.fsf@sermon.lab.mkp.net>
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To: "Martin K. Petersen" <martin.petersen@oracle.com>, "Nicholas A. Bellinger" <nab@daterainc.com>
Cc: target-devel <target-devel@vger.kernel.org>, linux-scsi <linux-scsi@vger.kernel.org>, linux-kernel <linux-kernel@vger.kernel.org>, Christoph Hellwig <hch@lst.de>, Hannes Reinecke <hare@suse.de>, Sagi Grimberg <sagig@mellanox.com>, Or Gerlitz <ogerlitz@mellanox.com>, Nicholas Bellinger <nab@linux-iscsi.org>
List-Id: linux-scsi@vger.kernel.org

<SNIP>

> nab> This patch adds support for exposing DIF protection device
> nab> attributes via configfs.  This includes:
>
> nab>    pi_prot_type: Protection Type (0, 1, 3 currently support)
> nab>    pi_prot_version: Protection Version (DIF v1 currently supported)
>
> What's DIF v2?
>
> nab>    pi_guard_type: Guard Type (1=DIF CRC, 2=IP CRC)
>
> The IP checksum is only supported by DIX between OS and initiator, not
> by the target. I guess we could signal to the initiator via a
> vendor-private VPD that IP checksum is supported directly. But now what
> we have hardware-accelerated T10 CRC I don't think it's a big deal.

shouldn't it stick around if it is not deprecated yet, the transport is 
required to support ip-csum->CRC conversion anyhow.

> (scsi_debug supports IP checksum because it's both initiator and
> target).
>