From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <thomas.monjalon@6wind.com>
Received: from mail-wg0-f43.google.com (mail-wg0-f43.google.com [74.125.82.43])
 by dpdk.org (Postfix) with ESMTP id 5996D7E9A
 for <dev@dpdk.org>; Tue, 28 Oct 2014 14:09:02 +0100 (CET)
Received: by mail-wg0-f43.google.com with SMTP id n12so825443wgh.2
 for <dev@dpdk.org>; Tue, 28 Oct 2014 06:17:49 -0700 (PDT)
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
 d=1e100.net; s=20130820;
 h=x-gm-message-state:from:to:cc:subject:date:message-id:organization
 :user-agent:in-reply-to:references:mime-version
 :content-transfer-encoding:content-type;
 bh=KfXfqLswI31nJijpWvCd6cNNeZ/lBZSoAJYZXbflV3U=;
 b=UPvK89AWjRiim8ha3nP2WA3bKtE14Z6aK+SZ1Y//3d46BG9Jlcaea440GAlnd7ywkg
 iTT4makA7WVVLvXmyJTgOl2ZXiZ3zqxdqhfWIbtKmrWJbEySB/8BQj6UfdVnjjmDZO3h
 TNQO01i2fN5cj9v2sAfWmq3l2EttBcp2/0MzYpoFy9FSkGPyBusA/oBq2/JYHmJ/VI6T
 Omap7OR8fB8nKFM6USP2xlRsyT3W3EUMRIls+MnWq/eUC5w+axQdR0ywn52qt6G+Nos0
 4U2G7GPkD+79bSVVpRW7ECyEQEDAZh2xYGT6XPyhlmIYoOIssHALVqmyuBGjWqN0O3Oc
 9SYw==
X-Gm-Message-State: ALoCoQljHt/6GVlZRepyUeuauvavGc0GGdSNbVvek8RJQ6iGbo2K1aUQrItaCCTa9RdZ7MZ4DsWy
X-Received: by 10.194.63.229 with SMTP id j5mr4219689wjs.23.1414502269365;
 Tue, 28 Oct 2014 06:17:49 -0700 (PDT)
Received: from xps13.localnet (136-92-190-109.dsl.ovh.fr. [109.190.92.136])
 by mx.google.com with ESMTPSA id m6sm2188489wiy.16.2014.10.28.06.17.48
 for <multiple recipients>
 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128);
 Tue, 28 Oct 2014 06:17:48 -0700 (PDT)
From: Thomas Monjalon <thomas.monjalon@6wind.com>
To: "Wu, Jingjing" <jingjing.wu@intel.com>
Date: Tue, 28 Oct 2014 14:17:31 +0100
Message-ID: <1719360.TZiYukypUI@xps13>
Organization: 6WIND
User-Agent: KMail/4.14.2 (Linux/3.17.1-1-ARCH; KDE/4.14.2; x86_64; ; )
In-Reply-To: <9BB6961774997848B5B42BEC655768F8B2467E@SHSMSX104.ccr.corp.intel.com>
References: <1411711418-12881-1-git-send-email-jingjing.wu@intel.com>
 <3042428.RIRLHjG5pO@xps13>
 <9BB6961774997848B5B42BEC655768F8B2467E@SHSMSX104.ccr.corp.intel.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 7Bit
Content-Type: text/plain; charset="us-ascii"
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH v4 04/21] ethdev: define structures for
	adding/deleting flow director
X-BeenThere: dev@dpdk.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: patches and discussions about DPDK <dev.dpdk.org>
List-Unsubscribe: <http://dpdk.org/ml/options/dev>,
 <mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://dpdk.org/ml/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <http://dpdk.org/ml/listinfo/dev>,
 <mailto:dev-request@dpdk.org?subject=subscribe>
X-List-Received-Date: Tue, 28 Oct 2014 13:09:02 -0000

2014-10-28 01:18, Wu, Jingjing:
> From: Thomas Monjalon [mailto:thomas.monjalon@6wind.com]
> > 2014-10-22 09:01, Jingjing Wu:
> > > +#define RTE_ETH_FDIR_MAX_FLEXWORD_LEN  8
> > > +/**
> > > + * A structure used to contain extend input of flow  */ struct
> > > +rte_eth_fdir_flow_ext {
> > > +	uint16_t vlan_tci;
> > > +	uint8_t num_flexwords;         /**< number of flexwords */
> > > +	uint16_t flexwords[RTE_ETH_FDIR_MAX_FLEXWORD_LEN];
> > > +	uint16_t dest_id;              /**< destination vsi or pool id*/
> > > +};
> > 
> > Flexword should be explained.
> > 
> The flexword means the application can choose a part of packet's payload
> as key words to compare match. It is flexible.
> In Ixgbe, the flexwords is 1 word (2 bytes), while Fortville extend it to 8 words.

OK. The problem is that I don't know how to fill the flexwords bytes.
You should explain it in the doxygen comment.
You say it's flexible. Is it usable with a non-IP packet?
Please explain constraints and syntax.

> > > +struct rte_eth_fdir_input {
> > > +	enum rte_eth_flow_type flow_type;      /**< type of flow */
> > > +	union rte_eth_fdir_flow flow;          /**< specific flow structure */
> > > +	struct rte_eth_fdir_flow_ext flow_ext; /**< specific flow info */ };
> > 
> > I don't understand the logic behind flow/flow_ext.
> > Why flow_ext is not merged into flow ?
> > 
> The flow defines the key words for each flow_type, while the flow_ext
> has other elements which have little to do with flow_type.
> For example the flexword, dst_id (can used as pool id), I think it is not
> reasonable to make it as an element in the flow.

Sorry, I don't understand.
flow and flow_ext are associated with a flow type.
The comments are "specific flow structure" and "specific flow info" which
doesn't bring any useful information.

> > > +/**
> > > + * Flow director report status
> > > + */
> > > +enum rte_eth_fdir_status {
> > > +	RTE_ETH_FDIR_NO_REPORT_STATUS = 0, /**< no report FDIR. */
> > > +	RTE_ETH_FDIR_REPORT_FD_ID,         /**< only report FD ID. */
> > > +	RTE_ETH_FDIR_REPORT_FD_ID_FLEX_4,  /**< report FD ID and 4 flex bytes. */
> > > +	RTE_ETH_FDIR_REPORT_FLEX_8,        /**< report 8 flex bytes. */
> > > +};
> > 
> > The names and explanations are cryptics.
> 
> The enum defines what will be reported when FIR match.
> Can be FD_ID or flex bytes

Just to be sure, have you understood that I'm requesting more explanations
in the comments to allow users of your API to understand it?

> > > +/**
> > > + * A structure used to define an action when match FDIR packet filter.
> > > + */
> > > +struct rte_eth_fdir_action {
> > > +	uint16_t rx_queue;        /**< queue assigned to if fdir match. */
> > > +	uint16_t cnt_idx;         /**< statistic counter index */
> > 
> > what is the action of "statistic counter index"?
> 
> When FD match happened, the counter will increase.

Which counter?
Which value should be set in cnt_idx?

> Fortville can support to configure the different counter for filter entries.
> The action is a part of a filter entry, so this element means which counter the entry will use.

I perfectly understand that you are writing some code to allow usage of
Fortville features through DPDK. Thank you for bringing new features.
But I want to know if I'm allowed to use it without reading the Fortville datasheet?
And could this API be shared by other hardwares (e.g. ixgbe)?

> > > +	uint8_t  drop;            /**< accept or reject */
> > > +	uint8_t  flex_off;        /**< offset used define words to report */
> > 
> > still difficult to understand the flex logic
> 
> Just as mentioned above, Fortville can support 8 flex words comparing.
> But for reporting, only 4 or 8 bytes in the flex words can be reported.
> So need to specify the offset to choose the 4 or 8 bytes.

I don't even know what are the meaning of these 4 or 8 bytes.
Please don't consider that every DPDK user know the Fortville datasheet.

> > > +/**
> > > + * A structure used to define the flow director filter entry by
> > > +filter_ctl API
> > > + * to support RTE_ETH_FILTER_FDIR with RTE_ETH_FILTER_ADD and
> > > + * RTE_ETH_FILTER_DELETE operations.
> > > + */
> > > +struct rte_eth_fdir_filter {
> > > +	uint32_t soft_id;                   /**< id */
> > 
> > Should the application handle the id numbering?
> > Why is it soft_id instead of id?
> 
> Yes, the soft_id is just id, is also reported id when entry match.
> The id is specified by user, and can be used to identify this entry,
> application should handle it.

OK, so explain it in comments.
Or better, generate and return the id when creating a filter.

Thanks
-- 
Thomas