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From: Bing Zhao <bingz@nvidia.com>
To: NBU-Contact-Thomas Monjalon <thomas@monjalon.net>
Cc: Ori Kam <orika@nvidia.com>,
	"ferruh.yigit@intel.com" <ferruh.yigit@intel.com>,
	"arybchenko@solarflare.com" <arybchenko@solarflare.com>,
	"mdr@ashroe.eu" <mdr@ashroe.eu>,
	"nhorman@tuxdriver.com" <nhorman@tuxdriver.com>,
	"bernard.iremonger@intel.com" <bernard.iremonger@intel.com>,
	"beilei.xing@intel.com" <beilei.xing@intel.com>,
	"wenzhuo.lu@intel.com" <wenzhuo.lu@intel.com>,
	"dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH v3 2/6] ethdev: add new attributes to hairpin config
Date: Tue, 13 Oct 2020 13:21:31 +0000
Message-ID: <CY4PR1201MB0072920B644066D003949A61D0040@CY4PR1201MB0072.namprd12.prod.outlook.com> (raw)
In-Reply-To: <1745030.Et98dJ8b6a@thomas>

Hi Thomas,

> -----Original Message-----
> From: Thomas Monjalon <thomas@monjalon.net>
> Sent: Tuesday, October 13, 2020 8:42 PM
> To: Bing Zhao <bingz@nvidia.com>
> Cc: Ori Kam <orika@nvidia.com>; ferruh.yigit@intel.com;
> arybchenko@solarflare.com; mdr@ashroe.eu; nhorman@tuxdriver.com;
> bernard.iremonger@intel.com; beilei.xing@intel.com;
> wenzhuo.lu@intel.com; dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH v3 2/6] ethdev: add new attributes to
> hairpin config
> 
> External email: Use caution opening links or attachments
> 
> 
> 13/10/2020 14:29, Bing Zhao:
> > From: Thomas Monjalon <thomas@monjalon.net>
> > > 08/10/2020 14:05, Bing Zhao:
> > > >  struct rte_eth_hairpin_conf {
> > > > -     uint16_t peer_count; /**< The number of peers. */
> > > > +     uint32_t peer_count:16; /**< The number of peers. */
> > >
> > > Why not keeping uint16_t?
> >
> > The inside structure has a multiple of 4B, and the peer_count now
> only takes about 2B. AFAIK, usually, the structure will have an
> aligned length/offset and there will be some padding between the 2B
> + (2B pad) + 4B * 32 or 2B + (2B +2B) * 32 + 2B, depending on the
> compiler.
> > I changed to bit fields of a u32 due to the two facts:
> > 1. Using the 2B and keep the whole structure aligned. No waste
> except the reserved bits.
> > 2. Only u32 with bit fields is standard.
> 
> Oh I see, this is because u16 bit fields are not standard?

In some compiler, it is supported. But in the old compiler, it might not and some warning will be raised.
" nonstandard extension used : bit-field types other than int "

"
The following properties of bit fields are implementation-defined:

Whether bit fields of type int are treated as signed or unsigned
Whether types other than int, signed int, unsigned int, and _Bool (since C99) are permitted
"
In C11, it should be supported already.

> 
> > > > +     uint32_t tx_explicit:1; /**< Explicit TX flow rule mode.
> */
> > > > +     uint32_t manual_bind:1; /**< Manually bind hairpin
> queues.
> > > */
> > >
> > > Please describe more the expectations of these bits:
> > > What is changed at ethdev or PMD level?
> >
> > In ethdev level, there is almost no change. This attribute will be
> passed to PMD directly through the function pointer.
> > In PMD level, these bits should be checked and better to be saved.
> And the attribute fields should be checked for per queue pair and
> all the queues, and each queue pair should have the same attributes
> configured to make the behavior aligned. But it depends on the PMD
> itself to decide if all the queue pairs between a port pair should
> have the same attributes, or even all the queues from / to same port
> of all hairpin port pairs.
> > If manual_bind is not set, then the PMD will try to bind the
> queues and enable hairpin during device start stage and there is no
> need to call the bind / unbind API.
> > If tx_explicit is set, the application should insert the RX flow
> rules and TX flow rules separately and connect the RX/TX logic
> connection together.
> >
> > > What the application is supposed to do?
> >
> > The application should specify the new two attributes during the
> queue setup. And also, it could leave it unset (0 by default) to
> keep the behavior compatible with the previous release.
> > If manual_bind is set, then it is the application's responsibility
> to call the bind / unbind API to enable / disable the hairpin
> between specific ports.
> > If tx_explicit is set, as described above, the application should
> maintain the flows logic to make hairpin work as expected, e.g.,
> they can choose metadata (not the only method), in the RX flow, the
> metadata is set and in the TX flow, it is used for matching. Then
> even if the headers are changed with NAT action or encap, the
> hairpin function could work as expected.
> >
> > > Why choosing one mode or the other?
> >
> > If the application wants to have the full control of hairpin flows,
> it could chose the explicit TX flow mode.
> > If two or more ports involved into the hairpin, it is suggested to
> use the manual bind.
> > Please note, the actual supported attributes denpend on the PMD
> and HW.
> 
> The application impact must be described shortly in doxygen please.
> 
> 

OK, sure. I added into the commit message. I will also describe it shortly in the doc.

Thanks

  reply	other threads:[~2020-10-13 13:21 UTC|newest]

Thread overview: 81+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-11  4:51 [dpdk-dev] [RFC] introduce support for hairpin between two ports Bing Zhao
2020-09-13 15:48 ` [dpdk-dev] [RFC PATCH v2 0/4] " Bing Zhao
2020-09-13 15:48   ` [dpdk-dev] [RFC PATCH v2 1/4] ethdev: add support for flow item transmit queue Bing Zhao
2020-09-13 15:48   ` [dpdk-dev] [RFC PATCH v2 2/4] testpmd: add item transmit queue in flow CLI Bing Zhao
2020-09-13 15:48   ` [dpdk-dev] [RFC PATCH v2 3/4] ethdev: add hairpin bind APIs Bing Zhao
2020-09-13 15:49   ` [dpdk-dev] [RFC PATCH v2 4/4] ethdev: add new attributes to hairpin queues config Bing Zhao
2020-10-01  0:25   ` [dpdk-dev] [PATCH 0/4] introduce support for hairpin between two ports Bing Zhao
2020-10-01  0:25     ` [dpdk-dev] [PATCH 1/4] ethdev: add hairpin bind and unbind APIs Bing Zhao
2020-10-04  9:20       ` Ori Kam
2020-10-07 11:21         ` Bing Zhao
2020-10-07 11:42           ` Ori Kam
2020-10-01  0:26     ` [dpdk-dev] [PATCH 2/4] ethdev: add new attributes to hairpin config Bing Zhao
2020-10-04  9:22       ` Ori Kam
2020-10-07 11:32         ` Bing Zhao
2020-10-01  0:26     ` [dpdk-dev] [PATCH 3/4] ethdev: add APIs for hairpin queue operation Bing Zhao
2020-10-04  9:34       ` Ori Kam
2020-10-07 11:34         ` Bing Zhao
2020-10-01  0:26     ` [dpdk-dev] [PATCH 4/4] app/testpmd: change hairpin queues setup Bing Zhao
2020-10-04  9:39       ` Ori Kam
2020-10-07 11:36         ` Bing Zhao
2020-10-04  9:45     ` [dpdk-dev] [PATCH 0/4] introduce support for hairpin between two ports Ori Kam
2020-10-08  8:51     ` [dpdk-dev] [PATCH v2 0/6] " Bing Zhao
2020-10-08  8:51       ` [dpdk-dev] [PATCH v2 1/6] ethdev: add hairpin bind and unbind APIs Bing Zhao
2020-10-08  9:07         ` Ori Kam
2020-10-08  8:51       ` [dpdk-dev] [PATCH v2 2/6] ethdev: add new attributes to hairpin config Bing Zhao
2020-10-08  9:23         ` Ori Kam
2020-10-08  8:51       ` [dpdk-dev] [PATCH v2 3/6] ethdev: add API to get hairpin peer ports list Bing Zhao
2020-10-08  9:40         ` Ori Kam
2020-10-08  8:51       ` [dpdk-dev] [PATCH v2 4/6] ethdev: add APIs for hairpin queue operation Bing Zhao
2020-10-08  9:44         ` Ori Kam
2020-10-08  8:51       ` [dpdk-dev] [PATCH v2 5/6] app/testpmd: change hairpin queues setup Bing Zhao
2020-10-08  9:45         ` Ori Kam
2020-10-08  8:51       ` [dpdk-dev] [PATCH v2 6/6] doc: update for two ports hairpin mode Bing Zhao
2020-10-08  9:47         ` Ori Kam
2020-10-08 12:05       ` [dpdk-dev] [PATCH v3 0/6] introduce support for hairpin between two ports Bing Zhao
2020-10-08 12:05         ` [dpdk-dev] [PATCH v3 1/6] ethdev: add hairpin bind and unbind APIs Bing Zhao
2020-10-14 14:35           ` Thomas Monjalon
2020-10-15  2:56             ` Bing Zhao
2020-10-15  7:31               ` Thomas Monjalon
2020-10-08 12:05         ` [dpdk-dev] [PATCH v3 2/6] ethdev: add new attributes to hairpin config Bing Zhao
2020-10-12 21:37           ` Thomas Monjalon
2020-10-13 12:29             ` Bing Zhao
2020-10-13 12:41               ` Thomas Monjalon
2020-10-13 13:21                 ` Bing Zhao [this message]
2020-10-08 12:05         ` [dpdk-dev] [PATCH v3 3/6] ethdev: add API to get hairpin peer ports list Bing Zhao
2020-10-08 12:31           ` Ori Kam
2020-10-08 12:05         ` [dpdk-dev] [PATCH v3 4/6] ethdev: add APIs for hairpin queue operation Bing Zhao
2020-10-08 12:05         ` [dpdk-dev] [PATCH v3 5/6] app/testpmd: change hairpin queues setup Bing Zhao
2020-10-08 12:05         ` [dpdk-dev] [PATCH v3 6/6] doc: update for two ports hairpin mode Bing Zhao
2020-10-12 21:30           ` Thomas Monjalon
2020-10-13  1:13             ` Bing Zhao
2020-10-13  6:37               ` Thomas Monjalon
2020-10-13  6:40                 ` Bing Zhao
2020-10-13 16:19         ` [dpdk-dev] [PATCH v4 0/5] introduce support for hairpin between two ports Bing Zhao
2020-10-13 16:19           ` [dpdk-dev] [PATCH v4 1/5] ethdev: add hairpin bind and unbind APIs Bing Zhao
2020-10-14 14:43             ` Thomas Monjalon
2020-10-15  2:59               ` Bing Zhao
2020-10-13 16:19           ` [dpdk-dev] [PATCH v4 2/5] ethdev: add new attributes to hairpin config Bing Zhao
2020-10-13 16:19           ` [dpdk-dev] [PATCH v4 3/5] ethdev: add API to get hairpin peer ports list Bing Zhao
2020-10-14 15:02             ` Thomas Monjalon
2020-10-15  4:03               ` Bing Zhao
2020-10-13 16:19           ` [dpdk-dev] [PATCH v4 4/5] ethdev: add APIs for hairpin queue operation Bing Zhao
2020-10-13 16:19           ` [dpdk-dev] [PATCH v4 5/5] app/testpmd: change hairpin queues setup Bing Zhao
2020-10-15  5:35     ` [dpdk-dev] [PATCH v5 0/5] introduce support for hairpin between two ports Bing Zhao
2020-10-15  5:35       ` [dpdk-dev] [PATCH v5 1/5] ethdev: add hairpin bind and unbind APIs Bing Zhao
2020-10-15 10:34         ` Thomas Monjalon
2020-10-15 11:39           ` Bing Zhao
2020-10-15  5:35       ` [dpdk-dev] [PATCH v5 2/5] ethdev: add new attributes to hairpin config Bing Zhao
2020-10-15 10:46         ` Thomas Monjalon
2020-10-15 13:45           ` Bing Zhao
2020-10-15  5:35       ` [dpdk-dev] [PATCH v5 3/5] ethdev: add API to get hairpin peer ports list Bing Zhao
2020-10-15  5:35       ` [dpdk-dev] [PATCH v5 4/5] ethdev: add APIs for hairpin queue operation Bing Zhao
2020-10-15  5:35       ` [dpdk-dev] [PATCH v5 5/5] app/testpmd: change hairpin queues setup Bing Zhao
2020-10-15 13:08     ` [dpdk-dev] [PATCH v6 0/5] introduce support for hairpin between two ports Bing Zhao
2020-10-15 13:08       ` [dpdk-dev] [PATCH v6 1/5] ethdev: add hairpin bind and unbind APIs Bing Zhao
2020-10-15 13:08       ` [dpdk-dev] [PATCH v6 2/5] ethdev: add new attributes to hairpin config Bing Zhao
2020-10-15 13:08       ` [dpdk-dev] [PATCH v6 3/5] ethdev: add API to get hairpin peer ports list Bing Zhao
2020-10-15 13:08       ` [dpdk-dev] [PATCH v6 4/5] ethdev: add APIs for hairpin queue operation Bing Zhao
2020-10-15 13:08       ` [dpdk-dev] [PATCH v6 5/5] app/testpmd: change hairpin queues setup Bing Zhao
2020-10-15 23:03       ` [dpdk-dev] [PATCH v6 0/5] introduce support for hairpin between two ports Ferruh Yigit
2020-10-16  1:34         ` Bing Zhao

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