From mboxrd@z Thu Jan 1 00:00:00 1970 From: Panu Matilainen Subject: Re: [PATCH v3 0/2] slow data path communication between DPDK port and Linux Date: Wed, 16 Mar 2016 15:23:14 +0200 Message-ID: <56E95E42.9000206@redhat.com> References: <1455858349-14639-1-git-send-email-ferruh.yigit@intel.com> <56E917AD.2060701@redhat.com> <56E934E5.4080905@intel.com> <2637434.UE2LQEG9YB@xps13> <56E93FF2.8010501@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: dev@dpdk.org, David Marchand , Helin Zhang To: Ferruh Yigit , Thomas Monjalon Return-path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by dpdk.org (Postfix) with ESMTP id C5CB9558B for ; Wed, 16 Mar 2016 14:23:17 +0100 (CET) In-Reply-To: <56E93FF2.8010501@intel.com> List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 03/16/2016 01:13 PM, Ferruh Yigit wrote: > On 3/16/2016 10:45 AM, Thomas Monjalon wrote: >> 2016-03-16 10:26, Ferruh Yigit: >>> On 3/16/2016 8:22 AM, Panu Matilainen wrote: >>>> On 03/16/2016 10:19 AM, Ferruh Yigit wrote: >>>>> On 3/16/2016 7:26 AM, Panu Matilainen wrote: >>>>>> On 03/14/2016 05:32 PM, Ferruh Yigit wrote: >>>>>>> On 3/9/2016 11:17 AM, Ferruh Yigit wrote: >>>>>>>> This patch sent to keep record of latest status of the work. >>>>>>>> >>>>>>>> >>>>>>>> This is slow data path communication implementation based on existing KNI. >>>>>>>> >>>>>>>> Difference is: librte_kni converted into a PMD, kdp kernel module is almost >>>>>>>> same except all control path functionality removed and some simplification done. >>>>>>>> >>>>>>>> Motivation is to simplify slow path data communication. >>>>>>>> Now any application can use this new PMD to send/get data to Linux kernel. >>>>>>>> >>>>>>>> PMD supports two communication methods: >>>>>>>> >>>>>>>> 1) KDP kernel module >>>>>>>> PMD initialization functions handles creating virtual interfaces (with help of >>>>>>>> kdp kernel module) and created FIFO. FIFO is used to share data between >>>>>>>> userspace and kernelspace. This is default method. >>>>>>>> >>>>>>>> 2) tun/tap module >>>>>>>> When KDP module is not inserted, PMD creates tap interface and transfers >>>>>>>> packets using tap interface. >>>>>>>> >>>>>>>> In long term this patch intends to replace the KNI and KNI will be >>>>>>>> depreciated. >>>>>>>> >>>>>>> >>>>>>> Self-NACK: Will work on another option that does not introduce new >>>>>>> kernel module. >>>>>>> >>>>>> >>>>>> Hmm, care to elaborate a bit? The second mode of this PMD already was >>>>>> free of external kernel modules. Do you mean you'll be just removing >>>>>> mode 1) from the PMD or looking at something completely different? >>>>>> >>>>>> Just thinking that tun/tap PMD sounds like a useful thing to have, I >>>>>> hope you're not abandoning that. >>>>>> >>>>> >>>>> It will be KNI PMD. >>>>> Plan is to have something like KDP, but with existing KNI kernel module. >>>>> There will be tun/tap support as fallback. >>>> >>>> Hum, now I'm confused. I was under the impression everybody hated KNI >>>> and wanted to get rid of it, and certainly not build future solutions on >>>> top of it? >>> >>> We can't remove it. >> >> Why? >> >>> We can't replace/improve it -you were one of the major opposition to this. >>> This doesn't leave more option other than using it. >> >> Why cannot we replace it by something upstream? >> > I doubt KDP is upstream-able to Linux community. If somebody can, that > is great. > > Even for KCP, upstreaming task is still under discussion, and as a heads > up, it is likely to be dropped. If KCP/KDP are not upstreamable then the solution is to find another way that is. Easier said than done, no doubt. - Panu -