From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7F176C433F5 for ; Mon, 18 Oct 2021 04:17:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5BD8F6101B for ; Mon, 18 Oct 2021 04:17:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229825AbhJRET6 (ORCPT ); Mon, 18 Oct 2021 00:19:58 -0400 Received: from fllv0015.ext.ti.com ([198.47.19.141]:53646 "EHLO fllv0015.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229682AbhJRET5 (ORCPT ); Mon, 18 Oct 2021 00:19:57 -0400 Received: from fllv0034.itg.ti.com ([10.64.40.246]) by fllv0015.ext.ti.com (8.15.2/8.15.2) with ESMTP id 19I4HgBa015750; Sun, 17 Oct 2021 23:17:42 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1634530662; bh=uK8Un6BEAjJA4vFp0uQJcU/uxzHzMOhc/QjBLD/GMCs=; h=Subject:To:CC:References:From:Date:In-Reply-To; b=g9jYvVt088hxRhZCH11fN0WaPuyGsreOUz8IDsDx1BxzEo5VZ3PjmwtshCsocu8+G sXz+gMZ5Q6116yy5ip1jfwxkY7LOLv8OTMncvHEp6x5jeUiV7HIj5/3DSnJq2jtUzx zXVffl7Wi2djwFuFT+1LgNdIOnhpr0B/rZNAyS6E= Received: from DFLE114.ent.ti.com (dfle114.ent.ti.com [10.64.6.35]) by fllv0034.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 19I4HgRb100323 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Sun, 17 Oct 2021 23:17:42 -0500 Received: from DFLE111.ent.ti.com (10.64.6.32) by DFLE114.ent.ti.com (10.64.6.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.14; Sun, 17 Oct 2021 23:17:42 -0500 Received: from lelv0326.itg.ti.com (10.180.67.84) by DFLE111.ent.ti.com (10.64.6.32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.14 via Frontend Transport; Sun, 17 Oct 2021 23:17:42 -0500 Received: from [10.250.233.6] (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0326.itg.ti.com (8.15.2/8.15.2) with ESMTP id 19I4Hd7w035463; Sun, 17 Oct 2021 23:17:40 -0500 Subject: Re: Linux PCIe EP NTB function To: Frank Li , "kw@linux.com" , Sherry Sun , Richard Zhu CC: "linux-pci@vger.kernel.org" References: From: Kishon Vijay Abraham I Message-ID: <459745d1-9fe7-e792-3532-33ee9552bc4d@ti.com> Date: Mon, 18 Oct 2021 09:47:39 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Hi Frank, On 15/10/21 2:10 am, Frank Li wrote: > Sorry, correct Linux-pci mail list address. > >> -----Original Message----- >> From: Frank Li >> Sent: Thursday, October 14, 2021 3:35 PM >> To: kishon@ti.com; kw@linux.com; Sherry Sun ; Richard >> Zhu >> Cc: inux-pci@vger.kernel.org >> Subject: Linux PCIe EP NTB function >> >> Kishon: >> >> We use VOP(virtio over PCIe) communication between PCI RC and EP side. >> But VOP already removed and switch into NTB solution. >> I saw you submit patch and already accepted by community about pci- >> epf-ntb. >> >> According to document, whole system work as Device1 (PCI host) -> EP1 >> -> EP2 -> Device2(PCI host). >> But our user case is Device 1(RC Host) -> Device 2(EP). >> >> I am not sure how to apply ntb frame work into this user case. NTB by definition is PCIe RC-to-RC communication. For RC-to-EP, see pci_endpoint_test.c (RC) and pci-epf-test.c (EP) that provides sample endpoint usecase. One more RC<->EP communication model was built in [1], but that is not yet upstreamed. [1] -> https://lore.kernel.org/r/20200702082143.25259-1-kishon@ti.com Thanks, Kishon >> >> I think we can modify pci-epf-ntb to register a ntb devices. But I am >> not sure that this is recommunicate method. I think this user case is >> quite common. I don't want to implement a local solution. >> >> Any suggestion? >> >> >> Best regards >> Frank Li