From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 66ACDA0487 for ; Wed, 3 Jul 2019 10:26:53 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 768C81D9E; Wed, 3 Jul 2019 10:26:52 +0200 (CEST) Received: from mail-io1-f68.google.com (mail-io1-f68.google.com [209.85.166.68]) by dpdk.org (Postfix) with ESMTP id 25060F04 for ; Wed, 3 Jul 2019 10:26:51 +0200 (CEST) Received: by mail-io1-f68.google.com with SMTP id k8so2833317iot.1 for ; Wed, 03 Jul 2019 01:26:51 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=mSSFty7nKOmTVW3QA4hhn8+QvNowifkRcYtO4rR75MI=; b=aE1uiGzzX8ryP5DsVqDHWkMQc8Y4oblZl09sNQTNg+2cWfv7jbOnWt4xxqj6WQYVfc 0gaTkHKnfTTUiZ8aEx3rf2OPAId0avN3p0/8dGgRY4joEXmbSTVeUyCgjxBF2p7Om/eC bIKrXn8hHKwhLXr2ZDRklfTpsH2k1yOw1It2QWkEEjHRBHUjn8QWPeUUgK/7HGo/bFuc wnvP3BvUKWZhbkmLnJmyl3vhKHEvSuTeVO8tvPRdjvyVj2lQ93ZxTctMNC0uZIXvsZSm yL++wJxko3VUInKj22FeuUuMzpxizjzRkwub97Tt65TTDlHUtwaXt6BSQUmOcV0g2eyk xS7w== X-Gm-Message-State: APjAAAVQzUsI3SJYiIGgHU+n1g77p+OtfQKqZuSRT1SBtg01woxXhA9N fKhp4rL/gpDSCH2z3MbVLdXjixiWrGPytWwihHSBRw== X-Google-Smtp-Source: APXvYqx3GNhS5QWYVyBGPLXiTyi8+End4m6e0o1vS49LFygG2EHPFnm8Je/kPEN85BY5sh91Bp1GYo3L/IKphO9N0zI= X-Received: by 2002:a6b:e203:: with SMTP id z3mr5991341ioc.23.1562142410447; Wed, 03 Jul 2019 01:26:50 -0700 (PDT) MIME-Version: 1.0 References: <20190703054508.22824-1-tiwei.bie@intel.com> <20190703073314.GA18868@___> <20190703075657.GA20458@___> <20190703081550.GA25721@___> In-Reply-To: <20190703081550.GA25721@___> From: David Marchand Date: Wed, 3 Jul 2019 10:26:39 +0200 Message-ID: To: Tiwei Bie Cc: dev , "Burakov, Anatoly" Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Subject: Re: [dpdk-dev] [RFC PATCH] bus/pci: avoid depending on private value in kernel source X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Wed, Jul 3, 2019 at 10:17 AM Tiwei Bie wrote: > On Wed, Jul 03, 2019 at 10:01:44AM +0200, David Marchand wrote: > > On Wed, Jul 3, 2019 at 9:58 AM Tiwei Bie wrote: > > > > On Wed, Jul 03, 2019 at 09:36:26AM +0200, David Marchand wrote: > > > On Wed, Jul 3, 2019 at 9:35 AM Tiwei Bie > wrote: > > > > > > Hi David, > > > > > > On Wed, Jul 03, 2019 at 09:02:59AM +0200, David Marchand wrote: > > > > Hello, > > > > > > > > On Wed, Jul 3, 2019 at 7:47 AM Tiwei Bie < > tiwei.bie@intel.com> > > wrote: > > > > > > > > The value 40 used in VFIO_GET_REGION_ADDR() is a private > value > > > > (VFIO_PCI_OFFSET_SHIFT) defined in Linux kernel source > [1]. It > > > > is not part of VFIO API, and we should not depend on it. > > > > > > > > [1] > https://github.com/torvalds/linux/blob/6fbc7275c7a9/drivers > > /vfio/ > > > pci/ > > > > vfio_pci_private.h#L19 > > > > > > > > > > > > > > > > I did not follow linux kernel changes, is there something > that > > would > > > change > > > > this offset? > > > > It looks like a cleanup (did not look into the details yet), > do we > > need > > > this > > > > now? > > > > > > In VFIO/mdev [1], the offset can be something different. It > depends > > > on the parent device. It's not just a cleanup. It's a > preparation > > > for the mdev support in DPDK. > > > > > > [1] > https://github.com/torvalds/linux/blob/master/Documentation/ > > > vfio-mediated-device.txt > > > > > > > > > > > > Ok, thanks. > > > So we can wait for mdev to be ready before working on this. > > > > What do you mean by "mdev to be ready"? RFC ready? I don't see > > anything blocking the discussion on this now. > > > > PS. I already sent a RFC series of the mdev support in DPDK > > to the mailing list 3 month ago. > > > > > > If you need it and the mdev support has been posted already, why not > send a n+1 > > patchset with this patch in it? > > > > This patch alone looked odd to me. > > That series was using the old API which assumes the shift > is 40 which may not work in some cases. And this patch is > to fix the API. I think this patch is actually trying to > fix a relatively independent issue -- i.e. switching to using > the proper VFIO API to get the region offsets instead of > depending on kernel code's internal value. > > Fix, then there is something broken ? You said this is for mdev support which is not currently part of the features supported by DPDK. This patch breaks the ABI by extending rte_pci_device. You must rework it to avoid this break. -- David Marchand