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 X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8AB43C55178 for ; Fri, 30 Oct 2020 19:24:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3ABDA20739 for ; Fri, 30 Oct 2020 19:24:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727473AbgJ3TYe (ORCPT ); Fri, 30 Oct 2020 15:24:34 -0400 Received: from mga09.intel.com ([134.134.136.24]:12905 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727433AbgJ3TX2 (ORCPT ); Fri, 30 Oct 2020 15:23:28 -0400 IronPort-SDR: q6N7pUku2XYlF6xhMuFHFQRLRnQi2j22TO3QY8pXV7cunPPIvTTOaIV8LjLQ/uxKxCTjTyU/TT tjgGsOpqwl7A== X-IronPort-AV: E=McAfee;i="6000,8403,9790"; a="168785723" X-IronPort-AV: E=Sophos;i="5.77,434,1596524400"; d="scan'208";a="168785723" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Oct 2020 12:23:27 -0700 IronPort-SDR: J083DTSf5KrEclLElMX4J9d4yYtZLfrQ/WjhdYtL1l/35c9Bj17YuA6xFIcqQbKC+9g4MfKN49 1pUTShJksB6g== X-IronPort-AV: E=Sophos;i="5.77,434,1596524400"; d="scan'208";a="351968478" Received: from otc-nc-03.jf.intel.com (HELO otc-nc-03) ([10.54.39.36]) by fmsmga004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Oct 2020 12:23:26 -0700 Date: Fri, 30 Oct 2020 12:23:25 -0700 From: "Raj, Ashok" To: Jason Gunthorpe Cc: Dave Jiang , vkoul@kernel.org, megha.dey@intel.com, maz@kernel.org, bhelgaas@google.com, tglx@linutronix.de, alex.williamson@redhat.com, jacob.jun.pan@intel.com, yi.l.liu@intel.com, baolu.lu@intel.com, kevin.tian@intel.com, sanjay.k.kumar@intel.com, tony.luck@intel.com, jing.lin@intel.com, dan.j.williams@intel.com, kwankhede@nvidia.com, eric.auger@redhat.com, parav@mellanox.com, rafael@kernel.org, netanelg@mellanox.com, shahafs@mellanox.com, yan.y.zhao@linux.intel.com, pbonzini@redhat.com, samuel.ortiz@intel.com, mona.hossain@intel.com, Megha Dey , dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org, Ashok Raj Subject: Re: [PATCH v4 00/17] Add VFIO mediated device support and DEV-MSI support for the idxd driver Message-ID: <20201030192325.GA105832@otc-nc-03> References: <160408357912.912050.17005584526266191420.stgit@djiang5-desk3.ch.intel.com> <20201030185858.GI2620339@nvidia.com> <20201030191706.GK2620339@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201030191706.GK2620339@nvidia.com> User-Agent: Mutt/1.5.24 (2015-08-30) Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Fri, Oct 30, 2020 at 04:17:06PM -0300, Jason Gunthorpe wrote: > On Fri, Oct 30, 2020 at 12:13:48PM -0700, Dave Jiang wrote: > > > > > > On 10/30/2020 11:58 AM, Jason Gunthorpe wrote: > > > On Fri, Oct 30, 2020 at 11:50:47AM -0700, Dave Jiang wrote: > > > > .../ABI/stable/sysfs-driver-dma-idxd | 6 + > > > > Documentation/driver-api/vfio/mdev-idxd.rst | 404 ++++++ > > > > MAINTAINERS | 1 + > > > > drivers/dma/Kconfig | 9 + > > > > drivers/dma/idxd/Makefile | 2 + > > > > drivers/dma/idxd/cdev.c | 6 +- > > > > drivers/dma/idxd/device.c | 294 ++++- > > > > drivers/dma/idxd/idxd.h | 67 +- > > > > drivers/dma/idxd/init.c | 86 ++ > > > > drivers/dma/idxd/irq.c | 6 +- > > > > drivers/dma/idxd/mdev.c | 1121 +++++++++++++++++ > > > > drivers/dma/idxd/mdev.h | 116 ++ > > > > > > Again, a subsytem driver belongs in the directory hierarchy of the > > > subsystem, not in other random places. All this mdev stuff belongs > > > under drivers/vfio > > > > Alex seems to have disagreed last time.... > > https://lore.kernel.org/dmaengine/20200917113016.425dcde7@x1.home/ > > Nobody else in the kernel is splitting subsystems up anymore > > > And I do agree with his perspective. The mdev is an extension of the PF > > driver. It's a bit awkward to be a stand alone mdev driver under vfio/mdev/. > > By this logic we'd have giagantic drivers under drivers/ethernet > touching netdev, rdma, scsi, vdpa, etc just because that is where the > PF driver came from. What makes you think this is providing services like scsi/rdma/vdpa etc.. ? for DSA this playes the exact same role, not a different function as you highlight above. these mdev's are creating DSA for virtualization use. They aren't providing a completely different role or subsystem per-se. Cheers, Ashok