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=-2.2 required=3.0 tests=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 88C6FC282DD for ; Thu, 9 Jan 2020 14:36:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5F8C02084D for ; Thu, 9 Jan 2020 14:36:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730394AbgAIOgQ (ORCPT ); Thu, 9 Jan 2020 09:36:16 -0500 Received: from verein.lst.de ([213.95.11.211]:55012 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729577AbgAIOgQ (ORCPT ); Thu, 9 Jan 2020 09:36:16 -0500 Received: by verein.lst.de (Postfix, from userid 2407) id 9F9BD68BFE; Thu, 9 Jan 2020 15:36:13 +0100 (CET) Date: Thu, 9 Jan 2020 15:36:13 +0100 From: Christoph Hellwig To: Jon Derrick Cc: iommu@lists.linux-foundation.org, linux-pci@vger.kernel.org, Bjorn Helgaas , Lorenzo Pieralisi , Keith Busch , Joerg Roedel , Christoph Hellwig , David Woodhouse , Lu Baolu Subject: Re: [RFC 4/5] PCI: vmd: Stop overriding dma_map_ops Message-ID: <20200109143613.GC22656@lst.de> References: <1577823863-3303-1-git-send-email-jonathan.derrick@intel.com> <1577823863-3303-5-git-send-email-jonathan.derrick@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1577823863-3303-5-git-send-email-jonathan.derrick@intel.com> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Tue, Dec 31, 2019 at 01:24:22PM -0700, Jon Derrick wrote: > Devices on the VMD domain use the VMD endpoint's requester-id and have > been relying on the VMD endpoint's dma operations. The downside of this > was that VMD domain devices would use the VMD endpoint's attributes when > doing DMA and IOMMU mapping. We can be smarter about this by only using > the VMD endpoint when mapping and providing the correct child device's > attributes during dma operations. > > This patch adds a new dma alias mechanism by adding a hint to a pci_dev > to point to a singular DMA requester's pci_dev. This integrates into the > existing dma alias infrastructure to reduce the impact of the changes > required to support this mode. If we want to lift this check into common code I think it should go into struct device, as that is what DMA operates on normally. That being said given that this insane hack only exists for braindamage in Intel hardware I'd rather keep it as isolated as possible. 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=-2.2 required=3.0 tests=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 12D1FC282DD for ; Thu, 9 Jan 2020 14:36:20 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E149D20656 for ; Thu, 9 Jan 2020 14:36:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E149D20656 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id B5C9586824; Thu, 9 Jan 2020 14:36:19 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Omjckepqd71N; Thu, 9 Jan 2020 14:36:19 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by whitealder.osuosl.org (Postfix) with ESMTP id 32ACE86462; Thu, 9 Jan 2020 14:36:19 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 23C7EC18DC; Thu, 9 Jan 2020 14:36:19 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 6EAD0C0881 for ; Thu, 9 Jan 2020 14:36:18 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id 54CAC88012 for ; Thu, 9 Jan 2020 14:36:18 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id rKQ7RIN6ROkZ for ; Thu, 9 Jan 2020 14:36:17 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by hemlock.osuosl.org (Postfix) with ESMTPS id 46AEF88007 for ; Thu, 9 Jan 2020 14:36:17 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 9F9BD68BFE; Thu, 9 Jan 2020 15:36:13 +0100 (CET) Date: Thu, 9 Jan 2020 15:36:13 +0100 From: Christoph Hellwig To: Jon Derrick Subject: Re: [RFC 4/5] PCI: vmd: Stop overriding dma_map_ops Message-ID: <20200109143613.GC22656@lst.de> References: <1577823863-3303-1-git-send-email-jonathan.derrick@intel.com> <1577823863-3303-5-git-send-email-jonathan.derrick@intel.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1577823863-3303-5-git-send-email-jonathan.derrick@intel.com> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: linux-pci@vger.kernel.org, iommu@lists.linux-foundation.org, Bjorn Helgaas , Keith Busch , David Woodhouse , Christoph Hellwig X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Tue, Dec 31, 2019 at 01:24:22PM -0700, Jon Derrick wrote: > Devices on the VMD domain use the VMD endpoint's requester-id and have > been relying on the VMD endpoint's dma operations. The downside of this > was that VMD domain devices would use the VMD endpoint's attributes when > doing DMA and IOMMU mapping. We can be smarter about this by only using > the VMD endpoint when mapping and providing the correct child device's > attributes during dma operations. > > This patch adds a new dma alias mechanism by adding a hint to a pci_dev > to point to a singular DMA requester's pci_dev. This integrates into the > existing dma alias infrastructure to reduce the impact of the changes > required to support this mode. If we want to lift this check into common code I think it should go into struct device, as that is what DMA operates on normally. That being said given that this insane hack only exists for braindamage in Intel hardware I'd rather keep it as isolated as possible. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu