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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 DC0CCC2B9F4 for ; Fri, 25 Jun 2021 13:19:06 +0000 (UTC) Received: from smtp3.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (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 9128861963 for ; Fri, 25 Jun 2021 13:19:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9128861963 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=8bytes.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id 4FFE6607E7; Fri, 25 Jun 2021 13:19:06 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Z7uqktJRM7al; Fri, 25 Jun 2021 13:19:05 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [IPv6:2605:bc80:3010:104::8cd3:938]) by smtp3.osuosl.org (Postfix) with ESMTPS id 3A42B607D1; Fri, 25 Jun 2021 13:19:05 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 0F1C4C001A; Fri, 25 Jun 2021 13:19:05 +0000 (UTC) Received: from smtp3.osuosl.org (smtp3.osuosl.org [IPv6:2605:bc80:3010::136]) by lists.linuxfoundation.org (Postfix) with ESMTP id 0606BC000E for ; Fri, 25 Jun 2021 13:19:04 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id DAA83607B2 for ; Fri, 25 Jun 2021 13:19:03 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id TK9h_J_lGAUl for ; Fri, 25 Jun 2021 13:19:03 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.8.0 Received: from theia.8bytes.org (8bytes.org [IPv6:2a01:238:4383:600:38bc:a715:4b6d:a889]) by smtp3.osuosl.org (Postfix) with ESMTPS id 46295605F0 for ; Fri, 25 Jun 2021 13:19:03 +0000 (UTC) Received: by theia.8bytes.org (Postfix, from userid 1000) id A7AA23FC; Fri, 25 Jun 2021 15:18:59 +0200 (CEST) Date: Fri, 25 Jun 2021 15:18:58 +0200 From: Joerg Roedel To: Douglas Anderson Subject: Re: [PATCH v2 0/3] iommu: Enable non-strict DMA on QCom SD/MMC Message-ID: References: <20210624171759.4125094-1-dianders@chromium.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210624171759.4125094-1-dianders@chromium.org> Cc: ulf.hansson@linaro.org, linux-doc@vger.kernel.org, Peter Zijlstra , linux-pci@vger.kernel.org, Konrad Dybcio , Thierry Reding , joel@joelfernandes.org, rajatja@google.com, will@kernel.org, robdclark@chromium.org, saravanak@google.com, Jonathan Corbet , quic_c_gdjako@quicinc.com, linux-arm-kernel@lists.infradead.org, Viresh Kumar , vbadigan@codeaurora.org, "Paul E. McKenney" , linux-arm-msm@vger.kernel.org, bhelgaas@google.com, sonnyrao@chromium.org, Vlastimil Babka , Randy Dunlap , linux-mmc@vger.kernel.org, adrian.hunter@intel.com, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, Andrew Morton , robin.murphy@arm.com, "Maciej W. Rozycki" 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" Hi Douglas, On Thu, Jun 24, 2021 at 10:17:56AM -0700, Douglas Anderson wrote: > The goal of this patch series is to get better SD/MMC performance on > Qualcomm eMMC controllers and in generally nudge us forward on the > path of allowing some devices to be in strict mode and others to be in > non-strict mode. So if I understand it right, this patch-set wants a per-device decision about setting dma-mode to strict vs. non-strict. I think we should get to the reason why strict mode is used by default first. Is the default on ARM platforms to use iommu-strict mode by default and if so, why? The x86 IOMMUs use non-strict mode by default (yes, it is a security trade-off). Regards, Joerg _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu