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, URIBL_BLOCKED,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 4C18AC433E6 for ; Wed, 10 Mar 2021 09:25:44 +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 97F1164FC4 for ; Wed, 10 Mar 2021 09:25:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 97F1164FC4 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 smtp3.osuosl.org (Postfix) with ESMTP id 303486F521; Wed, 10 Mar 2021 09:25:43 +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 mchWsEDzrPMR; Wed, 10 Mar 2021 09:25:42 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [IPv6:2605:bc80:3010:104::8cd3:938]) by smtp3.osuosl.org (Postfix) with ESMTP id 21259605C1; Wed, 10 Mar 2021 09:25:42 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id A55EAC000B; Wed, 10 Mar 2021 09:25:41 +0000 (UTC) Received: from smtp2.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id E31BEC0001; Wed, 10 Mar 2021 09:25:40 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id D0D45431A5; Wed, 10 Mar 2021 09:25:40 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id V1bcMZgOaSoK; Wed, 10 Mar 2021 09:25:40 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.8.0 X-Greylist: from auto-whitelisted by SQLgrey-1.8.0 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by smtp2.osuosl.org (Postfix) with ESMTPS id 34A924314A; Wed, 10 Mar 2021 09:25:40 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 2657568B05; Wed, 10 Mar 2021 10:25:34 +0100 (CET) Date: Wed, 10 Mar 2021 10:25:33 +0100 From: Christoph Hellwig To: Robin Murphy Subject: Re: [PATCH 14/17] iommu: remove DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE Message-ID: <20210310092533.GA6819@lst.de> References: <20210301084257.945454-1-hch@lst.de> <20210301084257.945454-15-hch@lst.de> <1658805c-ed28-b650-7385-a56fab3383e3@arm.com> <20210310091501.GC5928@lst.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210310091501.GC5928@lst.de> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: kvm@vger.kernel.org, Will Deacon , linuxppc-dev@lists.ozlabs.org, dri-devel@lists.freedesktop.org, Li Yang , iommu@lists.linux-foundation.org, netdev@vger.kernel.org, David Woodhouse , linux-arm-kernel@lists.infradead.org, Michael Ellerman , virtualization@lists.linux-foundation.org, freedreno@lists.freedesktop.org, Christoph Hellwig , linux-arm-msm@vger.kernel.org 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 Wed, Mar 10, 2021 at 10:15:01AM +0100, Christoph Hellwig wrote: > On Thu, Mar 04, 2021 at 03:25:27PM +0000, Robin Murphy wrote: > > On 2021-03-01 08:42, Christoph Hellwig wrote: > >> Use explicit methods for setting and querying the information instead. > > > > Now that everyone's using iommu-dma, is there any point in bouncing this > > through the drivers at all? Seems like it would make more sense for the x86 > > drivers to reflect their private options back to iommu_dma_strict (and > > allow Intel's caching mode to override it as well), then have > > iommu_dma_init_domain just test !iommu_dma_strict && > > domain->ops->flush_iotlb_all. > > Hmm. I looked at this, and kill off ->dma_enable_flush_queue for > the ARM drivers and just looking at iommu_dma_strict seems like a > very clear win. > > OTOH x86 is a little more complicated. AMD and intel defaul to lazy > mode, so we'd have to change the global iommu_dma_strict if they are > initialized. Also Intel has not only a "static" option to disable > lazy mode, but also a "dynamic" one where it iterates structure. So > I think on the get side we're stuck with the method, but it still > simplifies the whole thing. Actually... Just mirroring the iommu_dma_strict value into struct iommu_domain should solve all of that with very little boilerplate code. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu