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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,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 91ED2C3A5A0 for ; Mon, 20 Apr 2020 07:42:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7337322247 for ; Mon, 20 Apr 2020 07:42:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="BM8Iccy/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726109AbgDTHmY (ORCPT ); Mon, 20 Apr 2020 03:42:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42846 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726100AbgDTHmY (ORCPT ); Mon, 20 Apr 2020 03:42:24 -0400 Received: from mail-wr1-x443.google.com (mail-wr1-x443.google.com [IPv6:2a00:1450:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1E6A4C061A0F for ; Mon, 20 Apr 2020 00:42:24 -0700 (PDT) Received: by mail-wr1-x443.google.com with SMTP id t14so10783355wrw.12 for ; Mon, 20 Apr 2020 00:42:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=36LtjihBEpeBnaRGeeCm9e2L3d20jrMG7L1AL/HArJs=; b=BM8Iccy/hIQbCpSekYbFcZATX4MvhvRHEo8t56sYYDBHLuWrWlNfN2U/Avqh8pAzQ+ lJSChUqVOtITG+ntElIAo3FofQYlSUeJmVFTj1QctC3aH4uQ5UOifop/IzHxEXYnZ5my opGELuSrSZd/x7koJ8jWqGqe0lytTCYPvTb7bSWeBNbpH/ZOHDSjLzxqvp1xpOJsbc7o xGsbkEr+LTYIBgtKOpVnk5Pox8r0hmqVt3bRtQ6GUZafBrjVD4r2u3tGSKQbcyjfOLch 9Sfd2Iw3VJ/3lDfpUqoBIiiH3MRh0hqtXjIK8Ip29Za7xcLJ1b9QXuz0Pl6RJ3xDyOUI iYMQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=36LtjihBEpeBnaRGeeCm9e2L3d20jrMG7L1AL/HArJs=; b=odj1++3+pd3XD3ke1Ro9cjwcwGseI6PUjOod78BJYUcXY/zleLeoC51HQqBQlCyYdb mvXFnIaJPvfwPB1x3RaCMBhy1Q5XY2MGXE4EZV1oE6QX8T2FSKDtK2iTsXa3bHO3Oe9E q0hu0shA6aG04tGElMU2fMjHhmy0CKZSCmNVlcTtilMf3sn4wMfKbjQAEQTLHgoKifDc ech+vHg50j9t5La6GvOM5muZ+IFi0DVkJqZkYOQdkBOVK0yqVGzXcB11LtHAUo4r/tpW wVdUxQiWdSjeb6hp2jJxLvsm1GpJneN/lzaQjy/kz3cFUjSf2RdrhX1OCpwJftN0mBgR syvA== X-Gm-Message-State: AGi0PuZ3XSG/yy8TlgdxC7T50a9ZWj8jLjpLrIlqhcapvZWAQTZtqVq3 My63TFdQZ1BF/ta1763myB1Kdw== X-Google-Smtp-Source: APiQypIBGqen1kzX4d4Wf5UYEkYdzKCnAPaaEvwxdtpe+zlIYgN/+aoVVamwm9Ox3hy3wg9aLlAaUA== X-Received: by 2002:a5d:6107:: with SMTP id v7mr16380670wrt.270.1587368542719; Mon, 20 Apr 2020 00:42:22 -0700 (PDT) Received: from myrica ([2001:171b:226b:54a0:116c:c27a:3e7f:5eaf]) by smtp.gmail.com with ESMTPSA id i25sm203507wml.43.2020.04.20.00.42.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 20 Apr 2020 00:42:22 -0700 (PDT) Date: Mon, 20 Apr 2020 09:42:13 +0200 From: Jean-Philippe Brucker To: Christoph Hellwig Cc: iommu@lists.linux-foundation.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pci@vger.kernel.org, linux-mm@kvack.org, joro@8bytes.org, catalin.marinas@arm.com, will@kernel.org, robin.murphy@arm.com, kevin.tian@intel.com, baolu.lu@linux.intel.com, Jonathan.Cameron@huawei.com, jacob.jun.pan@linux.intel.com, christian.koenig@amd.com, zhangfei.gao@linaro.org, jgg@ziepe.ca, xuzaibo@huawei.com Subject: Re: [PATCH v5 02/25] iommu/sva: Manage process address spaces Message-ID: <20200420074213.GA3180232@myrica> References: <20200414170252.714402-1-jean-philippe@linaro.org> <20200414170252.714402-3-jean-philippe@linaro.org> <20200416072852.GA32000@infradead.org> <20200416085402.GB1286150@myrica> <20200416121331.GA18661@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200416121331.GA18661@infradead.org> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Thu, Apr 16, 2020 at 05:13:31AM -0700, Christoph Hellwig wrote: > On Thu, Apr 16, 2020 at 10:54:02AM +0200, Jean-Philippe Brucker wrote: > > On Thu, Apr 16, 2020 at 12:28:52AM -0700, Christoph Hellwig wrote: > > > > + rcu_read_lock(); > > > > + hlist_for_each_entry_rcu(bond, &io_mm->devices, mm_node) > > > > + io_mm->ops->invalidate(bond->sva.dev, io_mm->pasid, io_mm->ctx, > > > > + start, end - start); > > > > + rcu_read_unlock(); > > > > +} > > > > > > What is the reason that the devices don't register their own notifiers? > > > This kinds of multiplexing is always rather messy, and you do it for > > > all the methods. > > > > This sends TLB and ATC invalidations through the IOMMU, it doesn't go > > through device drivers > > I don't think we mean the same thing, probably because of my rather > imprecise use of the word device. > > What I mean is that the mmu_notifier should not be embedded into the > io_mm structure (whch btw, seems to have a way to generic name, just > like all other io_* prefixed names), but instead into the > iommu_bond structure. That avoid the whole multiplexing layer. Right, I can see the appeal. I still like having a single mmu notifier per mm because it ensures we allocate a single PASID per mm (as required by x86). I suppose one alternative is to maintain a hashtable of mm->pasid, to avoid iterating over all bonds during allocation. Thanks, Jean