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=-5.8 required=3.0 tests=BAYES_00,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 8516BC11F65 for ; Wed, 30 Jun 2021 07:08:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6955F61C72 for ; Wed, 30 Jun 2021 07:08:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232809AbhF3HLH (ORCPT ); Wed, 30 Jun 2021 03:11:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40478 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232598AbhF3HLE (ORCPT ); Wed, 30 Jun 2021 03:11:04 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 52C92C061766; Wed, 30 Jun 2021 00:08:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=p7u2nhiPZvS5G76wt+ReyJp7BmL9rTijTlM9kJWCQB0=; b=jU5tD1CKWUN2AvCok5TsR6gq5q 81SLjO6tt7FaxBgRBWbUqVQXYcd+87wzkSA8t5M/0YIYGHDaAwJ4mVWYqS08CyL9xA6xYGazt+zVu HrOCne0sUDUViBVSpeOcH9BlQuxUE5WmHnJVoZsMw3FEjm0KkUb8Aq2UrpreawCFSPumgz0hExF8S em/wR9b6nST13qoCMk80+oupPxiPawRJp+WiDrdGomoU04Ed39H4EOEgR4+PX08HWhhS+5oSGU4kD zqug+xGjvphgGP9lDwW0JcYkroBQHh5Yo7oW/WgF188MFE86PE4qMxwhIKJNTjr1CtqGaHMXS8Mwm WKtY+Mxw==; Received: from hch by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1lyUK4-0051XX-C6; Wed, 30 Jun 2021 07:07:57 +0000 Date: Wed, 30 Jun 2021 08:07:48 +0100 From: Christoph Hellwig To: Jason Gunthorpe Cc: Jason Wang , Jean-Philippe Brucker , "Tian, Kevin" , "Jiang, Dave" , "Raj, Ashok" , "kvm@vger.kernel.org" , Jonathan Corbet , David Woodhouse , LKML , "iommu@lists.linux-foundation.org" , Alex Williamson , Kirti Wankhede , Robin Murphy , David Gibson Subject: Re: [RFC] /dev/ioasid uAPI proposal Message-ID: References: <20210602180925.GH1002214@nvidia.com> <20210602130053.615db578.alex.williamson@redhat.com> <20210602195404.GI1002214@nvidia.com> <20210602143734.72fb4fa4.alex.williamson@redhat.com> <6a9426d7-ed55-e006-9c4c-6b7c78142e39@redhat.com> <20210603130927.GZ1002214@nvidia.com> <65614634-1db4-7119-1a90-64ba5c6e9042@redhat.com> <20210604115805.GG1002214@nvidia.com> <895671cc-5ef8-bc1a-734c-e9e2fdf03652@redhat.com> <20210607141424.GF1002214@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210607141424.GF1002214@nvidia.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 07, 2021 at 11:14:24AM -0300, Jason Gunthorpe wrote: > "non-coherent DMA" is some general euphemism that evokes images of > embedded platforms that don't have coherent DMA at all and have low > cost ways to regain coherence. This is not at all what we are talking > about here at all. It literally is the same way of working. And not just low-end embedded platforms use this, but a lot of older server platforms did as well. 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See http://www.infradead.org/rpr.html Cc: Jean-Philippe Brucker , "Tian, Kevin" , "Jiang, Dave" , "Raj, Ashok" , "kvm@vger.kernel.org" , Jonathan Corbet , Robin Murphy , Jason Wang , LKML , Kirti Wankhede , "iommu@lists.linux-foundation.org" , Alex Williamson , David Woodhouse , David Gibson 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 Mon, Jun 07, 2021 at 11:14:24AM -0300, Jason Gunthorpe wrote: > "non-coherent DMA" is some general euphemism that evokes images of > embedded platforms that don't have coherent DMA at all and have low > cost ways to regain coherence. This is not at all what we are talking > about here at all. It literally is the same way of working. And not just low-end embedded platforms use this, but a lot of older server platforms did as well. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu