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=-5.0 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_FAIL,SPF_HELO_NONE,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 00162C55ABD for ; Mon, 9 Nov 2020 16:47:26 +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 31E1A20E65 for ; Mon, 9 Nov 2020 16:47:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=deltatee.com header.i=@deltatee.com header.b="J7+Mv2hm" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 31E1A20E65 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=deltatee.com 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 92DB886A91; Mon, 9 Nov 2020 16:47:25 +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 z+BTliKLyHZ4; Mon, 9 Nov 2020 16:47:25 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by whitealder.osuosl.org (Postfix) with ESMTP id 312A7866D3; Mon, 9 Nov 2020 16:47:25 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 11030C08A1; Mon, 9 Nov 2020 16:47:25 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id D1570C088B for ; Mon, 9 Nov 2020 16:47:23 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id BCCDA86A93 for ; Mon, 9 Nov 2020 16:47:23 +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 L9GVODDfbxCG for ; Mon, 9 Nov 2020 16:47:23 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from ale.deltatee.com (ale.deltatee.com [204.191.154.188]) by whitealder.osuosl.org (Postfix) with ESMTPS id 326E886A91 for ; Mon, 9 Nov 2020 16:47:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=deltatee.com; s=20200525; h=Subject:Content-Transfer-Encoding:Content-Type: In-Reply-To:MIME-Version:Date:Message-ID:From:References:Cc:To:Sender: Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender :Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=M+FlpbSeF5MJfdXFDHCsfOBW2uUFOxuE0dG6gfttals=; b=J7+Mv2hmxQ4d09bkdoSjlqM2hY vOukZfUTBRpLH8UGn1KHGgk0N/mPDRhd8A08oEOiCCh7q0cCAQVeglBNPPwfDNvy1V8uyt6Yu6ZUv B226XvqReVoUsnygDkmcgOzKoZH3chhJ0pctPMiVhnGnBjWg9+3MBnhgwV0R2hIc8OBD0D4YeHHv3 0EhQ5E/lzpaFxooyniSTwwoOSq1y/+/a4VGSBpzogy8zYQeSpf0UXlcEzEqG/fRetW7/w+rJj2q0x 1m0DXzXIw3LJaLolwWEGKvxt4TbNZ8TqfPtxCyHuIFLEYgVlgR1OZb3qgvysUDswJ3GahxJvXZhyY skh+Vrug==; Received: from guinness.priv.deltatee.com ([172.16.1.162]) by ale.deltatee.com with esmtp (Exim 4.92) (envelope-from ) id 1kcAK2-00011d-Rd; Mon, 09 Nov 2020 09:47:15 -0700 To: Christoph Hellwig References: <20201106170036.18713-1-logang@deltatee.com> <20201106170036.18713-5-logang@deltatee.com> <20201109091258.GB28918@lst.de> From: Logan Gunthorpe Message-ID: <4e336c7e-207b-31fa-806e-c4e8028524a5@deltatee.com> Date: Mon, 9 Nov 2020 09:47:11 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.3.1 MIME-Version: 1.0 In-Reply-To: <20201109091258.GB28918@lst.de> Content-Language: en-CA X-SA-Exim-Connect-IP: 172.16.1.162 X-SA-Exim-Rcpt-To: daniel.vetter@ffwll.ch, willy@infradead.org, ddutile@redhat.com, jhubbard@nvidia.com, iweiny@intel.com, christian.koenig@amd.com, jgg@ziepe.ca, dan.j.williams@intel.com, sbates@raithlin.com, iommu@lists.linux-foundation.org, linux-mm@kvack.org, linux-pci@vger.kernel.org, linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, hch@lst.de X-SA-Exim-Mail-From: logang@deltatee.com Subject: Re: [RFC PATCH 04/15] lib/scatterlist: Add flag for indicating P2PDMA segments in an SGL X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Cc: Jason Gunthorpe , linux-pci@vger.kernel.org, Daniel Vetter , Ira Weiny , linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, Stephen Bates , linux-block@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org, Matthew Wilcox , John Hubbard , Dan Williams , =?UTF-8?Q?Christian_K=c3=b6nig?= 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 2020-11-09 2:12 a.m., Christoph Hellwig wrote: > On Fri, Nov 06, 2020 at 10:00:25AM -0700, Logan Gunthorpe wrote: >> We make use of the top bit of the dma_length to indicate a P2PDMA >> segment. > > I don't think "we" can. There is nothing limiting the size of a SGL > segment. Yes, I expected this would be the unacceptable part. Any alternative ideas? Logan _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu