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, 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 209A4C49EA6 for ; Thu, 24 Jun 2021 05:34:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 024E7613CB for ; Thu, 24 Jun 2021 05:34:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230110AbhFXFgo (ORCPT ); Thu, 24 Jun 2021 01:36:44 -0400 Received: from verein.lst.de ([213.95.11.211]:53067 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229448AbhFXFgn (ORCPT ); Thu, 24 Jun 2021 01:36:43 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id 02FF167373; Thu, 24 Jun 2021 07:34:22 +0200 (CEST) Date: Thu, 24 Jun 2021 07:34:21 +0200 From: Christoph Hellwig To: Oded Gabbay Cc: Jason Gunthorpe , Christian =?iso-8859-1?Q?K=F6nig?= , Christian =?iso-8859-1?Q?K=F6nig?= , Gal Pressman , sleybo@amazon.com, linux-rdma , Oded Gabbay , Christoph Hellwig , Linux Kernel Mailing List , dri-devel , "moderated list:DMA BUFFER SHARING FRAMEWORK" , Doug Ledford , Tomer Tayar , amd-gfx list , Greg KH , Alex Deucher , Leon Romanovsky , "open list:DMA BUFFER SHARING FRAMEWORK" Subject: Re: [Linaro-mm-sig] [PATCH v3 1/2] habanalabs: define uAPI to export FD for DMA-BUF Message-ID: <20210624053421.GA25165@lst.de> References: <20210622152343.GO1096940@ziepe.ca> <3fabe8b7-7174-bf49-5ffe-26db30968a27@amd.com> <20210622154027.GS1096940@ziepe.ca> <09df4a03-d99c-3949-05b2-8b49c71a109e@amd.com> <20210622160538.GT1096940@ziepe.ca> <20210623182435.GX1096940@ziepe.ca> <20210623185045.GY1096940@ziepe.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On Wed, Jun 23, 2021 at 10:00:29PM +0300, Oded Gabbay wrote: > I understand the argument and I agree that for the generic case, the > top of the stack can't assume anything. > Having said that, in this case the SGL is encapsulated inside a dma-buf object. But the scatterlist is defined to have a valid page. If in dma-bufs you can't do that dmabufs are completely broken. Apparently the gpu folks can somehow live with that and deal with the pitfals, but for dma-buf users outside of their little fiefdom were they arbitrarily break rules it simply is not acceptable. 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 CE99EC49EA5 for ; Thu, 24 Jun 2021 07:06:21 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 54FBC613E0 for ; Thu, 24 Jun 2021 07:06:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 54FBC613E0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=amd-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 028E26EA1B; Thu, 24 Jun 2021 07:06:19 +0000 (UTC) Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by gabe.freedesktop.org (Postfix) with ESMTPS id 0AB366E9E5; Thu, 24 Jun 2021 05:34:25 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 02FF167373; Thu, 24 Jun 2021 07:34:22 +0200 (CEST) Date: Thu, 24 Jun 2021 07:34:21 +0200 From: Christoph Hellwig To: Oded Gabbay Subject: Re: [Linaro-mm-sig] [PATCH v3 1/2] habanalabs: define uAPI to export FD for DMA-BUF Message-ID: <20210624053421.GA25165@lst.de> References: <20210622152343.GO1096940@ziepe.ca> <3fabe8b7-7174-bf49-5ffe-26db30968a27@amd.com> <20210622154027.GS1096940@ziepe.ca> <09df4a03-d99c-3949-05b2-8b49c71a109e@amd.com> <20210622160538.GT1096940@ziepe.ca> <20210623182435.GX1096940@ziepe.ca> <20210623185045.GY1096940@ziepe.ca> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-Mailman-Approved-At: Thu, 24 Jun 2021 07:06:12 +0000 X-BeenThere: amd-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussion list for AMD gfx List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-rdma , Christian =?iso-8859-1?Q?K=F6nig?= , sleybo@amazon.com, Oded Gabbay , Gal Pressman , dri-devel , Christoph Hellwig , "moderated list:DMA BUFFER SHARING FRAMEWORK" , Jason Gunthorpe , Doug Ledford , Tomer Tayar , amd-gfx list , Greg KH , Alex Deucher , Leon Romanovsky , Christian =?iso-8859-1?Q?K=F6nig?= , Linux Kernel Mailing List , "open list:DMA BUFFER SHARING FRAMEWORK" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: amd-gfx-bounces@lists.freedesktop.org Sender: "amd-gfx" On Wed, Jun 23, 2021 at 10:00:29PM +0300, Oded Gabbay wrote: > I understand the argument and I agree that for the generic case, the > top of the stack can't assume anything. > Having said that, in this case the SGL is encapsulated inside a dma-buf object. But the scatterlist is defined to have a valid page. If in dma-bufs you can't do that dmabufs are completely broken. Apparently the gpu folks can somehow live with that and deal with the pitfals, but for dma-buf users outside of their little fiefdom were they arbitrarily break rules it simply is not acceptable. _______________________________________________ amd-gfx mailing list amd-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/amd-gfx