Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932301AbbEHTTN (ORCPT ); Fri, 8 May 2015 15:19:13 -0400 Received: from 251.110.2.81.in-addr.arpa ([81.2.110.251]:46321 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752886AbbEHTTJ (ORCPT ); Fri, 8 May 2015 15:19:09 -0400 Date: Fri, 8 May 2015 20:18:43 +0100 From: One Thousand Gnomes To: Daniel Vetter Cc: Thierry Reding , Benjamin Gaignard , "linux-media@vger.kernel.org" , Linux Kernel Mailing List , "dri-devel@lists.freedesktop.org" , Hans Verkuil , Laurent Pinchart , Rob Clark , Dave Airlie , Sumit Semwal , Tom Gall Subject: Re: [RFC] How implement Secure Data Path ? Message-ID: <20150508201843.3447049b@lxorguk.ukuu.org.uk> In-Reply-To: <20150508083735.GB15256@phenom.ffwll.local> References: <20150505175405.2787db4b@lxorguk.ukuu.org.uk> <20150506083552.GF30184@phenom.ffwll.local> <20150506091919.GC16325@ulmo.nvidia.com> <20150506131532.GC30184@phenom.ffwll.local> <20150507132218.GA24541@ulmo.nvidia.com> <20150507135212.GD30184@phenom.ffwll.local> <20150507174003.2a5b42e6@lxorguk.ukuu.org.uk> <20150508083735.GB15256@phenom.ffwll.local> Organization: Intel Corporation X-Mailer: Claws Mail 3.11.1 (GTK+ 2.24.27; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1314 Lines: 33 > dma-buf user handles are fds, which means anything allocated can be passed > around nicely already. The question really is whether we'll have one ioctl > on top of a special dev node or a syscall. I thought that in these cases > where the dev node is only ever used to allocate the real thing, a syscall > is the preferred way to go. So you'd go for fd = dmabuf_alloc(blah..., O_whatever) ? Whichever I guess.. really we want open("/dev/foo/parameters.....") but we missed that chance a long time ago. The billion dollar question is how is the resource managed, who owns the object, who is charged for it, how to does containerise. We really ought to have a clear answer to that. > > I guess the same kind of logic as with GEM (except preferably without > > the DoS security holes) applies as to why its useful to have handles to > > the DMA buffers. > > We have handles (well file descriptors) to dma-bufs already, I'm a bit > confused what you mean? I was agreeing with your argument - with GEM as an example that it works for the CPU accessing case. Alan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/