From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751170AbdALWfV (ORCPT ); Thu, 12 Jan 2017 17:35:21 -0500 Received: from ale.deltatee.com ([207.54.116.67]:56103 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751133AbdALWfQ (ORCPT ); Thu, 12 Jan 2017 17:35:16 -0500 To: Stephen Bates References: <20170105190113.GA12587@obsidianresearch.com> <20170105195424.GB2166@redhat.com> <20170105200719.GB31047@obsidianresearch.com> <20170105201935.GC2166@redhat.com> <20170105224215.GA3855@obsidianresearch.com> <20170105232352.GB6426@redhat.com> <20170106003034.GB4670@obsidianresearch.com> <20170106015831.GA2226@gmail.com> <20170106173722.GB3804@redhat.com> <20170106182625.GB5724@obsidianresearch.com> <2a148b6e-86bc-4c4d-2f22-d733e2cc94cc@deltatee.com> Cc: Jason Gunthorpe , Jerome Glisse , david1.zhou@amd.com, qiang.yu@amd.com, "'linux-rdma@vger.kernel.org'" , "'linux-nvdimm@lists.01.org'" , "Kuehling, Felix" , Serguei Sagalovitch , "'linux-kernel@vger.kernel.org'" , "'dri-devel@lists.freedesktop.org'" , "Koenig, Christian" , hch@infradead.org, "Deucher, Alexander" , "Sander, Ben" , "Suthikulpanit, Suravee" , "'linux-pci@vger.kernel.org'" , Jerome Glisse , "Blinzer, Paul" , "'Linux-media@vger.kernel.org'" From: Logan Gunthorpe Message-ID: <8bda88d4-1e7c-7889-7d20-1a0eb43de31a@deltatee.com> Date: Thu, 12 Jan 2017 15:35:07 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Icedove/45.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 172.16.1.111 X-SA-Exim-Rcpt-To: linux-media@vger.kernel.org, paul.blinzer@amd.com, j.glisse@gmail.com, linux-pci@vger.kernel.org, suravee.suthikulpanit@amd.com, ben.sander@amd.com, alexander.deucher@amd.com, hch@infradead.org, christian.koenig@amd.com, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, serguei.sagalovitch@amd.com, felix.kuehling@amd.com, linux-nvdimm@ml01.01.org, linux-rdma@vger.kernel.org, qiang.yu@amd.com, david1.zhou@amd.com, jglisse@redhat.com, jgunthorpe@obsidianresearch.com, sbates@raithlin.com X-SA-Exim-Mail-From: logang@deltatee.com Subject: Re: Enabling peer to peer device transactions for PCIe devices X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/01/17 09:54 PM, Stephen Bates wrote: > The iopmem patchset addressed all the use cases above and while it is not > an in kernel API it could have been modified to be one reasonably easily. > As Logan states the driver can then choose to pass the VMAs to user-space > in a manner that makes sense. Just to clarify: the iopmem patchset had one patch that allowed for slightly more flexible zone device mappings which ought to be useful for everyone. The other patch (which was iopmem proper) was more of an example of how the zone_device memory _could_ be exposed to userspace with "iopmem" hardware that looks similar to nvdimm hardware. Iopmem was not really useful, in itself, for NVMe devices and it was never expected to be useful for GPUs. Logan