Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756934AbdGLHkq (ORCPT ); Wed, 12 Jul 2017 03:40:46 -0400 Received: from mail-wr0-f194.google.com ([209.85.128.194]:36788 "EHLO mail-wr0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756657AbdGLHkn (ORCPT ); Wed, 12 Jul 2017 03:40:43 -0400 Date: Wed, 12 Jul 2017 09:40:38 +0200 From: Daniel Vetter To: "Zhang, Tina" Cc: Daniel Vetter , Gerd Hoffmann , "Tian, Kevin" , "linux-kernel@vger.kernel.org" , "intel-gfx@lists.freedesktop.org" , "alex.williamson@redhat.com" , "zhenyuw@linux.intel.com" , "chris@chris-wilson.co.uk" , Kirti Wankhede , "Lv, Zhiyuan" , "intel-gvt-dev@lists.freedesktop.org" , "Wang, Zhi A" Subject: Re: [PATCH v10] vfio: ABI for mdev display dma-buf operation Message-ID: <20170712074038.izr6ureby4vwtq27@phenom.ffwll.local> Mail-Followup-To: "Zhang, Tina" , Gerd Hoffmann , "Tian, Kevin" , "linux-kernel@vger.kernel.org" , "intel-gfx@lists.freedesktop.org" , "alex.williamson@redhat.com" , "zhenyuw@linux.intel.com" , "chris@chris-wilson.co.uk" , Kirti Wankhede , "Lv, Zhiyuan" , "intel-gvt-dev@lists.freedesktop.org" , "Wang, Zhi A" References: <1499293795-6265-1-git-send-email-tina.zhang@intel.com> <980a5c09-fa8a-255d-19ad-acf4bb29d271@nvidia.com> <1499753648.8257.3.camel@redhat.com> <20170711091236.run4zirxmr34kazb@phenom.ffwll.local> <237F54289DF84E4997F34151298ABEBC7C57BF86@SHSMSX101.ccr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <237F54289DF84E4997F34151298ABEBC7C57BF86@SHSMSX101.ccr.corp.intel.com> X-Operating-System: Linux phenom 4.11.0-1-amd64 User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2357 Lines: 56 On Wed, Jul 12, 2017 at 02:31:40AM +0000, Zhang, Tina wrote: > > > > -----Original Message----- > > From: intel-gvt-dev [mailto:intel-gvt-dev-bounces@lists.freedesktop.org] On > > Behalf Of Daniel Vetter > > Sent: Tuesday, July 11, 2017 5:13 PM > > To: Gerd Hoffmann > > Cc: Tian, Kevin ; linux-kernel@vger.kernel.org; intel- > > gfx@lists.freedesktop.org; alex.williamson@redhat.com; > > zhenyuw@linux.intel.com; chris@chris-wilson.co.uk; Kirti Wankhede > > ; Lv, Zhiyuan ; > > daniel@ffwll.ch; Zhang, Tina ; intel-gvt- > > dev@lists.freedesktop.org; Wang, Zhi A > > Subject: Re: [PATCH v10] vfio: ABI for mdev display dma-buf operation > > > > On Tue, Jul 11, 2017 at 08:14:08AM +0200, Gerd Hoffmann wrote: > > > Hi, > > > > > > > > +struct vfio_device_query_gfx_plane { > > > > > + __u32 argsz; > > > > > + __u32 flags; > > > > > + struct vfio_device_gfx_plane_info plane_info; > > > > > + __u32 plane_type; > > > > > + __s32 fd; /* dma-buf fd */ > > > > > + __u32 plane_id; > > > > > +}; > > > > > + > > > > > > > > It would be better to have comment here about what are expected > > > > values for plane_type and plane_id. > > > > > > plane_type is DRM_PLANE_TYPE_*. > > > > > > yes, a comment saying so would be good, same for drm_format which is > > > DRM_FORMAT_*. While looking at these two: renaming plane_type to > > > drm_plane_type (for consistency) is probably a good idea too. > > > > > > plane_id needs a specification. > > > > Why do you need plane_type? With universal planes the plane_id along is > > sufficient to identify a plane on a given drm device instance. I'd just remove it. > > -Daniel > The plane_type here, is to ask the mdev vendor driver to return the information according to the value in field plane_type. So, it's a input field. > The values in plane_type field is the same of drm_plane_type. And yes, it's better to use drm_plane_type instead of plane_id. I have no idea what you mean here, I guess that just shows that discussing an ioctl struct without solid definitions of what field does what and why is not all that useful. What exactly it plane_id for then? This just confused me more ... -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch