From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755169AbdEKIpK (ORCPT ); Thu, 11 May 2017 04:45:10 -0400 Received: from mga07.intel.com ([134.134.136.100]:17632 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754796AbdEKIpJ (ORCPT ); Thu, 11 May 2017 04:45:09 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.38,323,1491289200"; d="scan'208";a="1146536417" From: "Chen, Xiaoguang" To: Alex Williamson , Gerd Hoffmann CC: "Tian, Kevin" , "intel-gfx@lists.freedesktop.org" , "linux-kernel@vger.kernel.org" , "zhenyuw@linux.intel.com" , "Lv, Zhiyuan" , "intel-gvt-dev@lists.freedesktop.org" , "Wang, Zhi A" Subject: RE: [RFC PATCH 6/6] drm/i915/gvt: support QEMU getting the dmabuf Thread-Topic: [RFC PATCH 6/6] drm/i915/gvt: support QEMU getting the dmabuf Thread-Index: AQHSwAN47y043l0J90m8wsAsHWts2aHgTQ8AgAGNjMCAAazCQIAAU9qAgAD30YCAAIqCgIAJhcZQ Date: Thu, 11 May 2017 08:45:03 +0000 Message-ID: References: <1493372130-27727-1-git-send-email-xiaoguang.chen@intel.com> <1493372130-27727-7-git-send-email-xiaoguang.chen@intel.com> <1493718658.8581.82.camel@redhat.com> <20170504100833.199bc8ba@t450s.home> <1493967331.371.53.camel@redhat.com> <20170505091115.7a680636@t450s.home> In-Reply-To: <20170505091115.7a680636@t450s.home> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: dlp-product: dlpe-windows dlp-version: 10.0.102.7 dlp-reaction: no-action x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id v4B8jLVI023496 Hi Alex, >-----Original Message----- >From: intel-gvt-dev [mailto:intel-gvt-dev-bounces@lists.freedesktop.org] On >Behalf Of Alex Williamson >Sent: Friday, May 05, 2017 11:11 PM >To: Gerd Hoffmann >Cc: Tian, Kevin ; intel-gfx@lists.freedesktop.org; linux- >kernel@vger.kernel.org; zhenyuw@linux.intel.com; Lv, Zhiyuan >; Chen, Xiaoguang ; intel- >gvt-dev@lists.freedesktop.org; Wang, Zhi A >Subject: Re: [RFC PATCH 6/6] drm/i915/gvt: support QEMU getting the dmabuf > >On Fri, 05 May 2017 08:55:31 +0200 >Gerd Hoffmann wrote: > >> Hi, >> >> > > >>Hmm, that looks like a rather strange way to return a file descriptor. >> > > >> >> > > >>What is the reason to not use ioctls on the vfio file handle, like >> > > >>older version of these patches did? >> > > >If I understood correctly that Alex prefer not to change the >> > > >ioctls on the vfio file handle like the old version. >> > > >So I used this way the smallest change to general vfio framework >> > > >only adding a subregion definition. >> > >> > I think I was hoping we could avoid a separate file descriptor >> > altogether and use a vfio region instead. >> >> What exactly did you have in mind? Put the framebuffer information >> (struct intel_vgpu_dmabuf) into the vfio region, then access it using >> read/write/mmap? > >Yeah, that was my hope. Adding a new file descriptor means we have one more >reference floating around complicating the life cycle of the device, group, and >container. Furthermore this one is really only visible to the mdev vendor driver, >so we can't rely on vfio-core, the vendor driver will need to consider the >reference when releasing the device. While read the framebuffer region we have to tell the vendor driver which framebuffer we want to read? There are two framebuffers now in KVMGT that is primary and cursor. There are two methods to implement this: 1) write the plane id first and then read the framebuffer. 2) create 2 vfio regions one for primary and one for cursor. Which method do you prefer? Or do you have other idea to handle this problem? chenxg From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Chen, Xiaoguang" Subject: RE: [RFC PATCH 6/6] drm/i915/gvt: support QEMU getting the dmabuf Date: Thu, 11 May 2017 08:45:03 +0000 Message-ID: References: <1493372130-27727-1-git-send-email-xiaoguang.chen@intel.com> <1493372130-27727-7-git-send-email-xiaoguang.chen@intel.com> <1493718658.8581.82.camel@redhat.com> <20170504100833.199bc8ba@t450s.home> <1493967331.371.53.camel@redhat.com> <20170505091115.7a680636@t450s.home> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <20170505091115.7a680636@t450s.home> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Alex Williamson , Gerd Hoffmann Cc: "Tian, Kevin" , "intel-gfx@lists.freedesktop.org" , "linux-kernel@vger.kernel.org" , "zhenyuw@linux.intel.com" , "Lv, Zhiyuan" , "intel-gvt-dev@lists.freedesktop.org" , "Wang, Zhi A" List-Id: intel-gfx@lists.freedesktop.org SGkgQWxleCwNCg0KPi0tLS0tT3JpZ2luYWwgTWVzc2FnZS0tLS0tDQo+RnJvbTogaW50ZWwtZ3Z0 LWRldiBbbWFpbHRvOmludGVsLWd2dC1kZXYtYm91bmNlc0BsaXN0cy5mcmVlZGVza3RvcC5vcmdd IE9uDQo+QmVoYWxmIE9mIEFsZXggV2lsbGlhbXNvbg0KPlNlbnQ6IEZyaWRheSwgTWF5IDA1LCAy MDE3IDExOjExIFBNDQo+VG86IEdlcmQgSG9mZm1hbm4gPGtyYXhlbEByZWRoYXQuY29tPg0KPkNj OiBUaWFuLCBLZXZpbiA8a2V2aW4udGlhbkBpbnRlbC5jb20+OyBpbnRlbC1nZnhAbGlzdHMuZnJl ZWRlc2t0b3Aub3JnOyBsaW51eC0NCj5rZXJuZWxAdmdlci5rZXJuZWwub3JnOyB6aGVueXV3QGxp bnV4LmludGVsLmNvbTsgTHYsIFpoaXl1YW4NCj48emhpeXVhbi5sdkBpbnRlbC5jb20+OyBDaGVu LCBYaWFvZ3VhbmcgPHhpYW9ndWFuZy5jaGVuQGludGVsLmNvbT47IGludGVsLQ0KPmd2dC1kZXZA bGlzdHMuZnJlZWRlc2t0b3Aub3JnOyBXYW5nLCBaaGkgQSA8emhpLmEud2FuZ0BpbnRlbC5jb20+ DQo+U3ViamVjdDogUmU6IFtSRkMgUEFUQ0ggNi82XSBkcm0vaTkxNS9ndnQ6IHN1cHBvcnQgUUVN VSBnZXR0aW5nIHRoZSBkbWFidWYNCj4NCj5PbiBGcmksIDA1IE1heSAyMDE3IDA4OjU1OjMxICsw MjAwDQo+R2VyZCBIb2ZmbWFubiA8a3JheGVsQHJlZGhhdC5jb20+IHdyb3RlOg0KPg0KPj4gICBI aSwNCj4+DQo+PiA+ID4gPj5IbW0sIHRoYXQgbG9va3MgbGlrZSBhIHJhdGhlciBzdHJhbmdlIHdh eSB0byByZXR1cm4gYSBmaWxlIGRlc2NyaXB0b3IuDQo+PiA+ID4gPj4NCj4+ID4gPiA+PldoYXQg aXMgdGhlIHJlYXNvbiB0byBub3QgdXNlIGlvY3RscyBvbiB0aGUgdmZpbyBmaWxlIGhhbmRsZSwg bGlrZQ0KPj4gPiA+ID4+b2xkZXIgdmVyc2lvbiBvZiB0aGVzZSBwYXRjaGVzIGRpZD8NCj4+ID4g PiA+SWYgSSB1bmRlcnN0b29kIGNvcnJlY3RseSB0aGF0IEFsZXggcHJlZmVyIG5vdCB0byBjaGFu Z2UgdGhlDQo+PiA+ID4gPmlvY3RscyBvbiB0aGUgdmZpbyBmaWxlIGhhbmRsZSBsaWtlIHRoZSBv bGQgdmVyc2lvbi4NCj4+ID4gPiA+U28gSSB1c2VkIHRoaXMgd2F5IHRoZSBzbWFsbGVzdCBjaGFu Z2UgdG8gZ2VuZXJhbCB2ZmlvIGZyYW1ld29yaw0KPj4gPiA+ID5vbmx5IGFkZGluZyBhIHN1YnJl Z2lvbiBkZWZpbml0aW9uLg0KPj4gPg0KPj4gPiBJIHRoaW5rIEkgd2FzIGhvcGluZyB3ZSBjb3Vs ZCBhdm9pZCBhIHNlcGFyYXRlIGZpbGUgZGVzY3JpcHRvcg0KPj4gPiBhbHRvZ2V0aGVyIGFuZCB1 c2UgYSB2ZmlvIHJlZ2lvbiBpbnN0ZWFkLg0KPj4NCj4+IFdoYXQgZXhhY3RseSBkaWQgeW91IGhh dmUgaW4gbWluZD8gIFB1dCB0aGUgZnJhbWVidWZmZXIgaW5mb3JtYXRpb24NCj4+IChzdHJ1Y3Qg aW50ZWxfdmdwdV9kbWFidWYpIGludG8gdGhlIHZmaW8gcmVnaW9uLCB0aGVuIGFjY2VzcyBpdCB1 c2luZw0KPj4gcmVhZC93cml0ZS9tbWFwPw0KPg0KPlllYWgsIHRoYXQgd2FzIG15IGhvcGUuICBB ZGRpbmcgYSBuZXcgZmlsZSBkZXNjcmlwdG9yIG1lYW5zIHdlIGhhdmUgb25lIG1vcmUNCj5yZWZl cmVuY2UgZmxvYXRpbmcgYXJvdW5kIGNvbXBsaWNhdGluZyB0aGUgbGlmZSBjeWNsZSBvZiB0aGUg ZGV2aWNlLCBncm91cCwgYW5kDQo+Y29udGFpbmVyLiAgRnVydGhlcm1vcmUgdGhpcyBvbmUgaXMg cmVhbGx5IG9ubHkgdmlzaWJsZSB0byB0aGUgbWRldiB2ZW5kb3IgZHJpdmVyLA0KPnNvIHdlIGNh bid0IHJlbHkgb24gdmZpby1jb3JlLCB0aGUgdmVuZG9yIGRyaXZlciB3aWxsIG5lZWQgdG8gY29u c2lkZXIgdGhlDQo+cmVmZXJlbmNlIHdoZW4gcmVsZWFzaW5nIHRoZSBkZXZpY2UuDQpXaGlsZSBy ZWFkIHRoZSBmcmFtZWJ1ZmZlciByZWdpb24gd2UgaGF2ZSB0byB0ZWxsIHRoZSB2ZW5kb3IgZHJp dmVyIHdoaWNoIGZyYW1lYnVmZmVyIHdlIHdhbnQgdG8gcmVhZD8gVGhlcmUgYXJlIHR3byBmcmFt ZWJ1ZmZlcnMgbm93IGluIEtWTUdUIHRoYXQgaXMgcHJpbWFyeSBhbmQgY3Vyc29yLg0KVGhlcmUg YXJlIHR3byBtZXRob2RzIHRvIGltcGxlbWVudCB0aGlzOg0KMSkgd3JpdGUgdGhlIHBsYW5lIGlk IGZpcnN0IGFuZCB0aGVuIHJlYWQgdGhlIGZyYW1lYnVmZmVyLg0KMikgY3JlYXRlIDIgdmZpbyBy ZWdpb25zIG9uZSBmb3IgcHJpbWFyeSBhbmQgb25lIGZvciBjdXJzb3IuDQoNCldoaWNoIG1ldGhv ZCBkbyB5b3UgcHJlZmVyPyBPciBkbyB5b3UgaGF2ZSBvdGhlciBpZGVhIHRvIGhhbmRsZSB0aGlz IHByb2JsZW0/DQoNCmNoZW54Zw0K