From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55555) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WzkrF-0001AI-82 for qemu-devel@nongnu.org; Wed, 25 Jun 2014 06:55:24 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Wzkr7-0001E3-PR for qemu-devel@nongnu.org; Wed, 25 Jun 2014 06:55:17 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44707) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Wzkr7-0001Dr-Gz for qemu-devel@nongnu.org; Wed, 25 Jun 2014 06:55:09 -0400 Date: Wed, 25 Jun 2014 13:55:12 +0300 From: "Michael S. Tsirkin" Message-ID: <20140625105512.GA7037@redhat.com> References: <53AA9480.1010005@intel.com> <53AA96DF.6070501@redhat.com> <53AA9B58.6050803@intel.com> <20140625095533.GE6357@redhat.com> <53AA9D79.3080003@redhat.com> <53AA9F3A.5030004@intel.com> <20140625102119.GJ6357@redhat.com> <53AAA452.2090301@intel.com> <20140625103211.GA6884@redhat.com> <53AAA66B.5050401@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <53AAA66B.5050401@intel.com> Subject: Re: [Qemu-devel] [v5][PATCH 0/5] xen: add Intel IGD passthrough support List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Chen, Tiejun" Cc: peter.maydell@linaro.org, xen-devel@lists.xensource.com, stefano.stabellini@eu.citrix.com, allen.m.kay@intel.com, Kelly.Zytaruk@amd.com, qemu-devel@nongnu.org, anthony.perard@citrix.com, anthony@codemonkey.ws, yang.z.zhang@intel.com, Paolo Bonzini On Wed, Jun 25, 2014 at 06:37:31PM +0800, Chen, Tiejun wrote: > On 2014/6/25 18:32, Michael S. Tsirkin wrote: > >On Wed, Jun 25, 2014 at 06:28:34PM +0800, Chen, Tiejun wrote: > >>On 2014/6/25 18:21, Michael S. Tsirkin wrote: > >>>On Wed, Jun 25, 2014 at 06:06:50PM +0800, Chen, Tiejun wrote: > >>>>On 2014/6/25 17:59, Paolo Bonzini wrote: > >>>>>Il 25/06/2014 11:55, Michael S. Tsirkin ha scritto: > >>>>>>>You're saying we will reserve a free BAR to address those > >>>>>>information to > >>>>>>>expose to guest, but which device does this free BAR belong to? The > >>>>>>video > >>>>>>>device? Or PCH/MCH? > >>>>>> > >>>>>>If you just want to pass a couple of IDs, then don't, it's a waste. > >>>>>>But I still don't know what problem you are trying to solve, > >>>>>>looking at guest driver did not help. > >>>>> > >>>>>It's not just a couple of IDs, it's also random fields of the MCH > >>>>>configuration space. Grep drivers/gpu/drm/i915 for bridge_dev. > >>>>> > >>>> > >>>>Paolo, > >>>> > >>>>No, we're not pointing the bridge_dev here, which is a host bridge at > >>>>00:00.0. > >>>> > >>>>Here it should be a ISA bridge at 00:1f.0. Please see intel_detect_pch() to > >>>>know why we need this. > >>>> > >>>>Thanks > >>>>Tiejun > >>>> > >>> > >>>So what if you dont? > >>> > >>> if (!pch) > >>> DRM_DEBUG_KMS("No PCH found.\n"); > >>> > >>>Is that all? Seems harmless enough. > >>> > >> > >>I don't read the whole driver completely so I don't know now. I guess the > >>driver may go other live path even without this setting in a live, or this > >>is a real bug to this driver on Intel platform. > >> > >>But anyway, I think we should guarantee the driver work under the same > >>configuration as the native in the passthrough case. > >> > >>Thanks > >>Tiejun > > > >Just get it working as a first step. Then address theoretical > >issues in follow-up patches. > > > > I'm not sure if we can simply. So I will post this to the driver developer > to ask more. > > Thanks > Tiejun Please do. The main issue in my mind is that you are implementing a non working ISA bridge. If guest uses it for anything - boom. -- MST From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [v5][PATCH 0/5] xen: add Intel IGD passthrough support Date: Wed, 25 Jun 2014 13:55:12 +0300 Message-ID: <20140625105512.GA7037@redhat.com> References: <53AA9480.1010005@intel.com> <53AA96DF.6070501@redhat.com> <53AA9B58.6050803@intel.com> <20140625095533.GE6357@redhat.com> <53AA9D79.3080003@redhat.com> <53AA9F3A.5030004@intel.com> <20140625102119.GJ6357@redhat.com> <53AAA452.2090301@intel.com> <20140625103211.GA6884@redhat.com> <53AAA66B.5050401@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <53AAA66B.5050401@intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org Sender: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org To: "Chen, Tiejun" Cc: peter.maydell@linaro.org, xen-devel@lists.xensource.com, stefano.stabellini@eu.citrix.com, allen.m.kay@intel.com, Kelly.Zytaruk@amd.com, qemu-devel@nongnu.org, anthony.perard@citrix.com, anthony@codemonkey.ws, yang.z.zhang@intel.com, Paolo Bonzini List-Id: xen-devel@lists.xenproject.org On Wed, Jun 25, 2014 at 06:37:31PM +0800, Chen, Tiejun wrote: > On 2014/6/25 18:32, Michael S. Tsirkin wrote: > >On Wed, Jun 25, 2014 at 06:28:34PM +0800, Chen, Tiejun wrote: > >>On 2014/6/25 18:21, Michael S. Tsirkin wrote: > >>>On Wed, Jun 25, 2014 at 06:06:50PM +0800, Chen, Tiejun wrote: > >>>>On 2014/6/25 17:59, Paolo Bonzini wrote: > >>>>>Il 25/06/2014 11:55, Michael S. Tsirkin ha scritto: > >>>>>>>You're saying we will reserve a free BAR to address those > >>>>>>information to > >>>>>>>expose to guest, but which device does this free BAR belong to? The > >>>>>>video > >>>>>>>device? Or PCH/MCH? > >>>>>> > >>>>>>If you just want to pass a couple of IDs, then don't, it's a waste. > >>>>>>But I still don't know what problem you are trying to solve, > >>>>>>looking at guest driver did not help. > >>>>> > >>>>>It's not just a couple of IDs, it's also random fields of the MCH > >>>>>configuration space. Grep drivers/gpu/drm/i915 for bridge_dev. > >>>>> > >>>> > >>>>Paolo, > >>>> > >>>>No, we're not pointing the bridge_dev here, which is a host bridge at > >>>>00:00.0. > >>>> > >>>>Here it should be a ISA bridge at 00:1f.0. Please see intel_detect_pch() to > >>>>know why we need this. > >>>> > >>>>Thanks > >>>>Tiejun > >>>> > >>> > >>>So what if you dont? > >>> > >>> if (!pch) > >>> DRM_DEBUG_KMS("No PCH found.\n"); > >>> > >>>Is that all? Seems harmless enough. > >>> > >> > >>I don't read the whole driver completely so I don't know now. I guess the > >>driver may go other live path even without this setting in a live, or this > >>is a real bug to this driver on Intel platform. > >> > >>But anyway, I think we should guarantee the driver work under the same > >>configuration as the native in the passthrough case. > >> > >>Thanks > >>Tiejun > > > >Just get it working as a first step. Then address theoretical > >issues in follow-up patches. > > > > I'm not sure if we can simply. So I will post this to the driver developer > to ask more. > > Thanks > Tiejun Please do. The main issue in my mind is that you are implementing a non working ISA bridge. If guest uses it for anything - boom. -- MST