From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49545) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WzkRf-0003Vl-32 for qemu-devel@nongnu.org; Wed, 25 Jun 2014 06:28:58 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WzkRT-0000tK-SL for qemu-devel@nongnu.org; Wed, 25 Jun 2014 06:28:51 -0400 Received: from mga09.intel.com ([134.134.136.24]:33395) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WzkRT-0000sz-Nd for qemu-devel@nongnu.org; Wed, 25 Jun 2014 06:28:39 -0400 Message-ID: <53AAA452.2090301@intel.com> Date: Wed, 25 Jun 2014 18:28:34 +0800 From: "Chen, Tiejun" MIME-Version: 1.0 References: <53AA8ACF.3070101@redhat.com> <20140625084835.GF32652@redhat.com> <53AA8E7D.809@intel.com> <20140625090925.GH32652@redhat.com> <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> In-Reply-To: <20140625102119.GJ6357@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit 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: "Michael S. Tsirkin" 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 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 From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Chen, Tiejun" Subject: Re: [v5][PATCH 0/5] xen: add Intel IGD passthrough support Date: Wed, 25 Jun 2014 18:28:34 +0800 Message-ID: <53AAA452.2090301@intel.com> References: <53AA8ACF.3070101@redhat.com> <20140625084835.GF32652@redhat.com> <53AA8E7D.809@intel.com> <20140625090925.GH32652@redhat.com> <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> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20140625102119.GJ6357@redhat.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: "Michael S. Tsirkin" 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 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