From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47815) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WzkKH-0000Br-Pw for qemu-devel@nongnu.org; Wed, 25 Jun 2014 06:21:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WzkKB-0006cq-Hg for qemu-devel@nongnu.org; Wed, 25 Jun 2014 06:21:13 -0400 Received: from mx1.redhat.com ([209.132.183.28]:28240) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WzkKB-0006cf-9f for qemu-devel@nongnu.org; Wed, 25 Jun 2014 06:21:07 -0400 Date: Wed, 25 Jun 2014 13:21:19 +0300 From: "Michael S. Tsirkin" Message-ID: <20140625102119.GJ6357@redhat.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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <53AA9F3A.5030004@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 06:06:50PM +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.