From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41323) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WznY3-00086H-Dk for qemu-devel@nongnu.org; Wed, 25 Jun 2014 09:47:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WznXv-0007vu-RZ for qemu-devel@nongnu.org; Wed, 25 Jun 2014 09:47:39 -0400 Received: from mx1.redhat.com ([209.132.183.28]:4885) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WznXv-0007vo-Jo for qemu-devel@nongnu.org; Wed, 25 Jun 2014 09:47:31 -0400 Date: Wed, 25 Jun 2014 16:47:27 +0300 From: "Michael S. Tsirkin" Message-ID: <20140625134727.GB14578@redhat.com> References: <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> <53AABC81.2090206@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <53AABC81.2090206@redhat.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: Paolo Bonzini 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, "Chen, Tiejun" On Wed, Jun 25, 2014 at 02:11:45PM +0200, Paolo Bonzini wrote: > Il 25/06/2014 12:21, Michael S. Tsirkin ha scritto: > >So what if you dont? > > > > if (!pch) > > DRM_DEBUG_KMS("No PCH found.\n"); > > > >Is that all? Seems harmless enough. > > > > The switch statement above sets dev_priv->pch_type. If it is set wrong, > everything goes wrong. grep for HAS_PCH_. > > Paolo OK, so how about doing this: either for the ISA bridge, or for the VGA card itself: set subsystem vendor id to PCI_VENDOR_ID_XEN, set subsystem device id to PCH device id Your patch seems to emulate revision as well but I don't see driver using that anywhere. I would then just update driver with that info. If you feel the need to support old guests without such a patch, we could add some generic hook where users supply device vendor revision id and class, and we create a dummy device. Let xen management worry about making that match PCH ISA bridge, or whatever, but let's also create a clean path going forward. -- MST