From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967277AbaFTMst (ORCPT ); Fri, 20 Jun 2014 08:48:49 -0400 Received: from mail-wi0-f179.google.com ([209.85.212.179]:41135 "EHLO mail-wi0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966820AbaFTMsr (ORCPT ); Fri, 20 Jun 2014 08:48:47 -0400 Message-ID: <53A42DAA.80406@redhat.com> Date: Fri, 20 Jun 2014 14:48:42 +0200 From: Paolo Bonzini User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: Tiejun Chen , daniel.vetter@ffwll.ch, jani.nikula@linux.intel.com, airlied@linux.ie CC: intel-gfx@lists.freedesktop.org, xen-devel@lists.xensource.com, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, qemu-devel@nongnu.org Subject: Re: [RFC][PATCH] gpu:drm:i915:intel_detect_pch: back to check devfn instead of check class type References: <1403171631-3452-1-git-send-email-tiejun.chen@intel.com> In-Reply-To: <1403171631-3452-1-git-send-email-tiejun.chen@intel.com> X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Il 19/06/2014 11:53, Tiejun Chen ha scritto: > so this mean that isa bridge is still represented with Dev31:Func0 > like the native OS. Furthermore, currently we're pushing VGA > passthrough support into qemu upstream, and with some discussion, > we wouldn't set the bridge class type and just expose this devfn. Even this is not really optimal. It just happens to work just because QEMU's machine is currently a PCI machine with the ISA bridge on 00:01.0. As soon as you'll try doing integrated graphics passthrough on a PCIe machine type (such as QEMU's "-M q35") things will break down just as badly. Paolo From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47667) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WxyFW-0004H9-Hk for qemu-devel@nongnu.org; Fri, 20 Jun 2014 08:49:07 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WxyFN-0006QK-GO for qemu-devel@nongnu.org; Fri, 20 Jun 2014 08:48:58 -0400 Received: from mail-wi0-x232.google.com ([2a00:1450:400c:c05::232]:40737) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WxyFN-0006Q4-9D for qemu-devel@nongnu.org; Fri, 20 Jun 2014 08:48:49 -0400 Received: by mail-wi0-f178.google.com with SMTP id n15so737445wiw.17 for ; Fri, 20 Jun 2014 05:48:46 -0700 (PDT) Sender: Paolo Bonzini Message-ID: <53A42DAA.80406@redhat.com> Date: Fri, 20 Jun 2014 14:48:42 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <1403171631-3452-1-git-send-email-tiejun.chen@intel.com> In-Reply-To: <1403171631-3452-1-git-send-email-tiejun.chen@intel.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC][PATCH] gpu:drm:i915:intel_detect_pch: back to check devfn instead of check class type List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Tiejun Chen , daniel.vetter@ffwll.ch, jani.nikula@linux.intel.com, airlied@linux.ie Cc: intel-gfx@lists.freedesktop.org, xen-devel@lists.xensource.com, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, qemu-devel@nongnu.org Il 19/06/2014 11:53, Tiejun Chen ha scritto: > so this mean that isa bridge is still represented with Dev31:Func0 > like the native OS. Furthermore, currently we're pushing VGA > passthrough support into qemu upstream, and with some discussion, > we wouldn't set the bridge class type and just expose this devfn. Even this is not really optimal. It just happens to work just because QEMU's machine is currently a PCI machine with the ISA bridge on 00:01.0. As soon as you'll try doing integrated graphics passthrough on a PCIe machine type (such as QEMU's "-M q35") things will break down just as badly. Paolo