From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43404) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WmHK1-0003E8-GJ for qemu-devel@nongnu.org; Mon, 19 May 2014 02:45:23 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WmHJt-0008LX-9d for qemu-devel@nongnu.org; Mon, 19 May 2014 02:45:17 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34427) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WmHJt-0008Jg-1m for qemu-devel@nongnu.org; Mon, 19 May 2014 02:45:09 -0400 Message-ID: <1400481887.32155.34.camel@nilsson.home.kraxel.org> From: Gerd Hoffmann Date: Mon, 19 May 2014 08:44:47 +0200 In-Reply-To: <1400237624-8505-5-git-send-email-tiejun.chen@intel.com> References: <1400237624-8505-1-git-send-email-tiejun.chen@intel.com> <1400237624-8505-5-git-send-email-tiejun.chen@intel.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [v2][PATCH 4/8] xen, gfx passthrough: reserve 00:02.0 for INTEL IGD List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Tiejun Chen Cc: peter.maydell@linaro.org, xen-devel@lists.xensource.com, mst@redhat.com, allen.m.kay@intel.com, stefano.stabellini@eu.citrix.com, weidong.han@intel.com, Kelly.Zytaruk@amd.com, jean.guyader@eu.citrix.com, qemu-devel@nongnu.org, yang.z.zhang@intel.com, anthony@codemonkey.ws, anthony.perard@citrix.com Hi, > + /* > + * Some video bioses and gfx drivers will assume the bdf of IGD is 00:02.0. > + * So user need to set it to 00:02.0 in Xen configure file explicitly, > + * otherwise IGD will fail to work. > + */ > + pci_reserve_pci_devfn(b, PCI_DEVFN(2, 0)); That is asking for trouble. Slot 2 is used by the qemu vga cards by default, and for quite a while (before memory api was merged) it even was impossible to change it. libvirt still places the vga card at slot 2 for that reason -> boom. I wouldn't be surprised if you find that assumption in other management libs / apps too. Why do you need that patch in the first place? It should be possible to configure qemu to not occupy slot 2 if you need it that way. Just pass '-vga none' to qemu. Which you probably want anyway if you pass-through a vga to the guest. And explicitly configure a slot (via addr= property) for all your pci devices. Doing it only for the IGD works too if you list the device before any other pci device on the qemu command line. cheers, Gerd