From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40129) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aRbHX-00074j-3T for qemu-devel@nongnu.org; Fri, 05 Feb 2016 02:58:20 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aRbHT-0005QG-Ob for qemu-devel@nongnu.org; Fri, 05 Feb 2016 02:58:19 -0500 Received: from mx1.redhat.com ([209.132.183.28]:43505) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aRbHT-0005QA-Ij for qemu-devel@nongnu.org; Fri, 05 Feb 2016 02:58:15 -0500 Message-ID: <1454659091.5539.16.camel@redhat.com> From: Gerd Hoffmann Date: Fri, 05 Feb 2016 08:58:11 +0100 In-Reply-To: <20160204175823.75cc7e25@nial.brq.redhat.com> References: <20160202201023.5353.65948.stgit@gimli.home> <20160204175823.75cc7e25@nial.brq.redhat.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 Subject: Re: [Qemu-devel] [SeaBIOS] [RFC PATCH v2] fw/pci: Add support for mapping Intel IGD OpRegion via QEMU List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Igor Mammedov Cc: Alex Williamson , seabios@seabios.org, qemu-devel@nongnu.org Hi, > > + if (file->copy(file, opregion, file->size) < 0) { > Is opregion content on host immutable? > if not then copying it probably wrong and it should be passed-through. The OpRegion is used for communication between bios and driver, it is *not* something going directly to the hardware. There is also the VBT (video bios table) with some configuration information (most notably laptop panel info). The latter will be used by the guest driver. To make stuff like brightness control work is is not enough to pass-through the opregion, we would also have to somehow forward acpi notifications and acpi calls between host and guest, so the guest driver can talk to the host bios. That is seriously non-trivial, for little (if any) gain. cheers, Gerd