From mboxrd@z Thu Jan 1 00:00:00 1970 From: Igor Mammedov Subject: Re: [Qemu-devel] [RFC PATCH v4] fw/pci: Add support for mapping Intel IGD via QEMU Date: Wed, 11 May 2016 12:07:41 +0200 Message-ID: <20160511120741.73e74d1b@nial.brq.redhat.com> References: <20160216213540.14607.97134.stgit@gimli.home> <20160223152233.GB17600@morn.lan> <20160510091952.23c9e0d2@t450s.home> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: "Kevin O'Connor" , kvm@vger.kernel.org, "Michael S. Tsirkin" , seabios@seabios.org, allen.m.kay@intel.com, qemu-devel@nongnu.org To: Alex Williamson Return-path: Received: from mx1.redhat.com ([209.132.183.28]:33582 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932082AbcEKKHp (ORCPT ); Wed, 11 May 2016 06:07:45 -0400 In-Reply-To: <20160510091952.23c9e0d2@t450s.home> Sender: kvm-owner@vger.kernel.org List-ID: On Tue, 10 May 2016 09:19:52 -0600 Alex Williamson wrote: > On Tue, 23 Feb 2016 10:22:33 -0500 > "Kevin O'Connor" wrote: > > > On Tue, Feb 16, 2016 at 02:39:27PM -0700, Alex Williamson wrote: > > > QEMU provides two fw_cfg files to support IGD. The first holds the > > > OpRegion data which holds the Video BIOS Table (VBT). This needs to > > > be copied into reserved memory and the address stored in the ASL > > > Storage register of the device at 0xFC offset in PCI config space. > > > The OpRegion is generally 8KB. This file is named "etc/igd-opregion". > > > > > > The second file tells us the required size of the stolen memory space > > > for the device. This is a dummy file, it has no backing so we only > > > allocate the space without copying anything into it. This space > > > requires 1MB alignment and is generally either 1MB or 2MB, depending > > > on the hardware config. If the user has opted in QEMU to expose > > > additional stolen memory beyond the GTT (GGMS), the GMS may add an > > > additional 32MB to 512MB. The base address of the reserved memory > > > allocated for this is written back to the Base Data of Stolen Memory > > > register (BDSM) at PCI config offset 0x5C on the device. This file is > > > named "etc/igd-bdsm". > > > > Thanks. I'd be interested in seeing how the discussion with Michael > > and Igor works out (wrt using a standardized interface for > > communicating addresses between qemu and firmware) before adopting > > this interface in SeaBIOS. > > Apologies if I missed it, but I haven't seen any work in this > direction, please point me to it if I'm wrong. Now that QEMU 2.6 is As far as I know it was only Michael's suggestion but I've not seen actual patches either. As for me, I'm not planning to look at it in near future. > wrapping up, I'd like to get IGD assignment support in for 2.7, but we > can't do that without BIOS support. How shall we proceed? Thanks, > > Alex >