From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [IGDVFIO] [PATCH 3/8] RFC and help completing: Intel IGD Direct Assignment with VFIO Date: Wed, 24 Sep 2014 22:31:43 +0200 Message-ID: <54232A2F.9020107@redhat.com> References: <1411588026.24563.153.camel@ul30vt.home> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-qg0-f45.google.com (mail-qg0-f45.google.com [209.85.192.45]) by gabe.freedesktop.org (Postfix) with ESMTP id 76DBA89C56 for ; Wed, 24 Sep 2014 13:31:51 -0700 (PDT) Received: by mail-qg0-f45.google.com with SMTP id q108so6503356qgd.18 for ; Wed, 24 Sep 2014 13:31:50 -0700 (PDT) In-Reply-To: <1411588026.24563.153.camel@ul30vt.home> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: Alex Williamson , Andrew Barnes Cc: intel-gfx@lists.freedesktop.org, qemu-devel@nongnu.org List-Id: intel-gfx@lists.freedesktop.org Il 24/09/2014 21:47, Alex Williamson ha scritto: > So the opregion is mapped by a config write on the IGD device itself and > the other 3 regions, that we know about so far, are mapped via writes to > the host bridge. AFAIU the opregion is mapped by the (host) BIOS, that writes the address to a well-known scratch dword in the configuration space. The host reads from the dword and finds the opregion that way. Paolo