From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54339) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VqOlz-00057s-UV for qemu-devel@nongnu.org; Tue, 10 Dec 2013 09:59:02 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VqOlt-0006IZ-Rk for qemu-devel@nongnu.org; Tue, 10 Dec 2013 09:58:55 -0500 Received: from mx1.redhat.com ([209.132.183.28]:51588) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VqOlt-0006IR-JK for qemu-devel@nongnu.org; Tue, 10 Dec 2013 09:58:49 -0500 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id rBAEwlEt013905 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 10 Dec 2013 09:58:48 -0500 Message-ID: <52A72C24.3080209@redhat.com> Date: Tue, 10 Dec 2013 15:58:44 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: <1385401393-14291-1-git-send-email-pbonzini@redhat.com> <20131128102652.GA24261@redhat.com> <52A714AC.3050703@redhat.com> <1386687211.15686.21.camel@nilsson.home.kraxel.org> In-Reply-To: <1386687211.15686.21.camel@nilsson.home.kraxel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH rebased for-1.8] i386: pc: align gpa<->hpa on 1GB boundary (v6) List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Gerd Hoffmann Cc: Marcelo Tosatti , qemu-devel@nongnu.org, "Michael S. Tsirkin" Il 10/12/2013 15:53, Gerd Hoffmann ha scritto: > Hi, > >> If we could make a small guset visible change, it would be simpler to >> always make the PCI hole 1GB in size; it is currently 256MB for i440FX >> and 1.25GB for q35. > > Easy for i440fx. > > Tricky for q35 as the firmware knows qemu will not map ram above > 0xb000000 and places the mmconfig bar @ 0xb0000000. Making the window > smaller (1.25GB -> 1GB) will create a conflict there. Making it larger > (2G) will work. It's done this way to keep 0xc0000000+ free for pci > bars, and we can map up to 512MB-sized bars there. 0xc0000000-0xfebfffff is almost 1GB, so there is room for 1 512MB-size BAR. mmconfig could move to 0xf0000000-0xf7ffffff; firmware is not a problem because this would be only for new machine types. Unless I'm missing something of course. Paolo >> We can take a look as soon as the SeaBIOS patches >> are in to use QEMU-built ACPI tables. > > This is in master already. > > cheers, > Gerd > >