From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9C5DCC43603 for ; Fri, 6 Dec 2019 16:17:02 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 696DC2464E for ; Fri, 6 Dec 2019 16:17:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="OiozvRk/" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 696DC2464E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:40608 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1idGHs-0002wI-SR for qemu-devel@archiver.kernel.org; Fri, 06 Dec 2019 11:17:00 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:54363) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1idF3u-00061v-Ko for qemu-devel@nongnu.org; Fri, 06 Dec 2019 09:58:31 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1idF3t-0003Xa-GB for qemu-devel@nongnu.org; Fri, 06 Dec 2019 09:58:30 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:25551 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1idF3r-0003VY-Ft for qemu-devel@nongnu.org; Fri, 06 Dec 2019 09:58:27 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1575644305; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=T0eE1Ell3ER1XzngozBueUW3DTe4Cka2OH3WB8BQShA=; b=OiozvRk/bcfU7ynOcqSNFVR6qotlolnhmENWS8/CiqiHsMm3r7rjcGu0sYWXv+j7d9zg5f dlqDuAiVdpW1x4hSHxw6DoYA9rt79wVdd4n6dOl2joS25NfuES7PI4N6yhryrpibABwmNr xwso3mzlexqzFjlhW6P2eBk7pvfL5qw= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-434-0nMwB1tYMc6cLRruGrdLnA-1; Fri, 06 Dec 2019 05:57:48 -0500 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id C49C41005502 for ; Fri, 6 Dec 2019 10:57:47 +0000 (UTC) Received: from sirius.home.kraxel.org (ovpn-116-67.ams2.redhat.com [10.36.116.67]) by smtp.corp.redhat.com (Postfix) with ESMTP id DB17960BF4; Fri, 6 Dec 2019 10:57:42 +0000 (UTC) Received: by sirius.home.kraxel.org (Postfix, from userid 1000) id CC19416E18; Fri, 6 Dec 2019 11:57:41 +0100 (CET) Date: Fri, 6 Dec 2019 11:57:41 +0100 From: Gerd Hoffmann To: Thomas Huth Subject: Re: [PATCH 0/3] Remove deprecated pc-0.x machine types and related hacks Message-ID: <20191206105741.zeckqevl3gglgdhg@sirius.home.kraxel.org> References: <20191205160652.23493-1-thuth@redhat.com> <874kyeosmg.fsf@dusky.pond.sub.org> MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-MC-Unique: 0nMwB1tYMc6cLRruGrdLnA-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Content-Disposition: inline X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 205.139.110.120 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Eduardo Habkost , "Michael S. Tsirkin" , libvir-list@redhat.com, Markus Armbruster , qemu-devel@nongnu.org, Paolo Bonzini Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" > > $ git-grep pc-0 > > hw/display/vga-pci.c: /* compatibility with pc-0.13 and older */ > > hw/display/vga.c: /* With pc-0.12 and below we map both the PCI BAR = and the fixed VBE region, > > hw/display/vmware_vga.c: /* compatibility with pc-0.13 and older= */ >=20 > These are the "rombar" hacks that I've mentioned above. The question is > whether we want to remove them or whether I should just adjust the commen= ts? Hmm. All that cruft ... vga maps the framebuffer @ 0xe0000000 with rombar=3Doff. It's an alias of the pci memory bar. rombar=3Doff is basically a flag for "really old firmware" here, vgabios used to have that address hardcoded, a decade ago. We fixed that roughly the same timeframe where we switched to seabios, which in turn allowed us to place the vgabios in the pci rom bar (instead of copying it to 0xa000 in guest ram). Which is probably the reason why we have only one switch for both. I don't expect anyone actually sets the rombar property for vga devices (it's more common for NICs, for network boot tweaks), so I guess we can get away with simply dropping the hacks in vga-pci.c and vmware_vga.c. The comment in vga.c is not fully correct though, isa-vga needs that too, so we have to keep vga_init_vbe for the time being ... cheers, Gerd