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=-5.0 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 779C0C433F5 for ; Wed, 8 Sep 2021 16:37:57 +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 20318610A3 for ; Wed, 8 Sep 2021 16:37:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 20318610A3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:57668 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mO0aC-0003Lf-9l for qemu-devel@archiver.kernel.org; Wed, 08 Sep 2021 12:37:56 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:50482) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mO0Z3-0001wd-4Z for qemu-devel@nongnu.org; Wed, 08 Sep 2021 12:36:45 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:41765) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mO0Z1-0007nj-Iu for qemu-devel@nongnu.org; Wed, 08 Sep 2021 12:36:44 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1631119002; h=from:from:reply-to: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=ylUGIHvW9S/mY+tIUN4RnDq7SEZiAhBNenAXsgiNPMI=; b=MUrl9Og2Pi31wQOEDUN9lQCO1DEE+hI0q2PpO0JJ9uvfsVh0AvGN5rk3R5ey9M7chdJ6EN V+073AEYPZC2EKYW1whpZKJGHM5SsfsSyLkXC2f8WqMvYd1LCnovQXclYrJlaS9crjzt8G i7HzDd35IiAUmbyuK/PlY9iO0heJFEM= 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-500-Xe-WT_t-PaeKH1MCrlSX7A-1; Wed, 08 Sep 2021 12:36:37 -0400 X-MC-Unique: Xe-WT_t-PaeKH1MCrlSX7A-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0422C1006AA1 for ; Wed, 8 Sep 2021 16:36:37 +0000 (UTC) Received: from redhat.com (unknown [10.39.193.206]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 5FDF26060F; Wed, 8 Sep 2021 16:36:32 +0000 (UTC) Date: Wed, 8 Sep 2021 17:36:29 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Paolo Bonzini Subject: Re: Compatibility between -device sga and -machine graphics=off Message-ID: References: <364031a0-982d-f6bd-cbcc-9f6d9be4ba69@redhat.com> MIME-Version: 1.0 In-Reply-To: <364031a0-982d-f6bd-cbcc-9f6d9be4ba69@redhat.com> User-Agent: Mutt/2.0.7 (2021-05-04) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.393, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action 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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: qemu-devel@nongnu.org, "Dr. David Alan Gilbert" , Gerd Hoffmann Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, Sep 08, 2021 at 06:28:01PM +0200, Paolo Bonzini wrote: > On 08/09/21 18:08, Daniel P. Berrangé wrote: > > Despite this difference, I was able migrate from a x86 guest using SGA > > to a guest using graphics=off without errors being reported. So it > > doesn't seem to change the migration data sections sent on the wire > > at least. > > It would probably break with Windows XP/2003 guests on AMD processors, as > those are the ones that use kvmvapic. On other guests and processors, it's > a no-op. After running an incoming migrate, the target QEMU's 'info mtree' changed to reflect what the src QEMU originally reported. So whatever difference 'graphics=off' causes compared to -device sga initially, appears to have been eliminated by running the migrate. Not sure if that's true in the general case or not - I'm just testing with a minimalist CLI and no real OS running qemu-system-x86_64 -nodefaults -display sdl -device VGA -serial stdio -device sga vs qemu-system-x86_64 -nodefaults -display sdl -device VGA -serial stdio -machine graphics=off Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|