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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 8BC79C33CB1 for ; Tue, 14 Jan 2020 09:00:04 +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 57D992075B for ; Tue, 14 Jan 2020 09:00:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="S0hSgH+W" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 57D992075B 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]:34718 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1irI3P-0001sJ-EB for qemu-devel@archiver.kernel.org; Tue, 14 Jan 2020 04:00:03 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:53460) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1irI2o-0001Ns-A9 for qemu-devel@nongnu.org; Tue, 14 Jan 2020 03:59:27 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1irI2m-0007Zp-2z for qemu-devel@nongnu.org; Tue, 14 Jan 2020 03:59:26 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:57752 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 1irI2m-0007Zd-03 for qemu-devel@nongnu.org; Tue, 14 Jan 2020 03:59:24 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1578992363; 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=5dJMmsXdoA6huBXa0xhsiMffQui5qpFsk32GpCC0Vvk=; b=S0hSgH+WGnaVkr16nSip/jLQQddMR1tOjzSp36WlVhqUwvVgST76gx4AGGrTn6CFmPnVi+ TCpJxHBMpbBmhrydBnnwDrKTHGPxe69IhNn/gIkb/oVDIf1cK4BlGnUjozqC1X3s7IQiFR WdOkeGm/S0r1mq82XhtnRAuZERE/qkg= 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-8-rOCVM3TEPqC0-TcC_SGlRg-1; Tue, 14 Jan 2020 03:59:20 -0500 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5084C1005502; Tue, 14 Jan 2020 08:59:19 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-116-131.ams2.redhat.com [10.36.116.131]) by smtp.corp.redhat.com (Postfix) with ESMTPS id F263F5C1D6; Tue, 14 Jan 2020 08:59:11 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 175CB1138600; Tue, 14 Jan 2020 09:59:10 +0100 (CET) From: Markus Armbruster To: Paolo Bonzini Subject: Re: Priority of -accel References: <20200106130951.29873-1-philmd@redhat.com> <12334054-4ae7-e580-9727-2d322bfa2bda@redhat.com> <1A5859EA-4403-4921-B527-DFD07C59C702@redhat.com> <360fa010-ba80-b02b-3a35-19c2b48a462d@redhat.com> <87d0bnwct1.fsf@dusky.pond.sub.org> Date: Tue, 14 Jan 2020 09:59:10 +0100 In-Reply-To: (Paolo Bonzini's message of "Mon, 13 Jan 2020 17:25:04 +0100") Message-ID: <87lfqajtwh.fsf@dusky.pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-MC-Unique: rOCVM3TEPqC0-TcC_SGlRg-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain Content-Transfer-Encoding: quoted-printable 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: Kevin Wolf , Thomas Huth , Daniel Berrange , qemu-block@nongnu.org, qemu-devel@nongnu.org, Wainer dos Santos Moschetta , Max Reitz , Christophe de Dinechin , Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Paolo Bonzini writes: > On 13/01/20 17:17, Markus Armbruster wrote: >> Perfect opportunity to change the default to something more useful. > > I am not sure acutally if it's that more useful, now that we have > sanctioned qemu-kvm as the fast alternative. If there is a fast alternative, why ship the slow one? > Particularly it would be confusing for qemu-system-x86_64 to use > hardware virtualization on Linux, but not on other operating systems > where the accelerators are not stable enough. Hardly more confusing than qemu-kvm not using hardware virtualization when /dev/kvm is unavailable. No matter what we do, somebody is going to be confused. How to resolve such a conundrum? Utilitarian philosophy teaches us to pursue the greatest confusion of the greatest numbers. I think not using x86 hardware virtualization by default has been admirably successful there. ;-P