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=-2.0 required=3.0 tests=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 464A2C33C8C for ; Tue, 7 Jan 2020 15:04:18 +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 0FF6E208C4 for ; Tue, 7 Jan 2020 15:04:18 +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="P1LPNRgZ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0FF6E208C4 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]:50842 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ioqP2-00056U-Ve for qemu-devel@archiver.kernel.org; Tue, 07 Jan 2020 10:04:17 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:38273) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ioppo-00074X-FA for qemu-devel@nongnu.org; Tue, 07 Jan 2020 09:27:53 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ioppn-0005mG-5l for qemu-devel@nongnu.org; Tue, 07 Jan 2020 09:27:52 -0500 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:58089 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 1ioppm-0005lk-UC for qemu-devel@nongnu.org; Tue, 07 Jan 2020 09:27:51 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1578407270; 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=ky0xuTdKS0oC7J5xeh4jTsKqem76ETVJ2E83Coo4SEU=; b=P1LPNRgZr2xJa/ajtgZZ6+emN4mkT/HBL2YvPSutmshpX3GeSzUIudH89T5RuKQgcCKyhK FZx4668wbN+0EwPmgOGIyQmClMnLvQLO/zF5zszqkvdU6fq0aqZjrGIRYHm9uuiljDOkfO 98EUr6pptJQiJ71HzSdNO0KgAMPHu0E= 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-1-lUKR1D-cPQCy_VEHW0UhBg-1; Tue, 07 Jan 2020 09:27:47 -0500 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 5FC7F477; Tue, 7 Jan 2020 14:27:46 +0000 (UTC) Received: from redhat.com (ovpn-112-61.ams2.redhat.com [10.36.112.61]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 676F1858B0; Tue, 7 Jan 2020 14:27:38 +0000 (UTC) Date: Tue, 7 Jan 2020 14:27:35 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= Subject: Re: Priority of -accel Message-ID: <20200107142735.GC3368802@redhat.com> References: <20200106130951.29873-1-philmd@redhat.com> <12334054-4ae7-e580-9727-2d322bfa2bda@redhat.com> <58eb34db-7d32-8b0e-d9ef-98648209486b@redhat.com> <656169fc-1abe-b521-20a3-e7041739b914@redhat.com> <20200107125451.GL3368802@redhat.com> <3241dff4-6223-404f-55d4-846991763046@redhat.com> <2ae2dee3-cd16-a247-971b-4b3482e596a5@redhat.com> MIME-Version: 1.0 In-Reply-To: <2ae2dee3-cd16-a247-971b-4b3482e596a5@redhat.com> User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-MC-Unique: lUKR1D-cPQCy_VEHW0UhBg-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=utf-8 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: 207.211.31.81 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: Kevin Wolf , Thomas Huth , qemu-block@nongnu.org, Markus Armbruster , Wainer dos Santos Moschetta , qemu-devel@nongnu.org, Paolo Bonzini , Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, Jan 07, 2020 at 03:20:40PM +0100, Philippe Mathieu-Daud=C3=A9 wrote= : > On 1/7/20 3:14 PM, Thomas Huth wrote: > > On 07/01/2020 13.54, Daniel P. Berrang=C3=A9 wrote: > > > On Tue, Jan 07, 2020 at 01:23:18PM +0100, Paolo Bonzini wrote: > > > > On 07/01/20 13:18, Thomas Huth wrote: > > > > > I don't think we need a separate priority parameter here. But IMH= O it's > > > > > really rather common practice to prioritize the last option. So= while > > > > > it might be more "self-explanatory" to a CLI newbie if the first > > > > > occurrence got the highest priority, it might be rather confusing > > > > > instead for a CLI veteran...? > > > >=20 > > > > Prioritising the last certainly makes sense for a choose-one-only > > > > option, but I'm not sure it's the same for a choose-best option. A= fter > > > > all it was -machine accel=3Dkvm:tcg, not -machine accel=3Dtcg:kvm..= . > > >=20 > > > IIUC, the main use case for specifying multiple accelerators is > > > so that lazy invokations can ask for a hardware virt, but then get > > > fallback to TCG if not available. For things that should be platform > > > portabile, there's more than just kvm to consider though, as we have > > > many accelerators. Listing all possible accelerators is kind of > > > crazy though no matter what the syntax is. > > >=20 > > > How about taking a completely different approach, inspired by the > > > -cpu arg and implement: > > >=20 > > > -machine accel=3Dbest > >=20 > > Something like that sounds like the best solution to me, but I'd maybe > > rather not call it "best", since the definition of "best" might depend > > on your use-case (e.g. do you want to use a CPU close to the host or > > something different which might be better emulated by TCG?). > >=20 > > What about "-accel any" or "-accel fastest" or something similar? >=20 > 'any' is a russian roulette, you don't want it to return 'qtest' ;) We could make it return "qtest" only on April 1st ;-P Regards, Daniel --=20 |: 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= :|