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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 61830C04AB3 for ; Mon, 27 May 2019 19:00:46 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3DF1A20859 for ; Mon, 27 May 2019 19:00:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3DF1A20859 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 ([127.0.0.1]:49619 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hVKrV-0002kZ-HY for qemu-devel@archiver.kernel.org; Mon, 27 May 2019 15:00:45 -0400 Received: from eggs.gnu.org ([209.51.188.92]:40174) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hVKqK-000232-Mi for qemu-devel@nongnu.org; Mon, 27 May 2019 14:59:33 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hVKqI-0004Ay-Se for qemu-devel@nongnu.org; Mon, 27 May 2019 14:59:32 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41222) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hVKqI-00049i-Nh for qemu-devel@nongnu.org; Mon, 27 May 2019 14:59:30 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E37F7307D926; Mon, 27 May 2019 18:59:17 +0000 (UTC) Received: from localhost (ovpn-116-14.gru2.redhat.com [10.97.116.14]) by smtp.corp.redhat.com (Postfix) with ESMTP id 58B3360126; Mon, 27 May 2019 18:59:15 +0000 (UTC) Date: Mon, 27 May 2019 15:59:12 -0300 From: Eduardo Habkost To: Andrea Bolognani Message-ID: <20190527185912.GC22103@habkost.net> References: <20190513184237.i2ha3ixvhjqzkn5q@kamzik.brq.redhat.com> <87bm05ab6c.fsf@dusky.pond.sub.org> <20190514090225.vel4xm4x743o4rge@kamzik.brq.redhat.com> <20190514164838.48fc7603@Igors-MacBook-Pro> <20190515081854.kcpjm4zd2bzc7f6o@kamzik.brq.redhat.com> <20190515125229.1784f586@redhat.com> <20190515115413.cqvzjkky7xubnsuo@kamzik.brq.redhat.com> <2186eb85f8541b0c9cc69cacae9321ace8addaa6.camel@redhat.com> <20190524182434.GH10764@habkost.net> <2a5ef002257fe66ff6c4c88008ace24f8cffb86f.camel@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2a5ef002257fe66ff6c4c88008ace24f8cffb86f.camel@redhat.com> User-Agent: Mutt/1.11.3 (2019-02-01) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.48]); Mon, 27 May 2019 18:59:25 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] How do we do user input bitmap properties? X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: peter.maydell@linaro.org, Andrew Jones , Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= , qemu-devel@nongnu.org, Markus Armbruster , Igor Mammedov , Dave.Martin@arm.com, dgilbert@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, May 27, 2019 at 06:29:44PM +0200, Andrea Bolognani wrote: > On Fri, 2019-05-24 at 15:24 -0300, Eduardo Habkost wrote: > > On Thu, May 23, 2019 at 10:35:24AM +0200, Andrea Bolognani wrote: > > > [...] the above looks good to > > > me as a general direction, but note that you'll have to implement at > > > the very least the query-cpu-model-expansion QMP command for the > > > introspection to work. > > > > Why is query-cpu-model-expansion needed? Isn't > > device-list-properties enough? > > Good question. > > I'll have to check with Jirka, but from playing with both commands > it looks like the latter returns a superset of what the former does, > so for the purpose of figuring out which vector lengths the QEMU > binary recognizes it should be good enough; I suspect, however, that > query-cpu-model-expansion might be (made to be) smarter and for > example not report vector lengths that the underlying hardware > doesn't support, which would be valuable for the purpose of user > friendly error reporting and allowing applications to decide which > vector lengths to request when creating guests. Yes, query-cpu-model-expansion returns additional information, so it depends on what exactly you are looking for. If you want to know which properties a given QEMU binary supports in the command-line, `device-list-properties` is supposed to be enough. If you need to know which properties can be really enabled in a given host (based on QEMU+KVM+hardware capabilities), you'll need `query-cpu-model-expansion model=max`. -- Eduardo