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=-5.1 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 AD03DC48BCD for ; Wed, 9 Jun 2021 11:54:45 +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 4053E61249 for ; Wed, 9 Jun 2021 11:54:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4053E61249 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]:57536 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lqwnD-0003WD-Ud for qemu-devel@archiver.kernel.org; Wed, 09 Jun 2021 07:54:43 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:34796) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lqwmd-0002pU-IA for qemu-devel@nongnu.org; Wed, 09 Jun 2021 07:54:07 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:34672) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lqwmZ-0001Q7-Gm for qemu-devel@nongnu.org; Wed, 09 Jun 2021 07:54:06 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1623239642; 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=Qazg5EYp2vWzf5uM7lsIdi3tq9UV4VUp4Hf4vy4JAII=; b=L4gDBi4voNNEMzQ7Gpx1DpDJHK1UvZ9RNCYXmpqCsI3BFwNVGITAXmZAm3U1e8Q9B41o1O tVkspUu3dSLmfheF50j6+Wkdm2jaZ9vsPCsUMdJG7psjw2xnr0myNA6AmJJ3OpEMzSSCBg v7TMlfQkh74+GhzyyVPPIkWerGHMOSY= 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-406-Ed3wSF9COGe556geREXLyA-1; Wed, 09 Jun 2021 07:54:01 -0400 X-MC-Unique: Ed3wSF9COGe556geREXLyA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 6CA45100CF6A for ; Wed, 9 Jun 2021 11:54:00 +0000 (UTC) Received: from redhat.com (ovpn-115-127.ams2.redhat.com [10.36.115.127]) by smtp.corp.redhat.com (Postfix) with ESMTPS id AD5DA19C45; Wed, 9 Jun 2021 11:53:49 +0000 (UTC) Date: Wed, 9 Jun 2021 12:53:46 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Gerd Hoffmann Subject: Re: [RFC QEMU PATCH] ui: Make the DisplayType enum entries conditional Message-ID: References: <20210609100240.1285032-1-thuth@redhat.com> <20210609112405.pyv62l22g5ympoe4@sirius.home.kraxel.org> <20210609114921.mc4upvizeobfruaw@sirius.home.kraxel.org> MIME-Version: 1.0 In-Reply-To: <20210609114921.mc4upvizeobfruaw@sirius.home.kraxel.org> User-Agent: Mutt/2.0.7 (2021-05-04) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 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: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.199, 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_H4=0.001, RCVD_IN_MSPIKE_WL=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: Thomas Huth , libvir-list@redhat.com, smitterl@redhat.com, Markus Armbruster , qemu-devel@nongnu.org, Eric Blake Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, Jun 09, 2021 at 01:49:21PM +0200, Gerd Hoffmann wrote: > On Wed, Jun 09, 2021 at 12:29:58PM +0100, Daniel P. Berrangé wrote: > > On Wed, Jun 09, 2021 at 01:24:05PM +0200, Gerd Hoffmann wrote: > > > On Wed, Jun 09, 2021 at 12:02:40PM +0200, Thomas Huth wrote: > > > > Libvirt's "domcapabilities" command has a way to state whether > > > > certain graphic frontends are available in QEMU or not. Originally, > > > > libvirt looked at the "--help" output of the QEMU binary to determine > > > > whether SDL was available or not (by looking for the "-sdl" parameter > > > > in the help text), but since libvirt stopped doing this analysis of > > > > the help text, the detection of SDL is currently broken, see: > > > > > > > > https://bugzilla.redhat.com/show_bug.cgi?id=1790902 > > > > > > > > QEMU should provide a way via the QMP interface instead. The simplest > > > > way, without introducing additional commands, is to make the DisplayType > > > > enum entries conditional, so that the enum only contains the entries if > > > > the corresponding CONFIG_xxx switches have been set. > > > > > > Hmm, that'll break for the "dnf remove qemu-ui-sdl" case ... > > > > Note tht libvirt invalidates its cache of QEMU capabilities when it > > sees the /usr/lib64/qemu directory timestamp change. So it ought to > > pick up changes caused by installing/removing QEMU modules, and apply > > this to future queries for domcapabilities, or when starting future > > QEMU guests. > > That'll work fine for modules implementing qom objects / devices, > because the list of available objects changes accordingly and libvirt > can see that. > > The #if CONFIG_SDL approach will not work because qemu will continue to > report sdl as supported even when the sdl module is not installed any > more. Ah see what you mean now. So libvirt can't merely query members of the DisplayType enum. We need an actual 'query-display-types' command that returns an array of DisplayType values corresponding to what is actually built-in or available as a module at that instant. 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 :|