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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 352A4C433EF for ; Mon, 6 Dec 2021 09:58:04 +0000 (UTC) Received: from localhost ([::1]:39898 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1muAl1-00028J-5n for qemu-devel@archiver.kernel.org; Mon, 06 Dec 2021 04:58:03 -0500 Received: from eggs.gnu.org ([209.51.188.92]:34360) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1muAkJ-00018V-22 for qemu-devel@nongnu.org; Mon, 06 Dec 2021 04:57:19 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:39941) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1muAkE-0002oI-WC for qemu-devel@nongnu.org; Mon, 06 Dec 2021 04:57:17 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1638784633; 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:in-reply-to:in-reply-to: references:references; bh=3Y8qVZHLC5gwvCmzN2KRQqzUZEH+5qDtRC306lDZNLI=; b=ZeeHexREKp8jwL5KqzRDx7XKsdOraa3X+HZ9WpiJgXmhmZQQrw+s+3jaNm0q6JgbWgMwco zuO45EeE5Ga93nCxoS4xjB5/gFGMAdMv6oxq7yWik3NUwLHMXWavZ5wPUhZeqNqh41dxvT 1Lx/Et5w2BsRYi8/lxqp16PojjvzM1Q= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-341-Xp8MS_CmPaeLTW574RHOVw-1; Mon, 06 Dec 2021 04:57:07 -0500 X-MC-Unique: Xp8MS_CmPaeLTW574RHOVw-1 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 D07A41926DA1; Mon, 6 Dec 2021 09:57:05 +0000 (UTC) Received: from redhat.com (unknown [10.33.36.73]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 9292479454; Mon, 6 Dec 2021 09:56:53 +0000 (UTC) Date: Mon, 6 Dec 2021 09:56:51 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Thomas Huth Subject: Re: [PATCH for-7.0] i386: Deprecate the -no-hpet QEMU command line option Message-ID: References: <20211206084012.49277-1-thuth@redhat.com> <10bc4172-f6c0-504b-cecb-e7caf9edb074@redhat.com> <1fd3a291-0970-5a5f-9428-9539afc8559b@redhat.com> MIME-Version: 1.0 In-Reply-To: User-Agent: Mutt/2.1.3 (2021-09-10) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 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 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -33 X-Spam_score: -3.4 X-Spam_bar: --- X-Spam_report: (-3.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.619, 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_H3=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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: Eduardo Habkost , Peter Krempa , "Michael S. Tsirkin" , Libvirt , Richard Henderson , qemu-devel@nongnu.org, Paolo Bonzini Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, Dec 06, 2021 at 10:44:50AM +0100, Thomas Huth wrote: > On 06/12/2021 10.19, Peter Krempa wrote: > > On Mon, Dec 06, 2021 at 10:02:44 +0100, Thomas Huth wrote: > > > On 06/12/2021 09.57, Peter Krempa wrote: > > > > On Mon, Dec 06, 2021 at 09:47:58 +0100, Thomas Huth wrote: > > > > > On 06/12/2021 09.40, Thomas Huth wrote: > > > > > > The HPET setting has been turned into a machine property a while ago > > > > > > already, so we should finally do the next step and deprecate the > > > > > > legacy CLI option, too. > > > > > > While we're at it, add a proper help text for the machine property, too. > > > > > > > > > > > > Signed-off-by: Thomas Huth > > > > > > --- > > > > > > docs/about/deprecated.rst | 6 ++++++ > > > > > > hw/i386/pc.c | 2 ++ > > > > > > qemu-options.hx | 2 +- > > > > > > softmmu/vl.c | 1 + > > > > > > 4 files changed, 10 insertions(+), 1 deletion(-) > > > > > > > > > > > > diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst > > > > > > index 5693abb663..1dfe69aa6a 100644 > > > > > > --- a/docs/about/deprecated.rst > > > > > > +++ b/docs/about/deprecated.rst > > > > > > @@ -198,6 +198,12 @@ form is preferred. > > > > > > Using ``-drive if=none`` to configure the OTP device of the sifive_u > > > > > > RISC-V machine is deprecated. Use ``-drive if=pflash`` instead. > > > > > > +``-no-hpet`` (since 7.0) > > > > > > +'''''''''''''''''''''''' > > > > > > + > > > > > > +The HPET setting has been turned into a machine property. > > > > > > +Use ``-machine hpet=off`` instead. > > > > > [...] > > > > > > > > > > Forgot to CC: the libvirt folks, doing so now. > > > > > > > > > > Seems like libvirt is still using -no-hpet in some few spots, so I guess > > > > > these would need to be changed first, before we could finally remove this > > > > > option in QEMU? > > > > > > > > Yes we need to switch to the new property first. > > > > > > > > Is the new way via -machine property by any chance usable with > > > > qemu-2.11? If yes, then we can do it unconditionally, otherwise we'll > > > > need a witness to detect the support for the new flag as a qemu > > > > capability. > > > > > > The machine property has been added just a year ago: > > > > > > https://gitlab.com/qemu-project/qemu/-/commit/0259c78ca79 > > > > > > So it's just available on QEMU v5.2.0 and newer. > > > > Okay, so we can't unfortunately always use the new way. > > > > I had a brief look in what libvirt queries to build the capability list > > and unfortunately neither query-command-line-options nor query-machines > > list anything which we could detect. > > > > Since only the config knob is changing the presence in qom-list-types > > doesn't help either. > > > > So if qemu want's to deprecate the '-no-hpet' spelling we need something > > which we can detect by one of the above means or other probe command to > > use the new spelling. > > I just had another chat with Peter on IRC, and seems like it could be > detected by running "qom-list-properties" on e.g. the "generic-pc-machine" > object. However, libvirt does not have that information in their test data > yet, so it's not a very trivial change to support this in libvirt. It is mostly just a tedious matter of getting sample QMP replies for the qom-list-properties command on various older QEMU versions to make sure our test suite does the right thing. > Thus, please don't merge this patch yet, it will currently cause more hassle > than benefit. I don't see any problem in QEMU going ahead with this. If it is deprecated in 7.0, then it won't be until 7.2 that its deleted, which is Dec 2022 timeframe. A year is enough time for libvirt to adapt. 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 :|