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=-6.5 required=3.0 tests=BAYES_00,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 DF5FAC432BE for ; Fri, 27 Aug 2021 12:39:49 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 9C49E60F25 for ; Fri, 27 Aug 2021 12:39:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 9C49E60F25 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=citrix.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.173636.316781 (Exim 4.92) (envelope-from ) id 1mJb8x-0001qJ-E7; Fri, 27 Aug 2021 12:39:35 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 173636.316781; Fri, 27 Aug 2021 12:39:35 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1mJb8x-0001qC-Au; Fri, 27 Aug 2021 12:39:35 +0000 Received: by outflank-mailman (input) for mailman id 173636; Fri, 27 Aug 2021 12:39:34 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1mJb8w-0001q2-2L for xen-devel@lists.xenproject.org; Fri, 27 Aug 2021 12:39:34 +0000 Received: from esa5.hc3370-68.iphmx.com (unknown [216.71.155.168]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 5d09bd03-ba72-49c4-b3c4-56676f9c5e35; Fri, 27 Aug 2021 12:39:33 +0000 (UTC) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 5d09bd03-ba72-49c4-b3c4-56676f9c5e35 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=citrix.com; s=securemail; t=1630067972; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=JKZQsjN7ju7Me1IUvRh5OReB4tNtVugl2ImK3Tp92k0=; b=iPXwO20VS+NzVyZFETDs9MYvNPSenIuAvos4yTfplqcg9H/J5QI3qCqp 2NRcNCEie4phvDFGygf0VpTf+H/wzJgtTc2mp0VwQGuLsZVXbtDp9/SNU I2veqY0OwTWZcsSByGGH+A98PNdFOF9DfWAuFb5grCmcAdofIB+pK1evF w=; Authentication-Results: esa5.hc3370-68.iphmx.com; dkim=none (message not signed) header.i=none IronPort-SDR: cSuv7s1/V6AL/lsoTeijC4tfUux0hD0BlrHsDyfkDHS84dq3wFekXgy0ZvreG6RDj3Fci+/Wj7 Pjd30cu9WF0J1kxbGRBcu2DInPqLQzEHKesEq3E+NMO8IFWK/6HGek1tLvCOfaeQdw91HWH7Ff gv3gF/C+wnAXfGfHmffRw749G5ranm8hTa1kMAD8UvEIHCn1O5/teIN5HzIfShUQt/GolVn3o2 ExjJtZStRg5PQ+S5e7V8Y3YFH7bsRy+ZOrjmpXJWngM9ic83E0Ww81Kfx21DM8fc4fRLST0EAx qV1pJI3v0ouXVWhPbMdeGtxJ X-SBRS: 5.1 X-MesageID: 51071069 X-Ironport-Server: esa5.hc3370-68.iphmx.com X-Remote-IP: 162.221.156.83 X-Policy: $RELAYED IronPort-HdrOrdr: A9a23:OyGKc64WUb+NEtzTAwPXwAzXdLJyesId70hD6qkQc3Fom62j5q WTdZEgvyMc5wx/ZJhNo7690cq7MBHhHPxOgbX5VI3KNGXbUQOTR72KhrGSoAEIdReeygZcv5 0QCZSXCrfLfCVHZRCR2njFLz4iquP3j5xBnY3lvhNQpZkBUdAZ0+9+YDzrdXFedU19KrcSMo GT3cZDryrIQwVtUizqbkN1OdQqvrfw5evbXSI= X-IronPort-AV: E=Sophos;i="5.84,356,1620705600"; d="scan'208";a="51071069" Date: Fri, 27 Aug 2021 13:39:28 +0100 From: Anthony PERARD To: Ian Jackson CC: Jan Beulich , Olaf Hering , "xen-devel@lists.xenproject.org" , "George Dunlap" , Stefano Stabellini , Wei Liu , Julien Grall Subject: Re: QEMU 6.0+ in 4.15 and 4.14 (Re: preparations for 4.15.1 and 4.13.4) Message-ID: References: <48cc22b9-6d0a-2cfc-ce34-6aabeb84b160@suse.com> <24862.34174.101215.640300@mariner.uk.xensource.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <24862.34174.101215.640300@mariner.uk.xensource.com> On Thu, Aug 19, 2021 at 05:23:26PM +0100, Ian Jackson wrote: > Anthony PERARD writes ("Re: preparations for 4.15.1 and 4.13.4"): > > Can we backport support of QEMU 6.0 to Xen 4.15? I'm pretty sure > > distributions are going to want to use the latest QEMU and latest Xen, > > without needed to build two different QEMU binaries. > > I think this is appropriate. Xen 4.15 is still now, and there was an > unfortunate interaction between release dates. Your argument makes > sense. > > > [XEN PATCH v2 0/8] Fix libxl with QEMU 6.0 + remove some more deprecated usages. > > <20210511092810.13759-1-anthony.perard@citrix.com> > > Commits: d5f54009db^..fe6630ddc4 > > > > Some more QEMU 6.0 fixes > > <20210628100157.5010-1-anthony.perard@citrix.com> > > Commits: 217eef30f7 3bc3be978f > > So I have queued all these. > > > Also, Olaf want them to be backported to 4.14, see > > <20210629095952.7b0b94c1.olaf@aepfle.de> > > I'm unsure about this. The diff seems moderately large. Also, are we > sure that it wouldn't break anything other than very old qemu ? OTOH > compat problems with newer qemu are indeed a problem especially for > distros. I've check all commits, beside two commits they all have a fallback mechanism so we still are compatible with old qemus. There is these two commits libxl: Fix QEMU cmdline for scsi device libxl: Use -device for cd-rom drives which replace command line arguments, but it is to use something that has been available since QEMU 0.15, so before the first version that libxl as evert supported. So overall, I don't think we break compatibility with very old qemus. It would take a couple more QMP command to run some feature as libxl would try the new command first before falling back to previous ones. > I'm currently leaning towards "no" but I am very open to being > convinced this is a good idea. I don't know if it is a good idea, but at least it doesn't seems to be a bad one. -- Anthony PERARD