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 (lists1p.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 E1BEEEA3C59 for ; Thu, 9 Apr 2026 13:30:12 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1wApS1-0005yo-To; Thu, 09 Apr 2026 09:29:41 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wApRx-0005yW-PA for qemu-devel@nongnu.org; Thu, 09 Apr 2026 09:29:37 -0400 Received: from proxmox-new.maurer-it.com ([94.136.29.106]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wApRv-0000MV-Ou for qemu-devel@nongnu.org; Thu, 09 Apr 2026 09:29:37 -0400 Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id 2F0EEE09AA; Thu, 09 Apr 2026 15:29:33 +0200 (CEST) Date: Thu, 09 Apr 2026 15:29:29 +0200 From: Fabian =?iso-8859-1?q?Gr=FCnbichler?= Subject: Re: [PATCH 0/2] migration: include timing and RAM stats on destination when query-migrate To: Claudio Fontana , Fabiano Rosas , Peter Xu Cc: "Daniel P." =?iso-8859-1?q?Berrang=E9?= , Fiona Ebner , Jim Fehlig , qemu-devel@nongnu.org, Trieu Huynh References: <20260405152612.93027-1-viking4@gmail.com> <878qb05gq7.fsf@suse.de> <5f29c2dd-95eb-44c6-b22e-1909f7453cdf@suse.de> <1775739757.quazquvuzm.astroid@yuna.none> In-Reply-To: MIME-Version: 1.0 User-Agent: astroid/0.17.0 (https://github.com/astroidmail/astroid) Message-Id: <1775741078.tmw3evkjts.astroid@yuna.none> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Bm-Milter-Handled: 55990f41-d878-4baa-be0a-ee34c49e34d2 X-Bm-Transport-Timestamp: 1775741303746 Received-SPF: pass client-ip=94.136.29.106; envelope-from=f.gruenbichler@proxmox.com; helo=proxmox-new.maurer-it.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=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: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On April 9, 2026 3:17 pm, Claudio Fontana wrote: > On 4/9/26 15:08, Fabian Gr=C3=BCnbichler wrote: >> On April 9, 2026 12:08 pm, Claudio Fontana wrote: >>> On 4/8/26 22:04, Peter Xu wrote: >>>> On Mon, Apr 06, 2026 at 11:02:56AM -0300, Fabiano Rosas wrote: >>>>> Trieu Huynh writes: >>>>> >>>>>> From: Trieu Huynh >>>>>> >>>>>> When query-migrate is called on the *destination* QEMU after a preco= py >>>>>> migration completes it returns only {"status": "completed"} =E2=80= =94 no timing, >>>>>> no RAM statistics. The source correctly returns total-time, downtim= e, >>>>>> setup-time, and full ram stats. >>=20 >>>>>> [..] >>>>>> >>>>> >>>>> Hi, remember to copy the interested people in your series. Using >>>>> get_maintainers is correct, but when there's already a discussion abo= ut >>>>> the topic it's good to add some CCs manually. >>>>> >>>>> +CC Daniel and Claudio >>>> >>>> The request is a valid one. Said that, redo accounting on both sides = seem >>>> to be a duplicated work and overkill to me, if src has everything. >>>> >>>> Is there a way we can make Libvirt always query the results before src= dies >>>> and report it somewhere? I recall these info were captured somewhere,= do >>>> we at least dump them into logs? >>>> >>>> Thanks, >>>> >>> >>> I am interested in the outcome, but I think the approach shown here is = fine, the amount of duplication seems minimal to me. >>> >>> That said if we _have_ to keep libvirt in the picture, I think I see a = possible alternative, but then the feature is not available to anyone that = does not use libvirt. At the same time, if libvirt is not used, one is free= to keep source QEMU alive and query the stats, like I think Proxmox does. >>=20 >> that is correct, we call query-migrate in a loop while migrating both to >> log progress and to manage migration parameters, and manually switch >> execution and ownership over to the target node once the migration has >> converged: >>=20 >> https://git.proxmox.com/?p=3Dqemu-server.git;a=3Dblob;f=3Dsrc/PVE/QemuMi= grate.pm;h=3Df7ec322770a47dcc8b89109ecfa6f15ea140f30f;hb=3DHEAD#l1423 >=20 > Hello Fabian, thanks for the confirmation, > would it simplify your code if you had the stats already carried over by = QEMU to the new QEMU instance? not really - the source node is driving the migration anyway, so it can also do the polling + logging. there is no management task running on the target node/side, after the initial spawning of the VM process. > I suspect you don't want to touch that code without a very compelling rea= son, but at least in principle it should make things easier?