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=-0.3 required=3.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 1BC14C433E0 for ; Wed, 17 Jun 2020 14:42:31 +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 DADC020888 for ; Wed, 17 Jun 2020 14:42:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="fWJOa5jG" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DADC020888 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:35340 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jlZGo-0005eb-6m for qemu-devel@archiver.kernel.org; Wed, 17 Jun 2020 10:42:30 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:42534) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jlZG7-0004qT-CA; Wed, 17 Jun 2020 10:41:47 -0400 Received: from mail-wr1-x443.google.com ([2a00:1450:4864:20::443]:37248) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jlZG5-0000W3-Rp; Wed, 17 Jun 2020 10:41:47 -0400 Received: by mail-wr1-x443.google.com with SMTP id a6so655482wrm.4; Wed, 17 Jun 2020 07:41:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=yHSsY/mYJuBAJ4v9IJFk56qDIweETBolJgGoG/xtXWU=; b=fWJOa5jGPdsHGyhdY40cezjHnMUlDHFFdhpIupbTEK+OXzStj/l/MmqC3SwcjziQgv psDMfHW9Ioyw0AeFS5rKI70BfJ4d09Fq71B/rCxRdWjW+j3O8pG3kLRM/5gZap/YIqks Np3ROi5DATpuPiHne68PhVoy6haMzgGY5M3uM0/rJYrEJL3jAMo7fbnpmZ7XWWOzqSDI fPxK9rCWzMOyhZ6OL0XdBRwMbqQPBx/9UjzSGccFB8Dyr8IPPfaZOAaSD6vCeUIoRFGv 0wX/j7zshyiKUt+NtLdFuyZE6Mh8QRRGbzPgrAuzTuWFi+X+Ly3xTDXffAQ6dXMrSlJI DSyA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=yHSsY/mYJuBAJ4v9IJFk56qDIweETBolJgGoG/xtXWU=; b=Jm9Fz1AKbZeYZzlZ1S42WQ2xBI0ZT19QaRCtTLscHUKUBd9F6IeVVNyQfMSgpuMT0Q NyqvXQH3vuePofr7A8W5lt2qBMCGy9LlY8rPwVRcW6j4O7BURMoVSVAoMwZp5qOkAm4R cDaCOpUCp1+ra29EIsOYCuWtGNcejvB5VpwAn4P7FlIuh8zxA/BuOLSoQ42rD9LAf23c hCFZDKGan3pNJ/roTHkFt03Lp3JPRVZzirm0+B8+0PzRbuAPC/m3ZPuEd1aU8kky/Leg ETP0LHNqYPdKytO00n0nZ3Jk3Ub6DyLrdnlTItwHNDEJkbptJViLjT43WKTC0HgTfoNC OOdw== X-Gm-Message-State: AOAM532gHO+HEKwSbJoC7R74EospnitjaqbuUu9aMkZMFF22J7HdRCEu lNS9UYA9Hk2mqTa9JUzcrdo= X-Google-Smtp-Source: ABdhPJzV8l5J+SO2pz/4ERhQrB65EYAdqGftHPUDUi3HC5ah149q6B0iB/MbILBGLd6gNtmz0twV4w== X-Received: by 2002:adf:ea8b:: with SMTP id s11mr9005221wrm.168.1592404903898; Wed, 17 Jun 2020 07:41:43 -0700 (PDT) Received: from localhost ([51.15.41.238]) by smtp.gmail.com with ESMTPSA id f13sm602063wmb.33.2020.06.17.07.41.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 17 Jun 2020 07:41:42 -0700 (PDT) Date: Wed, 17 Jun 2020 15:41:41 +0100 From: Stefan Hajnoczi To: Lukas Straub Subject: Re: [PATCH v4 0/4] Introduce 'yank' oob qmp command to recover from hanging qemu Message-ID: <20200617144141.GK1728005@stefanha-x1.localdomain> References: <20200606213038.43538439@luklap> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="Jtds+vpI57xq70EV" Content-Disposition: inline In-Reply-To: <20200606213038.43538439@luklap> Received-SPF: pass client-ip=2a00:1450:4864:20::443; envelope-from=stefanha@gmail.com; helo=mail-wr1-x443.google.com X-detected-operating-system: by eggs.gnu.org: No matching host in p0f cache. That's all we know. X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=_AUTOLEARN 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: , Cc: Kevin Wolf , Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= , qemu-block , Juan Quintela , "Dr. David Alan Gilbert" , qemu-devel , =?iso-8859-1?Q?Marc-Andr=E9?= Lureau , Paolo Bonzini , Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --Jtds+vpI57xq70EV Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sat, Jun 06, 2020 at 09:30:38PM +0200, Lukas Straub wrote: > On Mon, 25 May 2020 17:44:12 +0200 > Lukas Straub wrote: >=20 > > Hello Everyone, > > In many cases, if qemu has a network connection (qmp, migration, charde= v, etc.) > > to some other server and that server dies or hangs, qemu hangs too. > > These patches introduce the new 'yank' out-of-band qmp command to recov= er from > > these kinds of hangs. The different subsystems register callbacks which= get > > executed with the yank command. For example the callback can shutdown()= a > > socket. This is intended for the colo use-case, but it can be used for = other > > things too of course. > >=20 > > Regards, > > Lukas Straub >=20 > Hello Everyone, > Can this be reviewed, it would be cool to have this in qemu 5.1. Please see my reply to a previous version. Code that executes in the oob environment needs to take special precautions, this needs to be documented so that yank API users know what the limitations are. Stefan --Jtds+vpI57xq70EV Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAl7qK6UACgkQnKSrs4Gr c8gjzQf/QJ20213uQ4UoGQM1p9gVC+g+9b4q+ce92Exe2oVRPluK81YmQ2fis8lG CxWAREM0IiLlH3iL44R06+eewQkUSWwGZY5NM0ri2bsO4yT1uIcMBHwEsnDP8zyA 4zcI752bWbjAY14aVNL7Ry7TaND4KMye240mEEJNeXWLHVt7lBebgoP5xNmi5pgS lk7LUc7NegENWGn8UfAjrAlX5eRWUeYRnztD7jeJhhNmbYqilKxqx9uy8Bs8ITu4 6F7Ubclq8ZBVHTrvoU4hOvlTMVtK1uyhJrzPeou02EKL4q39CuD7/AUAuD44nF7n TkQsQvl31crdwX40hUCusnimuaCWRw== =G63M -----END PGP SIGNATURE----- --Jtds+vpI57xq70EV--