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 87755C5AD49 for ; Fri, 6 Jun 2025 15:48:22 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uNZIi-0008Vy-Mr; Fri, 06 Jun 2025 11:48:12 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uNZIg-0008Vj-4R for qemu-devel@nongnu.org; Fri, 06 Jun 2025 11:48:10 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uNZIe-0002hu-G4 for qemu-devel@nongnu.org; Fri, 06 Jun 2025 11:48:09 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1749224887; 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=ScYKysA/aFPDA/diWe5BA2GYW1b333PRuX+VsYidxVA=; b=eipbr69ZAu3YoBblPxeopJRYi8cAh5K4P3ZNaEqpl3AjvSbciPYyOG89EiFJD4mSzhImTO Vt/XkGrg54+g/c6ycwGhYCbgUq45dfxERjh8hOXN4gP1AP3oco6DN0fEJHs5ZAvv2rqzvP WDqYpkFL9gQI+IYIiV5dnta3ajaideM= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-625-QdcsKXj4PIeiWaTC_GJoXg-1; Fri, 06 Jun 2025 11:48:04 -0400 X-MC-Unique: QdcsKXj4PIeiWaTC_GJoXg-1 X-Mimecast-MFC-AGG-ID: QdcsKXj4PIeiWaTC_GJoXg_1749224883 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 46751180883C; Fri, 6 Jun 2025 15:48:00 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.55]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 3853618002BA; Fri, 6 Jun 2025 15:47:58 +0000 (UTC) Date: Fri, 6 Jun 2025 16:47:55 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: JAEHOON KIM Cc: Fabiano Rosas , qemu-devel@nongnu.org, jjherne@linux.ibm.com, steven.sistare@oracle.com, peterx@redhat.com Subject: Re: [PATCH v1] migration: Wait for cpr.sock file to appear before connecting Message-ID: References: <20250605230808.1278840-1-jhkim@linux.ibm.com> <87plfhvvig.fsf@suse.de> <9da21b91-3e4c-4a74-8e90-6d70eadf314c@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <9da21b91-3e4c-4a74-8e90-6d70eadf314c@linux.ibm.com> User-Agent: Mutt/2.2.14 (2025-02-20) X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 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: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.104, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, 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: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Fri, Jun 06, 2025 at 09:48:41AM -0500, JAEHOON KIM wrote: > > On 6/6/2025 8:40 AM, Fabiano Rosas wrote: > > Jaehoon Kim writes: > > > > > When the source VM attempts to connect to the destination VM's Unix > > > domain socket(cpr.sock) during CPR transfer, the socket file might not > > > yet be exist if the destination side hasn't completed the bind > > > operation. This can lead to connection failures when running tests with > > > the qtest framework. > > > > > Could you provide us the output of qtest in this case? Are you simply running > > make check or something else? > > Yes, I'm simply running 'make check-qtest-s390x'. > > Here's the qtest output from the failure: >  # { >  #     "error": { >  #         "class": "GenericError", >  #         "desc": "Failed to connect to '/tmp/migration-test-ZC7Z72/cpr.sock': No such file or directory" >  #     } >  # } >  not ok /s390x/migration/mode/transfer - ERROR:../tests/qtest/libqtest.c:1453:qtest_vqmp_assert_success_ref: assertion failed: (qdict_haskey(response, "return")) >  Bail out! So this is showing a failure when using $QEMU -incoming cpr:...address... as opposed to $QEMU -incoming cpr:defer I presume in the former case, the test is spawning QEMU, but the startup of QEMU & its listening on the UNIX socket is not synchronized with the parent process. In the latter case usnig 'defer', listening will be synchronized by the QMP command used to setup the incoming socket. So why do we see a race with "-incoming cpr:..address", but not with a traditional "-incoming ...address.." for non-CPR code ? With 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 :|