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 BBD1EC677C4 for ; Tue, 10 Jun 2025 17:06:25 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uP2QU-0007a1-HL; Tue, 10 Jun 2025 13:06:19 -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 1uP2QO-0007R8-7k for qemu-devel@nongnu.org; Tue, 10 Jun 2025 13:06:16 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uP2QM-0004zv-IN for qemu-devel@nongnu.org; Tue, 10 Jun 2025 13:06:11 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1749575167; 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=SjzsZmC3fCn150B3hwMh5JWwz1oxCXshyj5qDRiKeb0=; b=STlExGkFQZnsBXx0X2CqThFuFVkl1zzrY5B84FcWk6/g7bwKCEU6cBqOXlEVxqt6+5JmrZ OYl/PKkJX5981yydkqNSbCpu+0gIVtnFn+M17fntkm1wgYITRfbyhzlwTYBpQd2tYkp6ZG FI0dbPUe0r92fDdFxzHFKyNkAblpKzI= Received: from mx-prod-mc-06.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-392-EkhQG4ldPJqCXUpOLvJJrQ-1; Tue, 10 Jun 2025 13:06:05 -0400 X-MC-Unique: EkhQG4ldPJqCXUpOLvJJrQ-1 X-Mimecast-MFC-AGG-ID: EkhQG4ldPJqCXUpOLvJJrQ_1749575164 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (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-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 5ADD5180029E; Tue, 10 Jun 2025 17:06:04 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.87]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 41D7F19560B2; Tue, 10 Jun 2025 17:06:00 +0000 (UTC) Date: Tue, 10 Jun 2025 18:05:57 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Jaehoon Kim Cc: qemu-devel@nongnu.org, jjherne@linux.ibm.com, steven.sistare@oracle.com, peterx@redhat.com, farosas@suse.de, lvivier@redhat.com, pbonzini@redhat.com Subject: Re: [PATCH v2] migration: Setup pre-listened cpr.sock to remove race-condition. Message-ID: References: <20250610150849.326194-1-jhkim@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20250610150849.326194-1-jhkim@linux.ibm.com> User-Agent: Mutt/2.2.14 (2025-02-20) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com 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, DKIMWL_WL_HIGH=-0.001, 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 Tue, Jun 10, 2025 at 10:08:49AM -0500, Jaehoon Kim wrote: > When the source VM attempts to connect to the destination VM's Unix > domain socket (cpr.sock) during a cpr-transfer test, race conditions can > occur if the socket file isn't ready. This can lead to connection > failures when running tests. > > This patch creates and listens on the socket in advance, and passes the > pre-listened FD directly. This avoids timing issues and improves the > reliability of CPR tests. > > Reviewed-by: Jason J. Herne > Signed-off-by: Jaehoon Kim > > --- > Changes since v1: > - In v1, the patch added a wait loop to poll the existence of the socket > file (cpr_validate_socket_path()). > > - This version instead creates the socket beforehand and passes its FD > to the destination QEMU, eliminating the race condition entirely. > > - Commit title and message changed accordingly. > --- > migration/cpr-transfer.c | 3 +- > tests/qtest/migration/cpr-tests.c | 72 ++++++++++++++++++++++++++++++- > 2 files changed, 72 insertions(+), 3 deletions(-) > > diff --git a/migration/cpr-transfer.c b/migration/cpr-transfer.c > index e1f140359c..7c9de70bad 100644 > --- a/migration/cpr-transfer.c > +++ b/migration/cpr-transfer.c > @@ -46,7 +46,8 @@ QEMUFile *cpr_transfer_input(MigrationChannel *channel, Error **errp) > MigrationAddress *addr = channel->addr; > > if (addr->transport == MIGRATION_ADDRESS_TYPE_SOCKET && > - addr->u.socket.type == SOCKET_ADDRESS_TYPE_UNIX) { > + (addr->u.socket.type == SOCKET_ADDRESS_TYPE_UNIX || > + addr->u.socket.type == SOCKET_ADDRESS_TYPE_FD)) { > > g_autoptr(QIOChannelSocket) sioc = NULL; > SocketAddress *saddr = &addr->u.socket; This will likely cause a crash in tracing code that is below this diff: trace_cpr_transfer_input(addr->u.socket.u.q_unix.path); q_unix.path is NOT valid to access with TYPE_FD. 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 :|