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 48DCEC5B552 for ; Mon, 9 Jun 2025 13:21:27 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uOcRA-0004sG-Ds; Mon, 09 Jun 2025 09:21:16 -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 1uOcR5-0004rf-VX for qemu-devel@nongnu.org; Mon, 09 Jun 2025 09:21:12 -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 1uOcR3-0007I1-04 for qemu-devel@nongnu.org; Mon, 09 Jun 2025 09:21:11 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1749475266; 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=/ot59GsmA0h1+ooIuG8wBIHrM4zzwGkJA1OziySa4kA=; b=Ukx4k2n++GOxeiIhqJWKyYjJL+RCAU8fxFI3X2E335tPyzHg8JNLbuWwre9nLxMp/3kJqD spFye+9FSJRkfhmc/sx+X44yfA8TDfDiLqIQ6N2b4HR8ujfMXOqHjebOa5fwxg+FBK5aUG xL4hD/7jiBF1iUGqF/jqPthb/x6+ZNE= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-203-r6ENYNb1POClnLOHwrqjSw-1; Mon, 09 Jun 2025 09:21:03 -0400 X-MC-Unique: r6ENYNb1POClnLOHwrqjSw-1 X-Mimecast-MFC-AGG-ID: r6ENYNb1POClnLOHwrqjSw_1749475262 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-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 3170619560A2; Mon, 9 Jun 2025 13:21:02 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.45]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id B198B180045C; Mon, 9 Jun 2025 13:20:59 +0000 (UTC) Date: Mon, 9 Jun 2025 14:20:56 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Steven Sistare Cc: JAEHOON KIM , qemu-devel@nongnu.org, jjherne@linux.ibm.com, peterx@redhat.com, farosas@suse.de Subject: Re: [PATCH v1] migration: Wait for cpr.sock file to appear before connecting Message-ID: References: <3004c91e-d515-4e22-902c-42cea83ce64b@oracle.com> <760af012-1265-4845-b7d2-793fe75c3a51@linux.ibm.com> <7dc8d42d-47f1-49c1-9bff-ab2d09d0b6f3@oracle.com> <5f211f67-17f7-4b1d-a60a-4ff62645fbfa@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: 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: -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 Mon, Jun 09, 2025 at 09:12:27AM -0400, Steven Sistare wrote: > On 6/9/2025 4:06 AM, Daniel P. Berrangé wrote: > > On Fri, Jun 06, 2025 at 03:37:56PM -0400, Steven Sistare wrote: > > > > > > The easiest solution, with no interface changes, is adding wait_for_socket() in qtest, > > > with this addition from Daniel: > > > > > > "With the busy wait you risk looping forever if the child (target) QEMU > > > already exited for some reason without ever creating the socket. You > > > can mitigate this by using 'kill($PID, 0)' in the loop and looking > > > for -ERSCH, but this only works if you know the pid involved." > > > > > > Daniel also suggested: > > > "For the tests, passing a pre-opened UNIX socket FD could work" > > > > > > Note we can not use any of the standard chardev options to specify such a socket, > > > because the cpr socket is created before chardevs are created. > > > > > > Perhaps we could specify the fd in an extension of the MigrationChannel MigrationAddress. > > > { 'union': 'MigrationAddress', > > > 'base': { 'transport' : 'MigrationAddressType'}, > > > 'discriminator': 'transport', > > > 'data': { > > > 'socket': 'SocketAddress', > > > 'exec': 'MigrationExecCommand', > > > 'rdma': 'InetSocketAddress', > > > 'file': 'FileMigrationArgs', > > > 'fd': 'FdMigrationArgs' } } <-- add this > > > > > > That would be useful for all clients, but this is asking a lot from you, > > > when you are just trying to fix the tests. > > > > Note, 'SocketAddress' already has an option for declaring a FD that > > represents a socket. > > Yes, but if I understand, you proposed passing an fd that represents a > pre-listened socket, which requires target qemu to accept() first. The > existing FdSocketAddress is ready to read. We could add a boolean to enable > the new behavior. It can do both actually - it depends on what APIs the QEMU uses the SocketAddress with. If it is used with qio_channel_socket_connect* the FD must be an active peer connection. If it is used with qio_channel_socket_listen*/qio_net_listener* the FD must be listener socket. 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 :|