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 EE4ACC021A6 for ; Fri, 14 Feb 2025 13:55:42 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tiw9W-0003Jl-F1; Fri, 14 Feb 2025 08:54:46 -0500 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 1tiw9U-0003JY-1M for qemu-devel@nongnu.org; Fri, 14 Feb 2025 08:54:44 -0500 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 1tiw9R-00010X-Mv for qemu-devel@nongnu.org; Fri, 14 Feb 2025 08:54:43 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1739541280; h=from:from: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=CdQQ3IW6vQcL1egE3OIOS4WQdVEXI858c2F8SSryLGU=; b=HJqj8pO3xjCW6p8uwr2CT5ju/VoAdzwL/vmu5gpw3HbrTxHDNRTocvvEyh7YYcw46+ho6f T3BOyXDJxeOrAsoltsbESw8z7VuGaCWiQj7bVKHrVAE1mVQ0mBMfhnEGE0n+9id+EVIl0I qaZkhoAtP6O1XI04YS7k4nfTB+AJJ/I= Received: from mx-prod-mc-03.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-605-pqv_MmbxPJ6_SvHQyp67iQ-1; Fri, 14 Feb 2025 08:54:38 -0500 X-MC-Unique: pqv_MmbxPJ6_SvHQyp67iQ-1 X-Mimecast-MFC-AGG-ID: pqv_MmbxPJ6_SvHQyp67iQ_1739541277 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-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 9B2E11955F28 for ; Fri, 14 Feb 2025 13:54:36 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.45.242.22]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 53A691800352 for ; Fri, 14 Feb 2025 13:54:36 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id C067F21E6A28; Fri, 14 Feb 2025 14:54:33 +0100 (CET) From: Markus Armbruster To: Laurent Vivier Cc: qemu-devel@nongnu.org, =?utf-8?Q?Marc-Andr=C3=A9?= Lureau , Eric Blake , Jason Wang , Paolo Bonzini , Laine Stump , Stefano Brivio , "Michael S. Tsirkin" , =?utf-8?Q?Daniel_P=2E_Berrang=C3=A9?= Subject: Re: [PATCH] net: vhost-user: add QAPI events to report connection state In-Reply-To: <2c5358eb-1abe-4fce-8b28-7935c71f1cff@redhat.com> (Laurent Vivier's message of "Fri, 14 Feb 2025 11:18:55 +0100") References: <20250214072629.1033314-1-lvivier@redhat.com> <871pw07sdy.fsf@pond.sub.org> <2c5358eb-1abe-4fce-8b28-7935c71f1cff@redhat.com> Date: Fri, 14 Feb 2025 14:54:33 +0100 Message-ID: <87a5ao3a3q.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Received-SPF: pass client-ip=170.10.129.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -37 X-Spam_score: -3.8 X-Spam_bar: --- X-Spam_report: (-3.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.732, 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Laurent Vivier writes: > On 14/02/2025 11:06, Markus Armbruster wrote: >> Laurent Vivier writes: >> >>> The netdev reports NETDEV_VHOST_USER_CONNECTED event when >>> the chardev is connected, and NETDEV_VHOST_USER_DISCONNECTED >>> when it is disconnected. >>> >>> The NETDEV_VHOST_USER_CONNECTED event includes the ChardevInfo >>> (label, filename and frontend_open). >>> >>> This allows a system manager like libvirt to detect when the server >>> fails. >>> >>> For instance with passt: >>> >>> { 'execute': 'qmp_capabilities' } >>> { "return": { } } >>> >>> [killing passt here] >>> >>> { "timestamp": { "seconds": 1739517243, "microseconds": 115081 }, >>> "event": "NETDEV_VHOST_USER_DISCONNECTED", >>> "data": { "netdev-id": "netdev0" } } >>> >>> [automatic reconnection with reconnect-ms] >>> >>> { "timestamp": { "seconds": 1739517290, "microseconds": 343777 }, >>> "event": "NETDEV_VHOST_USER_CONNECTED", >>> "data": { "netdev-id": "netdev0", >>> "info": { "frontend-open": true, >>> "filename": "unix:", >>> "label": "chr0" } } } >>> >>> Signed-off-by: Laurent Vivier >> >> Standard question for events: if a management application misses an >> event, say because it restarts and reconnects, is there a way to obtain >> the missed information with a query command? > > query-chardev could help but it doesn't provide the netdev id. > > in HMP, "info network" has the information, but for QMP we had a try with a query-netdev in the past but the series has been reverted. > > f9bb0c1f9862 ("Revert "qapi: net: Add query-netdev command"") > d32ad10a14d4 ("qapi: net: Add query-netdev command") Hmm. Can management applications use these events without a matching query?