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 lists1p.gnu.org (lists1p.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 2616ACDB480 for ; Tue, 23 Jun 2026 10:01:48 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1wbxtA-00087t-4k; Tue, 23 Jun 2026 05:57:52 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wbxt8-0007u7-8I for qemu-devel@nongnu.org; Tue, 23 Jun 2026 05:57:50 -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 1wbxt6-0003mK-MO for qemu-devel@nongnu.org; Tue, 23 Jun 2026 05:57:50 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1782208668; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ujsKwFFgURa1HeOejuIFxe0Lo00uy5++usFNyisU6eQ=; b=PKdlI/GOO6fQWY/49HiDIVt7B25XDLUJxIVF6P+Ut0KuQZYcQJi8aTGHxuN4Zkgbl2d+1+ X2AdN18AKKaOyaJdmLKDQiioUkSgwFbDEDO85jVtjG+L3o3WTbcuvFCdJpJG2Jv6Z1ozN/ n7TmuTK4rupbryk2yggXnMusX87kgtA= 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-499-dzpWGB5LOjyzWIwcrd1v1A-1; Tue, 23 Jun 2026 05:57:43 -0400 X-MC-Unique: dzpWGB5LOjyzWIwcrd1v1A-1 X-Mimecast-MFC-AGG-ID: dzpWGB5LOjyzWIwcrd1v1A_1782208662 Received: from mx-prod-int-10.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-10.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.95]) (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 6F28C19540F0; Tue, 23 Jun 2026 09:57:42 +0000 (UTC) Received: from berrange.com (unknown [10.44.34.133]) by mx-prod-int-10.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 50F6D1686; Tue, 23 Jun 2026 09:57:39 +0000 (UTC) From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= To: qemu-devel@nongnu.org Cc: "Dr. David Alan Gilbert" , =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , Christian Brauner , devel@lists.libvirt.org, Markus Armbruster , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Paolo Bonzini , =?UTF-8?q?Alex=20Benn=C3=A9e?= , =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= Subject: [PATCH v4 29/35] tests/functional: add a stress test for monitor hot unplug Date: Tue, 23 Jun 2026 10:55:45 +0100 Message-ID: <20260623095551.2106712-30-berrange@redhat.com> In-Reply-To: <20260623095551.2106712-1-berrange@redhat.com> References: <20260623095551.2106712-1-berrange@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.6 on 10.30.177.95 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: 8 X-Spam_score: 0.8 X-Spam_bar: / X-Spam_report: (0.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.445, 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_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_SBL_CSS=3.335, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development 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 When unplugging a monitor there is a careful synchronization dance between the monitor handling the "object-del" command and the command processing for the monitor being deleted. The stress test runs a busy loop of 'query-qmp-schema' on a second monitor, while the primary monitor requests its deletion. Signed-off-by: Daniel P. Berrangé --- .../generic/test_monitor_hotplug.py | 62 +++++++++++++++++++ 1 file changed, 62 insertions(+) diff --git a/tests/functional/generic/test_monitor_hotplug.py b/tests/functional/generic/test_monitor_hotplug.py index 5d8a159eb0..55af8a238f 100755 --- a/tests/functional/generic/test_monitor_hotplug.py +++ b/tests/functional/generic/test_monitor_hotplug.py @@ -6,11 +6,16 @@ # # Copyright (c) 2026 Christian Brauner +import asyncio import os +import random +import threading +import time from qemu_test import QemuSystemTest from qemu.qmp.legacy import QEMUMonitorProtocol +from qemu.qmp import QMPClient class MonitorHotplug(QemuSystemTest): @@ -163,6 +168,63 @@ def test_events_after_negotiation(self): qmp.close() self._remove_monitor() + def stress_mon(self, sock): + async def main(): + qmp = QMPClient('testvm') + await qmp.connect(sock) + # Run query-version in a tight loop so that the + # monitor thread/dispatcher is very busy at the + # time we try to delete the monitor + while True: + try: + # A command which returns a lot of data to make + # it more likely we're in the I/O reply path + # when deleting the monitor + res = await qmp.execute('query-qmp-schema') + # Some commands which generate async events + # as those can trigger different code paths + res = await qmp.execute('stop') + res = await qmp.execute('cont') + except: + # we'll get here if the monitor is terminated + # by QEMU in which case we must disconnect + # out side, but.... + try: + await qmp.disconnect() + except (ConnectionResetError, EOFError, BrokenPipeError): + # ... disconnect() will probably see + # errors too, but we must try to call it + # regardless to cleanup asyncio state + # and prevent python warnings at GC time + pass + return + asyncio.run(main()) + + def test_hotplug_stress(self): + """ + Repeatedly hotplug and unplug a monitor, while another thread + concurrently issues commands on that monitor. This stresses + the synchronization with the monitor thread during cleanup + """ + self.set_machine('none') + self.vm.add_args('-nodefaults') + self.vm.launch() + + # Each loop sleeps at most 0.5 seconds, so this should + # give an upper bound of approx 5 seconds execution + # time which is reasonable to run by default + repeat = 10 + for i in range(repeat): + # First cycle + sock = self._add_monitor() + print ("# stress cycle %02d/%02d" % (i, repeat)) + stress = threading.Thread(target=self.stress_mon, args=[sock]) + stress.start() + # Sleep upto 1/2 second to vary the races + time.sleep(random.random() / 2) + self._remove_monitor() + stress.join() + if __name__ == '__main__': QemuSystemTest.main() -- 2.54.0