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 066FACD98F3 for ; Thu, 18 Jun 2026 11:01:23 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1waAUF-0000el-NE; Thu, 18 Jun 2026 07:00:43 -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 1waAUC-0000Xy-Fg for qemu-devel@nongnu.org; Thu, 18 Jun 2026 07:00:41 -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 1waAUA-00037U-LX for qemu-devel@nongnu.org; Thu, 18 Jun 2026 07:00:40 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1781780438; 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=cSwm7vXB/Snl0Um2pYfMMKh+d38PUI5UtqVWmqN/EJvqlRB0k5NulwqBWDpMzdvAJ48GOA FxKewCiwvIPoAI75bI8tk+kGFrr+D85ZMF9fX3PjnMikDiVDZREURvzN3mDuQ5UjZc6U65 7KY3SQ5whKtoOb0gYPb6h0vJHkHrRQA= 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-677-fLc72badO-C16MLB2ukDpA-1; Thu, 18 Jun 2026 07:00:35 -0400 X-MC-Unique: fLc72badO-C16MLB2ukDpA-1 X-Mimecast-MFC-AGG-ID: fLc72badO-C16MLB2ukDpA_1781780434 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-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 5A72A18007D2; Thu, 18 Jun 2026 11:00:34 +0000 (UTC) Received: from berrange.com (unknown [10.44.49.28]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 5BABD1956089; Thu, 18 Jun 2026 11:00:31 +0000 (UTC) From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= To: qemu-devel@nongnu.org Cc: devel@lists.libvirt.org, =?UTF-8?q?Alex=20Benn=C3=A9e?= , Christian Brauner , Markus Armbruster , =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , "Dr. David Alan Gilbert" , Paolo Bonzini , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= Subject: [PATCH v3 29/35] tests/functional: add a stress test for monitor hot unplug Date: Thu, 18 Jun 2026 11:58:30 +0100 Message-ID: <20260618105836.991609-30-berrange@redhat.com> In-Reply-To: <20260618105836.991609-1-berrange@redhat.com> References: <20260618105836.991609-1-berrange@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 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: -24 X-Spam_score: -2.5 X-Spam_bar: -- X-Spam_report: (-2.5 / 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, SPF_HELO_PASS=-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: 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