From patchwork Tue Jun 2 19:48:44 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Snow X-Patchwork-Id: 281481 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 36956C433DF for ; Tue, 2 Jun 2020 19:49:39 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id F1C25206A2 for ; Tue, 2 Jun 2020 19:49:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="I28ykuJ4" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F1C25206A2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:42106 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jgCuo-0001XL-7j for qemu-devel@archiver.kernel.org; Tue, 02 Jun 2020 15:49:38 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:33466) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jgCu4-0000iL-Ba for qemu-devel@nongnu.org; Tue, 02 Jun 2020 15:48:52 -0400 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:29145 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jgCu3-0001Wy-9o for qemu-devel@nongnu.org; Tue, 02 Jun 2020 15:48:52 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591127330; 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=LhgS+VypqX8QJVMO7omhr2+aVFOu2bacOpeOb8X4PDQ=; b=I28ykuJ42q4Iee4wGT5XVHUbKMxdciNNVwhcBS6hj8xDmV4axkW7aHVLyCLEhCkoMiYTiM RCfyEaz4fM2e1BWG8u5hcKIfuY084Nl3jUHlABt7tkDGFTP4JoS5WY4w1/ZguvxR7YffdG xOuiSpzQA39OAKwDxFhVrbwIYwuAbec= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-248-bTyQIBxaO4i6BjVym90o0Q-1; Tue, 02 Jun 2020 15:48:48 -0400 X-MC-Unique: bTyQIBxaO4i6BjVym90o0Q-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A99A2107B0E1 for ; Tue, 2 Jun 2020 19:48:47 +0000 (UTC) Received: from probe.redhat.com (ovpn-112-142.rdu2.redhat.com [10.10.112.142]) by smtp.corp.redhat.com (Postfix) with ESMTP id 69F5878EFE; Tue, 2 Jun 2020 19:48:46 +0000 (UTC) From: John Snow To: qemu-devel@nongnu.org Subject: [PATCH v2 1/1] python/machine.py: refactor shutdown Date: Tue, 2 Jun 2020 15:48:44 -0400 Message-Id: <20200602194844.15258-2-jsnow@redhat.com> In-Reply-To: <20200602194844.15258-1-jsnow@redhat.com> References: <20200602194844.15258-1-jsnow@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=205.139.110.61; envelope-from=jsnow@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/02 03:23:32 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] 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_H2=-0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, Eduardo Habkost , philmd@redhat.com, Markus Armbruster , Cleber Rosa , John Snow Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" This is done primarily to avoid the 'bare except' pattern, which suppresses ALL exceptions and not just ones that we are anticipating to see. Replace this with a pattern that isolates the different kind of shutdown paradigms and a new fallback shutdown handler that gracefully attempts one before the other. Move all of the post-shutdown code into _post_shutdown, and adjust the main shutdown() function to ALWAYS call the post_shutdown logic no matter what kind of error we encountered: An expected one (subprocess wait timeout) or an unexpected one (Everything else). In cases where we encounter an expected error in the graceful shutdown timeout, we will not re-raise an exception above shutdown(). Otherwise, after post_shutdown cleanup, we will. I anticipate that this WILL lead to additional bug reports filed against this module, but that is unfortunately somewhat the point: This code shouldn't be hiding failures that exist elsewhere within the python code. Signed-off-by: John Snow --- python/qemu/machine.py | 93 +++++++++++++++++++++++++++++------------- 1 file changed, 65 insertions(+), 28 deletions(-) diff --git a/python/qemu/machine.py b/python/qemu/machine.py index 041c615052e..a2abd2c35e3 100644 --- a/python/qemu/machine.py +++ b/python/qemu/machine.py @@ -283,6 +283,8 @@ def _post_launch(self): self._qmp.accept() def _post_shutdown(self): + self._load_io_log() + if self._qemu_log_file is not None: self._qemu_log_file.close() self._qemu_log_file = None @@ -296,6 +298,17 @@ def _post_shutdown(self): while len(self._remove_files) > 0: self._remove_if_exists(self._remove_files.pop()) + exitcode = self.exitcode() + if exitcode is not None and exitcode < 0: + msg = 'qemu received signal %i; command: "%s"' + if self._qemu_full_args: + command = ' '.join(self._qemu_full_args) + else: + command = '' + LOG.warning(msg, -int(exitcode), command) + + self._launched = False + def launch(self): """ Launch the VM and make sure we cleanup and expose the @@ -344,12 +357,53 @@ def wait(self): self._popen.wait() if self._qmp: self._qmp.close() - self._load_io_log() self._post_shutdown() - def shutdown(self, has_quit=False, hard=False): + def _hard_shutdown(self) -> None: """ - Terminate the VM and clean up + Kill the VM if it is running. + """ + if not self.is_running(): + return + + self._popen.kill() + self._popen.wait(timeout=60) + + def _soft_shutdown(self, has_quit: bool = False, timeout: int = 3) -> None: + """ + Attempt to shutdown the VM gracefully if it is running. + + :param has_quit: When True, don't attempt to issue 'quit' QMP command + :param timeout: Timeout for graceful shutdown. Default 3 seconds. + """ + if not self.is_running(): + return + + if self._qmp is not None: + if not has_quit: + self._qmp.cmd('quit') + self._qmp.close() + + self._popen.wait(timeout=timeout) + + def _do_shutdown(self, has_quit: bool = False, timeout: int = 3) -> None: + """ + Attempt to shutdown the VM gracefully; fallback to a hard shutdown. + + :param has_quit: When True, don't attempt to issue 'quit' QMP command + :param timeout: Timeout for graceful shutdown. Default 3 seconds. + """ + try: + self._soft_shutdown(has_quit, timeout) + except subprocess.TimeoutExpired: + self._hard_shutdown() + except: + self._hard_shutdown() + raise + + def shutdown(self, has_quit: bool = False, hard: bool = False) -> None: + """ + Terminate the VM (gracefully if possible) and perform cleanup. """ # If we keep the console socket open, we may deadlock waiting # for QEMU to exit, while QEMU is waiting for the socket to @@ -358,35 +412,18 @@ def shutdown(self, has_quit=False, hard=False): self._console_socket.close() self._console_socket = None - if self.is_running(): + try: if hard: - self._popen.kill() - elif self._qmp: - try: - if not has_quit: - self._qmp.cmd('quit') - self._qmp.close() - self._popen.wait(timeout=3) - except: - self._popen.kill() - self._popen.wait() - - self._load_io_log() - self._post_shutdown() - - exitcode = self.exitcode() - if exitcode is not None and exitcode < 0 and \ - not (exitcode == -9 and hard): - msg = 'qemu received signal %i: %s' - if self._qemu_full_args: - command = ' '.join(self._qemu_full_args) + self._hard_shutdown() else: - command = '' - LOG.warning(msg, -int(exitcode), command) - - self._launched = False + self._do_shutdown(has_quit) + finally: + self._post_shutdown() def kill(self): + """ + Terminate the VM forcefully and perform cleanup. + """ self.shutdown(hard=True) def set_qmp_monitor(self, enabled=True):