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 408D4C433EF for ; Wed, 25 May 2022 16:25:54 +0000 (UTC) Received: from localhost ([::1]:48382 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nttpZ-0006M0-A3 for qemu-devel@archiver.kernel.org; Wed, 25 May 2022 12:25:53 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:37764) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nttWj-00038A-PT for qemu-devel@nongnu.org; Wed, 25 May 2022 12:06:28 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:47888) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nttWh-0004vN-RW for qemu-devel@nongnu.org; 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Wed, 25 May 2022 16:06:20 +0000 (UTC) Received: from redhat.com (unknown [10.33.36.177]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 98088401E63; Wed, 25 May 2022 16:06:19 +0000 (UTC) Date: Wed, 25 May 2022 17:06:16 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Damien Hedde Cc: qemu-devel@nongnu.org, John Snow , Cleber Rosa , Beraldo Leal , Markus Armbruster Subject: Re: [RFC PATCH] python: add qmp-send program to send raw qmp commands to qemu Message-ID: References: <20220316095455.6473-1-damien.hedde@greensocs.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20220316095455.6473-1-damien.hedde@greensocs.com> User-Agent: Mutt/2.2.1 (2022-02-19) X-Scanned-By: MIMEDefang 2.85 on 10.11.54.10 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: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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" On Wed, Mar 16, 2022 at 10:54:55AM +0100, Damien Hedde wrote: > +def raw_load(file: TextIO) -> List[QMPMessage]: > + """parse a raw qmp command file. > + > + JSON formatted commands can expand on several lines but must > + be separated by an end-of-line (two commands can not share the > + same line). > + File must not end with empty lines. > + """ > + cmds: List[QMPMessage] = [] > + linecnt = 0 > + while True: > + buf = file.readline() > + if not buf: > + return cmds If you change this to 'break'... > + prev_err_pos = None > + buf_linecnt = 1 > + while True: > + try: > + cmds.append(json.loads(buf)) ...and this to yield json.loads(buf) then.... > + break > + except json.JSONDecodeError as err: > + if prev_err_pos == err.pos: > + # adding a line made no progress so > + # + either we're at EOF and json data is truncated > + # + or the parsing error is before > + raise QmpRawDecodeError(err.msg, linecnt + err.lineno, > + err.colno) from err > + prev_err_pos = err.pos > + buf += file.readline() > + buf_linecnt += 1 > + linecnt += buf_linecnt > + > + > +def report_error(msg: str) -> None: > + """Write an error to stderr.""" > + sys.stderr.write('ERROR: %s\n' % msg) > + > + > +def main() -> None: > + """ > + qmp-send entry point: parse command line arguments and start the REPL. > + """ > + parser = argparse.ArgumentParser( > + description=""" > + Send raw qmp commands to qemu as long as they succeed. It either > + connects to a remote qmp server using the provided socket or wrap > + the qemu process. It stops sending the provided commands when a > + command fails (disconnection or error response). > + """, > + epilog=""" > + When qemu wrap option is used, this script waits for qemu > + to terminate but never send any quit or kill command. This > + needs to be done manually. > + """) > + > + parser.add_argument('-f', '--file', action='store', > + help='Input file containing the commands') > + parser.add_argument('-s', '--socket', action='store', > + help='< UNIX socket path | TCP address:port >') > + parser.add_argument('-v', '--verbose', action='store_true', > + help='Verbose (echo commands sent and received)') > + parser.add_argument('-p', '--pretty', action='store_true', > + help='Pretty-print JSON') > + > + parser.add_argument('--wrap', nargs=argparse.REMAINDER, > + help='QEMU command line to invoke') > + > + args = parser.parse_args() > + > + socket = args.socket > + wrap_qemu = args.wrap is not None > + > + if wrap_qemu: > + if len(args.wrap) != 0: > + qemu_cmdline = args.wrap > + else: > + qemu_cmdline = ["qemu-system-x86_64"] > + if socket is None: > + socket = "qmp-send-wrap-%d" % os.getpid() > + qemu_cmdline += ["-qmp", "unix:%s" % socket] > + > + try: > + address = QMPSend.parse_address(socket) > + except QMPBadPortError: > + parser.error(f"Bad port number: {socket}") > + return # pycharm doesn't know error() is noreturn > + > + try: > + with open(args.file, mode='rt', encoding='utf8') as file: > + qmp_cmds = raw_load(file) > + except QmpRawDecodeError as err: > + report_error(str(err)) > + sys.exit(1) ...change this to fh = sys.stdin if args.file is not None and args.file != '-': fh = open(args.file, mode='rt', encoding='utf8') .... > + > + try: > + with QMPSend(address, args.pretty, args.verbose, > + server=wrap_qemu) as qmp: > + # starting with python 3.7 we could use contextlib.nullcontext > + qemu = Popen(qemu_cmdline) if wrap_qemu else contextlib.suppress() > + with qemu: > + try: > + qmp.setup_connection() > + except ConnectError as err: > + if isinstance(err.exc, OSError): > + report_error(f"Couldn't connect to {socket}: {err!s}") > + else: > + report_error(str(err)) > + sys.exit(1) > + try: > + for cmd in qmp_cmds: ...finally this to for cmd in raw_load(fh) This means we can use qmp-send in a pipeline with commands sent to QEMU on the fly as they arrive, rather than having to read all the commands upfront before QEMU is started. BTW, as an example usage I was trying your impl here in the following way to extract information about CPUs that are deprecated echo -e '{ "execute": "query-cpu-definitions"}\n{"execute": "quit"}' | \ qmp-send -v -p --wrap ./build/qemu-system-x86_64 -nodefaults -vnc :1 | \ jq -r --slurp '.[1].return[] | [.name, .deprecated] | @csv' > + qmp.execute_cmd(cmd) > + except QMPError as err: > + report_error(str(err)) > + sys.exit(1) > + finally: > + if wrap_qemu: > + os.unlink(socket) > + > + > +if __name__ == '__main__': > + main() 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 :|