From 0fc8f660c5c0d7b4513805f4798e97e4c371e486 Mon Sep 17 00:00:00 2001 From: Robert Foley Date: Wed, 1 Jul 2020 14:56:24 +0100 Subject: [PATCH] python/qemu: Add ConsoleSocket for optional use in QEMUMachine MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We add the ConsoleSocket object, which has a socket interface and which will consume all arriving characters on the socket, placing them into an in memory buffer. This will also provide those chars via recv() as would a regular socket. ConsoleSocket also has the option of dumping the console bytes to a log file. We also give QEMUMachine the option of using ConsoleSocket to drain and to use for logging console to a file. By default QEMUMachine does not use ConsoleSocket. This is added in preparation for use by basevm.py in a later commit. This is a workaround we found was needed for basevm.py since there is a known issue where QEMU will hang waiting for console characters to be consumed. Cc: Eduardo Habkost Cc: Cleber Rosa Signed-off-by: Robert Foley Reviewed-by: Peter Puhov Acked-by: Alex Bennée Tested-by: Philippe Mathieu-Daudé Signed-off-by: Alex Bennée Message-Id: <20200601211421.1277-9-robert.foley@linaro.org> Message-Id: <20200701135652.1366-13-alex.bennee@linaro.org> --- python/qemu/console_socket.py | 110 ++++++++++++++++++++++++++++++++++ python/qemu/machine.py | 23 +++++-- 2 files changed, 129 insertions(+), 4 deletions(-) create mode 100644 python/qemu/console_socket.py diff --git a/python/qemu/console_socket.py b/python/qemu/console_socket.py new file mode 100644 index 0000000000..830cb7c628 --- /dev/null +++ b/python/qemu/console_socket.py @@ -0,0 +1,110 @@ +#!/usr/bin/env python3 +# +# This python module implements a ConsoleSocket object which is +# designed always drain the socket itself, and place +# the bytes into a in memory buffer for later processing. +# +# Optionally a file path can be passed in and we will also +# dump the characters to this file for debug. +# +# Copyright 2020 Linaro +# +# Authors: +# Robert Foley +# +# This code is licensed under the GPL version 2 or later. See +# the COPYING file in the top-level directory. +# +import asyncore +import socket +import threading +import io +import os +import sys +from collections import deque +import time +import traceback + +class ConsoleSocket(asyncore.dispatcher): + + def __init__(self, address, file=None): + self._recv_timeout_sec = 300 + self._buffer = deque() + self._asyncore_thread = None + self._sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM) + self._sock.connect(address) + self._logfile = None + if file: + self._logfile = open(file, "w") + asyncore.dispatcher.__init__(self, sock=self._sock) + self._open = True + self._thread_start() + + def _thread_start(self): + """Kick off a thread to wait on the asyncore.loop""" + if self._asyncore_thread is not None: + return + self._asyncore_thread = threading.Thread(target=asyncore.loop, + kwargs={'timeout':1}) + self._asyncore_thread.daemon = True + self._asyncore_thread.start() + + def handle_close(self): + """redirect close to base class""" + # Call the base class close, but not self.close() since + # handle_close() occurs in the context of the thread which + # self.close() attempts to join. + asyncore.dispatcher.close(self) + + def close(self): + """Close the base object and wait for the thread to terminate""" + if self._open: + self._open = False + asyncore.dispatcher.close(self) + if self._asyncore_thread is not None: + thread, self._asyncore_thread = self._asyncore_thread, None + thread.join() + if self._logfile: + self._logfile.close() + self._logfile = None + + def handle_read(self): + """process arriving characters into in memory _buffer""" + try: + data = asyncore.dispatcher.recv(self, 1) + # latin1 is needed since there are some chars + # we are receiving that cannot be encoded to utf-8 + # such as 0xe2, 0x80, 0xA6. + string = data.decode("latin1") + except: + print("Exception seen.") + traceback.print_exc() + return + if self._logfile: + self._logfile.write("{}".format(string)) + self._logfile.flush() + for c in string: + self._buffer.extend(c) + + def recv(self, n=1, sleep_delay_s=0.1): + """Return chars from in memory buffer""" + start_time = time.time() + while len(self._buffer) < n: + time.sleep(sleep_delay_s) + elapsed_sec = time.time() - start_time + if elapsed_sec > self._recv_timeout_sec: + raise socket.timeout + chars = ''.join([self._buffer.popleft() for i in range(n)]) + # We choose to use latin1 to remain consistent with + # handle_read() and give back the same data as the user would + # receive if they were reading directly from the + # socket w/o our intervention. + return chars.encode("latin1") + + def set_blocking(self): + """Maintain compatibility with socket API""" + pass + + def settimeout(self, seconds): + """Set current timeout on recv""" + self._recv_timeout_sec = seconds diff --git a/python/qemu/machine.py b/python/qemu/machine.py index 041c615052..c25f0b42cf 100644 --- a/python/qemu/machine.py +++ b/python/qemu/machine.py @@ -26,6 +26,7 @@ import socket import tempfile from typing import Optional, Type from types import TracebackType +from qemu.console_socket import ConsoleSocket from . import qmp @@ -75,7 +76,8 @@ class QEMUMachine: def __init__(self, binary, args=None, wrapper=None, name=None, test_dir="/var/tmp", monitor_address=None, - socket_scm_helper=None, sock_dir=None): + socket_scm_helper=None, sock_dir=None, + drain_console=False, console_log=None): ''' Initialize a QEMUMachine @@ -86,6 +88,9 @@ class QEMUMachine: @param test_dir: where to create socket and log file @param monitor_address: address for QMP monitor @param socket_scm_helper: helper program, required for send_fd_scm() + @param sock_dir: where to create socket (overrides test_dir for sock) + @param console_log: (optional) path to console log file + @param drain_console: (optional) True to drain console socket to buffer @note: Qemu process is not started until launch() is used. ''' if args is None: @@ -122,6 +127,12 @@ class QEMUMachine: self._console_address = None self._console_socket = None self._remove_files = [] + self._console_log_path = console_log + if self._console_log_path: + # In order to log the console, buffering needs to be enabled. + self._drain_console = True + else: + self._drain_console = drain_console def __enter__(self): return self @@ -580,7 +591,11 @@ class QEMUMachine: Returns a socket connected to the console """ if self._console_socket is None: - self._console_socket = socket.socket(socket.AF_UNIX, - socket.SOCK_STREAM) - self._console_socket.connect(self._console_address) + if self._drain_console: + self._console_socket = ConsoleSocket(self._console_address, + file=self._console_log_path) + else: + self._console_socket = socket.socket(socket.AF_UNIX, + socket.SOCK_STREAM) + self._console_socket.connect(self._console_address) return self._console_socket