Re: [PATCH 6/6] tests/acceptance: Linux boot test for record/replay

[Willian Rampazzo <wrampazz@redhat.com>]

Hi Pavel,

On Thu, Jun 10, 2021 at 8:25 AM Pavel Dovgalyuk
<pavel.dovgalyuk@ispras.ru> wrote:
>
> From: Pavel Dovgalyuk <Pavel.Dovgaluk@gmail.com>
>
> This patch adds a test for record/replay, which boots Linux
> image from the disk and interacts with the network.
> The idea and code of this test is borrowed from boot_linux.py
> This test includes only x86_64 platform. Other platforms and
> machines will be added later after testing and improving
> record/replay to completely support them.
>
> Each test consists of the following phases:
>  - downloading the disk image
>  - recording the execution
>  - replaying the execution
>
> Replay does not validates the output, but waits until QEMU
> finishes the execution. This is reasonable, because
> QEMU usually hangs when replay goes wrong.
>

It took me some time to review this patch because I could not identify
what makes it an automated test. I mean, when I look at an automated
test I expect a pass/fail/skip output. I could not identify the
expected output of this test compared to the actual result. If I did
not miss anything, this test will always pass unless there is an
exception that, potentially, could not be related to the record/replay
mechanism.

Also, as far as I could check, you inherit from the LinuxTest class
but only use the cloudinit methods. Most of the other methods are not
used or overridden. In this case, I think it is worth splitting the
LinuxTest with a new mixin utility class to handle the cloudinit part.
If you need help with that, let me know.

> Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
> ---
>  MAINTAINERS                      |    1
>  tests/acceptance/replay_linux.py |  116 ++++++++++++++++++++++++++++++++++++++
>  2 files changed, 117 insertions(+)
>  create mode 100644 tests/acceptance/replay_linux.py
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 7d9cd29042..9675a1095b 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -2863,6 +2863,7 @@ F: include/sysemu/replay.h
>  F: docs/replay.txt
>  F: stubs/replay.c
>  F: tests/acceptance/replay_kernel.py
> +F: tests/acceptance/replay_linux.py
>  F: tests/acceptance/reverse_debugging.py
>  F: qapi/replay.json
>
> diff --git a/tests/acceptance/replay_linux.py b/tests/acceptance/replay_linux.py
> new file mode 100644
> index 0000000000..15953f9e49
> --- /dev/null
> +++ b/tests/acceptance/replay_linux.py
> @@ -0,0 +1,116 @@
> +# Record/replay test that boots a complete Linux system via a cloud image
> +#
> +# Copyright (c) 2020 ISP RAS
> +#
> +# Author:
> +#  Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
> +#
> +# This work is licensed under the terms of the GNU GPL, version 2 or
> +# later.  See the COPYING file in the top-level directory.
> +
> +import os
> +import logging
> +import time
> +
> +from avocado import skipUnless
> +from avocado.utils import cloudinit
> +from avocado.utils import network
> +from avocado.utils import vmimage
> +from avocado.utils import datadrainer
> +from avocado.utils.path import find_command
> +from avocado_qemu import LinuxTest
> +
> +class ReplayLinux(LinuxTest):
> +    """
> +    Boots a Linux system, checking for a successful initialization
> +    """
> +
> +    timeout = 1800
> +    chksum = None
> +    hdd = 'ide-hd'
> +    cd = 'ide-cd'
> +    bus = 'ide'
> +
> +    def setUp(self):
> +        super(ReplayLinux, self).setUp()
> +        self.boot_path = self.download_boot()
> +        self.cloudinit_path = self.prepare_cloudinit()
> +
> +    def vm_add_disk(self, vm, path, id, device):
> +        bus_string = ''
> +        if self.bus:
> +            bus_string = ',bus=%s.%d' % (self.bus, id,)
> +        vm.add_args('-drive', 'file=%s,snapshot,id=disk%s,if=none' % (path, id))
> +        vm.add_args('-drive',
> +            'driver=blkreplay,id=disk%s-rr,if=none,image=disk%s' % (id, id))
> +        vm.add_args('-device',
> +            '%s,drive=disk%s-rr%s' % (device, id, bus_string))
> +
> +    def launch_and_wait(self, record, args, shift):
> +        vm = self.get_vm()
> +        vm.add_args('-smp', '1')
> +        vm.add_args('-m', '1024')
> +        vm.add_args('-object', 'filter-replay,id=replay,netdev=hub0port0')
> +        if args:
> +            vm.add_args(*args)
> +        self.vm_add_disk(vm, self.boot_path, 0, self.hdd)
> +        self.vm_add_disk(vm, self.cloudinit_path, 1, self.cd)
> +        logger = logging.getLogger('replay')
> +        if record:
> +            logger.info('recording the execution...')
> +            mode = 'record'
> +        else:
> +            logger.info('replaying the execution...')
> +            mode = 'replay'
> +        replay_path = os.path.join(self.workdir, 'replay.bin')
> +        vm.add_args('-icount', 'shift=%s,rr=%s,rrfile=%s' %
> +                    (shift, mode, replay_path))
> +
> +        start_time = time.time()
> +
> +        vm.set_console()
> +        vm.launch()
> +        console_drainer = datadrainer.LineLogger(vm.console_socket.fileno(),
> +                                    logger=self.log.getChild('console'),
> +                                    stop_check=(lambda : not vm.is_running()))
> +        console_drainer.start()
> +        if record:
> +            cloudinit.wait_for_phone_home(('0.0.0.0', self.phone_home_port),
> +                                          self.name)
> +            vm.shutdown()
> +            logger.info('finished the recording with log size %s bytes'
> +                % os.path.getsize(replay_path))
> +        else:
> +            vm.event_wait('SHUTDOWN', self.timeout)
> +            vm.shutdown(True)
> +            logger.info('successfully fihished the replay')
> +        elapsed = time.time() - start_time
> +        logger.info('elapsed time %.2f sec' % elapsed)
> +        return elapsed
> +
> +    def run_rr(self, args=None, shift=7):
> +        t1 = self.launch_and_wait(True, args, shift)
> +        t2 = self.launch_and_wait(False, args, shift)
> +        logger = logging.getLogger('replay')
> +        logger.info('replay overhead {:.2%}'.format(t2 / t1 - 1))
> +
> +@skipUnless(os.getenv('AVOCADO_TIMEOUT_EXPECTED'), 'Test might timeout')
> +class ReplayLinuxX8664(ReplayLinux):
> +    """
> +    :avocado: tags=arch:x86_64
> +    :avocado: tags=accel:tcg
> +    """
> +
> +    chksum = 'e3c1b309d9203604922d6e255c2c5d098a309c2d46215d8fc026954f3c5c27a0'
> +
> +    def test_pc_i440fx(self):
> +        """
> +        :avocado: tags=machine:pc
> +        """
> +        self.run_rr(shift=1)
> +
> +    def test_pc_q35(self):
> +        """
> +        :avocado: tags=machine:q35
> +        """
> +        self.run_rr(shift=3)
>