Re: [PATCH 16/16] tests/acceptance: Test the MIPSsim machine

[Alex Bennée]

Daniel P. Berrangé <berrange@redhat.com> writes:

> On Tue, Sep 29, 2020 at 10:38:30AM +0100, Alex Bennée wrote:
>> 
>> Philippe Mathieu-Daudé <f4bug@amsat.org> writes:
>> 
>> > +Alex/Daniel
>> >
>> > On 9/28/20 10:33 PM, Willian Rampazzo wrote:
>> >> On Mon, Sep 28, 2020 at 2:31 PM Philippe Mathieu-Daudé <f4bug@amsat.org> 
>> >> wrote:
>> >>>
>> >>> Add a test for the mipssim machine, based on the recommended
>> >>> test setup from Thomas Huth:
>> >>> https://www.mail-archive.com/qemu-devel@nongnu.org/msg606846.html
>> >>>
>> >>> The test is quick and can be run as:
>> >>>
>> >>>   $ avocado --show=console run -t machine:mipssim tests/acceptance/
>> >>>    (1/1) 
>> >>> tests/acceptance/machine_mips_mipssim.py:MipsSimMachine.test_mipssim_linux_console:
>> >>>   console: Linux version 3.6.11 (root@711bb8ba16a7) (gcc version 4.8.3 
>> >>> (Buildroot 2014.11) ) #2 Sun Sep 27 13:39:35 UTC 2020
>> >>>   console: Setting default memory size 0x02000000
>> >>>   console: bootconsole [early0] enabled
>> >>>   console: CPU revision is: 00019300 (MIPS 24Kc)
>> >>>   console: FPU revision is: 00739300
>> >>>   ...
>> >>>   console: CPU frequency 12.00 MHz
>> >>>   console: Calibrating delay loop... 950.27 BogoMIPS (lpj=4751360)
>> >>>   ...
>> >>>   console: MIPSNet Ethernet driver. Version: 2007-11-17. (c)2005 MIPS 
>> >>> Technologies, Inc.
>> >>>   ...
>> >>>   console: Welcome to Buildroot
>> >>>   console: buildroot login: root
>> >>>   console: # root
>> >>>   console: -sh: root: not found
>> >>>   console: # ping -c 3 10.0.2.2
>> >>>   console: PING 10.0.2.2 (10.0.2.2): 56 data bytes
>> >>>   console: 64 bytes from 10.0.2.2: seq=0 ttl=255 time=48.231 ms
>> >>>   console: 64 bytes from 10.0.2.2: seq=1 ttl=255 time=9.407 ms
>> >>>   console: 64 bytes from 10.0.2.2: seq=2 ttl=255 time=2.298 ms
>> >>>   console: --- 10.0.2.2 ping statistics ---
>> >>>   console: 3 packets transmitted, 3 packets received, 0% packet loss
>> >>>   PASS (7.99 s)
>> >>>
>> >>> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
>> >>> ---
>> >>> Cc: Thomas Huth <huth@tuxfamily.org>
>> >>> ---
>> >>>  MAINTAINERS                              |  1 +
>> >>>  tests/acceptance/machine_mips_mipssim.py | 56 ++++++++++++++++++++++++
>> >>>  2 files changed, 57 insertions(+)
>> >>>  create mode 100644 tests/acceptance/machine_mips_mipssim.py
>> >>>
>> >>> diff --git a/MAINTAINERS b/MAINTAINERS
>> >>> index 5eed1e692b4..17d8a012b0e 100644
>> >>> --- a/MAINTAINERS
>> >>> +++ b/MAINTAINERS
>> >>> @@ -240,6 +240,7 @@ F: include/hw/misc/mips_*
>> >>>  F: include/hw/timer/mips_gictimer.h
>> >>>  F: tests/acceptance/linux_ssh_mips_malta.py
>> >>>  F: tests/acceptance/machine_mips_malta.py
>> >>> +F: tests/acceptance/machine_mips_mipssim.py
>> >>>  F: tests/tcg/mips/
>> >>>  K: ^Subject:.*(?i)mips
>> >>>
>> >>> diff --git a/tests/acceptance/machine_mips_mipssim.py 
>> >>> b/tests/acceptance/machine_mips_mipssim.py
>> >>> new file mode 100644
>> >>> index 00000000000..b2749917b08
>> >>> --- /dev/null
>> >>> +++ b/tests/acceptance/machine_mips_mipssim.py
>> >>> @@ -0,0 +1,56 @@
>> >>> +# Functional tests for the MIPS simulator (MIPSsim machine)
>> >>> +#
>> >>> +# Copyright (c) 2020 Philippe Mathieu-Daudé <f4bug@amsat.org>
>> >>> +#
>> >>> +# This work is licensed under the terms of the GNU GPL, version 2 or 
>> >>> later.
>> >>> +# See the COPYING file in the top-level directory.
>> >>> +#
>> >>> +# SPDX-License-Identifier: GPL-2.0-or-later
>> >>> +
>> >>> +import os
>> >>> +import logging
>> >>> +import time
>> >>> +
>> >>> +from avocado import skipUnless
>> >>> +from avocado_qemu import Test
>> >>> +from avocado_qemu import exec_command_and_wait_for_pattern
>> >>> +from avocado_qemu import interrupt_interactive_console_until_pattern
>> >>> +from avocado_qemu import wait_for_console_pattern
>> >>> +
>> >>> +class MipsSimMachine(Test):
>> >>> +
>> >>> +    timeout = 30
>> >>> +    KERNEL_COMMON_COMMAND_LINE = 'printk.time=0 '
>> >>> +
>> >>> +    @skipUnless(os.getenv('AVOCADO_ALLOW_UNTRUSTED_CODE'), 'untrusted 
>> >>> code')
>> >>> +    def test_mipssim_linux_console(self):
>> >>> +        """
>> >>> +        Boots the Linux kernel and checks that the console is 
>> >>> operational
>> >>> +        :avocado: tags=arch:mipsel
>> >>> +        :avocado: tags=machine:mipssim
>> >>> +        :avocado: tags=device:mipsnet
>> >>> +        """
>> >>> +        kernel_url = ('https://github.com/philmd/qemu-testing-blob/raw/'
>> >>> +                      '32ea5764e1de8fffa0d59366c44822cd06d7c8e0/'
>> >>> +                      'mips/mipssim/mipsel/vmlinux')
>> >> 
>> >> So, are you willing to maintain some images on your GitHub to avoid
>> >> the image changes when they are not found?
>> >
>> > No, I am not willing to do that.
>> >
>> > But I see it pointless to have everyone (including CI) to spend 1h
>> > building this image, when the sources and build recipe is available,
>> > making the built image reproducible.
>> 
>> I agree we don't want to build from scratch each time. However as we
>> move from relying on third parties (which outside of the major distros
>> has proved very flaky) we are getting to the point of managing our GPL
>> liabilities.
>
> I'm wondering what the 1 hour time to build the images is
> spent on, and what does the image need to actually do ?

Buildroot will also build the toolchain and libc of chouce before
building it's rootfs. To be honest the rootfs part of the build is
fairly minimal if it's mostly busybox.

> Is it anything more than boot the kernel successfully ?
>
> I've not tried a timed build, but surely a minimal / tiny
> Linx kernel build is much less than an hour ? Combine with
> a tiny C program that simply prints "OK" as /bin/init and
> powers off the VM. Or we need more advanced then a minimal
> busybox build.

Starting from a buildroot is useful for development certainly because
it's a lot easier to add stuff to it if you need to.

> I think it'd be great if we could self-build a minimal
> kernel+init for all platforms we target, using distro
> provided cross-compilers.

We've been down this round before haven't we? Wasn't that what the JeOS
builds where all about?

Anyway things have moved on from the bad old days of crosstool and the
distros are better at packaging sane cross compilers that can build
kernels and basic user space. However leaving everyone to use their own
distro compiler is going to lead to repeatability problems - or maybe we
just treat it like we do with the existing TCG tests?

>
>
> Regards,
> Daniel


-- 
Alex Bennée