Re: [RFC PATCH] tests/avocado: re-factor igb test to avoid timeouts

["Alex Bennée" <alex.bennee@linaro.org>]

Akihiko Odaki <akihiko.odaki@daynix.com> writes:

> On 2023/03/22 3:17, Alex Bennée wrote:
>> The core of the test was utilising "ethtool -t eth1 offline" to run
>> through a test sequence. For reasons unknown the test hangs under some
>> configurations of the build on centos8-stream. Fundamentally running
>> the old fedora-31 cloud-init is just too much for something that is
>> directed at testing one device. So we:
>>    - replace fedora with a custom kernel + buildroot rootfs
>>    - rename the test from IGB to NetDevEthtool
>>    - re-factor the common code, add (currently skipped) tests for other
>>       devices which support ethtool
>>    - remove the KVM limitation as its fast enough to run in KVM or TCG
>
> I tried this but it seems the rootfs is corrupted:
> 2023-03-22 13:53:06,728 __init__         L0153 DEBUG| EXT4-fs (sda):
> INFO: recovery required on readonly filesystem
> 2023-03-22 13:53:06,728 __init__         L0153 DEBUG| EXT4-fs (sda):
> write access will be enabled during recovery
> (snip)
> 2023-03-22 13:54:24,534 __init__         L0153 DEBUG| EXT4-fs (sda):
> I/O error while writing superblock
> 2023-03-22 13:54:24,535 __init__         L0153 DEBUG| EXT4-fs (sda):
> error loading journal
> 2023-03-22 13:54:24,542 __init__         L0153 DEBUG| VFS: Cannot open
> root device "sda" or unknown-block(8,0): error -5

That's weird. I'm not seeing it when running here. However I can
regenerate the whole thing and re-upload. Are there any other network
tools worth adding?

> I have a few more comments:
>
> - It may be possible to use microvm to trim it down further.

Does microvm have PCI now? Most of the saving comes down to having a
much lighter rootfs than the full cloud init of fedora. I think there is
only really a syslogd and a klogd running at the start.

> - I'm worried that having a rootfs for a single test is too costly to
>   maintain. If you just want to avoid cloud-init, you can just
>  specify:
> init=/bin/sh

Not really too bad. Buildroot makes it pretty easy. The config can be
found here:

  https://fileserver.linaro.org/s/Lk8z7kN3s3ds7kd

>
> - "time.sleep(0.2)" for waiting commands may be too fragile. Instead,
>   you may write a fully-automated shell script which does not need any
>   synchronization.

Yeah this a hangover of the avocado system and how it deals with the
console output that it can't handle login prompts without newlines.

> For example, you may specify something like the
>   following as the kernel parameter and run self.vm.kill() after the
>   tests finish:
> init=/bin/ethtool -- -t eth1 offline

I can do that. It does cause the kernel to panic once ethtool is done
but we've passed the test by that point.

>
> - If I remember correctly, e1000 and e1000e tests include some checks
>   contradicting with the datasheet. I suspect it is because their
>   tests are written for some other devices in the same product family,
>   but I haven't investigated further.
>
> Regards,
> Akihiko Odaki
>
>> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
>> Cc: Akihiko Odaki <akihiko.odaki@daynix.com>
>> ---
>>   tests/avocado/igb.py            | 38 --------------
>>   tests/avocado/netdev-ethtool.py | 93 +++++++++++++++++++++++++++++++++
>>   2 files changed, 93 insertions(+), 38 deletions(-)
>>   delete mode 100644 tests/avocado/igb.py
>>   create mode 100644 tests/avocado/netdev-ethtool.py
>> diff --git a/tests/avocado/igb.py b/tests/avocado/igb.py
>> deleted file mode 100644
>> index abf5dfa07f..0000000000
>> --- a/tests/avocado/igb.py
>> +++ /dev/null
>> @@ -1,38 +0,0 @@
>> -# SPDX-License-Identifier: GPL-2.0-or-later
>> -# ethtool tests for igb registers, interrupts, etc
>> -
>> -from avocado_qemu import LinuxTest
>> -
>> -class IGB(LinuxTest):
>> -    """
>> -    :avocado: tags=accel:kvm
>> -    :avocado: tags=arch:x86_64
>> -    :avocado: tags=distro:fedora
>> -    :avocado: tags=distro_version:31
>> -    :avocado: tags=machine:q35
>> -    """
>> -
>> -    timeout = 180
>> -
>> -    def test(self):
>> -        self.require_accelerator('kvm')
>> -        kernel_url = self.distro.pxeboot_url + 'vmlinuz'
>> -        kernel_hash = '5b6f6876e1b5bda314f93893271da0d5777b1f3c'
>> -        kernel_path = self.fetch_asset(kernel_url, asset_hash=kernel_hash)
>> -        initrd_url = self.distro.pxeboot_url + 'initrd.img'
>> -        initrd_hash = 'dd0340a1b39bd28f88532babd4581c67649ec5b1'
>> -        initrd_path = self.fetch_asset(initrd_url, asset_hash=initrd_hash)
>> -
>> -        # Ideally we want to test MSI as well, but it is blocked by a bug
>> -        # fixed with:
>> - #
>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=28e96556baca7056d11d9fb3cdd0aba4483e00d8
>> -        kernel_params = self.distro.default_kernel_params + ' pci=nomsi'
>> -
>> -        self.vm.add_args('-kernel', kernel_path,
>> -                         '-initrd', initrd_path,
>> -                         '-append', kernel_params,
>> -                         '-accel', 'kvm',
>> -                         '-device', 'igb')
>> -        self.launch_and_wait()
>> -        self.ssh_command('dnf -y install ethtool')
>> -        self.ssh_command('ethtool -t eth1 offline')
>> diff --git a/tests/avocado/netdev-ethtool.py b/tests/avocado/netdev-ethtool.py
>> new file mode 100644
>> index 0000000000..da0a22d51c
>> --- /dev/null
>> +++ b/tests/avocado/netdev-ethtool.py
>> @@ -0,0 +1,93 @@
>> +# ethtool tests for emulated network devices
>> +#
>> +# This test leverages ethtool's --test sequence to validate network
>> +# device behaviour.
>> +#
>> +# SPDX-License-Identifier: GPL-2.0-or-later
>> +
>> +import time
>> +
>> +from avocado import skip
>> +
>> +from avocado_qemu import QemuSystemTest
>> +from avocado_qemu import exec_command, exec_command_and_wait_for_pattern
>> +from avocado_qemu import wait_for_console_pattern
>> +
>> +class NetDevEthtool(QemuSystemTest):
>> +    """
>> +    :avocado: tags=arch:x86_64
>> +    :avocado: tags=machine:q35
>> +    """
>> +
>> +    KERNEL_COMMON_COMMAND_LINE = 'printk.time=0 root=/dev/sda console=ttyS0 '
>> +    # Runs in about 20s under KVM, 26s under TCG, 37s under GCOV
>> +    timeout = 45
>> +
>> +    def common_test_code(self, netdev, extra_args=None):
>> +        base_url = ('https://fileserver.linaro.org/s/'
>> +                    'kE4nCFLdQcoBF9t/download?'
>> +                    'path=%2Figb-net-test&files=' )
>> +
>> +        # This custom kernel has drivers for all the supported network
>> +        # devices we can emulate in QEMU
>> +        kernel_url = base_url + 'bzImage'
>> +        kernel_hash = '784daede6dab993597f36efbf01f69f184c55152'
>> +        kernel_path = self.fetch_asset(name="bzImage",
>> +                                       locations=(kernel_url), asset_hash=kernel_hash)
>> +
>> +        rootfs_url = base_url + 'rootfs.ext4'
>> +        rootfs_hash = '7d28c1bf429de3b441a63756a51f163442ea574b'
>> +        rootfs_path = self.fetch_asset(name="rootfs.ext4",
>> +                                       locations=(rootfs_url),
>> +                                       asset_hash=rootfs_hash)
>> +
>> +        kernel_params = self.KERNEL_COMMON_COMMAND_LINE
>> +        if extra_args:
>> +            kernel_params += extra_args
>> +
>> +        self.vm.add_args('-kernel', kernel_path,
>> +                         '-append', kernel_params,
>> +                         '-blockdev',
>> +                         f"driver=raw,file.driver=file,file.filename={rootfs_path},node-name=hd0",
>> +                         '-device', 'driver=ide-hd,bus=ide.0,unit=0,drive=hd0',
>> +                         '-device', netdev)
>> +
>> +        self.vm.set_console(console_index=0)
>> +        self.vm.launch()
>> +
>> +        wait_for_console_pattern(self, "Welcome to Buildroot", vm=None)
>> +        time.sleep(0.2)
>> +        exec_command(self, 'root')
>> +        time.sleep(0.2)
>> +        exec_command_and_wait_for_pattern(self,
>> +                                          "ethtool -t eth1 offline",
>> +                                          "The test result is PASS",
>> +                                          "The test result is FAIL")
>> +        time.sleep(0.2)
>> +        exec_command_and_wait_for_pattern(self, 'halt', "reboot: System halted")
>> +
>> +    # Skip testing for MSI for now. Allegedly it was fixed by:
>> +    #   28e96556ba (igb: Allocate MSI-X vector when testing)
>> +    # but I'm seeing oops in the kernel
>> +    @skip("Kernel bug with MSI enabled")
>> +    def test_igb(self):
>> +        self.common_test_code("igb")
>> +
>> +    def test_igb_nomsi(self):
>> +        self.common_test_code("igb", "pci=nomsi")
>> +
>> +
>> +    # It seems the other popular cards we model in QEMU currently fail
>> +    # the pattern test with:
>> +    #
>> +    #   pattern test failed (reg 0x00178): got 0x00000000 expected 0x00005A5A
>> +    #
>> +    # So for now we skip them.
>> +
>> +    @skip("Incomplete reg 0x00178 support")
>> +    def test_e1000(self):
>> +        self.common_test_code("e1000")
>> +
>> +    @skip("Incomplete reg 0x00178 support")
>> +    def test_i82550(self):
>> +        self.common_test_code("i82550")


-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro