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

[Akihiko Odaki <akihiko.odaki@daynix.com>]

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

I have a few more comments:

- It may be possible to use microvm to trim it down further.

- 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

- "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. 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

- 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")