Re: [PATCH 1/1] avocado_qemu: Add SMMUv3 tests

[Cleber Rosa]

On Thu, Mar 25, 2021 at 10:57:12AM +0100, Eric Auger wrote:
> Add new tests checking the good behavior of the SMMUv3 protecting
> 2 virtio pci devices (block and net). We check the guest boots and
> we are able to install a package. Different guest configs are tested:
> standard, passthrough an strict=0. Given the version of the guest
> kernel in use (5.3.7 at this moment), range invalidation is not yet
> tested. This will be handled separately.
> 
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
> ---
>  tests/acceptance/smmu.py | 104 +++++++++++++++++++++++++++++++++++++++
>  1 file changed, 104 insertions(+)
>  create mode 100644 tests/acceptance/smmu.py
> 
> diff --git a/tests/acceptance/smmu.py b/tests/acceptance/smmu.py
> new file mode 100644
> index 0000000000..65ecac8f1a
> --- /dev/null
> +++ b/tests/acceptance/smmu.py
> @@ -0,0 +1,104 @@
> +# SMMUv3 Functional tests
> +#
> +# Copyright (c) 2021 Red Hat, Inc.
> +#
> +# Author:
> +#  Eric Auger <eric.auger@redhat.com>
> +#
> +# 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
> +
> +from avocado_qemu import LinuxTest, BUILD_DIR
> +from avocado.utils import ssh

This import is not needed, given that the you're not using them directly,
but only using the LinuxTest methods that wrap them.

> +
> +class SMMU(LinuxTest):
> +
> +    KERNEL_COMMON_PARAMS = ("root=UUID=b6950a44-9f3c-4076-a9c2-355e8475b0a7 
> ro "
> +                            "earlyprintk=pl011,0x9000000 ignore_loglevel "
> +                            "no_timer_check printk.time=1 rd_NO_PLYMOUTH "
> +                            "console=ttyAMA0 ")
> +    IOMMU_ADDON = ',iommu_platform=on,disable-modern=off,disable-legacy=on'
> +    IMAGE = ("https://archives.fedoraproject.org/pub/archive/fedora/";
> +             "linux/releases/31/Everything/aarch64/os/images/pxeboot/")
> +    kernel_path = None
> +    initrd_path = None
> +    kernel_params = None
> +
> +    def set_up_boot(self):
> +        path = self.download_boot()
> +        self.vm.add_args('-device', 'virtio-blk-pci,bus=pcie.0,scsi=off,' +
> +                         'drive=drv0,id=virtio-disk0,bootindex=1,'
> +                         'werror=stop,rerror=stop' + self.IOMMU_ADDON)
> +        self.vm.add_args('-drive',
> +                         'file=%s,if=none,cache=writethrough,id=drv0' % path)
> +
> +    def setUp(self):
> +        super(SMMU, self).setUp(None, 'virtio-net-pci' + self.IOMMU_ADDON)
> +
> +    def add_common_args(self):
> +        self.vm.add_args("-machine", "virt")
> +        self.vm.add_args('-bios', os.path.join(BUILD_DIR, 'pc-bios',
> +                                      'edk2-aarch64-code.fd'))
> +        self.vm.add_args('-device', 'virtio-rng-pci,rng=rng0')
> +        self.vm.add_args('-object',
> +                         'rng-random,id=rng0,filename=/dev/urandom')
> +
> +    def common_vm_setup(self, custom_kernel=None):
> +        self.require_accelerator("kvm")
> +        self.add_common_args()

I know you're following the previous test pattern/template, but maybe
combine add_command_args() and common_vm_setup()?  They seem to be
doing the same thing.

> +        self.vm.add_args("-accel", "kvm")
> +        self.vm.add_args("-cpu", "host")
> +        self.vm.add_args("-machine", "iommu=smmuv3")
> +
> +        if custom_kernel is None:
> +            return
> +
> +        kernel_url = self.IMAGE + 'vmlinuz'
> +        initrd_url = self.IMAGE + 'initrd.img'
> +        self.kernel_path = self.fetch_asset(kernel_url)
> +        self.initrd_path = self.fetch_asset(initrd_url)
> +
> +    def run_and_check(self):
> +        if self.kernel_path:
> +            self.vm.add_args('-kernel', self.kernel_path,
> +                             '-append', self.kernel_params,
> +                             '-initrd', self.initrd_path)
> +        self.launch_and_wait()
> +        self.ssh_command('cat /proc/cmdline')
> +        self.ssh_command('dnf -y install numactl-devel')

Would you expect the package installation to cover significant more
than, say, a package removal?  Not relying on the distro's package
repos (and external networking) would be an improvement to the test's
stability, but I wonder how much functional coverage would be lost.

FIY, I've tried it with 'dnf -y remove yum' instead, and test times
are also considerably lower.

> +
> +    def test_smmu(self):
> +        """
> +        :avocado: tags=accel:kvm
> +        :avocado: tags=cpu:host
> +        :avocado: tags=smmu
> +        """

These tags are common across all tests, so you can move them to the class'
docstring.  Also, you need to add ":avocado: tags=arch:aarch64" or else
these will be attempted to be executed with other targets.

> +
> +        self.common_vm_setup()
> +        self.run_and_check()
> +
> +    def test_smmu_passthrough(self):
> +        """
> +        :avocado: tags=accel:kvm
> +        :avocado: tags=cpu:host
> +        :avocado: tags=smmu
> +        """
> +        self.common_vm_setup(True)
> +
> +        self.kernel_params = self.KERNEL_COMMON_PARAMS + 
> 'iommu.passthrough=on'
> +
> +        self.run_and_check()
> +
> +    def test_smmu_nostrict(self):
> +        """
> +        :avocado: tags=accel:kvm
> +        :avocado: tags=cpu:host
> +        :avocado: tags=smmu
> +        """
> +        self.common_vm_setup(True)
> +
> +        self.kernel_params = self.KERNEL_COMMON_PARAMS + 'iommu.strict=0'
> +
> +        self.run_and_check()
> -- 
> 2.26.2
> 

Other than those comments, the tests work as expected:

$ ./tests/venv/bin/avocado run tests/acceptance/smmu.py
JOB ID     : 8b1f1bb775d41e5c593e727ec1907710f076b161
JOB LOG    : 
/home/cleber/avocado/job-results/job-2021-03-25T10.31-8b1f1bb/job.log
 (1/3) tests/acceptance/smmu.py:SMMU.test_smmu: PASS (42.99 s)
 (2/3) tests/acceptance/smmu.py:SMMU.test_smmu_passthrough: PASS (47.06 s)
 (3/3) tests/acceptance/smmu.py:SMMU.test_smmu_nostrict: PASS (47.54 s)
RESULTS    : PASS 3 | ERROR 0 | FAIL 0 | SKIP 0 | WARN 0 | INTERRUPT 0 | CANCEL 0
JOB TIME   : 138.56 s

And even with a bit of stress (running them in parallel) proved to be
quite stable:

./tests/venv/bin/avocado run --test-runner=nrunner tests/acceptance/smmu.py

JOB ID     : bb2c3a006bb491a7086612dfa1ef980b55db4105
JOB LOG    : 
/home/cleber/avocado/job-results/job-2021-03-25T10.30-bb2c3a0/job.log
 (2/3) tests/acceptance/smmu.py:SMMU.test_smmu_passthrough: STARTED
 (1/3) tests/acceptance/smmu.py:SMMU.test_smmu: STARTED
 (3/3) tests/acceptance/smmu.py:SMMU.test_smmu_nostrict: STARTED
 (1/3) tests/acceptance/smmu.py:SMMU.test_smmu: PASS (50.22 s)
 (2/3) tests/acceptance/smmu.py:SMMU.test_smmu_passthrough: PASS (57.98 s)
 (3/3) tests/acceptance/smmu.py:SMMU.test_smmu_nostrict: PASS (58.28 s)
RESULTS    : PASS 3 | ERROR 0 | FAIL 0 | SKIP 0 | WARN 0 | INTERRUPT 0 | CANCEL 0
JOB TIME   : 60.35 s

Regards,
- Cleber.

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