Re: [PATCH 11/13] PCI/P2PDMA: Add KUnit tests for ACS routing decisions

[Logan Gunthorpe <logang@deltatee.com>]

On 2026-08-02 09:09, Leon Romanovsky wrote:
> From: Leon Romanovsky <leonro@nvidia.com>
> 
> Add a KUnit suite exercising the ACS peer-to-peer routing logic:
> 
>   - pci_acs_p2pdma_decision(): the full PCIe table 6-11 truth table,
>     including the Egress Control Vector branches (bit set/clear, with and
>     without Request Redirect and Completion Redirect) that require a
>     switch implementing the Egress Control Vector and so cannot be
>     reached on commonly available hardware.
> 
>   - pci_acs_egress_port_valid(): the vector-size boundary, including the
>     "size 0 encodes 256 bits" case.
> 
>   - pci_acs_egress_ctrl_set(): driven through a fake pci_ops returning
>     canned config space, covering target Port Number extraction from
>     LNKCAP, the vector DWORD offset (target_port / 32), the bit position
>     (target_port % 32), the -ERANGE bound, and the unsupported-port
>     guards -- all without real hardware.
> 
> Run with:
> 
> cat > /tmp/pci-acs.kunitconfig <<'EOF'
> CONFIG_KUNIT=y
> CONFIG_PCI=y
> CONFIG_ZONE_DEVICE=y
> CONFIG_MEMORY_HOTPLUG=y
> CONFIG_MEMORY_HOTREMOVE=y
> CONFIG_SPARSEMEM_VMEMMAP=y
> CONFIG_PCI_P2PDMA=y
> CONFIG_PCI_ACS_KUNIT_TEST=y
> EOF
> 
> ./tools/testing/kunit/kunit.py run --arch=x86_64 \
>     --kunitconfig=/tmp/pci-acs.kunitconfig --jobs=$(nproc) pci_acs
> 
> Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
> Assisted-by: Claude Opus 4.8 <noreply@anthropic.com>

Great, I like having Kunit tests for this kind of things. Thanks!

Reviewd-by: Logan Gunthorpe <logang@deltatee.com>