Re: [PATCH v4 17/18] PCI: Add KUnit coverage for ACS isolation checks

[sashiko-bot@kernel.org]

> From: Leon Romanovsky <leonro@nvidia.com>
> 
> Direct Translated P2P and Egress Control both let a peer request reach
> the peer without Request Redirect, and whether Request Redirect still
> isolates depends further on Translation Blocking and on the flags the
> caller requests. Firmware owns these bits, so the combinations are not
> reachable on a given machine.
> 
> Drive pci_acs_flags_enabled() with a fake pci_ops supplying the ACS
> Control register and check each combination, in both scopes: an
> Untranslated-only caller such as pci_enable_pasid() is unaffected by
> Direct Translated P2P but still loses Request Redirect to Egress
> Control. Cover the two ways the check gives up as well: a device with no
> ACS capability, and a control register that cannot be read.
> 
> The function is exposed under CONFIG_KUNIT via VISIBLE_IF_KUNIT.
> 
> Tested-by: Tushar Dave <tdave@nvidia.com>
> Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
> Assisted-by: Claude:claude-opus-5
> Signed-off-by: Leon Romanovsky <leonro@nvidia.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20260821-fix-p2p-acs-v4-0-v4-0-94426b96de73@nvidia.com?part=17