Re: [PATCH 13/13] PCI: Add KUnit coverage for ACS isolation checks

Logan Gunthorpe <[email protected]> Tue, 4 Aug 2026 16:38:22 -0600
Newsgroups gmane.linux.documentation,gmane.linux.kernel.pci,gmane.linux.kernel
Message-ID <[email protected]>

On 2026-08-02 09:09, Leon Romanovsky wrote:
> From: Leon Romanovsky <[email protected]>
> 
> 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. The function is exposed
> under CONFIG_KUNIT via VISIBLE_IF_KUNIT.
> 
> Signed-off-by: Leon Romanovsky <[email protected]>
> Assisted-by: Claude Opus 5 <[email protected]>


Reviewed-by: Logan Gunthorpe <[email protected]>