On Tue, Oct 13, 2026 at 05:25:08PM +0300, Leon Romanovsky wrote: > PCI P2PDMA applies Request and Completion Redirect throughout both paths. > This misclassifies asymmetric and nested switches, and reports one answer > for every kind of TLP. > > Three ACS controls act on TLP attributes the Requester chooses rather > than on the topology: Translation Blocking and Direct Translated P2P act on > a Request's Address Type, and Completion Redirect skips Completions carrying > Relaxed Ordering. > > Evaluate each direction at the path divergence, decide every class from the > one walk, and treat a client with ATS enabled as translating unless its > driver declares per-mapping ATS. > > This completes the P2PDMA side; dma-buf and mlx5 follow separately. > > Signed-off-by: Leon Romanovsky <[email protected]> > --- > Changes in v11:
Bjorn, Could you please save me from the AI-bot attack? Every rebase seems to uncover another bizarre pre-existing issue. It never ends. Thanks <...> > --- > Leon Romanovsky (19): > PCI/P2PDMA: Honor device-specific ACS redirection > PCI/P2PDMA: Document the TLP attribute assumptions > PCI/P2PDMA: Derive routing from directional ACS controls > PCI: Reject unreadable ACS controls in isolation checks > PCI/P2PDMA: Evaluate ACS controls at the path divergence > PCI/P2PDMA: Document directional ACS routing > PCI/P2PDMA: Collect the path's ACS controls before deciding > PCI/P2PDMA: Answer routing per TLP class > PCI/P2PDMA: Route Relaxed Ordering Completions directly > PCI/P2PDMA: Reject Translated Requests blocked by Translation Blocking > PCI/P2PDMA: Route Translated Requests under Direct Translated P2P > PCI/P2PDMA: Log detailed ACS routing diagnostics > PCI/P2PDMA: Add KUnit tests for the ACS routing decisions > PCI/P2PDMA: Test the ACS P2P routing walk > PCI: Add KUnit coverage for ACS isolation checks > PCI/P2PDMA: Document TLP-class routing > PCI/P2PDMA: Let a client declare that it selects ATS per mapping > PCI/P2PDMA: Evaluate the ATS path for clients with ATS enabled > PCI/P2PDMA: Test the routing of clients with ATS enabled > > Documentation/admin-guide/kernel-parameters.txt | 11 +- > Documentation/driver-api/pci/p2pdma.rst | 105 ++ > drivers/pci/Kconfig | 15 + > drivers/pci/Makefile | 1 + > drivers/pci/p2pdma.c | 942 +++++++++++++++-- > drivers/pci/pci.c | 8 +- > drivers/pci/pci.h | 57 ++ > drivers/pci/pci_acs_test.c | 1225 > +++++++++++++++++++++++ > drivers/pci/quirks.c | 8 +- > include/linux/pci-p2pdma.h | 12 +- > 10 files changed, 2292 insertions(+), 92 deletions(-) > --- > base-commit: 36038f0e8377ef316b723d0d85b1510bc64069ab > change-id: 20260821-fix-p2p-acs-v4-0-e72455e3a261 > > Best regards, > -- > Leon Romanovsky <[email protected]> >
