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6fd7c5c81a
While every PCI Function that implements ATS has an independent ATS Extended Capability structure with a Read/Write Smallest Translation Unit (STU) field, the kernel manages SR-IOV ATS by requiring the IOMMU driver to configure the STU on the Physical Function (PF) before any any Virtual Functions (VFs) are created. Currently, pci_prepare_ats() bails out early for VFs, assuming that the PF has already been correctly prepared. However, this creates a potential mismatch if a VF is subsequently prepared with a different page shift. Update pci_prepare_ats() to validate that the requested page shift (ps) matches the STU already configured in the associated PF. This ensures early detection of incompatible configurations and maintains the kernel's policy of consistent STU sizing across all functions associated with a given SMMU. Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Samiullah Khawaja <skhawaja@google.com> Reviewed-by: Nicolin Chen <nicolinc@nvidia.com> Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Pranjal Shrivastava <praan@google.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
628 lines
14 KiB
628 lines
14 KiB