On Tue, Aug 01, 2023 at 02:31:23PM +0800, Lu Baolu wrote: > The PCI PASID enabling interface guarantees that the address space used > by each PASID is unique. This is achieved by checking that the PCI ACS > path is enabled for the device. If the path is not enabled, then the > PASID feature cannot be used. > > if (!pci_acs_path_enabled(pdev, NULL, PCI_ACS_RR | PCI_ACS_UF)) > return -EINVAL; > > The PASID array is not an attribute of the IOMMU group. It is more > natural to store the PASID array in the per-device IOMMU data. This > makes the code clearer and easier to understand. No functional changes > are intended. Is there a reason to do this? *PCI* requires the ACS/etc because PCI kind of messed up how switches handled PASID so PASID doesn't work otherwise. But there is nothing that says other bus type can't have working (non-PCI) PASID and still have device isolation issues. So unless there is a really strong reason to do this we should keep the PASID list in the group just like the domain. Jason
