On Tue, Jun 15, 2021 at 11:09:37PM +0000, Tian, Kevin wrote: > which information can you elaborate? This is the area which I'm not > familiar with thus would appreciate if you can help explain how this > bus specific information is utilized within the attach function or > sometime later. This is the idea that the device driver needs to specify which bus specific protocol it uses to issue DMA's when it attaches itself to an IOASID. For PCI: - Normal RID DMA - PASID DMA - ENQCMD triggered PASID DMA - ATS/PRI enabled or not And maybe more. Eg CXL has some other operating modes, I think The device knows what it is going to do, we need to convey that to the IOMMU layer so it is prepared properly. Jason
