SVA

PCIe PASID Lets One Device Carry Multiple Address-Space Contexts

PCIe PASID Lets One Device Carry Multiple Address-Space Contexts A PCIe function normally has a Requester ID derived from its bus, device, and function identity. That identifier tells platform components which function issued a transaction, but it is too coarse when one device serves work from several process address spaces at the same time. Process Address Space ID (PASID) adds another identity field to the transaction path. A PASID can select an address-space context beneath the same device function, allowing the IOMMU to distinguish memory traffic that belongs to different processes without requiring a separate PCIe function for each one.