Change Details

When a device is using an IOMMU remapped address, the address must be unique to avoid an upstream DMA transaction from being inadvertently redirected downstream. To avoid such conflicts, reserve within the range of allocable address space the region of memory the PCIe root port has assigned to devices with memory-mapped access.

IOMMU remapped (guest) addresses (IOVA) must not alias host addresses assigned to the same PCIe root port (i.e. device BARs etc). Aliased addresses may be routed by PCI without respect to translation. To avoid such aliasing, reserve within the range of allocable guest address space the regions of memory the PCIe root port has assigned or may assign to devices with memory-mapped access.

When a device is using an IOMMU remapped address, theIOMMU remapped (guest) addresses (IOVA) must not alias host address must bees uniqueassigned to avoid an upstream DMA transaction from being inadvertentlythe same PCIe root port (i.e. device BARs etc). Aliased redirected downstreamaddresses may be routed by PCI without respect to translation. To avoid such conflictsaliasing, reserve within the range of allocable addressguest address space the regions of memory the PCIe root port has assigned to devicesor may assign to devices with memory-mapped access.