Change Details

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.

PCI memory address space is shared between memory-mapped devices (MMIO) and host memory (which may be remapped by an IOMMU). Device accesses to an address within a memory aperture in a PCIe root port will be treated as peer-to-peer and not forwarded to an IOMMU. To avoid this, reserve the address space of the root port's memory apertures in the address space used by the IOMMU for remapping.

IOMMU remapped (guest) addresses (IOVA) must not alias host addressesPCI memory address space is shared between memory-mapped devices (MMIO) assigned to the same PCIe root port (i.e. device BARs etcand host memory (which may be remapped by an IOMMU). AliasedDevice accesses to addresses may be routed by PCI without respect to translation. To avoid such aliasing, reserve within the range of allocable guestn address within a memory aperture in a PCIe root port will be treated address space the regions of memory the PCIe root port has assigned oras peer-to-peer and not forwarded to an IOMMU. To avoid this, reserve may assign to devices withthe address space of the root port's memory-mapped access apertures in the address space used by the IOMMU for remapping.