Currently, xen uses shared iommu domain-id across all the VT-d units in the platform. The number of iommu domain-ids (NR_DID, e.g. 256) supported by each VT-d unit is reported in Capability register. The limitation of current implementation is it only can support at most NR_DID domains with VT-d in the entire platform, even though the platform can support N * NR_DID (where N is the number of VT-d units). Imagine a platform with several SR_IOV NICs, and each NIC supports 128 VFs. It possibly beyond the NR_DID. This patch implements iommu domain-id management per iommu (VT-d unit), hence solves above limitation. It removes the global domain-id bitmap, instead use domain-id bitmap in struct iommu, and also involve an array to map guest domain-id and iommu domain-id, which is used to iommu domain-id when flush context cache or IOTLB. When a device is assigned to a guest, choose an available iommu domain-id from the device''s iommu, and map guest domain id to the domain-id mapping array. When a device is deassigned from a guest, clear the domain-id bit in domain-id bitmap and clear the corresponding entry in domain-id map array if there is no other devices under the same iommu owned by the guest. Signed-off-by: Weidong Han <weidong.han@intel.com> _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel