On Thu, 2010-07-01 at 15:00 -0700, Zach Pfeffer wrote: > Additionally, the current IOMMU interface does not allow users to > associate one page table with multiple IOMMUs unless the user explicitly > wrote a muxed device underneith the IOMMU interface. This also could be > done, but would have to be done for every such use case. Since the > particular topology is run-time configurable all of these use-cases and > more can be expressed without pushing the topology into the low-level > IOMMU driver. > > The VCMM takes the long view. Its designed for a future in which the > number of IOMMUs will go up and the ways in which these IOMMUs are > composed will vary from system to system, and may vary at > runtime. Already, there are ~20 different IOMMU map implementations in > the kernel. Had the Linux kernel had the VCMM, many of those > implementations could have leveraged the mapping and topology management > of a VCMM, while focusing on a few key hardware specific functions (map > this physical address, program the page table base register). So if we include this code which "map implementations" could you collapse into this implementations ? Generally , what currently existing code can VCMM help to eliminate? Daniel -- Sent by a consultant of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>