[RFC 1/3 v3] mm: iommu: An API to unify IOMMU, CPU and device memory management

On Wed, Jul 14, 2010 at 01:11:49PM -0700, Zach Pfeffer wrote:

If the DMA-API contained functions to allocate virtual space separate
from physical space and reworked how chained buffers functioned it
would probably work - but then things start to look like the VCM API
which does graph based map management.

Every additional virtual mapping of a physical buffer results in
additional cache aliases on aliasing caches, and more workload for
developers to sort out the cache aliasing issues.

What does VCM to do mitigate that?