can later be mapped into that preallocated VA space (if dynamic memory mode
is enabled), and can optionally be mapped into it at startup.
+Support for Externally Allocated Memory
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+It is possible to use externally allocated memory in DPDK, using a set of malloc
+heap API's. Support for externally allocated memory is implemented through
+overloading the socket ID - externally allocated heaps will have socket ID's
+that would be considered invalid under normal circumstances. Requesting an
+allocation to take place from a specified externally allocated memory is a
+matter of supplying the correct socket ID to DPDK allocator, either directly
+(e.g. through a call to ``rte_malloc``) or indirectly (through data
+structure-specific allocation API's such as ``rte_ring_create``).
+
+Since there is no way DPDK can verify whether memory are is available or valid,
+this responsibility falls on the shoulders of the user. All multiprocess
+synchronization is also user's responsibility, as well as ensuring that all
+calls to add/attach/detach/remove memory are done in the correct order. It is
+not required to attach to a memory area in all processes - only attach to memory
+areas as needed.
+
+The expected workflow is as follows:
+
+* Get a pointer to memory area
+* Create a named heap
+* Add memory area(s) to the heap
+ - If IOVA table is not specified, IOVA addresses will be assumed to be
+ unavailable, and DMA mappings will not be performed
+ - Other processes must attach to the memory area before they can use it
+* Get socket ID used for the heap
+* Use normal DPDK allocation procedures, using supplied socket ID
+* If memory area is no longer needed, it can be removed from the heap
+ - Other processes must detach from this memory area before it can be removed
+* If heap is no longer needed, remove it
+ - Socket ID will become invalid and will not be reused
+
+For more information, please refer to ``rte_malloc`` API documentation,
+specifically the ``rte_malloc_heap_*`` family of function calls.
+
PCI Access
~~~~~~~~~~
Locks and atomic operations are per-architecture (i686 and x86_64).
+IOVA Mode Configuration
+~~~~~~~~~~~~~~~~~~~~~~~
+
+Auto detection of the IOVA mode, based on probing the bus and IOMMU configuration, may not report
+the desired addressing mode when virtual devices that are not directly attached to the bus are present.
+To facilitate forcing the IOVA mode to a specific value the EAL command line option ``--iova-mode`` can
+be used to select either physical addressing('pa') or virtual addressing('va').
+
Memory Segments and Memory Zones (memzone)
------------------------------------------