docs: add description of device memory lending
Signed-off-by: Daniel Boulby <daniel.boulby@arm.com>
Change-Id: I463c94a1014efd84e5665aec4a7eea0793f4064c
diff --git a/docs/secure-partition-manager/secure-partition-manager.rst b/docs/secure-partition-manager/secure-partition-manager.rst
index 9e97883..7b72f3c 100644
--- a/docs/secure-partition-manager/secure-partition-manager.rst
+++ b/docs/secure-partition-manager/secure-partition-manager.rst
@@ -1103,6 +1103,13 @@
correctly, such that any SP can't be given access and interfere with execution of
other components. More information in the :ref:`Threat Model`.
+Hafnium SPMC supports memory management transactions for device memory regions.
+Currently this is limited to only the ``FFA_MEM_LEND`` interface and
+to a single borrower. The device memory region used in the transaction must have
+been decalared in the SPMC manifest as described above. Memory defined in a device
+region node is given the attributes Device-nGnRnE, since this is the most restrictive
+memory type the memory must be lent with these attrbutes as well.
+
PE MMU configuration
--------------------