@@ -212,6 +212,41 @@ The namespace may be configured with additional parameters
the minimum memory page size (CAP.MPSMIN). The default value (``0``)
has this property inherit the ``mdts`` value.
+Flexible Data Placement
+-----------------------
+
+The device may be configured to support TP4146 ("Flexible Data Placement") by
+configuring it (``fdp=on``) on the subsystem::
+
+ -device nvme-subsys,id=nvme-subsys-0,nqn=subsys0,fdp=on,fdp.nruh=16
+
+The subsystem emulates a single Endurance Group, on which Flexible Data
+Placement will be supported. Also note that the device emulation deviates
+slightly from the specification, by always enabling the "FDP Mode" feature on
+the controller if the subsystems is configured for Flexible Data Placement.
+
+Enabling Flexible Data Placement on the subsyste enables the following
+parameters:
+
+``fdp.nrg`` (default: ``1``)
+ Set the number of Reclaim Groups.
+
+``fdp.nruh`` (default: ``0``)
+ Set the number of Reclaim Unit Handles. This is a mandatory paramater and
+ must be non-zero.
+
+``fdp.runs`` (default: ``96M``)
+ Set the Reclaim Unit Nominal Size. Defaults to 96 MiB.
+
+Namespaces within this subsystem may requests Reclaim Unit Handles::
+
+ -device nvme-ns,drive=nvm-1,fdp.ruhs=RUHLIST
+
+The ``RUHLIST`` is a semicolon separated list (i.e. ``0;1;2;3``) and may
+include ranges (i.e. ``0;8-15``). If no reclaim unit handle list is specified,
+the controller will assign the controller-specified reclaim unit handle to
+placement handle identifier 0.
+
Metadata
--------
@@ -320,4 +355,4 @@ controller are:
.. code-block:: console
- echo 0000:01:00.1 > /sys/bus/pci/drivers/nvme/bind
\ No newline at end of file
+ echo 0000:01:00.1 > /sys/bus/pci/drivers/nvme/bind