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| author | Klaus Jensen <k.jensen@samsung.com> | 2023-05-24 13:06:37 +0200 |
|---|---|---|
| committer | Klaus Jensen <k.jensen@samsung.com> | 2023-06-28 11:22:49 +0200 |
| commit | e409c9057b55e890a6e5f70386a36932a5137bcf (patch) | |
| tree | bbcc8bd955e991fc8f6e07720648ecc74bcecb3b /docs/system | |
| parent | ce8017736cc82e0250c1bc8e383335822f995510 (diff) | |
docs: update hw/nvme documentation for TP4146
Update documentation for TP4146 ("Flexible Data Placement") emulation.
Reviewed-by: Jesper Wendel Devantier <j.devantier@samsung.com>
Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
Diffstat (limited to 'docs/system')
| -rw-r--r-- | docs/system/devices/nvme.rst | 37 |
1 files changed, 36 insertions, 1 deletions
diff --git a/docs/system/devices/nvme.rst b/docs/system/devices/nvme.rst index 30f841ef62..a8bb8d729c 100644 --- a/docs/system/devices/nvme.rst +++ b/docs/system/devices/nvme.rst @@ -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 |