NAME¶
cxl-reserve-dpa - allocate device-physical address space
SYNOPSIS¶
cxl reserve-dpa <mem0> [<mem1>..<memN>] [<options>]
The CXL region provisioning process proceeds in multiple steps.
One of the steps is identifying and reserving the DPA span that each member
of the interleave-set (region) contributes in advance of attaching that
allocation to a region. For development, test, and debug purposes this
command is a helper to find the next available decoder on endpoint (memdev)
and mark a span of DPA as busy.
OPTIONS¶
<memory device(s)>
A memX device name, or a memdev id number.
Restrict the operation to the specified memdev(s). The keyword all can
be specified to indicate the lack of any restriction.
-S, --serial
Rather an a memdev id number, interpret the
<memdev> argument(s) as a list of serial numbers.
-b, --bus=
Restrict the operation to the specified bus.
-d, --decoder
Specify the decoder to attempt the allocation. The CXL
specification mandates that allocations must be ordered by DPA and decoder
instance. I.e. the lowest DPA allocation on the device is covered by decoder0,
and the last / highest DPA allocation is covered by the last decoder. This
ordering is enforced by the kernel. By default the tool picks the next
available decoder.
-t, --type
Select the partition for the allocation. CXL devices
implement a partition that divdes ram and pmem capacity, where
pmem capacity consumes the higher DPA capacity above the partition
boundary. The type defaults to pmem. Note that given CXL DPA allocation
constraints, once any pmem allocation is established then all remaining
ram capacity becomes reserved (skipped).
-f, --force
The kernel enforces CXL DPA allocation ordering
constraints, and the tool anticipates those and fails operations that are
expected to fail without sending them to the kernel. For test purposes,
continue to attempt "expected to fail" operations to exercise the
driver.
-s, --size
Specify the size of the allocation. This option supports
the suffixes "k" or "K" for KiB, "m" or
"M" for MiB, "g" or "G" for GiB and
"t" or "T" for TiB. This defaults to "all available
capacity of the specified type".
-v
Turn on verbose debug messages in the library (if libcxl
was built with logging and debug enabled).
COPYRIGHT¶
Copyright © 2016 - 2022, Intel Corporation. License GPLv2:
GNU GPL version 2 <http://gnu.org/licenses/gpl.html>. This is
free software: you are free to change and redistribute it. There is NO
WARRANTY, to the extent permitted by law.