cxl-create-region - Assemble a CXL region by setting up attributes of its constituent CXL memdevs.

       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.

       A CXL region is composed of one or more slices of CXL memdevs, with configurable interleave settings -
       both the number of interleave ways, and the interleave granularity.

       For create-region, a size can optionally be specified, but if not, the maximum possible size for each
       memdev will be used up to the available decode capacity in the system for the given memory type. For
       persistent regions a UUID can optionally be specified, but if not, one will be generated.

       If the region-creation operation is successful, a region object will be emitted on stdout in JSON format
       (see examples). If the specified arguments cannot be satisfied with a legal configuration, then an
       appropriate error will be emitted on stderr.

           #cxl create-region -m -d decoder0.1 -w 2 -g 1024 mem0 mem1
           {
             "region":"region0",
             "resource":"0xc90000000",
             "size":"512.00 MiB (536.87 MB)",
             "interleave_ways":2,
             "interleave_granularity":1024,
             "mappings":[
               {
                 "position":1,
                 "decoder":"decoder4.0"
               },
               {
                 "position":0,
                 "decoder":"decoder3.0"
               }
             ]
           }
           created 1 region

       cxl-create-region - Assemble a CXL region by setting up attributes of its constituent CXL memdevs.

       <target(s)>
           The CXL targets that should be used to form the region. The number of target arguments must match the
           --ways option (if provided).

       -b, --bus=
           Restrict the operation to the specified bus.

       -m, --memdevs
           Indicate that the non-option arguments for target(s) refer to memdev device names. If this option is
           omitted and no targets are specified then create-region uses the equivalent of cxllist-M-d$decoder internally as the target list. Note that depending on the topology, for example with
           switches, the automatic target list ordering may not be valid and manual specification of the target
           list is required.

       -s, --size=
           Specify the total size for the new region. This is optional, and by default, the maximum possible
           size will be used. The maximum possible size is gated by both the contiguous free HPA space remaining
           in the root decoder, and the available DPA space in the component memdevs.

       -t, --type=
           Specify the region type - pmem or ram. Default to root decoder capability, and if that is ambiguous,
           default to pmem.

       -U, --uuid=
           Specify a UUID for the new region. This shouldn’t usually need to be specified, as one will be
           generated by default. Only applicable to pmem regions.

       -w, --ways=
           The number of interleave ways for the new region’s interleave. This should be equal to the number of
           memdevs specified in --memdevs, if --memdevs is being supplied. If --ways is not specified, it will
           be determined based on the number of memdev targets provided.

       -g, --granularity=
           The interleave granularity for the new region. Must match the selected root decoder’s (if provided)
           granularity. If the root decoder is interleaved across more than one host-bridge then this value must
           match that granularity. Otherwise, for non-interleaved decode windows, any granularity can be
           specified as long as all devices support that setting.

       -d, --decoder=
           The root decoder that the region should be created under. If not supplied, the first cross-host
           bridge (if available), decoder that supports the largest interleave will be chosen.

       -u, --human
           By default the command will output machine-friendly raw-integer data. Instead, with this flag,
           numbers representing storage size will be formatted as human readable strings with units, other
           fields are converted to hexadecimal strings.

       --debug
           Turn on additional debug messages including library debug.

cxl-list(1),

cxl                                                2024-11-01                               CXL-CREATE-REGION(1)

cxlcreate-region[<options>]