NAME¶
cxl-create-region - Assemble a CXL region by setting up attributes
of its constituent CXL memdevs.
SYNOPSIS¶
cxl create-region [<options>]
DESCRIPTION¶
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.
EXAMPLE¶
#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
OPTIONS¶
<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 cxl list
-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.
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.