cxl-list - Man Page

List platform CXL objects, and their attributes, in json.

Synopsis

cxl list [<options>]

Walk the CXL capable device hierarchy in the system and list all device instances along with some of their major attributes.

Options can be specified to limit the output to specific objects. When a single object type is specified the return json object is an array of just those objects, when multiple objects types are specified the returned the returned object may be an array of arrays with the inner array named for the given object type. The top-level arrays are ellided when the objects can nest under a higher object-type in the hierararchy. The potential top-level array names and their nesting properties are:

"anon memdevs"

(disabled memory devices) do not nest

"buses"

do not nest

"ports"

nest under buses

"endpoints"

nest under ports or buses (if ports are not emitted)

"memdevs"

nest under endpoints or ports (if endpoints are not emitted) or buses (if endpoints and ports are not emitted)

"root decoders"

nest under buses

"port decoders"

nest under ports, or buses (if ports are not emitted)

"endpoint decoders"

nest under endpoints, or ports (if endpoints are not emitted) or buses (if endpoints and ports are not emitted)

Filters can by specifed as either a single identidier, a space separated quoted string, or a comma separated list. When multiple filter identifiers are specified within a filter string, like "-m mem0,mem1,mem2", they are combined as an OR filter. When multiple filter string types are specified, like "-m mem0,mem1,mem2 -p port10", they are combined as an AND filter. So, "-m mem0,mem1,mem2 -p port10" would only list objects that are beneath port10 AND map mem0, mem1, OR mem2.

Given that many topology queries seek to answer questions relative to a given memdev, buses, ports, endpoints, and decoders can be filtered by one or more memdevs. For example:

# cxl list -P -p switch,endpoint -m mem0
[
  {
    "port":"port1",
    "host":"ACPI0016:00",
    "endpoints:port1":[
      {
        "endpoint":"endpoint2",
        "host":"mem0"
      }
    ]
  }
]

Additionally, when provisioning new interleave configurations it is useful to know which memdevs can be referenced by a given decoder like a root decoder, or mapped by a given port if the decoders are not configured.

# cxl list -Mu -d decoder0.0
{
  "memdev":"mem0",
  "pmem_size":"256.00 MiB (268.44 MB)",
  "ram_size":0,
  "serial":"0",
  "host":"0000:35:00.0"
}

The --human option in addition to reformatting some fields to more human friendly strings also unwraps the array to reduce the number of lines of output.

Example

# cxl list --memdevs
[
  {
    "memdev":"mem0",
    "pmem_size":268435456,
    "ram_size":0,
    "serial":0,
    "host":"0000:35:00.0"
  }
]

# cxl list -BMu
[
  {
    "anon memdevs":[
      {
        "memdev":"mem0",
        "pmem_size":"256.00 MiB (268.44 MB)",
        "ram_size":0,
        "serial":"0"
      }
    ]
  },
  {
    "buses":[
      {
        "bus":"root0",
        "provider":"ACPI.CXL"
      }
    ]
  }
]

Options

-m,  --memdev=

Specify CXL memory device name(s), or device id(s), to filter the listing. For example:

# cxl list -M --memdev="0 mem3 5"
[
  {
    "memdev":"mem0",
    "pmem_size":268435456,
    "ram_size":0,
    "serial":0
  },
  {
    "memdev":"mem3",
    "pmem_size":268435456,
    "ram_size":268435456,
    "serial":2
  },
  {
    "memdev":"mem5",
    "pmem_size":268435456,
    "ram_size":268435456,
    "serial":4
  }
]
-s,  --serial=

Specify CXL memory device serial number(s) to filter the listing

-M,  --memdevs

Include CXL memory devices in the listing

-i,  --idle

Include idle (not enabled / zero-sized) devices in the listing

-H,  --health

Include health information in the memdev listing. Example listing:

# cxl list -m mem0 -H
[
  {
    "memdev":"mem0",
    "pmem_size":268435456,
    "ram_size":268435456,
    "health":{
      "maintenance_needed":true,
      "performance_degraded":true,
      "hw_replacement_needed":true,
      "media_normal":false,
      "media_not_ready":false,
      "media_persistence_lost":false,
      "media_data_lost":true,
      "media_powerloss_persistence_loss":false,
      "media_shutdown_persistence_loss":false,
      "media_persistence_loss_imminent":false,
      "media_powerloss_data_loss":false,
      "media_shutdown_data_loss":false,
      "media_data_loss_imminent":false,
      "ext_life_used":"normal",
      "ext_temperature":"critical",
      "ext_corrected_volatile":"warning",
      "ext_corrected_persistent":"normal",
      "life_used_percent":15,
      "temperature":25,
      "dirty_shutdowns":10,
      "volatile_errors":20,
      "pmem_errors":30
    }
  }
]
-I,  --partition

Include partition information in the memdev listing. Example listing:

# cxl list -m mem0 -I
[
  {
    "memdev":"mem0",
    "pmem_size":0,
    "ram_size":273535729664,
    "partition_info":{
      "total_size":273535729664,
      "volatile_only_size":0,
      "persistent_only_size":0,
      "partition_alignment_size":268435456
      "active_volatile_size":273535729664,
      "active_persistent_size":0,
      "next_volatile_size":0,
      "next_persistent_size":0,
    }
  }
]
-B,  --buses

Include bus / CXL root object(s) in the listing. Typically, on ACPI systems the bus object is a singleton associated with the ACPI0017 device, but there are test scenerios where there may be multiple CXL memory hierarchies.

# cxl list -B
[
  {
    "bus":"root3",
    "provider":"cxl_test"
  },
  {
    "bus":"root0",
    "provider":"ACPI.CXL"
  }
]
-b,  --bus=

Specify CXL root device name(s), device id(s), and / or CXL bus provider names to filter the listing. The supported provider names are "ACPI.CXL" and "cxl_test".

-P,  --ports

Include port objects (CXL / PCIe root ports + Upstream Switch Ports) in the listing.

-p,  --port=

Specify CXL Port device name(s), device id(s), and or port type names to filter the listing. The supported port type names are "root" and "switch". Note that a bus object is also a port, so the following two syntaxes are equivalent:

# cxl list -B
# cxl list -P -p root -S
...where the '-S/--single' is required since descendant ports are always
included in a port listing and '-S/--single' stops after listing the
bus.  Additionally, endpoint objects are ports so the following commands
are equivalent, and no '-S/--single' is required as endpoint ports are
terminal:
# cxl list -E
# cxl list -P -p endpoint
By default, only 'switch' ports are listed, i.e.
# cxl list -P
# cxl list -P -p switch
...are equivalent.
-S,  --single

Specify whether the listing should emit all the objects that are descendants of a port that matches the port filter, or only direct descendants of the individual ports that match the filter. By default all descendant objects are listed.

-E,  --endpoints

Include endpoint objects (CXL Memory Device decoders) in the listing.

# cxl list -E
[
  {
    "endpoint":"endpoint2",
    "host":"mem0"
  }
]
-e,  --endpoint

Specify CXL endpoint device name(s), or device id(s) to filter the emitted endpoint(s).

-D,  --decoders

Include decoder objects (CXL Memory decode capability instances in buses, ports, and endpoints) in the listing.

-d,  --decoder

Specify CXL decoder device name(s), device id(s), or decoder type names to filter the emitted decoder(s). The format for a decoder name is "decoder<port_id>.<instance_id>". The possible decoder type names are "root", "switch", or "endpoint", similar to the port filter syntax.

-T,  --targets

Extend decoder listings with downstream port target information, port and bus listings with the downstream port information, and / or regions with mapping information.

# cxl list -BTu -b ACPI.CXL
{
  "bus":"root0",
  "provider":"ACPI.CXL",
  "nr_dports":1,
  "dports":[
    {
      "dport":"ACPI0016:00",
      "alias":"pci0000:34",
      "id":"0"
    }
  ]
}
-R,  --regions

Include region objects in the listing.

-r,  --region

Specify CXL region device name(s), or device id(s), to filter the listing.

-v,  --verbose

Increase verbosity of the output. This can be specified multiple times to be even more verbose on the informational and miscellaneous output, and can be used to override omitted flags for showing specific information. Note that cxl list --verbose --verbose is equivalent to cxl list -vv.

--debug

If the cxl tool was built with debug enabled, turn on debug messages.

-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.

See Also

linkcxl:ndctl-list[1]

Info

08/24/2022