cxl

List CXL memory devices

$ cxl list

$ cxl list -vvv

$ cxl list -R

$ cxl list -H

$ cxl enable-memdev [mem0]

$ cxl create-region -d [decoder0.0] -m [mem0]

cxl command [options] [device]

cxl is the management utility for Compute Express Link (CXL) devices, a new interconnect standard for attaching memory and accelerators to CPUs. It manages CXL memory expanders, configures memory regions, and monitors device health.
CXL enables disaggregated memory architectures where memory can be pooled and dynamically allocated to different hosts. The cxl tool configures how this memory appears to the operating system through regions and decoders.
Common operations include listing available CXL devices, checking health status, creating memory regions that can be used by the system, and managing the device lifecycle.

list

List CXL devices, regions, or decoders.

Enable a memory device.

Disable a memory device.

Create a memory region.

Destroy a memory region.

Enable a memory region.

Disable a memory region.

Specify memory device.

Specify decoder.

List regions.

Include health information.

Increase verbosity (repeat for more).

Requires kernel 5.15+ with CXL support enabled. Hardware must support CXL (Intel 4th gen Xeon, AMD EPYC, etc.). Configuration changes may require system restart. CXL is evolving technology; some features depend on specific kernel versions.

CXL was developed by the CXL Consortium, founded in 2019 by Intel, with specifications contributed by major hardware vendors. The Linux cxl tool was developed as part of the ndctl project by Dan Williams at Intel. CXL 1.1 support appeared in Linux 5.12 (2021), with ongoing development adding features for newer CXL specifications (2.0, 3.0).

ndctl(1), daxctl(1), lspci(8)