NAME

NAME

cxl-inject-protocol-error - Inject CXL protocol errors into CXL downstream ports

SYNOPSIS

cxl inject-protocol-error <dport> [<options>]

Error injection can cause system instability and should only be used for debugging hardware and software error recovery flows. Use at your own risk!

Inject a CXL protocol error into a CXL downstream port (dport). Donwstream ports that support error injection will have their protocol_injectable attribute in cxl-list set to true.

The -p/–protocol and -s/–severity options are required for error injection. The -p option is used to specify the CXL protocol to inject an error on; either “mem” (CXL.mem) or “cache” (CXL.cache). The -s option specifies the severity of the error and can be one of: “correctable”, “uncorrectable”, or “fatal”.

The types of errors (and severities) available depends on the platform. To find the available error types for injection, see the “injectable_protocol_errors” attribute under the applicable CXL bus object in the output of cxl-list. For example:

# cxl list -B
[
  {
    "bus":"root0",
    "provider":"ACPI.CXL",
    "injectable_protocol_errors":[
      "mem-correctable",
      "mem-fatal",
    ]
  }
]

The dport to inject an error into is specified by host name (e.g. “0000:0e:01.1”). Here’s an example injection using the example bus listing above:

# cxl list -TP
 [
  {
    "port":"port1",
    "host":"pci0000:e0",
    "depth":1,
    "decoders_committed":1,
    "nr_dports":1,
    "dports":[
      {
        "dport":"0000:e0:01.1",
        "alias":"device:02",
        "id":0,
        "protocol_injectable":true
      }
    ]
  }
]

# cxl inject-protocol-error "0000:e0:01.1" -p mem -s correctable
cxl inject-protocol-error: inject_proto_err: injected mem-correctable protocol error.

CXL protocol (CXL.cache/mem) error injection requires the platform to support ACPI v6.5+ error injection (EINJ). In addition to platform support, the CONFIG_ACPI_APEI_EINJ and CONFIG_ACPI_APEI_EINJ_CXL kernel configuration options must be enabled. For more information, view the Linux kernel documentation on EINJ.

This command depends on the CXL debug filesystem (normally mounted at “/sys/kernel/debug/cxl”) to inject protocol errors. If the CXL debugfs is not accessible the “protocol_injectable” attribute of dports will always be set to false, and the “injectable_protocol_errors” attribute of CXL busses will always be empty.

OPTIONS

-p; --protocol
Which CXL protocol to inject an error on. Can be either “mem” (CXL.mem) or “cache (CXL.cache).

-s; --severity
Severity level of error to be injected. Can be one of the following: “correctable”, “uncorrectable”, or “fatal”.

--debug
Enable debug output

SEE ALSO

cxl-list