'\" t
.\"     Title: cxl-inject-protocol-error
.\"    Author: [see the "AUTHOR(S)" section]
.\" Generator: Asciidoctor 2.0.26
.\"      Date: 2026-03-31
.\"    Manual: cxl Manual
.\"    Source: cxl
.\"  Language: English
.\"
.TH "CXL\-INJECT\-PROTOCOL\-ERROR" "1" "2026-03-31" "cxl" "cxl Manual"
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.SH "NAME"
cxl-inject-protocol-error \- Inject CXL protocol errors into CXL downstream ports
.SH "SYNOPSIS"
.sp
.nf
\fIcxl inject\-protocol\-error\fP <dport> [<options>]
.fi
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.if n .sp
.RS 4
.it 1 an-trap
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.B Warning
.ps -1
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.sp
Error injection can cause system instability and should only be used
for debugging hardware and software error recovery flows. Use at your own risk!
.sp .5v
.RE
.sp
Inject a CXL protocol error into a CXL downstream port (dport). Donwstream ports
that support error injection will have their \fIprotocol_injectable\fP attribute
in \fIcxl\-list\fP set to true.
.sp
The \fI\-p\fP/\fI\-\-protocol\fP and \fI\-s\fP/\fI\-\-severity\fP options are required for error injection.
The \fI\-p\fP option is used to specify the CXL protocol to inject an error on; either
"mem" (CXL.mem) or "cache" (CXL.cache). The \fI\-s\fP option specifies the severity
of the error and can be one of: "correctable", "uncorrectable", or "fatal".
.sp
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 \fIcxl\-list\fP.
For example:
.sp
.if n .RS 4
.nf
.fam C
# cxl list \-B
[
  {
        "bus":"root0",
        "provider":"ACPI.CXL",
        "injectable_protocol_errors":[
          "mem\-correctable",
          "mem\-fatal",
        ]
  }
]
.fam
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.if n .RE
.sp
The dport to inject an error into is specified by host name (e.g. "0000:0e:01.1").
Here\(cqs an example injection using the example bus listing above:
.sp
.if n .RS 4
.nf
.fam C
# 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.
.fam
.fi
.if n .RE
.sp
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.
.sp
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.
.SH "OPTIONS"
.sp
\-p, \-\-protocol
.RS 4
Which CXL protocol to inject an error on. Can be either "mem" (CXL.mem)
or "cache (CXL.cache).
.RE
.sp
\-s, \-\-severity
.RS 4
Severity level of error to be injected. Can be one of the following:
"correctable", "uncorrectable", or "fatal".
.RE
.sp
\-\-debug
.RS 4
Enable debug output
.RE
.SH "SEE ALSO"
.sp
cxl\-list(1)