CXL-INJECT-PROTOCOL-ERROR(1)

🩺 CXL-INJECT-PROTOCOL-ERROR — bestie edition 💅

okay so this is the cxl-inject-protocol-error page, from the cxl manual, and it's literally about yeeting CXL protocol errors into CXL downstream ports 🎯 yes, on purpose. sit down, hydrate, let's go ✨

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✨ NAME ✨

cxl-inject-protocol-error — inject CXL protocol errors into CXL downstream ports 🫶

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🌸 SYNOPSIS 🌸

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

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🦋 DESCRIPTION 🦋

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

So what this does: it injects a CXL protocol error into a CXL downstream port (a dport). Not me being dramatic — downstream ports that support error injection will have their protocol_injectable attribute in cxl-list set to true. That's your vibe check right there 👑

The -p/--protocol and -s/--severity options are required for error injection. no cap, you can't skip them. Here's the deal:

• -p picks which CXL protocol to inject an error on — either "mem" (CXL.mem) or "cache" (CXL.cache).
• -s picks the severity of the error, and it can be one of: "correctable", "uncorrectable", or "fatal".

The types of errors (and severities) available depends on the platform — it's giving "everybody's different and that's beautiful" 🌈. To find the available error types for injection, look at 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 you're injecting 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.

iconic. it literally tells you it worked 😭💖

CXL protocol (CXL.cache/mem) error injection requires the platform to support ACPI v6.5+ error injection (EINJ). and that's not all — in addition to platform support, the CONFIG_ACPI_APEI_EINJ and CONFIG_ACPI_APEI_EINJ_CXL kernel configuration options must be enabled. so like, both of them, fr fr. 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. and if the CXL debugfs is not accessible? then 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 🫠 so if everything looks dead, check your mount first, bestie.

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💅 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. because sometimes you gotta see the receipts 👀

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🌟 SEE ALSO 🌟

• cxl-list(1)

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and that's the whole page, no crumbs left behind 🍓💜 — this cutie came from cxl, version dated 2026-06-30, and honestly? she ate. periodt. 👑✨