ENUM TB_SECURITY_LEVEL(9)

🦋 enum tb_security_level — the Thunderbolt security level glow-up 🦋

okay bestie, so this is a page straight out of the Kernel API Manual — enum tb_security_level(9), no cap. and it's literally about how locked-down your Thunderbolt port is. security levels?? in MY kernel?? it's more likely than you think 💅

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✨ NAME ✨

enum tb_security_level — the Thunderbolt security level, bestie ⚡🔒

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🌸 SYNOPSIS 🌸

here's the whole enum, verbatim, don't touch:

enum tb_security_level {
    TB_SECURITY_NONE ,
    TB_SECURITY_USER ,
    TB_SECURITY_SECURE ,
    TB_SECURITY_DPONLY ,
    TB_SECURITY_USBONLY ,
    TB_SECURITY_NOPCIE

};

like, that's the entire vibe right there 🎀

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👑 Constants 👑

these are the levels, from most chaotic to most locked-down-ish, in the order the page gives them:

• TB_SECURITY_NONE — no security at all, it's giving legacy mode 🙈 nothing is checking you, bestie.
• TB_SECURITY_USER — user approval is required at minimum 🫶 so like, you gotta say yes.
• TB_SECURITY_SECURE — a one time saved key is required at minimum 🔑✨ fancy.
• TB_SECURITY_DPONLY — only tunnels Display port (and USB) 🖥️ that's it, that's the whole tunnel.
• TB_SECURITY_USBONLY — only tunnels the USB controller of the connected Thunderbolt dock (and Display Port). all PCIe links downstream of the dock are removed 💀 like, gone gone.
• TB_SECURITY_NOPCIE — for USB4 systems, this level is used when PCIe tunneling is disabled from the BIOS 🧚 BIOS said no.

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🌈 SEE ALSO 🌈

go read these next, iykyk 👀:

• Kernel file ./include/linux/thunderbolt.h
• struct tb(9)
• struct tb_property_dir(9)
• struct tb_property(9)
• enum tb_link_width(9)
• struct tb_xdomain(9)
• struct tb_protocol_handler(9)
• struct tb_service(9)
• struct tb_service_driver(9)
• struct tb_nhi(9)
• struct tb_ring(9)
• enum ring_desc_flags(9)
• struct ring_frame(9)
• tb_ring_rx(9)
• tb_ring_tx(9)
• tb_ring_dma_device(9)

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💖 that's the whole page, bestie. every constant, every "at minimum," every removed PCIe link. nothing skipped, periodt.

kisses, and remember: this page lives in ./include/linux, dated October 2026, filed under enum tb_security_level(9) — slay 🎀🦋💜