xenbus_dev_error(9)

✨ xenbus_dev_error — the kernel API manual page, bestie edition ✨

okay so this is a kernel API manual page for xenbus_dev_error(9), and honestly? it's giving "tiny function, big responsibility" energy.

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🌸 NAME 🌸

xenbus_dev_error — place an error message into the store 💌

like, literally. it puts an error into the store. that's the whole vibe.

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🎀 SYNOPSIS 🎀

void xenbus_dev_error (struct xenbus_device *dev , int err , const char *fmt , ... );

no cap, that's the exact signature. void return, so it doesn't hand anything back to you — it just does its thing and dips. 💅

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🦋 ARGUMENTS 🦋

• dev — xenbus device 🫶 (the device you're reporting on, bestie)
• err — error to report 😭 (the error itself)
• fmt — error message format ✨ (your format string, printf-style)
• ... — variable arguments 🌸 (the extra bits that get slotted into fmt)

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💖 DESCRIPTION 💖

Report the given negative errno into the store, along with the given formatted message.

that's it. that's the whole function. it takes your negative errno and your formatted message, and it reports them into the store. iconic behaviour, honestly — no drama, just doing exactly what it says on the tin. 🔥

just a reminder that err is meant to be a negative errno — the manpage says negative and we're not gonna argue with it. 👑

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🌈 SEE ALSO 🌈

Kernel file ./drivers/xen/xenbus/xenbus_client.c, plus all these besties:

• xenbus_watch_path(9)
• xenbus_watch_pathfmt(9)
• xenbus_switch_state(9)
• xenbus_dev_fatal(9)
• xenbus_map_ring_valloc(9)
• xenbus_unmap_ring(9)
• xenbus_unmap_ring_vfree(9)
• xenbus_read_driver_state(9)

go read them, iykyk 💜

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and that's the page, bestie 🎀 this came out of ./drivers/xen/xenbus, dated October 2026, and it's xenbus_dev_error(9) from the Kernel API Manual — mwah, slay, periodt. 💅✨