virtqueue_enable_cb_prepare(9)

📦 version 7.3.1, in nixpkgs unstable

💖 virtqueue_enable_cb_prepare — the Kernel API Manual era 💖

okay so bestie, this one's from the Kernel API Manual, section 9, and it's literally called virtqueue_enable_cb_prepare. it's giving "the comeback kid" energy fr fr — we're turning callbacks back on after disable_cb had them in timeout. 🔥

✨ SYNOPSIS ✨

unsigned int virtqueue_enable_cb_prepare (struct virtqueue *_vq );

that's it, that's the whole vibe check. one arg, one unsigned int out. 🎀

🌸 ARGUMENTS 🌸

  • _vq — the struct virtqueue we're talking about. yes, the actual one, not a lookalike. this is the main character. 👑

🦋 DESCRIPTION 🦋

so basically this re-enables callbacks — like un-muting the group chat after you silenced it. 🔔 and it returns the current queue state in an opaque unsigned value. opaque means don't go poking at it and assuming stuff, it's not for you to read, it's for you to hand back later. 🙈

you're supposed to test that value later with virtqueue_poll, and the whole point is to catch a possible race between the driver checking for more work and enabling callbacks. it's giving "did something slip through while I was looking away" energy, and this is how you find out. ⭐

⚠️ important caveat, no cap: the caller must ensure we don't call this at the same time as other virtqueue operations (except where noted). so like, don't multitask on the same virtqueue, bestie. that's a situation. 💀

💜 SEE ALSO 💜

kernel file ./drivers/virtio/virtio_ring.c, plus the whole friend group:

mwah 💋 that's the page! live from ./drivers/virtio, dated October 2026, and brought to you by the Kernel API Manual, section 9 — virtqueue_enable_cb_prepare(9), obviously. slay, go enable those callbacks responsibly. 🫶🌈

📦 where this page comes from