iopt_pages_fill_xarray(9)

📦 version 7.3.1, in nixpkgs unstable

✨ iopt_pages_fill_xarray(9) — a Kernel API Manual moment ✨

okay SO bestie, we're diving into iopt_pages_fill_xarray from the Kernel API Manual (iopt_pages_fill_xarray(9), that's the whole page name, slay). Buckle up, it's giving kernel-internals realness 💅

🌸 NAME 🌸

iopt_pages_fill_xarray — literally just "Read PFNs" 🫶 that's the whole vibe.

🦋 SYNOPSIS 🦋

int iopt_pages_fill_xarray (struct iopt_pages *pages , unsigned long
start_index , unsigned long last_index , struct page **out_pages );

no cap, that's the exact signature, don't come for me about the line breaks 💀

🎀 ARGUMENTS 🎀

  • pages — the pages we're acting on. the main characters, honestly 👑
  • start_index — the first page index in the range. where the party starts 🎉
  • last_index — the last page index in the range. where it ends, periodt.
  • out_pages — the output array that the pages get returned in. heads up: it may be NULL 🙈 (yes, really, that's allowed)

💖 DESCRIPTION 💖

So what does this actually do? It populates the xarray and returns the pages in out_pages. Simple enough, right?

But here's the tea ☕ — as the slow path, this one is able to copy pages from other storage tiers into the xarray. like, it'll go fetch them from elsewhere if it has to. highkey dedicated 🔥

⚠️ Important caveat bestie: on failure the xarray is left unchanged. So if it doesn't work out, nothing gets messed up. no messy breakups, we keep it clean 💀✨

And for context, this is part of the SW iommu interface to read pages for in-kernel use. iykyk 🧚

🌈 SEE ALSO 🌈

Kernel file ./drivers/iommu/iommufd/pages.c — and also go check out these iconic functions, they're all in the same friend group:

and that's the whole page, bestie, go read some PFNs 🍓

source: ./drivers/iommu/iommufd · dated October 2026 · iopt_pages_fill_xarray(9) — mwah, thanks for reading, ily, bye! 💜🦋✨

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