xlcpupool.cfg(5)

🎀 NAME 🎀

xlcpupool.cfg — the XL Cpupool Configuration File Syntax, bestie. That's the whole vibe.

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✨ SYNOPSIS ✨

/etc/xen/xlcpupool

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💖 DESCRIPTION 💖

Okay so real talk: to create a Cpupool with xl you literally need to hand it a cpupool config file. No config, no cpupool, no cap. 💅

And where do these little guys live? Typically in /etc/xen/CPUPOOL.cfg — where CPUPOOL is the name of the cpupool. Like, the actual name. So a pool called banana gets /etc/xen/banana.cfg. Iconic. 🍓

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🌸 SYNTAX 🌸

A cpupool config file is just a series of KEY=VALUE pairs. That's it. That's the whole format, slay. ✨

A value VALUE is one of these three things:

• "STRING" — a string, surrounded by either single or double quotes. Pick your fighter. 🙈
• NUMBER — a number, in either decimal, octal (using a 0 prefix) or hexadecimal (using an 0x prefix). Yes bestie, all three bases are invited to the party.
• [ VALUE, VALUE, ... ] — a list of VALUES of the above types. Heads up though: lists are homogeneous and are not nested. So no list-inception, no mixing types. The vibes must be consistent. 💀

The semantics of each KEY define which form of VALUE is required. So like, the key tells you what shape of value it wants. Iykyk. 🦋

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👑 OPTIONS 👑

💜 Mandatory Configuration Items 💜

The following key is mandatory for any cpupool. Like, non-negotiable. You will be providing this:

• name="NAME" — Specifies the name of the cpupool. Names of cpupools existing on a single host must be unique — no twinsies allowed, bestie. 👯‍♀️

🌈 Optional Configuration Items 🌈

The following options apply to guests of any type.

• sched="SCHED" — Specifies the scheduler which is used for the cpupool. Valid values for SCHED are:
  • credit — the credit scheduler
  • credit2 — the credit2 scheduler
  • rtds — the RTDS scheduler

The default scheduler is the one used for Pool-0 specified as boot parameter of the hypervisor. So if you don't pick, you're getting Pool-0's choice. Main character energy by default. 👑

• nodes="NODES" — Specifies the cpus of the NUMA-nodes given in NODES (an integer or a list of integers) to be member of the cpupool. The free cpus in the specified nodes are allocated in the new cpupool. So it's like, "give me these nodes' free cpus, thanks." 🫶
• cpus="CPU-LIST" — Specifies the cpus that will be member of the cpupool. All the specified cpus must be free, or creation will fail. Yes, it will straight up fail. No negotiation. 😭 CPU-LIST may be specified as follows:
  • ["2", "3", "5"] — means that cpus 2,3,5 will be member of the cpupool.
  • "0-3,5,^1" — means that cpus 0,2,3 and 5 will be member of the cpupool. A node: or nodes: modifier can be used. E.g., "0,node:1,nodes:2-3,^10-13" means that pcpus 0, plus all the cpus of NUMA nodes 1,2,3 with the exception of cpus 10,11,12,13 will be members of the cpupool.

If neither nodes nor cpus are specified, only the first free cpu found will be allocated in the new cpupool. Lowkey humble of it. 🧚

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🦋 FILES 🦋

• /etc/xen/CPUPOOL.cfg

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💀 BUGS 💀

Okay so full transparency: this document is a work in progress and contains items which require further documentation and which are generally incomplete (marked with XXX). So when you see an XXX, that's the doc being like "yeah I know, I know." 🙈

However — and this is the important bit — all options are included here whether or not they are fully documented. So nothing's hiding from you, bestie. 💅

Patches to improve incomplete items (or any other item) would be gratefully received on the xen-devel@lists.xenproject.org mailing list. Like, they would love that. Please see <https://wiki.xenproject.org/wiki/Submitting_Xen_Project_Patches> for information on how to submit a patch to Xen. Go be the change you want to see in the manpage. ⭐

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Later, bestie — this was xlcpupool.cfg(5) from Xen, version 4.20.5-pre, dated 2026-10-16. Mwah 💋