xref: /linux/Documentation/admin-guide/sysctl/xen.rst (revision 5181afcdf99527dd92a88f80fc4d0d8013e1b510)
1===============
2/proc/sys/xen/
3===============
4
5Copyright (c) 2026, Shubham Chakraborty <chakrabortyshubham66@gmail.com>
6
7For general info and legal blurb, please look in
8Documentation/admin-guide/sysctl/index.rst.
9
10------------------------------------------------------------------------------
11
12These files show up in ``/proc/sys/xen/``, depending on the
13kernel configuration:
14
15.. contents:: :local:
16
17balloon/hotplug_unpopulated
18===========================
19
20This flag controls whether unpopulated memory ranges are automatically
21hotplugged as system RAM.
22
23- ``0``: Unpopulated ranges are not hotplugged (default).
24- ``1``: Unpopulated ranges are automatically hotplugged.
25
26When enabled, the Xen balloon driver will add memory regions that are
27marked as unpopulated in the Xen memory map to the system as usable RAM.
28This allows for dynamic memory expansion in Xen guest domains.
29
30This option is only available when the kernel is built with
31``CONFIG_XEN_BALLOON_MEMORY_HOTPLUG`` enabled.
32