1*136799e5SShubham Chakraborty=============== 2*136799e5SShubham Chakraborty/proc/sys/xen/ 3*136799e5SShubham Chakraborty=============== 4*136799e5SShubham Chakraborty 5*136799e5SShubham ChakrabortyCopyright (c) 2026, Shubham Chakraborty <chakrabortyshubham66@gmail.com> 6*136799e5SShubham Chakraborty 7*136799e5SShubham ChakrabortyFor general info and legal blurb, please look in 8*136799e5SShubham ChakrabortyDocumentation/admin-guide/sysctl/index.rst. 9*136799e5SShubham Chakraborty 10*136799e5SShubham Chakraborty------------------------------------------------------------------------------ 11*136799e5SShubham Chakraborty 12*136799e5SShubham ChakrabortyThese files show up in ``/proc/sys/xen/``, depending on the 13*136799e5SShubham Chakrabortykernel configuration: 14*136799e5SShubham Chakraborty 15*136799e5SShubham Chakraborty.. contents:: :local: 16*136799e5SShubham Chakraborty 17*136799e5SShubham Chakrabortyballoon/hotplug_unpopulated 18*136799e5SShubham Chakraborty=========================== 19*136799e5SShubham Chakraborty 20*136799e5SShubham ChakrabortyThis flag controls whether unpopulated memory ranges are automatically 21*136799e5SShubham Chakrabortyhotplugged as system RAM. 22*136799e5SShubham Chakraborty 23*136799e5SShubham Chakraborty- ``0``: Unpopulated ranges are not hotplugged (default). 24*136799e5SShubham Chakraborty- ``1``: Unpopulated ranges are automatically hotplugged. 25*136799e5SShubham Chakraborty 26*136799e5SShubham ChakrabortyWhen enabled, the Xen balloon driver will add memory regions that are 27*136799e5SShubham Chakrabortymarked as unpopulated in the Xen memory map to the system as usable RAM. 28*136799e5SShubham ChakrabortyThis allows for dynamic memory expansion in Xen guest domains. 29*136799e5SShubham Chakraborty 30*136799e5SShubham ChakrabortyThis option is only available when the kernel is built with 31*136799e5SShubham Chakraborty``CONFIG_XEN_BALLOON_MEMORY_HOTPLUG`` enabled. 32