CONFIG_IA64_SGI_SN_XP is not available for thedefaultarchitecture x86.
Result is shown for architecture ia64
default or selected kernelversion does not have config value CONFIG_IA64_SGI_SN_XP.
Result is shown for kernelversion 5.4.123

Support communication between SGI SSIs

modulename: xp.ko

and/or

xpc.ko

and/or

xpnet.ko

configname: CONFIG_IA64_SGI_SN_XP

IA-64 Linux Kernel Configuration
└─>Processor type and features
└─>Support communication between SGI SSIs
In linux kernel since version 2.6.12  
An SGI machine can be divided into multiple Single System
Images which act independently of each other and have
hardware based memory protection from the others. Enabling
this feature will allow for direct communication between SSIs
based on a network adapter and DMA messaging.

source code:
depends
CONFIG_MSPEC