CONFIG_ACRN_GUEST is not available for thedefaultarchitecture x86.
Result is shown for architecture 64BIT

ACRN Guest support

modulename: acrn.ko

configname: CONFIG_ACRN_GUEST

Linux Kernel Configuration
└─>Processor type and features
└─>Linux guest support
└─>ACRN Guest support
In linux kernel since version 4.14.326 (release Date: 2023-09-23)  
This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
a flexible, lightweight reference open-source hypervisor, built with
real-time and safety-criticality in mind. It is built for embedded
IOT with small footprint and real-time features. More details can be
found in https://projectacrn.org/.