System Management Mode emulation

configname: CONFIG_KVM_SMM

Linux Kernel Configuration
└─>Virtualization
└─>System Management Mode emulation
In linux kernel since version 6.2 (release Date: 2023-02-19)  
Provides support for KVM to emulate System Management Mode (SMM)
in virtual machines. This can be used by the virtual machine
firmware to implement UEFI secure boot.

If unsure, say Y.