default or selected kernelversion does not have config value CONFIG_SEV_GUEST.
Result is shown for kernelversion 6.9-rc1

AMD SEV Guest driver

modulename: sev-guest.ko

configname: CONFIG_SEV_GUEST

Linux Kernel Configuration
└─>Device Drivers
└─>Virtualization drivers
└─>AMD SEV Guest driver
In linux kernel since version 4.14.326 (release Date: 2023-09-23)  
SEV-SNP firmware provides the guest a mechanism to communicate with
the PSP without risk from a malicious hypervisor who wishes to read,
alter, drop or replay the messages sent. The driver provides
userspace interface to communicate with the PSP to request the
attestation report and more.

If you choose 'M' here, this module will be called sev-guest.

source code: