Can't launch SEV-SNP geust (SNP_LAUNCH_START ret=-25 fw_error=0)

[ksy980324]

I can't launch SEV-SNP guest.
It seems that a problem occurred while changing the version.
The following error occurs:

qemu-system-x86_64: sev_snp_launch_start: SNP_LAUNCH_START ret=-25 fw_error=0 ''
qemu-system-x86_64: sev_kvm_init: failed to create encryption context
qemu-system-x86_64: failed to initialize kvm: Operation not permitted

What should I do?

[tlendacky]

Did you change the version of both Qemu and the host kernel? You must keep these in lock-step.