KVM: x86: smm: number of GPRs in the SMRAM image depends on the image format
In the Linux kernel, the following vulnerability has been resolved:

KVM: x86: smm: number of GPRs in the SMRAM image depends on the image format

On 64 bit host, if the guest doesn't have X86_FEATURE_LM, KVM will
access 16 gprs to 32-bit smram image, causing out-ouf-bound ram
access.

On 32 bit host, the rsm_load_state_64/enter_smm_save_state_64
is compiled out, thus access overflow can't happen.