sev_register_encryption
sev_register_encryption(GDT_PAGE, PAGE_SIZE);
sev_register_encryption(BOOTARGS_PAGE, PAGE_SIZE);
sev_register_encryption(STACK_PAGE, PAGE_SIZE);
sev_register_encryption(addr, sz);
sev_register_encryption(addr, sz);
sev_register_encryption(addr, sz);
sev_register_encryption(dst, sz);
int sev_register_encryption(vaddr_t, size_t);