Use PlatformInfoHob->FeatureControlValue instead. OnMpServicesAvailable() will find PlatformInfoHob using GetFirstGuidHob() and pass a pointer to the WriteFeatureControl callback. Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Tested-by: Tom Lendacky <thomas.lendacky@amd.com> Acked-by: Ard Biesheuvel <ardb@kernel.org>