CONFIG_SIBYTE_ENABLE_LDT_IF_PCI is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

CONFIG_SIBYTE_ENABLE_LDT_IF_PCI (not configurable)

configname: CONFIG_SIBYTE_ENABLE_LDT_IF_PCI

Linux Kernel Configuration
└─>SIBYTE_ENABLE_LDT_IF_PCI
In linux kernel since version 2.6.21 (release Date: 2007-04-25)