FLAT_RING3_DS32    19 arch/x86/include/asm/xen/interface_64.h #define FLAT_KERNEL_DS32 FLAT_RING3_DS32
FLAT_RING3_DS32    29 arch/x86/include/asm/xen/interface_64.h #define FLAT_USER_DS32 FLAT_RING3_DS32