MACH2PHYS_VIRT_START  104 arch/x86/include/asm/xen/interface.h #define MACH2PHYS_NR_ENTRIES  ((MACH2PHYS_VIRT_END-MACH2PHYS_VIRT_START)>>__MACH2PHYS_SHIFT)
MACH2PHYS_VIRT_START   57 arch/x86/xen/enlighten.c unsigned long *machine_to_phys_mapping = (void *)MACH2PHYS_VIRT_START;