IDENTITY_FRAME_BIT 36 arch/x86/include/asm/xen/page.h #define IDENTITY_FRAME(m) ((m) | IDENTITY_FRAME_BIT) IDENTITY_FRAME_BIT 76 arch/x86/include/asm/xen/page.h mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT);