XENFB_IN_RING_SIZE   93 include/xen/interface/io/fbif.h #define XENFB_IN_RING_LEN (XENFB_IN_RING_SIZE / XENFB_IN_EVENT_SIZE)
XENFB_IN_RING_SIZE  102 include/xen/interface/io/fbif.h #define XENFB_OUT_RING_OFFS (XENFB_IN_RING_OFFS + XENFB_IN_RING_SIZE)