+#define MAX_PKT_BURST 32
+
+#define VHOST_MAX_ASYNC_IT (MAX_PKT_BURST * 2)
+#define VHOST_MAX_ASYNC_VEC (BUF_VECTOR_MAX * 4)
+
+#define PACKED_DESC_ENQUEUE_USED_FLAG(w) \
+ ((w) ? (VRING_DESC_F_AVAIL | VRING_DESC_F_USED | VRING_DESC_F_WRITE) : \
+ VRING_DESC_F_WRITE)
+#define PACKED_DESC_DEQUEUE_USED_FLAG(w) \
+ ((w) ? (VRING_DESC_F_AVAIL | VRING_DESC_F_USED) : 0x0)
+#define PACKED_DESC_SINGLE_DEQUEUE_FLAG (VRING_DESC_F_NEXT | \
+ VRING_DESC_F_INDIRECT)
+
+#define PACKED_BATCH_SIZE (RTE_CACHE_LINE_SIZE / \
+ sizeof(struct vring_packed_desc))
+#define PACKED_BATCH_MASK (PACKED_BATCH_SIZE - 1)
+
+#ifdef VHOST_GCC_UNROLL_PRAGMA
+#define vhost_for_each_try_unroll(iter, val, size) _Pragma("GCC unroll 4") \
+ for (iter = val; iter < size; iter++)
+#endif
+
+#ifdef VHOST_CLANG_UNROLL_PRAGMA
+#define vhost_for_each_try_unroll(iter, val, size) _Pragma("unroll 4") \
+ for (iter = val; iter < size; iter++)
+#endif
+
+#ifdef VHOST_ICC_UNROLL_PRAGMA
+#define vhost_for_each_try_unroll(iter, val, size) _Pragma("unroll (4)") \
+ for (iter = val; iter < size; iter++)
+#endif
+
+#ifndef vhost_for_each_try_unroll
+#define vhost_for_each_try_unroll(iter, val, num) \
+ for (iter = val; iter < num; iter++)
+#endif
+