Merge branch 'XDP-transmission-for-tuntap'

Jason Wang says:

====================
XDP transmission for tuntap

This series tries to implement XDP transmission (ndo_xdp_xmit) for
tuntap. Pointer ring was used for queuing both XDP buffers and
sk_buff, this is done by encoding the type into lowest bit of the
pointer and storin XDP metadata in the headroom of XDP buff.

Tests gets 3.05 Mpps when doing xdp_redirect_map from ixgbe to VM
(testpmd + virtio-net in guest). This gives us ~20% improvments
compared to use skb during redirect.

Please review.

Changes from V1:

- slient warnings
- fix typos
- add skb mode number in the commit log
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 22 insertions, 5 deletions

diff --git a/include/linux/if_tap.h b/include/linux/if_tap.h
index 3ecef57c31e3..8e66866c11be 100644
--- a/include/linux/if_tap.h
+++ b/include/linux/if_tap.h
@@ -4,7 +4,7 @@
 
 #if IS_ENABLED(CONFIG_TAP)
 struct socket *tap_get_socket(struct file *);
-struct skb_array *tap_get_skb_array(struct file *file);
+struct ptr_ring *tap_get_ptr_ring(struct file *file);
 #else
 #include <linux/err.h>
 #include <linux/errno.h>
@@ -14,7 +14,7 @@ static inline struct socket *tap_get_socket(struct file *f)
 {
 	return ERR_PTR(-EINVAL);
 }
-static inline struct skb_array *tap_get_skb_array(struct file *f)
+static inline struct ptr_ring *tap_get_ptr_ring(struct file *f)
 {
 	return ERR_PTR(-EINVAL);
 }
@@ -70,7 +70,7 @@ struct tap_queue {
 	u16 queue_index;
 	bool enabled;
 	struct list_head next;
-	struct skb_array skb_array;
+	struct ptr_ring ring;
 };
 
 rx_handler_result_t tap_handle_frame(struct sk_buff **pskb);
diff --git a/include/linux/if_tun.h b/include/linux/if_tun.h
index bf9bdf42d577..08e66827ad8e 100644
--- a/include/linux/if_tun.h
+++ b/include/linux/if_tun.h
@@ -17,9 +17,14 @@
 
 #include <uapi/linux/if_tun.h>
 
+#define TUN_XDP_FLAG 0x1UL
+
 #if defined(CONFIG_TUN) || defined(CONFIG_TUN_MODULE)
 struct socket *tun_get_socket(struct file *);
-struct skb_array *tun_get_skb_array(struct file *file);
+struct ptr_ring *tun_get_tx_ring(struct file *file);
+bool tun_is_xdp_buff(void *ptr);
+void *tun_xdp_to_ptr(void *ptr);
+void *tun_ptr_to_xdp(void *ptr);
 #else
 #include <linux/err.h>
 #include <linux/errno.h>
@@ -29,9 +34,21 @@ static inline struct socket *tun_get_socket(struct file *f)
 {
 	return ERR_PTR(-EINVAL);
 }
-static inline struct skb_array *tun_get_skb_array(struct file *f)
+static inline struct ptr_ring *tun_get_tx_ring(struct file *f)
 {
 	return ERR_PTR(-EINVAL);
 }
+static inline bool tun_is_xdp_buff(void *ptr)
+{
+	return false;
+}
+void *tun_xdp_to_ptr(void *ptr)
+{
+	return NULL;
+}
+void *tun_ptr_to_xdp(void *ptr)
+{
+	return NULL;
+}
 #endif /* CONFIG_TUN */
 #endif /* __IF_TUN_H */