4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jason Wang <jasowang@xxxxxxxxxx>
[ Upstream commit 1bb4f2e868a2891ab8bc668b8173d6ccb8c4ce6f ]
We don't flush batched XDP packets through xdp_do_flush_map(), this
will cause packets stall at TX queue. Consider we don't do XDP on NAPI
poll(), the only possible fix is to call xdp_do_flush_map()
immediately after xdp_do_redirect().
Note, this in fact won't try to batch packets through devmap, we could
address in the future.
Reported-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
Fixes: 761876c857cb ("tap: XDP support")
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/tun.c | 1 +
1 file changed, 1 insertion(+)
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1333,6 +1333,7 @@ static struct sk_buff *tun_build_skb(str
get_page(alloc_frag->page);
alloc_frag->offset += buflen;
err = xdp_do_redirect(tun->dev, &xdp, xdp_prog);
+ xdp_do_flush_map();
if (err)
goto err_redirect;
rcu_read_unlock();