From: Jesper Dangaard Brouer <brouer@redhat.com>
Date: Thu, 31 May 2018 11:00:08 +0200
Subject: virtio_net: implement flush flag for ndo_xdp_xmit
Patch-mainline: v4.18-rc1
Git-commit: 5d274cb4bbae481161737a1f652e276883d3d970
References: bsc#1109837

When passed the XDP_XMIT_FLUSH flag virtnet_xdp_xmit now performs the
same virtqueue_kick as virtnet_xdp_flush.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/virtio_net.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -487,7 +487,7 @@ static int virtnet_xdp_xmit(struct net_d
 	int err;
 	int i;
 
-	if (unlikely(flags & ~XDP_XMIT_FLAGS_NONE))
+	if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
 		return -EINVAL;
 
 	qp = vi->curr_queue_pairs - vi->xdp_queue_pairs + smp_processor_id();
@@ -513,6 +513,10 @@ static int virtnet_xdp_xmit(struct net_d
 			drops++;
 		}
 	}
+
+	if (flags & XDP_XMIT_FLUSH)
+		virtqueue_kick(sq->vq);
+
 	return n - drops;
 }