Linux Virtualization - May 2020 - [PATCH AUTOSEL 5.6 13/62] vhost/vsock: fix packet delivery order to monitoring devices

From: Stefano Garzarella <sgarzare at redhat.com>

[ Upstream commit 107bc0766b9feb5113074c753735a3f115c2141f ]

We want to deliver packets to monitoring devices before it is
put in the virtqueue, to avoid that replies can appear in the
packet capture before the transmitted packet.

Signed-off-by: Stefano Garzarella <sgarzare at redhat.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Sasha Levin <sashal at kernel.org>
---
 drivers/vhost/vsock.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index bb3f63386b475..53294c2f8cff4 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -181,14 +181,14 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
 			break;
 		}
 
-		vhost_add_used(vq, head, sizeof(pkt->hdr) + payload_len);
-		added = true;
-
-		/* Deliver to monitoring devices all correctly transmitted
-		 * packets.
+		/* Deliver to monitoring devices all packets that we
+		 * will transmit.
 		 */
 		virtio_transport_deliver_tap_pkt(pkt);
 
+		vhost_add_used(vq, head, sizeof(pkt->hdr) + payload_len);
+		added = true;
+
 		pkt->off += payload_len;
 		total_len += payload_len;
 
-- 
2.20.1