Commit 
501db511397f ("virtio: don't set VIRTIO_NET_HDR_F_DATA_VALID on
xmit") in fact disables VIRTIO_HDR_F_DATA_VALID on receiving path too,
fixing this by adding a hint (has_data_valid) and set it only on the
receiving path.
Cc: Rolf Neugebauer <rolf.neugebauer@docker.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Rolf Neugebauer <rolf.neugebauer@docker.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 
                        return -EINVAL;
 
                if (virtio_net_hdr_from_skb(skb, &vnet_hdr,
-                                           macvtap_is_little_endian(q)))
+                                           macvtap_is_little_endian(q), true))
                        BUG();
 
                if (copy_to_iter(&vnet_hdr, sizeof(vnet_hdr), iter) !=
 
                        return -EINVAL;
 
                if (virtio_net_hdr_from_skb(skb, &gso,
-                                           tun_is_little_endian(tun))) {
+                                           tun_is_little_endian(tun), true)) {
                        struct skb_shared_info *sinfo = skb_shinfo(skb);
                        pr_err("unexpected GSO type: "
                               "0x%x, gso_size %d, hdr_len %d\n",
 
                hdr = skb_vnet_hdr(skb);
 
        if (virtio_net_hdr_from_skb(skb, &hdr->hdr,
-                                   virtio_is_little_endian(vi->vdev)))
+                                   virtio_is_little_endian(vi->vdev), false))
                BUG();
 
        if (vi->mergeable_rx_bufs)
 
 
 static inline int virtio_net_hdr_from_skb(const struct sk_buff *skb,
                                          struct virtio_net_hdr *hdr,
-                                         bool little_endian)
+                                         bool little_endian,
+                                         bool has_data_valid)
 {
        memset(hdr, 0, sizeof(*hdr));   /* no info leak */
 
                                skb_checksum_start_offset(skb));
                hdr->csum_offset = __cpu_to_virtio16(little_endian,
                                skb->csum_offset);
+       } else if (has_data_valid &&
+                  skb->ip_summed == CHECKSUM_UNNECESSARY) {
+               hdr->flags = VIRTIO_NET_HDR_F_DATA_VALID;
        } /* else everything is zero */
 
        return 0;
 
                return -EINVAL;
        *len -= sizeof(vnet_hdr);
 
-       if (virtio_net_hdr_from_skb(skb, &vnet_hdr, vio_le()))
+       if (virtio_net_hdr_from_skb(skb, &vnet_hdr, vio_le(), true))
                return -EINVAL;
 
        return memcpy_to_msg(msg, (void *)&vnet_hdr, sizeof(vnet_hdr));
        if (po->has_vnet_hdr) {
                if (virtio_net_hdr_from_skb(skb, h.raw + macoff -
                                            sizeof(struct virtio_net_hdr),
-                                           vio_le())) {
+                                           vio_le(), true)) {
                        spin_lock(&sk->sk_receive_queue.lock);
                        goto drop_n_account;
                }