[dpdk-stable] patch 'vhost: fix IP checksum' has been queued to LTS release 16.11.3

[Yuanhan Liu]

Hi,

FYI, your patch has been queued to LTS release 16.11.3

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 07/19/17. So please
shout if anyone has objections.

Thanks.

	--yliu

---
>From a492f24ce1507c56a6ad9a605571a0ac7390c39e Mon Sep 17 00:00:00 2001
From: Jianfeng Tan <jianfeng.tan at intel.com>
Date: Wed, 7 Jun 2017 06:41:37 +0000
Subject: [PATCH] vhost: fix IP checksum

[ upstream commit b08b8cfeb2aea2a703d201ad8c4b258e8a0bde12 ]

There is no way to bypass IP checksum verification in Linux
kernel, no matter skb->ip_summed is assigned as CHECKSUM_UNNECESSARY
or CHECKSUM_PARTIAL.

So any packets with bad IP checksum will be dropped at VM IP layer.

To correct, we check this flag PKT_TX_IP_CKSUM to calculate IP csum.

Fixes: 859b480d5afd ("vhost: add guest offload setting")

Signed-off-by: Jianfeng Tan <jianfeng.tan at intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin at redhat.com>
Acked-by: Yuanhan Liu <yuanhan.liu at linux.intel.com>
---
 lib/librte_vhost/virtio_net.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
index 5d793de..7d5b04c 100644
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -169,6 +169,15 @@ virtio_enqueue_offload(struct rte_mbuf *m_buf, struct virtio_net_hdr *net_hdr)
 		}
 	}
 
+	/* IP cksum verification cannot be bypassed, then calculate here */
+	if (m_buf->ol_flags & PKT_TX_IP_CKSUM) {
+		struct ipv4_hdr *ipv4_hdr;
+
+		ipv4_hdr = rte_pktmbuf_mtod_offset(m_buf, struct ipv4_hdr *,
+						   m_buf->l2_len);
+		ipv4_hdr->hdr_checksum = rte_ipv4_cksum(ipv4_hdr);
+	}
+
 	if (m_buf->ol_flags & PKT_TX_TCP_SEG) {
 		if (m_buf->ol_flags & PKT_TX_IPV4)
 			net_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
-- 
2.7.4