From: Olivier Matz <olivier.matz@6wind.com>
Date: Thu, 13 Oct 2016 14:16:11 +0000 (+0200)
Subject: net/virtio: support TSO
X-Git-Tag: spdx-start~5606
X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=696573046e9e;p=dpdk.git

net/virtio: support TSO

Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
Acked-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
---

diff --git a/doc/guides/rel_notes/release_16_11.rst b/doc/guides/rel_notes/release_16_11.rst
index decf57b834..26cdd62587 100644
--- a/doc/guides/rel_notes/release_16_11.rst
+++ b/doc/guides/rel_notes/release_16_11.rst
@@ -87,6 +87,7 @@ New Features
 
   * Rx/Tx checksums
   * LRO
+  * TSO
 
 * **Added virtio NEON support for ARM.**
 
diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
index 157e44cd75..e6cd671e9b 100644
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -1593,6 +1593,7 @@ virtio_dev_link_update(struct rte_eth_dev *dev, __rte_unused int wait_to_complet
 static void
 virtio_dev_info_get(struct rte_eth_dev *dev, struct rte_eth_dev_info *dev_info)
 {
+	uint64_t tso_mask;
 	struct virtio_hw *hw = dev->data->dev_private;
 
 	if (dev->pci_dev)
@@ -1620,6 +1621,11 @@ virtio_dev_info_get(struct rte_eth_dev *dev, struct rte_eth_dev_info *dev_info)
 			DEV_TX_OFFLOAD_UDP_CKSUM |
 			DEV_TX_OFFLOAD_TCP_CKSUM;
 	}
+
+	tso_mask = (1ULL << VIRTIO_NET_F_HOST_TSO4) |
+		(1ULL << VIRTIO_NET_F_HOST_TSO6);
+	if ((hw->guest_features & tso_mask) == tso_mask)
+		dev_info->tx_offload_capa |= DEV_TX_OFFLOAD_TCP_TSO;
 }
 
 /*
diff --git a/drivers/net/virtio/virtio_ethdev.h b/drivers/net/virtio/virtio_ethdev.h
index cf8ee68730..de33b32042 100644
--- a/drivers/net/virtio/virtio_ethdev.h
+++ b/drivers/net/virtio/virtio_ethdev.h
@@ -63,6 +63,8 @@
 	 1u << VIRTIO_NET_F_CTRL_RX	  |	\
 	 1u << VIRTIO_NET_F_CTRL_VLAN	  |	\
 	 1u << VIRTIO_NET_F_CSUM	  |	\
+	 1u << VIRTIO_NET_F_HOST_TSO4	  |	\
+	 1u << VIRTIO_NET_F_HOST_TSO6	  |	\
 	 1u << VIRTIO_NET_F_MRG_RXBUF	  |	\
 	 1u << VIRTIO_RING_F_INDIRECT_DESC |    \
 	 1ULL << VIRTIO_F_VERSION_1       |	\
diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
index 0fa635a624..b4c4aa4722 100644
--- a/drivers/net/virtio/virtio_rxtx.c
+++ b/drivers/net/virtio/virtio_rxtx.c
@@ -209,10 +209,53 @@ virtqueue_enqueue_recv_refill(struct virtqueue *vq, struct rte_mbuf *cookie)
 	return 0;
 }
 
+/* When doing TSO, the IP length is not included in the pseudo header
+ * checksum of the packet given to the PMD, but for virtio it is
+ * expected.
+ */
+static void
+virtio_tso_fix_cksum(struct rte_mbuf *m)
+{
+	/* common case: header is not fragmented */
+	if (likely(rte_pktmbuf_data_len(m) >= m->l2_len + m->l3_len +
+			m->l4_len)) {
+		struct ipv4_hdr *iph;
+		struct ipv6_hdr *ip6h;
+		struct tcp_hdr *th;
+		uint16_t prev_cksum, new_cksum, ip_len, ip_paylen;
+		uint32_t tmp;
+
+		iph = rte_pktmbuf_mtod_offset(m, struct ipv4_hdr *, m->l2_len);
+		th = RTE_PTR_ADD(iph, m->l3_len);
+		if ((iph->version_ihl >> 4) == 4) {
+			iph->hdr_checksum = 0;
+			iph->hdr_checksum = rte_ipv4_cksum(iph);
+			ip_len = iph->total_length;
+			ip_paylen = rte_cpu_to_be_16(rte_be_to_cpu_16(ip_len) -
+				m->l3_len);
+		} else {
+			ip6h = (struct ipv6_hdr *)iph;
+			ip_paylen = ip6h->payload_len;
+		}
+
+		/* calculate the new phdr checksum not including ip_paylen */
+		prev_cksum = th->cksum;
+		tmp = prev_cksum;
+		tmp += ip_paylen;
+		tmp = (tmp & 0xffff) + (tmp >> 16);
+		new_cksum = tmp;
+
+		/* replace it in the packet */
+		th->cksum = new_cksum;
+	}
+}
+
 static inline int
 tx_offload_enabled(struct virtio_hw *hw)
 {
-	return vtpci_with_feature(hw, VIRTIO_NET_F_CSUM);
+	return vtpci_with_feature(hw, VIRTIO_NET_F_CSUM) ||
+		vtpci_with_feature(hw, VIRTIO_NET_F_HOST_TSO4) ||
+		vtpci_with_feature(hw, VIRTIO_NET_F_HOST_TSO6);
 }
 
 static inline void
@@ -274,8 +317,11 @@ virtqueue_enqueue_xmit(struct virtnet_tx *txvq, struct rte_mbuf *cookie,
 		idx = start_dp[idx].next;
 	}
 
+	/* Checksum Offload / TSO */
 	if (offload) {
-		/* Checksum Offload */
+		if (cookie->ol_flags & PKT_TX_TCP_SEG)
+			cookie->ol_flags |= PKT_TX_TCP_CKSUM;
+
 		switch (cookie->ol_flags & PKT_TX_L4_MASK) {
 		case PKT_TX_UDP_CKSUM:
 			hdr->csum_start = cookie->l2_len + cookie->l3_len;
@@ -297,9 +343,22 @@ virtqueue_enqueue_xmit(struct virtnet_tx *txvq, struct rte_mbuf *cookie,
 			break;
 		}
 
-		hdr->gso_type = 0;
-		hdr->gso_size = 0;
-		hdr->hdr_len = 0;
+		/* TCP Segmentation Offload */
+		if (cookie->ol_flags & PKT_TX_TCP_SEG) {
+			virtio_tso_fix_cksum(cookie);
+			hdr->gso_type = (cookie->ol_flags & PKT_TX_IPV6) ?
+				VIRTIO_NET_HDR_GSO_TCPV6 :
+				VIRTIO_NET_HDR_GSO_TCPV4;
+			hdr->gso_size = cookie->tso_segsz;
+			hdr->hdr_len =
+				cookie->l2_len +
+				cookie->l3_len +
+				cookie->l4_len;
+		} else {
+			hdr->gso_type = 0;
+			hdr->gso_size = 0;
+			hdr->hdr_len = 0;
+		}
 	}
 
 	do {