[dpdk-dev] [PATCH v3 12/12] net/virtio: add Tso support

Olivier Matz olivier.matz at 6wind.com
Thu Oct 13 16:16:11 CEST 2016


Signed-off-by: Olivier Matz <olivier.matz at 6wind.com>
---
 drivers/net/virtio/virtio_ethdev.c |   6 ++
 drivers/net/virtio/virtio_ethdev.h |   2 +
 drivers/net/virtio/virtio_rxtx.c   | 133 +++++++++++++++++++++++++++++++++++--
 3 files changed, 136 insertions(+), 5 deletions(-)

diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
index 109f855..969edb6 100644
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -1572,6 +1572,7 @@ 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)
@@ -1599,6 +1600,11 @@ 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 d55e7ed..f77f618 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 0fa635a..4b01ea3 100644
--- a/drivers/net/virtio/virtio_rxtx.c
+++ b/drivers/net/virtio/virtio_rxtx.c
@@ -209,10 +209,117 @@ 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;
+	} else {
+		const struct ipv4_hdr *iph;
+		struct ipv4_hdr iph_copy;
+		union {
+			uint16_t u16;
+			uint8_t u8[2];
+		} prev_cksum, new_cksum, ip_len, ip_paylen, ip_csum;
+		uint32_t tmp;
+
+		/* Same code than above, but we use rte_pktmbuf_read()
+		 * or we read/write in mbuf data one byte at a time to
+		 * avoid issues if the packet is multi segmented.
+		 */
+
+		uint8_t ip_version;
+
+		ip_version = *rte_pktmbuf_mtod_offset(m, uint8_t *,
+			m->l2_len) >> 4;
+
+		/* calculate ip checksum (API imposes to set it to 0)
+		 * and get ip payload len */
+		if (ip_version == 4) {
+			*rte_pktmbuf_mtod_offset(m, uint8_t *,
+				m->l2_len + 10) = 0;
+			*rte_pktmbuf_mtod_offset(m, uint8_t *,
+				m->l2_len + 11) = 0;
+			iph = rte_pktmbuf_read(m, m->l2_len,
+				sizeof(*iph), &iph_copy);
+			ip_csum.u16 = rte_ipv4_cksum(iph);
+			*rte_pktmbuf_mtod_offset(m, uint8_t *,
+				m->l2_len + 10) = ip_csum.u8[0];
+			*rte_pktmbuf_mtod_offset(m, uint8_t *,
+				m->l2_len + 11) = ip_csum.u8[1];
+
+			ip_len.u8[0] = *rte_pktmbuf_mtod_offset(m, uint8_t *,
+				m->l2_len + 2);
+			ip_len.u8[1] = *rte_pktmbuf_mtod_offset(m, uint8_t *,
+				m->l2_len + 3);
+
+			ip_paylen.u16 = rte_cpu_to_be_16(
+				rte_be_to_cpu_16(ip_len.u16) - m->l3_len);
+		} else {
+			ip_paylen.u8[0] = *rte_pktmbuf_mtod_offset(m, uint8_t *,
+				m->l2_len + 4);
+			ip_paylen.u8[1] = *rte_pktmbuf_mtod_offset(m, uint8_t *,
+				m->l2_len + 5);
+		}
+
+		/* calculate the new phdr checksum not including ip_paylen */
+		/* get phdr cksum at offset 16 of TCP header */
+		prev_cksum.u8[0] = *rte_pktmbuf_mtod_offset(m, uint8_t *,
+			m->l2_len + m->l3_len + 16);
+		prev_cksum.u8[1] = *rte_pktmbuf_mtod_offset(m, uint8_t *,
+			m->l2_len + m->l3_len + 17);
+		tmp = prev_cksum.u16;
+		tmp += ip_paylen.u16;
+		tmp = (tmp & 0xffff) + (tmp >> 16);
+		new_cksum.u16 = tmp;
+
+		/* replace it in the packet */
+		*rte_pktmbuf_mtod_offset(m, uint8_t *,
+			m->l2_len + m->l3_len + 16) = new_cksum.u8[0];
+		*rte_pktmbuf_mtod_offset(m, uint8_t *,
+			m->l2_len + m->l3_len + 17) = new_cksum.u8[1];
+	}
+}
+
 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 +381,11 @@ 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 +407,22 @@ 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 {
-- 
2.8.1



More information about the dev mailing list