[dpdk-dev] [PATCH v5 4/4] example/vhost: add virtio offload test in vhost sample

[Jijiang Liu <jijiang.liu@intel.com>]

Change the codes in vhost sample to test virtio offload feature.

These changes include,

1. add two test options: tx-csum and tso.

2. add virtio_tx_offload() function to test vhost TX offload feature for VM to NIC case; 
however, for VM to VM case, it doesn't need to call this function, the reason is explained in patch 2.
  
Signed-off-by: Jijiang Liu <jijiang.liu@intel.com>
---
 examples/vhost/main.c |  105 +++++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 102 insertions(+), 3 deletions(-)

diff --git a/examples/vhost/main.c b/examples/vhost/main.c
index 044c680..210e631 100644
--- a/examples/vhost/main.c
+++ b/examples/vhost/main.c
@@ -51,6 +51,9 @@
 #include <rte_malloc.h>
 #include <rte_virtio_net.h>
 #include <rte_ip.h>
+#include <rte_tcp.h>
+#include <rte_udp.h>
+#include <rte_sctp.h>
 
 #include "main.h"
 
@@ -198,6 +201,13 @@ typedef enum {
 static uint32_t enable_stats = 0;
 /* Enable retries on RX. */
 static uint32_t enable_retry = 1;
+
+/* Disable TX checksum offload */
+static uint32_t enable_tx_csum;
+
+/* Disable TSO offload */
+static uint32_t enable_tso;
+
 /* Specify timeout (in useconds) between retries on RX. */
 static uint32_t burst_rx_delay_time = BURST_RX_WAIT_US;
 /* Specify the number of retries on RX. */
@@ -428,6 +438,14 @@ port_init(uint8_t port)
 
 	if (port >= rte_eth_dev_count()) return -1;
 
+	if (enable_tx_csum == 0)
+		rte_vhost_feature_disable(1ULL << VIRTIO_NET_F_CSUM);
+
+	if (enable_tso == 0) {
+		rte_vhost_feature_disable(1ULL << VIRTIO_NET_F_HOST_TSO4);
+		rte_vhost_feature_disable(1ULL << VIRTIO_NET_F_HOST_TSO6);
+	}
+
 	rx_rings = (uint16_t)dev_info.max_rx_queues;
 	/* Configure ethernet device. */
 	retval = rte_eth_dev_configure(port, rx_rings, tx_rings, &port_conf);
@@ -563,7 +581,9 @@ us_vhost_usage(const char *prgname)
 	"		--rx-desc-num [0-N]: the number of descriptors on rx, "
 			"used only when zero copy is enabled.\n"
 	"		--tx-desc-num [0-N]: the number of descriptors on tx, "
-			"used only when zero copy is enabled.\n",
+			"used only when zero copy is enabled.\n"
+	"		--tx-csum [0|1] disable/enable TX checksum offload.\n"
+	"		--tso [0|1] disable/enable TCP segement offload.\n",
 	       prgname);
 }
 
@@ -589,6 +609,8 @@ us_vhost_parse_args(int argc, char **argv)
 		{"zero-copy", required_argument, NULL, 0},
 		{"rx-desc-num", required_argument, NULL, 0},
 		{"tx-desc-num", required_argument, NULL, 0},
+		{"tx-csum", required_argument, NULL, 0},
+		{"tso", required_argument, NULL, 0},
 		{NULL, 0, 0, 0},
 	};
 
@@ -643,6 +665,28 @@ us_vhost_parse_args(int argc, char **argv)
 				}
 			}
 
+			/* Enable/disable TX checksum offload. */
+			if (!strncmp(long_option[option_index].name, "tx-csum", MAX_LONG_OPT_SZ)) {
+				ret = parse_num_opt(optarg, 1);
+				if (ret == -1) {
+					RTE_LOG(INFO, VHOST_CONFIG, "Invalid argument for tx-csum [0|1]\n");
+					us_vhost_usage(prgname);
+					return -1;
+				} else
+					enable_tx_csum = ret;
+			}
+
+			/* Enable/disable TSO offload. */
+			if (!strncmp(long_option[option_index].name, "tso", MAX_LONG_OPT_SZ)) {
+				ret = parse_num_opt(optarg, 1);
+				if (ret == -1) {
+					RTE_LOG(INFO, VHOST_CONFIG, "Invalid argument for tso [0|1]\n");
+					us_vhost_usage(prgname);
+					return -1;
+				} else
+					enable_tso = ret;
+			}
+
 			/* Specify the retries delay time (in useconds) on RX. */
 			if (!strncmp(long_option[option_index].name, "rx-retry-delay", MAX_LONG_OPT_SZ)) {
 				ret = parse_num_opt(optarg, INT32_MAX);
@@ -1101,6 +1145,58 @@ find_local_dest(struct virtio_net *dev, struct rte_mbuf *m,
 	return 0;
 }
 
+static uint16_t
+get_psd_sum(void *l3_hdr, uint64_t ol_flags)
+{
+	if (ol_flags & PKT_TX_IPV4)
+		return rte_ipv4_phdr_cksum(l3_hdr, ol_flags);
+	else /* assume ethertype == ETHER_TYPE_IPv6 */
+		return rte_ipv6_phdr_cksum(l3_hdr, ol_flags);
+}
+
+static void virtio_tx_offload(struct rte_mbuf *m)
+{
+	void *l3_hdr;
+	struct ipv4_hdr *ipv4_hdr = NULL;
+	struct tcp_hdr *tcp_hdr = NULL;
+	struct udp_hdr *udp_hdr = NULL;
+	struct sctp_hdr *sctp_hdr = NULL;
+	struct ether_hdr *eth_hdr = rte_pktmbuf_mtod(m, struct ether_hdr *);
+
+	l3_hdr = (char *)eth_hdr + m->l2_len;
+
+	if (m->tso_segsz != 0) {
+		ipv4_hdr = (struct ipv4_hdr *)l3_hdr;
+		tcp_hdr = (struct tcp_hdr *)((char *)l3_hdr + m->l3_len);
+		m->ol_flags |= PKT_TX_IP_CKSUM;
+		ipv4_hdr->hdr_checksum = 0;
+		tcp_hdr->cksum = get_psd_sum(l3_hdr, m->ol_flags);
+		return;
+	}
+
+	if (m->ol_flags & PKT_TX_L4_MASK) {
+		switch (m->ol_flags & PKT_TX_L4_MASK) {
+		case PKT_TX_TCP_CKSUM:
+			tcp_hdr = (struct tcp_hdr *)
+					((char *)l3_hdr + m->l3_len);
+			tcp_hdr->cksum = get_psd_sum(l3_hdr, m->ol_flags);
+			break;
+		case PKT_TX_UDP_CKSUM:
+			udp_hdr = (struct udp_hdr *)
+					((char *)l3_hdr + m->l3_len);
+			udp_hdr->dgram_cksum = get_psd_sum(l3_hdr, m->ol_flags);
+			break;
+		case PKT_TX_SCTP_CKSUM:
+			sctp_hdr = (struct sctp_hdr *)
+					((char *)l3_hdr + m->l3_len);
+			sctp_hdr->cksum = 0;
+			break;
+		default:
+			break;
+		}
+	}
+}
+
 /*
  * This function routes the TX packet to the correct interface. This may be a local device
  * or the physical port.
@@ -1143,7 +1239,7 @@ virtio_tx_route(struct vhost_dev *vdev, struct rte_mbuf *m, uint16_t vlan_tag)
 			(vh->vlan_tci != vlan_tag_be))
 			vh->vlan_tci = vlan_tag_be;
 	} else {
-		m->ol_flags = PKT_TX_VLAN_PKT;
+		m->ol_flags |= PKT_TX_VLAN_PKT;
 
 		/*
 		 * Find the right seg to adjust the data len when offset is
@@ -1167,6 +1263,9 @@ virtio_tx_route(struct vhost_dev *vdev, struct rte_mbuf *m, uint16_t vlan_tag)
 		m->vlan_tci = vlan_tag;
 	}
 
+	if ((m->ol_flags & PKT_TX_L4_MASK) || (m->ol_flags & PKT_TX_TCP_SEG))
+		virtio_tx_offload(m);
+
 	tx_q->m_table[len] = m;
 	len++;
 	if (enable_stats) {
@@ -1828,7 +1927,7 @@ virtio_tx_route_zcp(struct virtio_net *dev, struct rte_mbuf *m,
 		mbuf->buf_physaddr = m->buf_physaddr;
 		mbuf->buf_addr = m->buf_addr;
 	}
-	mbuf->ol_flags = PKT_TX_VLAN_PKT;
+	mbuf->ol_flags |= PKT_TX_VLAN_PKT;
 	mbuf->vlan_tci = vlan_tag;
 	mbuf->l2_len = sizeof(struct ether_hdr);
 	mbuf->l3_len = sizeof(struct ipv4_hdr);
-- 
1.7.7.6