-----Original Message-----
From: Ouyang, Changchun
Sent: Monday, August 31, 2015 8:29 PM
To: Liu, Jijiang; dev@dpdk.org
Cc: Ouyang, Changchun
Subject: RE: [dpdk-dev] [RFC PATCH 4/8] driver/virtio:enqueue TSO offload

quoted

-----Original Message-----
From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Jijiang Liu
Sent: Monday, August 31, 2015 5:42 PM
To: dev@dpdk.org
Subject: [dpdk-dev] [RFC PATCH 4/8] driver/virtio:enqueue TSO offload

Enqueue TSO4/6 offload.

Signed-off-by: Jijiang Liu <redacted>
---
 drivers/net/virtio/virtio_rxtx.c |   23 +++++++++++++++++++++++
 1 files changed, 23 insertions(+), 0 deletions(-)

diff --git a/drivers/net/virtio/virtio_rxtx.c

b/drivers/net/virtio/virtio_rxtx.c
index c5b53bb..4c2d838 100644

--- a/drivers/net/virtio/virtio_rxtx.c
+++ b/drivers/net/virtio/virtio_rxtx.c

@@ -198,6 +198,28 @@ virtqueue_enqueue_recv_refill(struct virtqueue

*vq, struct rte_mbuf *cookie)
 	return 0;
 }

+static void
+virtqueue_enqueue_offload(struct virtqueue *txvq, struct rte_mbuf *m,
+			uint16_t idx, uint16_t hdr_sz)
+{
+	struct virtio_net_hdr *hdr = (struct virtio_net_hdr *)(uintptr_t)
+				(txvq->virtio_net_hdr_addr + idx * hdr_sz);
+
+	if (m->tso_segsz != 0 && m->ol_flags & PKT_TX_TCP_SEG) {
+		if (m->ol_flags & PKT_TX_IPV4) {
+			if (!vtpci_with_feature(txvq->hw,
VIRTIO_NET_F_HOST_TSO4))
+				return;

Do we need return error if host can't handle tso for the packet?

quoted

+			hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
+		} else if (m->ol_flags & PKT_TX_IPV6) {
+			if (!vtpci_with_feature(txvq->hw,
VIRTIO_NET_F_HOST_TSO6))
+				return;

Same as above

quoted

+			hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
+		}

Do we need else branch for the case of neither tcpv4 nor tcpv6?

quoted

+		hdr->gso_size = m->tso_segsz;
+		hdr->hdr_len = m->l2_len + m->l3_len + m->l4_len;
+	}
+}
+
 static int
 virtqueue_enqueue_xmit(struct virtqueue *txvq, struct rte_mbuf
*cookie) { @@ -221,6 +243,7 @@ virtqueue_enqueue_xmit(struct virtqueue
*txvq, struct rte_mbuf *cookie)
 	dxp->cookie = (void *)cookie;
 	dxp->ndescs = needed;

+	virtqueue_enqueue_offload(txvq, cookie, idx, head_size);

If TSO is not enabled in the feature bit, how to resolve here?

The TSO enablement  check is in the function.

If TSO is not enabled, and don't need to fill virtio_net_hdr now.

quoted

 	start_dp = txvq->vq_ring.desc;
 	start_dp[idx].addr =
 		txvq->virtio_net_hdr_mem + idx * head_size;
--
1.7.7.6