[PATCH v2] kni: add chained mbufs support

[Ferruh Yigit <ferruh.yigit@intel.com>]

rx_q fifo may have chained mbufs, merge them into single skb before
handing to the network stack.

Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
---
 .../linuxapp/eal/include/exec-env/rte_kni_common.h |  4 +-
 lib/librte_eal/linuxapp/kni/kni_net.c              | 83 ++++++++++++++++------
 2 files changed, 64 insertions(+), 23 deletions(-)

diff --git a/lib/librte_eal/linuxapp/eal/include/exec-env/rte_kni_common.h b/lib/librte_eal/linuxapp/eal/include/exec-env/rte_kni_common.h
index 7e5e598..2acdfd9 100644
--- a/lib/librte_eal/linuxapp/eal/include/exec-env/rte_kni_common.h
+++ b/lib/librte_eal/linuxapp/eal/include/exec-env/rte_kni_common.h
@@ -113,7 +113,9 @@ struct rte_kni_mbuf {
 	void *buf_addr __attribute__((__aligned__(RTE_CACHE_LINE_SIZE)));
 	char pad0[10];
 	uint16_t data_off;      /**< Start address of data in segment buffer. */
-	char pad1[4];
+	char pad1[2];
+	uint8_t nb_segs;        /**< Number of segments. */
+	char pad4[1];
 	uint64_t ol_flags;      /**< Offload features. */
 	char pad2[4];
 	uint32_t pkt_len;       /**< Total pkt len: sum of all segment data_len. */
diff --git a/lib/librte_eal/linuxapp/kni/kni_net.c b/lib/librte_eal/linuxapp/kni/kni_net.c
index cfa8339..44f49cc 100644
--- a/lib/librte_eal/linuxapp/kni/kni_net.c
+++ b/lib/librte_eal/linuxapp/kni/kni_net.c
@@ -156,7 +156,8 @@ kni_net_rx_normal(struct kni_dev *kni)
 	/* Transfer received packets to netif */
 	for (i = 0; i < num_rx; i++) {
 		kva = (void *)va[i] - kni->mbuf_va + kni->mbuf_kva;
-		len = kva->data_len;
+		len = kva->pkt_len;
+
 		data_kva = kva->buf_addr + kva->data_off - kni->mbuf_va
 				+ kni->mbuf_kva;
 
@@ -165,22 +166,41 @@ kni_net_rx_normal(struct kni_dev *kni)
 			KNI_ERR("Out of mem, dropping pkts\n");
 			/* Update statistics */
 			kni->stats.rx_dropped++;
+			continue;
 		}
-		else {
-			/* Align IP on 16B boundary */
-			skb_reserve(skb, 2);
+
+		/* Align IP on 16B boundary */
+		skb_reserve(skb, 2);
+
+		if (kva->nb_segs == 1) {
 			memcpy(skb_put(skb, len), data_kva, len);
-			skb->dev = dev;
-			skb->protocol = eth_type_trans(skb, dev);
-			skb->ip_summed = CHECKSUM_UNNECESSARY;
+		} else {
+			int nb_segs;
+			int kva_nb_segs = kva->nb_segs;
 
-			/* Call netif interface */
-			netif_rx_ni(skb);
+			for (nb_segs = 0; nb_segs < kva_nb_segs; nb_segs++) {
+				memcpy(skb_put(skb, kva->data_len),
+					data_kva, kva->data_len);
 
-			/* Update statistics */
-			kni->stats.rx_bytes += len;
-			kni->stats.rx_packets++;
+				if (!kva->next)
+					break;
+
+				kva = kva->next - kni->mbuf_va + kni->mbuf_kva;
+				data_kva = kva->buf_addr + kva->data_off
+					- kni->mbuf_va + kni->mbuf_kva;
+			}
 		}
+
+		skb->dev = dev;
+		skb->protocol = eth_type_trans(skb, dev);
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+		/* Call netif interface */
+		netif_rx_ni(skb);
+
+		/* Update statistics */
+		kni->stats.rx_bytes += len;
+		kni->stats.rx_packets++;
 	}
 
 	/* Burst enqueue mbufs into free_q */
@@ -317,7 +337,7 @@ kni_net_rx_lo_fifo_skb(struct kni_dev *kni)
 	/* Copy mbufs to sk buffer and then call tx interface */
 	for (i = 0; i < num; i++) {
 		kva = (void *)va[i] - kni->mbuf_va + kni->mbuf_kva;
-		len = kva->data_len;
+		len = kva->pkt_len;
 		data_kva = kva->buf_addr + kva->data_off - kni->mbuf_va +
 				kni->mbuf_kva;
 
@@ -338,20 +358,39 @@ kni_net_rx_lo_fifo_skb(struct kni_dev *kni)
 		if (skb == NULL) {
 			KNI_ERR("Out of mem, dropping pkts\n");
 			kni->stats.rx_dropped++;
+			continue;
 		}
-		else {
-			/* Align IP on 16B boundary */
-			skb_reserve(skb, 2);
+
+		/* Align IP on 16B boundary */
+		skb_reserve(skb, 2);
+
+		if (kva->nb_segs == 1) {
 			memcpy(skb_put(skb, len), data_kva, len);
-			skb->dev = dev;
-			skb->ip_summed = CHECKSUM_UNNECESSARY;
+		} else {
+			int nb_segs;
+			int kva_nb_segs = kva->nb_segs;
 
-			kni->stats.rx_bytes += len;
-			kni->stats.rx_packets++;
+			for (nb_segs = 0; nb_segs < kva_nb_segs; nb_segs++) {
+				memcpy(skb_put(skb, kva->data_len),
+					data_kva, kva->data_len);
+
+				if (!kva->next)
+					break;
 
-			/* call tx interface */
-			kni_net_tx(skb, dev);
+				kva = kva->next - kni->mbuf_va + kni->mbuf_kva;
+				data_kva = kva->buf_addr + kva->data_off
+					- kni->mbuf_va + kni->mbuf_kva;
+			}
 		}
+
+		skb->dev = dev;
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+		kni->stats.rx_bytes += len;
+		kni->stats.rx_packets++;
+
+		/* call tx interface */
+		kni_net_tx(skb, dev);
 	}
 
 	/* enqueue all the mbufs from rx_q into free_q */
-- 
2.5.5