[dpdk-dev] [PATCH] virtio: Support mergeable buffer in virtio PMD.

Ouyang Changchun changchun.ouyang at intel.com
Sat Jul 12 04:24:22 CEST 2014


This patch supports mergeable buffer feature in DPDK based virtio PMD, which can
receive jumbo frame with larger size, like 3K, 4K or even 9K. 

Signed-off-by: Ouyang Changchun <changchun.ouyang at intel.com>
---
 lib/librte_pmd_virtio/virtio_ethdev.c |  20 ++--
 lib/librte_pmd_virtio/virtio_ethdev.h |   3 +
 lib/librte_pmd_virtio/virtio_rxtx.c   | 172 ++++++++++++++++++++++++++++++----
 lib/librte_pmd_virtio/virtqueue.h     |  35 ++++---
 4 files changed, 193 insertions(+), 37 deletions(-)

diff --git a/lib/librte_pmd_virtio/virtio_ethdev.c b/lib/librte_pmd_virtio/virtio_ethdev.c
index d4730f9..57f32f3 100644
--- a/lib/librte_pmd_virtio/virtio_ethdev.c
+++ b/lib/librte_pmd_virtio/virtio_ethdev.c
@@ -340,7 +340,7 @@ int virtio_dev_queue_setup(struct rte_eth_dev *dev,
 		snprintf(vq_name, sizeof(vq_name), "port%d_tvq%d_hdrzone",
 			dev->data->port_id, queue_idx);
 		vq->virtio_net_hdr_mz = rte_memzone_reserve_aligned(vq_name,
-			vq_size * sizeof(struct virtio_net_hdr),
+			vq_size * hw->vtnet_hdr_size,
 			socket_id, 0, CACHE_LINE_SIZE);
 		if (vq->virtio_net_hdr_mz == NULL) {
 			rte_free(vq);
@@ -349,7 +349,7 @@ int virtio_dev_queue_setup(struct rte_eth_dev *dev,
 		vq->virtio_net_hdr_mem =
 			(void *)(uintptr_t)vq->virtio_net_hdr_mz->phys_addr;
 		memset(vq->virtio_net_hdr_mz->addr, 0,
-			vq_size * sizeof(struct virtio_net_hdr));
+			vq_size * hw->vtnet_hdr_size);
 	} else if (queue_type == VTNET_CQ) {
 		/* Allocate a page for control vq command, data and status */
 		snprintf(vq_name, sizeof(vq_name), "port%d_cvq_hdrzone",
@@ -526,9 +526,6 @@ virtio_negotiate_features(struct virtio_hw *hw)
 	mask |= VIRTIO_NET_F_GUEST_TSO4 | VIRTIO_NET_F_GUEST_TSO6 | VIRTIO_NET_F_GUEST_ECN;
 	mask |= VTNET_LRO_FEATURES;
 
-	/* rx_mbuf should not be in multiple merged segments */
-	mask |= VIRTIO_NET_F_MRG_RXBUF;
-
 	/* not negotiating INDIRECT descriptor table support */
 	mask |= VIRTIO_RING_F_INDIRECT_DESC;
 
@@ -677,7 +674,6 @@ eth_virtio_dev_init(__rte_unused struct eth_driver *eth_drv,
 	}
 
 	eth_dev->dev_ops = &virtio_eth_dev_ops;
-	eth_dev->rx_pkt_burst = &virtio_recv_pkts;
 	eth_dev->tx_pkt_burst = &virtio_xmit_pkts;
 
 	if (rte_eal_process_type() == RTE_PROC_SECONDARY)
@@ -733,10 +729,13 @@ eth_virtio_dev_init(__rte_unused struct eth_driver *eth_drv,
 	virtio_negotiate_features(hw);
 
 	/* Setting up rx_header size for the device */
-	if (vtpci_with_feature(hw, VIRTIO_NET_F_MRG_RXBUF))
+	if (vtpci_with_feature(hw, VIRTIO_NET_F_MRG_RXBUF)) {
+		eth_dev->rx_pkt_burst = &virtio_recv_mergeable_pkts;
 		hw->vtnet_hdr_size = sizeof(struct virtio_net_hdr_mrg_rxbuf);
-	else
+	} else {
+		eth_dev->rx_pkt_burst = &virtio_recv_pkts;
 		hw->vtnet_hdr_size = sizeof(struct virtio_net_hdr);
+	}
 
 	/* Allocate memory for storing MAC addresses */
 	eth_dev->data->mac_addrs = rte_zmalloc("virtio", ETHER_ADDR_LEN, 0);
@@ -932,7 +931,7 @@ static void virtio_dev_free_mbufs(struct rte_eth_dev *dev)
 
 		while ((buf = (struct rte_mbuf *)virtqueue_detatch_unused(
 					dev->data->rx_queues[i])) != NULL) {
-			rte_pktmbuf_free_seg(buf);
+			rte_pktmbuf_free(buf);
 			mbuf_num++;
 		}
 
@@ -951,7 +950,8 @@ static void virtio_dev_free_mbufs(struct rte_eth_dev *dev)
 		mbuf_num = 0;
 		while ((buf = (struct rte_mbuf *)virtqueue_detatch_unused(
 					dev->data->tx_queues[i])) != NULL) {
-			rte_pktmbuf_free_seg(buf);
+			rte_pktmbuf_free(buf);
+
 			mbuf_num++;
 		}
 
diff --git a/lib/librte_pmd_virtio/virtio_ethdev.h b/lib/librte_pmd_virtio/virtio_ethdev.h
index 858e644..d2e1eed 100644
--- a/lib/librte_pmd_virtio/virtio_ethdev.h
+++ b/lib/librte_pmd_virtio/virtio_ethdev.h
@@ -104,6 +104,9 @@ int  virtio_dev_tx_queue_setup(struct rte_eth_dev *dev, uint16_t tx_queue_id,
 uint16_t virtio_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
 		uint16_t nb_pkts);
 
+uint16_t virtio_recv_mergeable_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
+		uint16_t nb_pkts);
+
 uint16_t virtio_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
 		uint16_t nb_pkts);
 
diff --git a/lib/librte_pmd_virtio/virtio_rxtx.c b/lib/librte_pmd_virtio/virtio_rxtx.c
index 6f02a61..671c2d3 100644
--- a/lib/librte_pmd_virtio/virtio_rxtx.c
+++ b/lib/librte_pmd_virtio/virtio_rxtx.c
@@ -127,7 +127,7 @@ virtio_dev_vring_start(struct rte_eth_dev *dev, struct virtqueue *vq, int queue_
 			error = virtqueue_enqueue_recv_refill(vq, m);
 
 			if (error) {
-				rte_pktmbuf_free_seg(m);
+				rte_pktmbuf_free(m);
 				break;
 			}
 			nbufs++;
@@ -259,7 +259,7 @@ virtio_discard_rxbuf(struct virtqueue *vq, struct rte_mbuf *m)
 	error = virtqueue_enqueue_recv_refill(vq, m);
 	if (unlikely(error)) {
 		RTE_LOG(ERR, PMD, "cannot requeue discarded mbuf");
-		rte_pktmbuf_free_seg(m);
+		rte_pktmbuf_free(m);
 	}
 }
 
@@ -307,19 +307,18 @@ virtio_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
 
 		rxm->pkt.in_port = rxvq->port_id;
 		rxm->pkt.data = (char *)rxm->buf_addr + RTE_PKTMBUF_HEADROOM;
+
 		rxm->pkt.nb_segs = 1;
 		rxm->pkt.next = NULL;
-		rxm->pkt.pkt_len  = (uint32_t)(len[i]
-					       - sizeof(struct virtio_net_hdr));
-		rxm->pkt.data_len = (uint16_t)(len[i]
-					       - sizeof(struct virtio_net_hdr));
+		rxm->pkt.pkt_len = (uint32_t)(len[i] - hw->vtnet_hdr_size);
+		rxm->pkt.data_len = (uint16_t)(len[i] - hw->vtnet_hdr_size);
 
 		VIRTIO_DUMP_PACKET(rxm, rxm->pkt.data_len);
 
 		rx_pkts[nb_rx++] = rxm;
-		hw->eth_stats.ibytes += len[i] - sizeof(struct virtio_net_hdr);
-		hw->eth_stats.q_ibytes[rxvq->queue_id] += len[i]
-			- sizeof(struct virtio_net_hdr);
+		hw->eth_stats.ibytes += rx_pkts[nb_rx - 1]->pkt.pkt_len;
+		hw->eth_stats.q_ibytes[rxvq->queue_id] +=
+					rx_pkts[nb_rx - 1]->pkt.pkt_len;
 	}
 
 	hw->eth_stats.ipackets += nb_rx;
@@ -335,11 +334,149 @@ virtio_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
 		}
 		error = virtqueue_enqueue_recv_refill(rxvq, new_mbuf);
 		if (unlikely(error)) {
-			rte_pktmbuf_free_seg(new_mbuf);
+			rte_pktmbuf_free(new_mbuf);
 			break;
 		}
 		nb_enqueued++;
 	}
+
+	if (likely(nb_enqueued)) {
+		if (unlikely(virtqueue_kick_prepare(rxvq))) {
+			virtqueue_notify(rxvq);
+			PMD_RX_LOG(DEBUG, "Notified\n");
+		}
+	}
+
+	vq_update_avail_idx(rxvq);
+
+	return nb_rx;
+}
+
+uint16_t
+virtio_recv_mergeable_pkts(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
+{
+	struct virtqueue *rxvq = rx_queue;
+	struct virtio_hw *hw = rxvq->hw;
+	struct rte_mbuf *rxm, *new_mbuf;
+	uint16_t nb_used, num, nb_rx = 0;
+	uint32_t len[VIRTIO_MBUF_BURST_SZ];
+	struct rte_mbuf *rcv_pkts[VIRTIO_MBUF_BURST_SZ];
+	struct rte_mbuf *prev;
+	int error;
+	uint32_t i = 0, nb_enqueued = 0;
+	uint32_t seg_num = 0;
+	uint16_t extra_idx = 0;
+
+	nb_used = VIRTQUEUE_NUSED(rxvq);
+
+	rmb();
+
+	if (nb_used == 0)
+		return 0;
+
+	while (i < nb_used) {
+		struct virtio_net_hdr_mrg_rxbuf * header;
+		char *head_ptr;
+
+		if (nb_rx >= nb_pkts)
+			break;
+
+		num = virtqueue_dequeue_burst_rx(rxvq, rcv_pkts, len, 1);
+		i += num;
+
+		PMD_RX_LOG(DEBUG, "used:%d dequeue:%d\n", nb_used, num);
+		PMD_RX_LOG(DEBUG, "packet len:%d\n", len[i]);
+
+		rxm = rcv_pkts[0];
+		extra_idx = 0;
+
+		if (unlikely(len[0]
+			     < (uint32_t)hw->vtnet_hdr_size + ETHER_HDR_LEN)) {
+			PMD_RX_LOG(ERR, "Packet drop\n");
+			nb_enqueued++;
+			virtio_discard_rxbuf(rxvq, rxm);
+			hw->eth_stats.ierrors++;
+			continue;
+		}
+
+		head_ptr = (char *)rxm->pkt.data;
+		head_ptr -= hw->vtnet_hdr_size;
+		header = (struct virtio_net_hdr_mrg_rxbuf *)head_ptr;
+		seg_num = header->num_buffers;
+
+		if (seg_num == 0)
+			seg_num = 1;
+
+		rxm->pkt.data = (char *)rxm->buf_addr + RTE_PKTMBUF_HEADROOM;
+		rxm->pkt.nb_segs = seg_num;
+		rxm->pkt.next = NULL;
+		rxm->pkt.pkt_len = (uint32_t)(len[0] - hw->vtnet_hdr_size);
+		rxm->pkt.data_len = (uint16_t)(len[0] - hw->vtnet_hdr_size);
+
+		rxm->pkt.in_port = rxvq->port_id;
+		rx_pkts[nb_rx] = rxm;
+
+		prev = rxm;
+
+		VIRTIO_DUMP_PACKET(rxm, rxm->pkt.data_len);
+
+		/*
+		 * Get extra segments for current uncompleted packet.
+		 */
+		if (VIRTQUEUE_NUSED(rxvq) >= seg_num - 1) {
+			uint32_t rx_num = virtqueue_dequeue_burst_rx(rxvq,
+				rcv_pkts, len, seg_num - 1);
+			i += rx_num;
+		} else {
+			PMD_RX_LOG(ERR, "No enough segments for packet.\n");
+			break;
+		}
+
+		while (extra_idx < seg_num - 1) {
+			rxm = rcv_pkts[extra_idx];
+
+			rxm->pkt.data =
+				(char *)rxm->buf_addr + RTE_PKTMBUF_HEADROOM;
+			rxm->pkt.next = NULL;
+			rxm->pkt.pkt_len = (uint32_t)(len[extra_idx]);
+			rxm->pkt.data_len = (uint16_t)(len[extra_idx]);
+
+			if (prev)
+				prev->pkt.next = rxm;
+
+			prev = rxm;
+			rx_pkts[nb_rx]->pkt.pkt_len += rxm->pkt.pkt_len;
+
+			extra_idx++;
+
+			VIRTIO_DUMP_PACKET(rxm, rxm->pkt.data_len);
+		};
+
+		hw->eth_stats.ibytes += rx_pkts[nb_rx]->pkt.pkt_len;
+		hw->eth_stats.q_ibytes[rxvq->queue_id] +=
+					rx_pkts[nb_rx]->pkt.pkt_len;
+		nb_rx++;
+	}
+
+	hw->eth_stats.ipackets += nb_rx;
+	hw->eth_stats.q_ipackets[rxvq->queue_id] += nb_rx;
+
+	/* Allocate new mbuf for the used descriptor */
+	error = ENOSPC;
+	while (likely(!virtqueue_full(rxvq))) {
+		new_mbuf = rte_rxmbuf_alloc(rxvq->mpool);
+		if (unlikely(new_mbuf == NULL)) {
+			hw->eth_stats.rx_nombuf++;
+			break;
+		}
+		error = virtqueue_enqueue_recv_refill(rxvq, new_mbuf);
+		if (unlikely(error)) {
+			rte_pktmbuf_free(new_mbuf);
+			break;
+		}
+		nb_enqueued++;
+	}
+
 	if (likely(nb_enqueued)) {
 		if (unlikely(virtqueue_kick_prepare(rxvq))) {
 			virtqueue_notify(rxvq);
@@ -375,12 +512,15 @@ virtio_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
 	num = (uint16_t)(likely(nb_used < VIRTIO_MBUF_BURST_SZ) ? nb_used : VIRTIO_MBUF_BURST_SZ);
 
 	while (nb_tx < nb_pkts) {
-		if (virtqueue_full(txvq) && num) {
-			virtqueue_dequeue_pkt_tx(txvq);
-			num--;
+		int need = tx_pkts[nb_tx]->pkt.nb_segs - txvq->vq_free_cnt;
+		if ((need > 0) && (num > 0)) {
+			do {
+				virtqueue_dequeue_pkt_tx(txvq);
+				num--;
+			} while (num > 0);
 		}
 
-		if (!virtqueue_full(txvq)) {
+		if (tx_pkts[nb_tx]->pkt.nb_segs <= txvq->vq_free_cnt) {
 			txm = tx_pkts[nb_tx];
 			/* Enqueue Packet buffers */
 			error = virtqueue_enqueue_xmit(txvq, txm);
@@ -394,9 +534,9 @@ virtio_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
 				break;
 			}
 			nb_tx++;
-			hw->eth_stats.obytes += txm->pkt.data_len;
+			hw->eth_stats.obytes += txm->pkt.pkt_len;
 			hw->eth_stats.q_obytes[txvq->queue_id]
-				+= txm->pkt.data_len;
+				+= txm->pkt.pkt_len;
 		} else {
 			PMD_TX_LOG(ERR, "No free tx descriptors to transmit\n");
 			break;
diff --git a/lib/librte_pmd_virtio/virtqueue.h b/lib/librte_pmd_virtio/virtqueue.h
index a63723d..0ac294a 100644
--- a/lib/librte_pmd_virtio/virtqueue.h
+++ b/lib/librte_pmd_virtio/virtqueue.h
@@ -297,12 +297,14 @@ static inline int __attribute__((always_inline))
 virtqueue_enqueue_recv_refill(struct virtqueue *vq, struct rte_mbuf *cookie)
 {
 	struct vq_desc_extra *dxp;
+	struct virtio_hw *hw = vq->hw;
 	struct vring_desc *start_dp;
 	uint16_t needed = 1;
 	uint16_t head_idx, idx;
 
 	if (unlikely(vq->vq_free_cnt == 0))
 		return -ENOSPC;
+
 	if (unlikely(vq->vq_free_cnt < needed))
 		return -EMSGSIZE;
 
@@ -316,9 +318,11 @@ virtqueue_enqueue_recv_refill(struct virtqueue *vq, struct rte_mbuf *cookie)
 	dxp->ndescs = needed;
 
 	start_dp = vq->vq_ring.desc;
-	start_dp[idx].addr  =
-		(uint64_t) (cookie->buf_physaddr + RTE_PKTMBUF_HEADROOM - sizeof(struct virtio_net_hdr));
-	start_dp[idx].len   = cookie->buf_len - RTE_PKTMBUF_HEADROOM + sizeof(struct virtio_net_hdr);
+	start_dp[idx].addr =
+		(uint64_t)(cookie->buf_physaddr + RTE_PKTMBUF_HEADROOM
+		- hw->vtnet_hdr_size);
+	start_dp[idx].len =
+		cookie->buf_len - RTE_PKTMBUF_HEADROOM + hw->vtnet_hdr_size;
 	start_dp[idx].flags =  VRING_DESC_F_WRITE;
 	idx = start_dp[idx].next;
 	vq->vq_desc_head_idx = idx;
@@ -335,8 +339,10 @@ virtqueue_enqueue_xmit(struct virtqueue *txvq, struct rte_mbuf *cookie)
 {
 	struct vq_desc_extra *dxp;
 	struct vring_desc *start_dp;
-	uint16_t needed = 2;
+	uint16_t seg_num = cookie->pkt.nb_segs;
+	uint16_t needed = 1 + seg_num;
 	uint16_t head_idx, idx;
+	uint16_t head_size = txvq->hw->vtnet_hdr_size;
 
 	if (unlikely(txvq->vq_free_cnt == 0))
 		return -ENOSPC;
@@ -349,18 +355,25 @@ virtqueue_enqueue_xmit(struct virtqueue *txvq, struct rte_mbuf *cookie)
 	idx = head_idx;
 	dxp = &txvq->vq_descx[idx];
 	if (dxp->cookie != NULL)
-		rte_pktmbuf_free_seg(dxp->cookie);
+		rte_pktmbuf_free(dxp->cookie);
 	dxp->cookie = (void *)cookie;
 	dxp->ndescs = needed;
 
 	start_dp = txvq->vq_ring.desc;
-	start_dp[idx].addr  = (uint64_t)(uintptr_t)txvq->virtio_net_hdr_mem + idx * sizeof(struct virtio_net_hdr);
-	start_dp[idx].len   = sizeof(struct virtio_net_hdr);
+	start_dp[idx].addr =
+		(uint64_t)(uintptr_t)txvq->virtio_net_hdr_mem + idx * head_size;
+	start_dp[idx].len = (uint32_t)head_size;
 	start_dp[idx].flags = VRING_DESC_F_NEXT;
-	idx = start_dp[idx].next;
-	start_dp[idx].addr  = RTE_MBUF_DATA_DMA_ADDR(cookie);
-	start_dp[idx].len   = cookie->pkt.data_len;
-	start_dp[idx].flags = 0;
+
+	for (; ((seg_num > 0) && (cookie != NULL)); seg_num--) {
+		idx = start_dp[idx].next;
+		start_dp[idx].addr = RTE_MBUF_DATA_DMA_ADDR(cookie);
+		start_dp[idx].len = cookie->pkt.data_len;
+		start_dp[idx].flags = VRING_DESC_F_NEXT;
+		cookie = cookie->pkt.next;
+	}
+
+	start_dp[idx].flags &= ~VRING_DESC_F_NEXT;
 	idx = start_dp[idx].next;
 	txvq->vq_desc_head_idx = idx;
 	if (txvq->vq_desc_head_idx == VQ_RING_DESC_CHAIN_END)
-- 
1.8.4.2



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