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* [dpdk-dev] [PATCH] net/virtio: fix mbuf data and pkt length mismatch
@ 2019-09-23 14:05 Marvin Liu
  2019-09-23 15:22 ` Stephen Hemminger
                   ` (3 more replies)
  0 siblings, 4 replies; 10+ messages in thread
From: Marvin Liu @ 2019-09-23 14:05 UTC (permalink / raw)
  To: maxime.coquelin, tiwei.bie, zhihong.wang, stephen; +Cc: dev, stable, Marvin Liu

If reserve virtio header room by function rte_pktmbuf_prepend, both
segment data length and packet length of mbuf will be increased.
Data length will be equal to descriptor length, while packet length
should be decreased as virtio-net header won't be taken into packet.
Thus will cause mismatch in mbuf structure. Fix this issue by access
mbuf data directly and increase descriptor length if it is needed.

Fixes: 58169a9c8153 ("net/virtio: support Tx checksum offload")
Fixes: 892dc798fa9c ("net/virtio: implement Tx path for packed queues")
Fixes: 4905ed3a523f ("net/virtio: optimize Tx enqueue for packed ring")
Fixes: e5f456a98d3c ("net/virtio: support in-order Rx and Tx")
Cc: stable@dpdk.org

Reported-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Marvin Liu <yong.liu@intel.com>

diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
index 27ead19fb..822cce06d 100644
--- a/drivers/net/virtio/virtio_rxtx.c
+++ b/drivers/net/virtio/virtio_rxtx.c
@@ -597,9 +597,8 @@ virtqueue_enqueue_xmit_inorder(struct virtnet_tx *txvq,
 		dxp->cookie = (void *)cookies[i];
 		dxp->ndescs = 1;
 
-		hdr = (struct virtio_net_hdr *)
-			rte_pktmbuf_prepend(cookies[i], head_size);
-		cookies[i]->pkt_len -= head_size;
+		hdr = (struct virtio_net_hdr *)(char *)cookies[i]->buf_addr +
+			cookies[i]->data_off - head_size;
 
 		/* if offload disabled, hdr is not zeroed yet, do it now */
 		if (!vq->hw->has_tx_offload)
@@ -608,9 +607,10 @@ virtqueue_enqueue_xmit_inorder(struct virtnet_tx *txvq,
 			virtqueue_xmit_offload(hdr, cookies[i], true);
 
 		start_dp[idx].addr  = VIRTIO_MBUF_DATA_DMA_ADDR(cookies[i], vq);
-		start_dp[idx].len   = cookies[i]->data_len;
+		start_dp[idx].len   = cookies[i]->data_len + head_size;
 		start_dp[idx].flags = 0;
 
+
 		vq_update_avail_ring(vq, idx);
 
 		idx++;
@@ -644,9 +644,8 @@ virtqueue_enqueue_xmit_packed_fast(struct virtnet_tx *txvq,
 	flags = vq->vq_packed.cached_flags;
 
 	/* prepend cannot fail, checked by caller */
-	hdr = (struct virtio_net_hdr *)
-		rte_pktmbuf_prepend(cookie, head_size);
-	cookie->pkt_len -= head_size;
+	hdr = (struct virtio_net_hdr *)(char *)cookie->buf_addr +
+		cookie->data_off - head_size;
 
 	/* if offload disabled, hdr is not zeroed yet, do it now */
 	if (!vq->hw->has_tx_offload)
@@ -655,7 +654,7 @@ virtqueue_enqueue_xmit_packed_fast(struct virtnet_tx *txvq,
 		virtqueue_xmit_offload(hdr, cookie, true);
 
 	dp->addr = VIRTIO_MBUF_DATA_DMA_ADDR(cookie, vq);
-	dp->len  = cookie->data_len;
+	dp->len  = cookie->data_len + head_size;
 	dp->id   = id;
 
 	if (++vq->vq_avail_idx >= vq->vq_nentries) {
@@ -687,6 +686,7 @@ virtqueue_enqueue_xmit_packed(struct virtnet_tx *txvq, struct rte_mbuf *cookie,
 	uint16_t head_size = vq->hw->vtnet_hdr_size;
 	struct virtio_net_hdr *hdr;
 	uint16_t prev;
+	bool prepend_header = false;
 
 	id = in_order ? vq->vq_avail_idx : vq->vq_desc_head_idx;
 
@@ -705,12 +705,9 @@ virtqueue_enqueue_xmit_packed(struct virtnet_tx *txvq, struct rte_mbuf *cookie,
 
 	if (can_push) {
 		/* prepend cannot fail, checked by caller */
-		hdr = (struct virtio_net_hdr *)
-			rte_pktmbuf_prepend(cookie, head_size);
-		/* rte_pktmbuf_prepend() counts the hdr size to the pkt length,
-		 * which is wrong. Below subtract restores correct pkt size.
-		 */
-		cookie->pkt_len -= head_size;
+		hdr = (struct virtio_net_hdr *)(char *)cookie->buf_addr +
+			cookie->data_off - head_size;
+		prepend_header = true;
 
 		/* if offload disabled, it is not zeroed below, do it now */
 		if (!vq->hw->has_tx_offload)
@@ -738,6 +735,11 @@ virtqueue_enqueue_xmit_packed(struct virtnet_tx *txvq, struct rte_mbuf *cookie,
 
 		start_dp[idx].addr = VIRTIO_MBUF_DATA_DMA_ADDR(cookie, vq);
 		start_dp[idx].len  = cookie->data_len;
+		if (prepend_header) {
+			start_dp[idx].len += head_size;
+			prepend_header = false;
+		}
+
 		if (likely(idx != head_idx)) {
 			flags = cookie->next ? VRING_DESC_F_NEXT : 0;
 			flags |= vq->vq_packed.cached_flags;
@@ -779,6 +781,7 @@ virtqueue_enqueue_xmit(struct virtnet_tx *txvq, struct rte_mbuf *cookie,
 	uint16_t seg_num = cookie->nb_segs;
 	uint16_t head_idx, idx;
 	uint16_t head_size = vq->hw->vtnet_hdr_size;
+	bool prepend_header = false;
 	struct virtio_net_hdr *hdr;
 
 	head_idx = vq->vq_desc_head_idx;
@@ -794,12 +797,9 @@ virtqueue_enqueue_xmit(struct virtnet_tx *txvq, struct rte_mbuf *cookie,
 
 	if (can_push) {
 		/* prepend cannot fail, checked by caller */
-		hdr = (struct virtio_net_hdr *)
-			rte_pktmbuf_prepend(cookie, head_size);
-		/* rte_pktmbuf_prepend() counts the hdr size to the pkt length,
-		 * which is wrong. Below subtract restores correct pkt size.
-		 */
-		cookie->pkt_len -= head_size;
+		hdr = (struct virtio_net_hdr *)(char *)cookie->buf_addr +
+			cookie->data_off - head_size;
+		prepend_header = true;
 
 		/* if offload disabled, it is not zeroed below, do it now */
 		if (!vq->hw->has_tx_offload)
@@ -838,6 +838,10 @@ virtqueue_enqueue_xmit(struct virtnet_tx *txvq, struct rte_mbuf *cookie,
 	do {
 		start_dp[idx].addr  = VIRTIO_MBUF_DATA_DMA_ADDR(cookie, vq);
 		start_dp[idx].len   = cookie->data_len;
+		if (prepend_header) {
+			start_dp[idx].len += head_size;
+			prepend_header = false;
+		}
 		start_dp[idx].flags = cookie->next ? VRING_DESC_F_NEXT : 0;
 		idx = start_dp[idx].next;
 	} while ((cookie = cookie->next) != NULL);
-- 
2.17.1


^ permalink raw reply	[flat|nested] 10+ messages in thread

end of thread, other threads:[~2019-10-15  8:14 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-09-23 14:05 [dpdk-dev] [PATCH] net/virtio: fix mbuf data and pkt length mismatch Marvin Liu
2019-09-23 15:22 ` Stephen Hemminger
2019-09-24  4:53   ` Liu, Yong
2019-09-27  9:30 ` Maxime Coquelin
2019-09-27  9:50 ` Maxime Coquelin
2019-10-07  7:17   ` Andrew Rybchenko
2019-10-14 15:15 ` Andrew Rybchenko
2019-10-14 15:28   ` Kevin Traynor
2019-10-15  5:33   ` Tiwei Bie
2019-10-15  8:14     ` Andrew Rybchenko

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