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* [dpdk-dev] [PATCH 1/2] net/virtio: setup Tx region for packed ring
@ 2020-09-28  8:20 Marvin Liu
  2020-09-28  8:20 ` [dpdk-dev] [PATCH 2/2] net/virtio: use indirect ring in packed datapath Marvin Liu
                   ` (2 more replies)
  0 siblings, 3 replies; 6+ messages in thread
From: Marvin Liu @ 2020-09-28  8:20 UTC (permalink / raw)
  To: maxime.coquelin, chenbo.xia, zhihong.wang; +Cc: dev, Marvin Liu

Add packed indirect descriptors format into virtio Tx region. When
initializing vring, packed indirect descriptors will be initialized if
ring type is packed.

Signed-off-by: Marvin Liu <yong.liu@intel.com>

diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
index 013a2904e..320f99836 100644
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -609,10 +609,9 @@ virtio_init_queue(struct rte_eth_dev *dev, uint16_t vtpci_queue_idx)
 		txr = hdr_mz->addr;
 		memset(txr, 0, vq_size * sizeof(*txr));
 		for (i = 0; i < vq_size; i++) {
-			struct vring_desc *start_dp = txr[i].tx_indir;
-
 			/* first indirect descriptor is always the tx header */
 			if (!vtpci_packed_queue(hw)) {
+				struct vring_desc *start_dp = txr[i].tx_indir;
 				vring_desc_init_split(start_dp,
 						      RTE_DIM(txr[i].tx_indir));
 				start_dp->addr = txvq->virtio_net_hdr_mem
@@ -621,6 +620,16 @@ virtio_init_queue(struct rte_eth_dev *dev, uint16_t vtpci_queue_idx)
 						   tx_hdr);
 				start_dp->len = hw->vtnet_hdr_size;
 				start_dp->flags = VRING_DESC_F_NEXT;
+			} else {
+				struct vring_packed_desc *start_dp =
+					txr[i].tx_packed_indir;
+				vring_desc_init_indirect_packed(start_dp,
+				      RTE_DIM(txr[i].tx_packed_indir));
+				start_dp->addr = txvq->virtio_net_hdr_mem
+					+ i * sizeof(*txr)
+					+ offsetof(struct virtio_tx_region,
+						   tx_hdr);
+				start_dp->len = hw->vtnet_hdr_size;
 			}
 		}
 	}
diff --git a/drivers/net/virtio/virtqueue.h b/drivers/net/virtio/virtqueue.h
index 6ed50648c..7d910a0a1 100644
--- a/drivers/net/virtio/virtqueue.h
+++ b/drivers/net/virtio/virtqueue.h
@@ -329,8 +329,11 @@ struct virtio_net_hdr_mrg_rxbuf {
 #define VIRTIO_MAX_TX_INDIRECT 8
 struct virtio_tx_region {
 	struct virtio_net_hdr_mrg_rxbuf tx_hdr;
-	struct vring_desc tx_indir[VIRTIO_MAX_TX_INDIRECT]
-		__rte_aligned(16);
+	union {
+		struct vring_desc tx_indir[VIRTIO_MAX_TX_INDIRECT];
+		struct vring_packed_desc
+			tx_packed_indir[VIRTIO_MAX_TX_INDIRECT];
+	} __rte_aligned(16);
 };
 
 static inline int
@@ -368,6 +371,16 @@ vring_desc_init_split(struct vring_desc *dp, uint16_t n)
 	dp[i].next = VQ_RING_DESC_CHAIN_END;
 }
 
+static inline void
+vring_desc_init_indirect_packed(struct vring_packed_desc *dp, int n)
+{
+	int i;
+	for (i = 0; i < n; i++) {
+		dp[i].id = (uint16_t)i;
+		dp[i].flags = VRING_DESC_F_WRITE;
+	}
+}
+
 /**
  * Tell the backend not to interrupt us. Implementation for packed virtqueues.
  */
-- 
2.17.1


^ permalink raw reply	[flat|nested] 6+ messages in thread

* [dpdk-dev] [PATCH 2/2] net/virtio: use indirect ring in packed datapath
  2020-09-28  8:20 [dpdk-dev] [PATCH 1/2] net/virtio: setup Tx region for packed ring Marvin Liu
@ 2020-09-28  8:20 ` Marvin Liu
  2020-09-30 15:24   ` Maxime Coquelin
  2020-09-30 16:19   ` Maxime Coquelin
  2020-09-30 15:19 ` [dpdk-dev] [PATCH 1/2] net/virtio: setup Tx region for packed ring Maxime Coquelin
  2020-09-30 16:19 ` Maxime Coquelin
  2 siblings, 2 replies; 6+ messages in thread
From: Marvin Liu @ 2020-09-28  8:20 UTC (permalink / raw)
  To: maxime.coquelin, chenbo.xia, zhihong.wang; +Cc: dev, Marvin Liu

Like split ring, packed ring will utilize indirect ring elements when
queuing mbufs need multiple descriptors. Thus each packet will take only
one slot when having multiple segments.

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 f915b8a2c..b3b1586a7 100644
--- a/drivers/net/virtio/virtio_rxtx.c
+++ b/drivers/net/virtio/virtio_rxtx.c
@@ -1756,7 +1756,7 @@ virtio_xmit_pkts_packed(void *tx_queue, struct rte_mbuf **tx_pkts,
 
 	for (nb_tx = 0; nb_tx < nb_pkts; nb_tx++) {
 		struct rte_mbuf *txm = tx_pkts[nb_tx];
-		int can_push = 0, slots, need;
+		int can_push = 0, use_indirect = 0, slots, need;
 
 		/* optimize ring usage */
 		if ((vtpci_with_feature(hw, VIRTIO_F_ANY_LAYOUT) ||
@@ -1768,12 +1768,15 @@ virtio_xmit_pkts_packed(void *tx_queue, struct rte_mbuf **tx_pkts,
 		    rte_is_aligned(rte_pktmbuf_mtod(txm, char *),
 			   __alignof__(struct virtio_net_hdr_mrg_rxbuf)))
 			can_push = 1;
-
+		else if (vtpci_with_feature(hw, VIRTIO_RING_F_INDIRECT_DESC) &&
+			 txm->nb_segs < VIRTIO_MAX_TX_INDIRECT)
+			use_indirect = 1;
 		/* How many main ring entries are needed to this Tx?
+		 * indirect   => 1
 		 * any_layout => number of segments
 		 * default    => number of segments + 1
 		 */
-		slots = txm->nb_segs + !can_push;
+		slots = use_indirect ? 1 : (txm->nb_segs + !can_push);
 		need = slots - vq->vq_free_cnt;
 
 		/* Positive value indicates it need free vring descriptors */
@@ -1791,7 +1794,8 @@ virtio_xmit_pkts_packed(void *tx_queue, struct rte_mbuf **tx_pkts,
 		if (can_push)
 			virtqueue_enqueue_xmit_packed_fast(txvq, txm, in_order);
 		else
-			virtqueue_enqueue_xmit_packed(txvq, txm, slots, 0,
+			virtqueue_enqueue_xmit_packed(txvq, txm, slots,
+						      use_indirect, 0,
 						      in_order);
 
 		virtio_update_packet_stats(&txvq->stats, txm);
diff --git a/drivers/net/virtio/virtio_rxtx_packed_avx.c b/drivers/net/virtio/virtio_rxtx_packed_avx.c
index 6a8214725..ce035b574 100644
--- a/drivers/net/virtio/virtio_rxtx_packed_avx.c
+++ b/drivers/net/virtio/virtio_rxtx_packed_avx.c
@@ -207,19 +207,26 @@ virtqueue_enqueue_single_packed_vec(struct virtnet_tx *txvq,
 	struct virtqueue *vq = txvq->vq;
 	struct virtio_hw *hw = vq->hw;
 	uint16_t hdr_size = hw->vtnet_hdr_size;
-	uint16_t slots, can_push;
+	uint16_t slots, can_push = 0, use_indirect = 0;
 	int16_t need;
 
+	/* optimize ring usage */
+	if ((vtpci_with_feature(hw, VIRTIO_F_ANY_LAYOUT) ||
+	      vtpci_with_feature(hw, VIRTIO_F_VERSION_1)) &&
+	    rte_mbuf_refcnt_read(txm) == 1 &&
+	    RTE_MBUF_DIRECT(txm) &&
+	    txm->nb_segs == 1 &&
+	    rte_pktmbuf_headroom(txm) >= hdr_size)
+		can_push = 1;
+	else if (vtpci_with_feature(hw, VIRTIO_RING_F_INDIRECT_DESC) &&
+		 txm->nb_segs < VIRTIO_MAX_TX_INDIRECT)
+		use_indirect = 1;
 	/* How many main ring entries are needed to this Tx?
+	 * indirect   => 1
 	 * any_layout => number of segments
 	 * default    => number of segments + 1
 	 */
-	can_push = rte_mbuf_refcnt_read(txm) == 1 &&
-		   RTE_MBUF_DIRECT(txm) &&
-		   txm->nb_segs == 1 &&
-		   rte_pktmbuf_headroom(txm) >= hdr_size;
-
-	slots = txm->nb_segs + !can_push;
+	slots = use_indirect ? 1 : (txm->nb_segs + !can_push);
 	need = slots - vq->vq_free_cnt;
 
 	/* Positive value indicates it need free vring descriptors */
@@ -234,7 +241,8 @@ virtqueue_enqueue_single_packed_vec(struct virtnet_tx *txvq,
 	}
 
 	/* Enqueue Packet buffers */
-	virtqueue_enqueue_xmit_packed(txvq, txm, slots, can_push, 1);
+	virtqueue_enqueue_xmit_packed(txvq, txm, slots, use_indirect,
+				can_push, 1);
 
 	txvq->stats.bytes += txm->pkt_len;
 	return 0;
diff --git a/drivers/net/virtio/virtqueue.h b/drivers/net/virtio/virtqueue.h
index 7d910a0a1..753dfb85c 100644
--- a/drivers/net/virtio/virtqueue.h
+++ b/drivers/net/virtio/virtqueue.h
@@ -686,7 +686,8 @@ virtqueue_xmit_offload(struct virtio_net_hdr *hdr,
 
 static inline void
 virtqueue_enqueue_xmit_packed(struct virtnet_tx *txvq, struct rte_mbuf *cookie,
-			      uint16_t needed, int can_push, int in_order)
+			      uint16_t needed, int use_indirect, int can_push,
+			      int in_order)
 {
 	struct virtio_tx_region *txr = txvq->virtio_net_hdr_mz->addr;
 	struct vq_desc_extra *dxp;
@@ -722,6 +723,25 @@ virtqueue_enqueue_xmit_packed(struct virtnet_tx *txvq, struct rte_mbuf *cookie,
 		/* if offload disabled, it is not zeroed below, do it now */
 		if (!vq->hw->has_tx_offload)
 			virtqueue_clear_net_hdr(hdr);
+	} else if (use_indirect) {
+		/* setup tx ring slot to point to indirect
+		 * descriptor list stored in reserved region.
+		 *
+		 * the first slot in indirect ring is already preset
+		 * to point to the header in reserved region
+		 */
+		start_dp[idx].addr  = txvq->virtio_net_hdr_mem +
+			RTE_PTR_DIFF(&txr[idx].tx_packed_indir, txr);
+		start_dp[idx].len   = (needed + 1) *
+			sizeof(struct vring_packed_desc);
+		/* reset flags for indirect desc */
+		head_flags = VRING_DESC_F_INDIRECT;
+		head_flags |= vq->vq_packed.cached_flags;
+		hdr = (struct virtio_net_hdr *)&txr[idx].tx_hdr;
+
+		/* loop below will fill in rest of the indirect elements */
+		start_dp = txr[idx].tx_packed_indir;
+		idx = 1;
 	} else {
 		/* setup first tx ring slot to point to header
 		 * stored in reserved region.
@@ -767,6 +787,15 @@ virtqueue_enqueue_xmit_packed(struct virtnet_tx *txvq, struct rte_mbuf *cookie,
 
 	start_dp[prev].id = id;
 
+	if (use_indirect) {
+		idx = head_idx;
+		if (++idx >= vq->vq_nentries) {
+			idx -= vq->vq_nentries;
+			vq->vq_packed.cached_flags ^=
+				VRING_PACKED_DESC_F_AVAIL_USED;
+		}
+	}
+
 	vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt - needed);
 	vq->vq_avail_idx = idx;
 
-- 
2.17.1


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [dpdk-dev] [PATCH 1/2] net/virtio: setup Tx region for packed ring
  2020-09-28  8:20 [dpdk-dev] [PATCH 1/2] net/virtio: setup Tx region for packed ring Marvin Liu
  2020-09-28  8:20 ` [dpdk-dev] [PATCH 2/2] net/virtio: use indirect ring in packed datapath Marvin Liu
@ 2020-09-30 15:19 ` Maxime Coquelin
  2020-09-30 16:19 ` Maxime Coquelin
  2 siblings, 0 replies; 6+ messages in thread
From: Maxime Coquelin @ 2020-09-30 15:19 UTC (permalink / raw)
  To: Marvin Liu, chenbo.xia, zhihong.wang; +Cc: dev

Hi Marvin,

Thanks for taking care of this!

I think we need to add Fixes tag
On 9/28/20 10:20 AM, Marvin Liu wrote:
> Add packed indirect descriptors format into virtio Tx region. When
> initializing vring, packed indirect descriptors will be initialized if
> ring type is packed.
> 
> Signed-off-by: Marvin Liu <yong.liu@intel.com>
> 

I will add below fixline:

Fixes: bc80357cd677 ("net/virtio: drop unused field in Tx region structure")
Cc: stable@dpdk.org

And change title to:

net/virtio: fix packed ring indirect descriptor setup

Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

Thanks,
Maxime


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [dpdk-dev] [PATCH 2/2] net/virtio: use indirect ring in packed datapath
  2020-09-28  8:20 ` [dpdk-dev] [PATCH 2/2] net/virtio: use indirect ring in packed datapath Marvin Liu
@ 2020-09-30 15:24   ` Maxime Coquelin
  2020-09-30 16:19   ` Maxime Coquelin
  1 sibling, 0 replies; 6+ messages in thread
From: Maxime Coquelin @ 2020-09-30 15:24 UTC (permalink / raw)
  To: Marvin Liu, chenbo.xia, zhihong.wang; +Cc: dev



On 9/28/20 10:20 AM, Marvin Liu wrote:
> Like split ring, packed ring will utilize indirect ring elements when
> queuing mbufs need multiple descriptors. Thus each packet will take only
> one slot when having multiple segments.
> 
> Signed-off-by: Marvin Liu <yong.liu@intel.com>
> 


In this patch also I would add Fixes tag and Cc stable:

Fixes: 892dc798fa9c ("net/virtio: implement Tx path for packed queues")
Cc: stable@dpdk.org

And would change the title to

net/virtio: fix indirect descriptor handling in packed datapaths

Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

Thanks,
Maxime


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [dpdk-dev] [PATCH 1/2] net/virtio: setup Tx region for packed ring
  2020-09-28  8:20 [dpdk-dev] [PATCH 1/2] net/virtio: setup Tx region for packed ring Marvin Liu
  2020-09-28  8:20 ` [dpdk-dev] [PATCH 2/2] net/virtio: use indirect ring in packed datapath Marvin Liu
  2020-09-30 15:19 ` [dpdk-dev] [PATCH 1/2] net/virtio: setup Tx region for packed ring Maxime Coquelin
@ 2020-09-30 16:19 ` Maxime Coquelin
  2 siblings, 0 replies; 6+ messages in thread
From: Maxime Coquelin @ 2020-09-30 16:19 UTC (permalink / raw)
  To: Marvin Liu, chenbo.xia, zhihong.wang; +Cc: dev



On 9/28/20 10:20 AM, Marvin Liu wrote:
> Add packed indirect descriptors format into virtio Tx region. When
> initializing vring, packed indirect descriptors will be initialized if
> ring type is packed.
> 
> Signed-off-by: Marvin Liu <yong.liu@intel.com>


Applied to dpdk-next-virtio/main with suggested commit message changes.

Thanks,
Maxime


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [dpdk-dev] [PATCH 2/2] net/virtio: use indirect ring in packed datapath
  2020-09-28  8:20 ` [dpdk-dev] [PATCH 2/2] net/virtio: use indirect ring in packed datapath Marvin Liu
  2020-09-30 15:24   ` Maxime Coquelin
@ 2020-09-30 16:19   ` Maxime Coquelin
  1 sibling, 0 replies; 6+ messages in thread
From: Maxime Coquelin @ 2020-09-30 16:19 UTC (permalink / raw)
  To: Marvin Liu, chenbo.xia, zhihong.wang; +Cc: dev



On 9/28/20 10:20 AM, Marvin Liu wrote:
> Like split ring, packed ring will utilize indirect ring elements when
> queuing mbufs need multiple descriptors. Thus each packet will take only
> one slot when having multiple segments.
> 
> Signed-off-by: Marvin Liu <yong.liu@intel.com>


Applied to dpdk-next-virtio/main with suggested commit messages changes.

Thanks,
Maxime


^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2020-09-30 16:20 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-09-28  8:20 [dpdk-dev] [PATCH 1/2] net/virtio: setup Tx region for packed ring Marvin Liu
2020-09-28  8:20 ` [dpdk-dev] [PATCH 2/2] net/virtio: use indirect ring in packed datapath Marvin Liu
2020-09-30 15:24   ` Maxime Coquelin
2020-09-30 16:19   ` Maxime Coquelin
2020-09-30 15:19 ` [dpdk-dev] [PATCH 1/2] net/virtio: setup Tx region for packed ring Maxime Coquelin
2020-09-30 16:19 ` Maxime Coquelin

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