Re: [dpdk-dev] [PATCH v7 5/8] net/virtio: implement transmit path for packed queues

[Jens Freimann <jfreimann@redhat.com>]

On Wed, Oct 10, 2018 at 09:27:31AM +0200, Maxime Coquelin wrote:
>
>
>On 10/03/2018 03:11 PM, Jens Freimann wrote:
>>This implements the transmit path for devices with
>>support for packed virtqueues.
>>
>>Signed-off-by: Jens Freiman <jfreimann@redhat.com>
>>---
>>  drivers/net/virtio/virtio_ethdev.c |  32 ++--
>>  drivers/net/virtio/virtio_ethdev.h |   2 +
>>  drivers/net/virtio/virtio_ring.h   |  15 +-
>>  drivers/net/virtio/virtio_rxtx.c   | 276 +++++++++++++++++++++++++++++
>>  drivers/net/virtio/virtqueue.h     |  18 +-
>>  5 files changed, 329 insertions(+), 14 deletions(-)
>>
>>diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
>>index d6a1613dd..c65ac365c 100644
>>--- a/drivers/net/virtio/virtio_ethdev.c
>>+++ b/drivers/net/virtio/virtio_ethdev.c
>>@@ -390,6 +390,8 @@ virtio_init_queue(struct rte_eth_dev *dev, uint16_t vtpci_queue_idx)
>>  	vq->hw = hw;
>>  	vq->vq_queue_index = vtpci_queue_idx;
>>  	vq->vq_nentries = vq_size;
>>+	if (vtpci_packed_queue(hw))
>>+		vq->vq_ring.avail_wrap_counter = 1;
>>  	/*
>>  	 * Reserve a memzone for vring elements
>>@@ -496,16 +498,22 @@ virtio_init_queue(struct rte_eth_dev *dev, uint16_t vtpci_queue_idx)
>>  		memset(txr, 0, vq_size * sizeof(*txr));
>>  		for (i = 0; i < vq_size; i++) {
>>  			struct vring_desc *start_dp = txr[i].tx_indir;
>>-
>>-			vring_desc_init_split(start_dp, RTE_DIM(txr[i].tx_indir));
>>-
>>+			struct vring_desc_packed*start_dp_packed = txr[i].tx_indir_pq;
>>+	
>>  			/* first indirect descriptor is always the tx header */
>>-			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;
>>-			start_dp->flags = VRING_DESC_F_NEXT;
>>+			if (vtpci_packed_queue(hw)) {
>No need to init desc here?

No, for split rings this is only done to chain descriptors (set the
next field). For packed rings we don't need this.

>
>>+				start_dp_packed->addr = txvq->virtio_net_hdr_mem
>>+					+ i * sizeof(*txr)
>>+					+ offsetof(struct virtio_tx_region, tx_hdr);
>>+				start_dp_packed->len = hw->vtnet_hdr_size;
>>+			} else {
>>+				vring_desc_init_split(start_dp, RTE_DIM(txr[i].tx_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;
>>+				start_dp->flags = VRING_DESC_F_NEXT;
>>+			}
>>  		}
>>  	}
>>@@ -1344,7 +1352,11 @@ set_rxtx_funcs(struct rte_eth_dev *eth_dev)
>>  		eth_dev->rx_pkt_burst = &virtio_recv_pkts;
>>  	}
>>-	if (hw->use_inorder_tx) {
>>+	if (vtpci_packed_queue(hw)) {
>>+		PMD_INIT_LOG(INFO, "virtio: using virtio 1.1 Tx path on port %u",
>>+			eth_dev->data->port_id);
>>+		eth_dev->tx_pkt_burst = virtio_xmit_pkts_packed;
>>+	} else if (hw->use_inorder_tx) {
>>  		PMD_INIT_LOG(INFO, "virtio: using inorder Tx path on port %u",
>>  			eth_dev->data->port_id);
>>  		eth_dev->tx_pkt_burst = virtio_xmit_pkts_inorder;
>>diff --git a/drivers/net/virtio/virtio_ethdev.h b/drivers/net/virtio/virtio_ethdev.h
>>index e0f80e5a4..05d355180 100644
>>--- a/drivers/net/virtio/virtio_ethdev.h
>>+++ b/drivers/net/virtio/virtio_ethdev.h
>>@@ -82,6 +82,8 @@ uint16_t virtio_recv_mergeable_pkts_inorder(void *rx_queue,
>>  uint16_t virtio_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
>>  		uint16_t nb_pkts);
>>+uint16_t virtio_xmit_pkts_packed(void *tx_queue, struct rte_mbuf **tx_pkts,
>>+		uint16_t nb_pkts);
>>  uint16_t virtio_xmit_pkts_inorder(void *tx_queue, struct rte_mbuf **tx_pkts,
>>  		uint16_t nb_pkts);
>>diff --git a/drivers/net/virtio/virtio_ring.h b/drivers/net/virtio/virtio_ring.h
>>index b9e63d4d4..dbffd4dcd 100644
>>--- a/drivers/net/virtio/virtio_ring.h
>>+++ b/drivers/net/virtio/virtio_ring.h
>>@@ -108,14 +108,25 @@ set_desc_avail(struct vring *vr, struct vring_desc_packed *desc)
>>  }
>>  static inline int
>>-desc_is_used(struct vring_desc_packed *desc, struct vring *vr)
>>+_desc_is_used(struct vring_desc_packed *desc)
>>  {
>>  	uint16_t used, avail;
>>  	used = !!(desc->flags & VRING_DESC_F_USED(1));
>>  	avail = !!(desc->flags & VRING_DESC_F_AVAIL(1));
>>-	return used == avail && used == vr->used_wrap_counter;
>>+	return used == avail;
>>+
>>+}
>>+
>>+static inline int
>>+desc_is_used(struct vring_desc_packed *desc, struct vring *vr)
>>+{
>>+	uint16_t used;
>>+
>>+	used = !!(desc->flags & VRING_DESC_F_USED(1));
>>+
>>+	return _desc_is_used(desc) && used == vr->used_wrap_counter;
>>  }
>
>This is not in the right patch.

yes, fixed.

>>  /* The standard layout for the ring is a continuous chunk of memory which
>>diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
>>index eb891433e..4078fba8e 100644
>>--- a/drivers/net/virtio/virtio_rxtx.c
>>+++ b/drivers/net/virtio/virtio_rxtx.c
>>@@ -38,6 +38,7 @@
>>  #define  VIRTIO_DUMP_PACKET(m, len) do { } while (0)
>>  #endif
>>+
>
>Remove trailing line.
>
>I need to review the remaining, but you can work on above comments in
>the mean time.

done. Thanks for the review!

regards,
Jens