[dpdk-dev] [PATCH v3 03/10] net/virtio: add Rx descriptor check

[Jianfeng Tan <jianfeng.tan@intel.com>]

Under interrupt mode, rx_descriptor_done is used as an indicator
for applications to check if some number of packets are ready to
be received.

This patch enables this by checking used ring's local consumed idx
with shared (with backend) idx.

Signed-off-by: Jianfeng Tan <jianfeng.tan@intel.com>
---
 drivers/net/virtio/virtio_ethdev.c | 1 +
 drivers/net/virtio/virtio_ethdev.h | 3 +++
 drivers/net/virtio/virtio_rxtx.c   | 9 +++++++++
 3 files changed, 13 insertions(+)

diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
index a790c46..bec2be2 100644
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -739,6 +739,7 @@ static const struct eth_dev_ops virtio_eth_dev_ops = {
 	.link_update             = virtio_dev_link_update,
 	.rx_queue_setup          = virtio_dev_rx_queue_setup,
 	.rx_queue_release        = virtio_dev_queue_release,
+	.rx_descriptor_done      = virtio_dev_rx_queue_done,
 	.tx_queue_setup          = virtio_dev_tx_queue_setup,
 	.tx_queue_release        = virtio_dev_queue_release,
 	/* collect stats per queue */
diff --git a/drivers/net/virtio/virtio_ethdev.h b/drivers/net/virtio/virtio_ethdev.h
index 27d9a19..4ab81c6 100644
--- a/drivers/net/virtio/virtio_ethdev.h
+++ b/drivers/net/virtio/virtio_ethdev.h
@@ -78,6 +78,9 @@ void virtio_dev_cq_start(struct rte_eth_dev *dev);
 /*
  * RX/TX function prototypes
  */
+
+int virtio_dev_rx_queue_done(void *rxq, uint16_t offset);
+
 int  virtio_dev_rx_queue_setup(struct rte_eth_dev *dev, uint16_t rx_queue_id,
 		uint16_t nb_rx_desc, unsigned int socket_id,
 		const struct rte_eth_rxconf *rx_conf,
diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
index 1e5a6b9..02154b7 100644
--- a/drivers/net/virtio/virtio_rxtx.c
+++ b/drivers/net/virtio/virtio_rxtx.c
@@ -72,6 +72,15 @@
 #define VIRTIO_SIMPLE_FLAGS ((uint32_t)ETH_TXQ_FLAGS_NOMULTSEGS | \
 	ETH_TXQ_FLAGS_NOOFFLOADS)
 
+int
+virtio_dev_rx_queue_done(void *rxq, uint16_t offset)
+{
+	struct virtnet_rx *rxvq = rxq;
+	struct virtqueue *vq = rxvq->vq;
+
+	return (VIRTQUEUE_NUSED(vq) >= offset);
+}
+
 static void
 vq_ring_free_chain(struct virtqueue *vq, uint16_t desc_idx)
 {
-- 
2.7.4