[dpdk-dev] [PATCH v5 2/7] virtio: add software rx ring, fake_buf into virtqueue

[Huawei Xie]

Changes in v3:
- Remove unnecessary NULL test for rte_free
- Remove unnecessary assign of local var vq after free

Add software RX ring in virtqueue.
Add fake_mbuf in virtqueue for wraparound processing.
Use global simple_rxtx to indicate whether simple rxtx is enabled

Signed-off-by: Huawei Xie <huawei.xie at intel.com>
---
 drivers/net/virtio/virtio_ethdev.c | 11 ++++++++++-
 drivers/net/virtio/virtio_rxtx.c   |  7 +++++++
 drivers/net/virtio/virtqueue.h     |  4 ++++
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/net/virtio/virtio_ethdev.c 
b/drivers/net/virtio/virtio_ethdev.c
index 79a3640..82676d3 100644
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -247,8 +247,8 @@ virtio_dev_queue_release(struct virtqueue *vq) {
                VIRTIO_WRITE_REG_2(hw, VIRTIO_PCI_QUEUE_SEL, vq->queue_id);
                VIRTIO_WRITE_REG_4(hw, VIRTIO_PCI_QUEUE_PFN, 0);

+               rte_free(vq->sw_ring);
                rte_free(vq);
-               vq = NULL;
        }
 }

@@ -292,6 +292,9 @@ int virtio_dev_queue_setup(struct rte_eth_dev *dev,
                        dev->data->port_id, queue_idx);
                vq = rte_zmalloc(vq_name, sizeof(struct virtqueue) +
                        vq_size * sizeof(struct vq_desc_extra), 
RTE_CACHE_LINE_SIZE);
+               vq->sw_ring = rte_zmalloc_socket("rxq->sw_ring",
+                       (RTE_PMD_VIRTIO_RX_MAX_BURST + vq_size) *
+                       sizeof(vq->sw_ring[0]), RTE_CACHE_LINE_SIZE, socket_id);
        } else if (queue_type == VTNET_TQ) {
                snprintf(vq_name, sizeof(vq_name), "port%d_tvq%d",
                        dev->data->port_id, queue_idx);
@@ -308,6 +311,12 @@ int virtio_dev_queue_setup(struct rte_eth_dev *dev,
                PMD_INIT_LOG(ERR, "%s: Can not allocate virtqueue", __func__);
                return (-ENOMEM);
        }
+       if (queue_type == VTNET_RQ && vq->sw_ring == NULL) {
+               PMD_INIT_LOG(ERR, "%s: Can not allocate RX soft ring",
+                       __func__);
+               rte_free(vq);
+               return -ENOMEM;
+       }

        vq->hw = hw;
        vq->port_id = dev->data->port_id;
diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
index 9324f7f..5c00e9d 100644
--- a/drivers/net/virtio/virtio_rxtx.c
+++ b/drivers/net/virtio/virtio_rxtx.c
@@ -62,6 +62,8 @@
 #define  VIRTIO_DUMP_PACKET(m, len) do { } while (0)
 #endif

+static int use_simple_rxtx;
+
 static void
 vq_ring_free_chain(struct virtqueue *vq, uint16_t desc_idx)
 {
@@ -299,6 +301,11 @@ virtio_dev_vring_start(struct virtqueue *vq, int 
queue_type)
                /* Allocate blank mbufs for the each rx descriptor */
                nbufs = 0;
                error = ENOSPC;
+
+               memset(&vq->fake_mbuf, 0, sizeof(vq->fake_mbuf));
+               for (i = 0; i < RTE_PMD_VIRTIO_RX_MAX_BURST; i++)
+                       vq->sw_ring[vq->vq_nentries + i] = &vq->fake_mbuf;
+
                while (!virtqueue_full(vq)) {
                        m = rte_rxmbuf_alloc(vq->mpool);
                        if (m == NULL)
diff --git a/drivers/net/virtio/virtqueue.h b/drivers/net/virtio/virtqueue.h
index 7789411..6a1ec48 100644
--- a/drivers/net/virtio/virtqueue.h
+++ b/drivers/net/virtio/virtqueue.h
@@ -190,6 +190,10 @@ struct virtqueue {
        uint16_t vq_avail_idx;
        phys_addr_t virtio_net_hdr_mem; /**< hdr for each xmit packet */

+       struct rte_mbuf **sw_ring; /**< RX software ring. */
+       /* dummy mbuf, for wraparound when processing RX ring. */
+       struct rte_mbuf fake_mbuf;
+
        /* Statistics */
        uint64_t        packets;
        uint64_t        bytes;
-- 
1.8.1.4