Add support copying scattered mbuf to vring which is done by dev_scatter_rx,
and check the 'next' pointer in mbuf on the fly to select suitable function to
rx packets.
Signed-off-by: Changchun Ouyang <changchun.ouyang at intel.com>
---
lib/librte_vhost/vhost_rxtx.c | 116 +++++++++++++++++++++++++++++++++++++++++-
1 file changed, 115 insertions(+), 1 deletion(-)
diff --git a/lib/librte_vhost/vhost_rxtx.c b/lib/librte_vhost/vhost_rxtx.c
index bb56ae1..3086bb4 100644
--- a/lib/librte_vhost/vhost_rxtx.c
+++ b/lib/librte_vhost/vhost_rxtx.c
@@ -46,7 +46,8 @@
* This function adds buffers to the virtio devices RX virtqueue. Buffers can
* be received from the physical port or from another virtio device. A packet
* count is returned to indicate the number of packets that are succesfully
- * added to the RX queue. This function works when mergeable is disabled.
+ * added to the RX queue. This function works when mergeable is disabled and
+ * the mbuf is not scattered.
*/
static inline uint32_t __attribute__((always_inline))
virtio_dev_rx(struct virtio_net *dev, uint16_t queue_id,
@@ -447,6 +448,103 @@ fill_buf_vec(struct vhost_virtqueue *vq, uint16_t id,
uint32_t *vec_idx)
}
/*
+ * This function works for scatter-gather RX.
+ */
+static inline uint32_t __attribute__((always_inline))
+virtio_dev_scatter_rx(struct virtio_net *dev, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint32_t count)
+{
+ struct vhost_virtqueue *vq;
+ uint32_t pkt_idx = 0, entry_success = 0;
+ uint16_t avail_idx;
+ uint16_t res_base_idx, res_end_idx;
+ uint8_t success = 0;
+
+ LOG_DEBUG(VHOST_DATA, "(%"PRIu64") virtio_dev_scatter_rx()\n",
+ dev->device_fh);
+ if (unlikely(queue_id != VIRTIO_RXQ))
+ LOG_DEBUG(VHOST_DATA, "mq isn't supported in this version.\n");
+
+ vq = dev->virtqueue[VIRTIO_RXQ];
+ count = RTE_MIN((uint32_t)MAX_PKT_BURST, count);
+
+ if (count == 0)
+ return 0;
+
+ for (pkt_idx = 0; pkt_idx < count; pkt_idx++) {
+ uint32_t secure_len = 0;
+ uint32_t vec_idx = 0;
+ uint32_t pkt_len = pkts[pkt_idx]->pkt_len + vq->vhost_hlen;
+
+ do {
+ /*
+ * As many data cores may want access to available
+ * buffers, they need to be reserved.
+ */
+ res_base_idx = vq->last_used_idx_res;
+ avail_idx = *((volatile uint16_t *)&vq->avail->idx);
+
+ if (unlikely(res_base_idx == avail_idx)) {
+ LOG_DEBUG(VHOST_DATA,
+ "(%"PRIu64") Failed "
+ "to get enough desc from "
+ "vring\n",
+ dev->device_fh);
+ return pkt_idx;
+ } else {
+ uint16_t wrapped_idx =
+ (res_base_idx) & (vq->size - 1);
+ uint32_t idx = vq->avail->ring[wrapped_idx];
+
+ update_secure_len(vq, idx, &secure_len);
+ }
+
+ if (pkt_len > secure_len) {
+ LOG_DEBUG(VHOST_DATA,
+ "(%"PRIu64") Failed "
+ "to get enough desc from "
+ "vring\n",
+ dev->device_fh);
+ return pkt_idx;
+ }
+
+ /* vq->last_used_idx_res is atomically updated. */
+ success = rte_atomic16_cmpset(&vq->last_used_idx_res,
+ res_base_idx,
+ res_base_idx + 1);
+ } while (success == 0);
+
+ fill_buf_vec(vq, res_base_idx, &vec_idx);
+
+ res_end_idx = res_base_idx + 1;
+
+ entry_success = copy_from_mbuf_to_vring(dev, res_base_idx,
+ res_end_idx, pkts[pkt_idx]);
+
+ rte_compiler_barrier();
+
+ /*
+ * Wait until it's our turn to add our buffer
+ * to the used ring.
+ */
+ while (unlikely(vq->last_used_idx != res_base_idx))
+ rte_pause();
+
+ *(volatile uint16_t *)&vq->used->idx += entry_success;
+ vq->last_used_idx = res_end_idx;
+
+ /* flush used->idx update before we read avail->flags. */
+ rte_mb();
+
+ /* Kick the guest if necessary. */
+ if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT))
+ eventfd_write((int)vq->callfd, 1);
+ }
+
+ return count;
+}
+
+/*
* This function works for mergeable RX.
*/
static inline uint32_t __attribute__((always_inline))
@@ -545,12 +643,28 @@ virtio_dev_merge_rx(struct virtio_net *dev, uint16_t
queue_id,
return count;
}
+/*
+ * Return 1 if any mbuf is scattered, otherwise return 0.
+ */
+static inline uint32_t __attribute__((always_inline))
+check_scatter(struct rte_mbuf **pkts, uint16_t count)
+{
+ uint32_t i;
+ for (i = 0; i < count; i++) {
+ if (pkts[i]->next != NULL)
+ return 1;
+ }
+ return 0;
+}
+
uint16_t
rte_vhost_enqueue_burst(struct virtio_net *dev, uint16_t queue_id,
struct rte_mbuf **pkts, uint16_t count)
{
if (unlikely(dev->features & (1 << VIRTIO_NET_F_MRG_RXBUF)))
return virtio_dev_merge_rx(dev, queue_id, pkts, count);
+ else if (unlikely(check_scatter(pkts, count) == 1))
+ return virtio_dev_scatter_rx(dev, queue_id, pkts, count);
else
return virtio_dev_rx(dev, queue_id, pkts, count);
}
--
1.8.4.2
