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....@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
