vmxnet3: support TSO

This commit adds vmxnet3 TSO support.

Verified with test-pmd (set fwd csum) that both tso and
non-tso pkts can be successfully transmitted and all
segmentes for a tso pkt are correct on the receiver side.

Signed-off-by: Yong Wang <yongwang@vmware.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>

diff --git a/doc/guides/rel_notes/release_16_04.rst b/doc/guides/rel_notes/release_16_04.rst
index 7461457..d9db2ab 100644 (file)
--- a/doc/guides/rel_notes/release_16_04.rst
+++ b/doc/guides/rel_notes/release_16_04.rst
@@ -56,6 +56,8 @@ This section should contain new features added in this release. Sample format:
 
   Support TCP/UDP checksum offload.
 
+* **Added vmxnet3 TSO support.**
+
 * **Virtio 1.0.**
 
   Enabled virtio 1.0 support for virtio pmd driver.

diff --git a/drivers/net/vmxnet3/vmxnet3_rxtx.c b/drivers/net/vmxnet3/vmxnet3_rxtx.c
index 2a74a22..6caf3b4 100644 (file)
--- a/drivers/net/vmxnet3/vmxnet3_rxtx.c
+++ b/drivers/net/vmxnet3/vmxnet3_rxtx.c
@@ -289,27 +289,45 @@ vmxnet3_dev_clear_queues(struct rte_eth_dev *dev)
        }
 }
 
+static int
+vmxnet3_unmap_pkt(uint16_t eop_idx, vmxnet3_tx_queue_t *txq)
+{
+       int completed = 0;
+       struct rte_mbuf *mbuf;
+
+       /* Release cmd_ring descriptor and free mbuf */
+       VMXNET3_ASSERT(txq->cmd_ring.base[eop_idx].txd.eop == 1);
+
+       mbuf = txq->cmd_ring.buf_info[eop_idx].m;
+       if (mbuf == NULL)
+               rte_panic("EOP desc does not point to a valid mbuf");
+       rte_pktmbuf_free(mbuf);
+
+       txq->cmd_ring.buf_info[eop_idx].m = NULL;
+
+       while (txq->cmd_ring.next2comp != eop_idx) {
+               /* no out-of-order completion */
+               VMXNET3_ASSERT(txq->cmd_ring.base[txq->cmd_ring.next2comp].txd.cq == 0);
+               vmxnet3_cmd_ring_adv_next2comp(&txq->cmd_ring);
+               completed++;
+       }
+
+       /* Mark the txd for which tcd was generated as completed */
+       vmxnet3_cmd_ring_adv_next2comp(&txq->cmd_ring);
+
+       return completed + 1;
+}
+
 static void
 vmxnet3_tq_tx_complete(vmxnet3_tx_queue_t *txq)
 {
        int completed = 0;
-       struct rte_mbuf *mbuf;
        vmxnet3_comp_ring_t *comp_ring = &txq->comp_ring;
        struct Vmxnet3_TxCompDesc *tcd = (struct Vmxnet3_TxCompDesc *)
                (comp_ring->base + comp_ring->next2proc);
 
        while (tcd->gen == comp_ring->gen) {
-               /* Release cmd_ring descriptor and free mbuf */
-               VMXNET3_ASSERT(txq->cmd_ring.base[tcd->txdIdx].txd.eop == 1);
-               while (txq->cmd_ring.next2comp != tcd->txdIdx) {
-                       mbuf = txq->cmd_ring.buf_info[txq->cmd_ring.next2comp].m;
-                       txq->cmd_ring.buf_info[txq->cmd_ring.next2comp].m = NULL;
-                       rte_pktmbuf_free_seg(mbuf);
-
-                       /* Mark the txd for which tcd was generated as completed */
-                       vmxnet3_cmd_ring_adv_next2comp(&txq->cmd_ring);
-                       completed++;
-               }
+               completed += vmxnet3_unmap_pkt(tcd->txdIdx, txq);
 
                vmxnet3_comp_ring_adv_next2proc(comp_ring);
                tcd = (struct Vmxnet3_TxCompDesc *)(comp_ring->base +
@@ -345,21 +363,43 @@ vmxnet3_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
                struct rte_mbuf *txm = tx_pkts[nb_tx];
                struct rte_mbuf *m_seg = txm;
                int copy_size = 0;
+               bool tso = (txm->ol_flags & PKT_TX_TCP_SEG) != 0;
+               /* # of descriptors needed for a packet. */
+               unsigned count = txm->nb_segs;
 
-               /* Is this packet execessively fragmented, then drop */
-               if (unlikely(txm->nb_segs > VMXNET3_MAX_TXD_PER_PKT)) {
-                       ++txq->stats.drop_too_many_segs;
-                       ++txq->stats.drop_total;
+               avail = vmxnet3_cmd_ring_desc_avail(&txq->cmd_ring);
+               if (count > avail) {
+                       /* Is command ring full? */
+                       if (unlikely(avail == 0)) {
+                               PMD_TX_LOG(DEBUG, "No free ring descriptors");
+                               txq->stats.tx_ring_full++;
+                               txq->stats.drop_total += (nb_pkts - nb_tx);
+                               break;
+                       }
+
+                       /* Command ring is not full but cannot handle the
+                        * multi-segmented packet. Let's try the next packet
+                        * in this case.
+                        */
+                       PMD_TX_LOG(DEBUG, "Running out of ring descriptors "
+                                  "(avail %d needed %d)", avail, count);
+                       txq->stats.drop_total++;
+                       if (tso)
+                               txq->stats.drop_tso++;
                        rte_pktmbuf_free(txm);
-                       ++nb_tx;
+                       nb_tx++;
                        continue;
                }
 
-               /* Is command ring full? */
-               avail = vmxnet3_cmd_ring_desc_avail(&txq->cmd_ring);
-               if (txm->nb_segs > avail) {
-                       ++txq->stats.tx_ring_full;
-                       break;
+               /* Drop non-TSO packet that is excessively fragmented */
+               if (unlikely(!tso && count > VMXNET3_MAX_TXD_PER_PKT)) {
+                       PMD_TX_LOG(ERR, "Non-TSO packet cannot occupy more than %d tx "
+                                  "descriptors. Packet dropped.", VMXNET3_MAX_TXD_PER_PKT);
+                       txq->stats.drop_too_many_segs++;
+                       txq->stats.drop_total++;
+                       rte_pktmbuf_free(txm);
+                       nb_tx++;
+                       continue;
                }
 
                if (txm->nb_segs == 1 && rte_pktmbuf_pkt_len(txm) <= VMXNET3_HDR_COPY_SIZE) {
@@ -376,11 +416,11 @@ vmxnet3_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
                do {
                        /* Remember the transmit buffer for cleanup */
                        tbi = txq->cmd_ring.buf_info + txq->cmd_ring.next2fill;
-                       tbi->m = m_seg;
 
                        /* NB: the following assumes that VMXNET3 maximum
-                          transmit buffer size (16K) is greater than
-                          maximum sizeof mbuf segment size. */
+                        * transmit buffer size (16K) is greater than
+                        * maximum size of mbuf segment size.
+                        */
                        gdesc = txq->cmd_ring.base + txq->cmd_ring.next2fill;
                        if (copy_size)
                                gdesc->txd.addr = rte_cpu_to_le_64(txq->data_ring.basePA +
@@ -399,6 +439,8 @@ vmxnet3_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
                        dw2 = txq->cmd_ring.gen << VMXNET3_TXD_GEN_SHIFT;
                } while ((m_seg = m_seg->next) != NULL);
 
+               /* set the last buf_info for the pkt */
+               tbi->m = txm;
                /* Update the EOP descriptor */
                gdesc->dword[3] |= VMXNET3_TXD_EOP | VMXNET3_TXD_CQ;
 
@@ -409,7 +451,17 @@ vmxnet3_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
                        gdesc->txd.tci = txm->vlan_tci;
                }
 
-               if (txm->ol_flags & PKT_TX_L4_MASK) {
+               if (tso) {
+                       uint16_t mss = txm->tso_segsz;
+
+                       VMXNET3_ASSERT(mss > 0);
+
+                       gdesc->txd.hlen = txm->l2_len + txm->l3_len + txm->l4_len;
+                       gdesc->txd.om = VMXNET3_OM_TSO;
+                       gdesc->txd.msscof = mss;
+
+                       deferred += (rte_pktmbuf_pkt_len(txm) - gdesc->txd.hlen + mss - 1) / mss;
+               } else if (txm->ol_flags & PKT_TX_L4_MASK) {
                        gdesc->txd.om = VMXNET3_OM_CSUM;
                        gdesc->txd.hlen = txm->l2_len + txm->l3_len;
 
@@ -425,17 +477,19 @@ vmxnet3_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
                                           txm->ol_flags & PKT_TX_L4_MASK);
                                abort();
                        }
+                       deferred++;
                } else {
                        gdesc->txd.hlen = 0;
                        gdesc->txd.om = VMXNET3_OM_NONE;
                        gdesc->txd.msscof = 0;
+                       deferred++;
                }
 
                /* flip the GEN bit on the SOP */
                rte_compiler_barrier();
                gdesc->dword[2] ^= VMXNET3_TXD_GEN;
 
-               txq_ctrl->txNumDeferred = rte_cpu_to_le_32(++deferred);
+               txq_ctrl->txNumDeferred = rte_cpu_to_le_32(deferred);
                nb_tx++;
        }