[dpdk-dev] [PATCH v2 6/6] net/mlx4: add loopback Tx from VF

Matan Azrad matan at mellanox.com
Tue Oct 3 12:48:31 CEST 2017


From: Moti Haimovsky <motih at mellanox.com>

This patch adds loopback functionality used when the chip is a VF
in order to enable packet transmission between VFs and between VFs and PF.

Signed-off-by: Moti Haimovsky <motih at mellanox.com>
---
 drivers/net/mlx4/mlx4_rxtx.c | 38 ++++++++++++++++++++++++++------------
 drivers/net/mlx4/mlx4_rxtx.h |  2 ++
 drivers/net/mlx4/mlx4_txq.c  |  2 ++
 3 files changed, 30 insertions(+), 12 deletions(-)

diff --git a/drivers/net/mlx4/mlx4_rxtx.c b/drivers/net/mlx4/mlx4_rxtx.c
index 1e91aaf..85fb6d7 100644
--- a/drivers/net/mlx4/mlx4_rxtx.c
+++ b/drivers/net/mlx4/mlx4_rxtx.c
@@ -320,10 +320,13 @@ struct pv {
 	struct mlx4_wqe_data_seg *dseg;
 	struct mlx4_sq *sq = &txq->msq;
 	struct rte_mbuf *buf;
+	union {
+		uint32_t flags;
+		uint16_t flags16[2];
+	} srcrb;
 	uint32_t head_idx = sq->head & sq->txbb_cnt_mask;
 	uint32_t lkey;
 	uintptr_t addr;
-	uint32_t srcrb_flags;
 	uint32_t owner_opcode = MLX4_OPCODE_SEND;
 	uint32_t byte_count;
 	int wqe_real_size;
@@ -421,21 +424,15 @@ struct pv {
 	/* Fill the control parameters for this packet. */
 	ctrl->fence_size = (wqe_real_size >> 4) & 0x3f;
 	/*
-	 * The caller should prepare "imm" in advance in order to support
-	 * VF to VF communication (when the device is a virtual-function
-	 * device (VF)).
-	*/
-	ctrl->imm = 0;
-	/*
 	 * For raw Ethernet, the SOLICIT flag is used to indicate that no icrc
 	 * should be calculated.
 	 */
 	txq->elts_comp_cd -= nr_txbbs;
 	if (unlikely(txq->elts_comp_cd <= 0)) {
 		txq->elts_comp_cd = txq->elts_comp_cd_init;
-		srcrb_flags = MLX4_WQE_CTRL_SOLICIT | MLX4_WQE_CTRL_CQ_UPDATE;
+		srcrb.flags = MLX4_WQE_CTRL_SOLICIT | MLX4_WQE_CTRL_CQ_UPDATE;
 	} else {
-		srcrb_flags = MLX4_WQE_CTRL_SOLICIT;
+		srcrb.flags = MLX4_WQE_CTRL_SOLICIT;
 	}
 	/* Enable HW checksum offload if requested */
 	if (txq->csum &&
@@ -449,13 +446,30 @@ struct pv {
 			owner_opcode |= MLX4_WQE_CTRL_IIP_HDR_CSUM |
 					MLX4_WQE_CTRL_IL4_HDR_CSUM;
 			if (pkt->ol_flags & PKT_TX_OUTER_IP_CKSUM)
-				srcrb_flags |= MLX4_WQE_CTRL_IP_HDR_CSUM;
+				srcrb.flags |= MLX4_WQE_CTRL_IP_HDR_CSUM;
 		} else {
-			srcrb_flags |= MLX4_WQE_CTRL_IP_HDR_CSUM |
+			srcrb.flags |= MLX4_WQE_CTRL_IP_HDR_CSUM |
 				      MLX4_WQE_CTRL_TCP_UDP_CSUM;
 		}
 	}
-	ctrl->srcrb_flags = rte_cpu_to_be_32(srcrb_flags);
+	/*
+	 * convert flags to BE before adding the mac address (if at all)
+	 * to it
+	 */
+	srcrb.flags = rte_cpu_to_be_32(srcrb.flags);
+	if (txq->lb) {
+		/*
+		 * Copy destination mac address to the wqe,
+		 * this allows loopback in eSwitch, so that VFs and PF
+		 * can communicate with each other.
+		 */
+		srcrb.flags16[0] = *(rte_pktmbuf_mtod(pkt, uint16_t *));
+		ctrl->imm = *(rte_pktmbuf_mtod_offset(pkt, uint32_t *,
+						      sizeof(uint16_t)));
+	} else {
+		ctrl->imm = 0;
+	}
+	ctrl->srcrb_flags = srcrb.flags;
 	/*
 	 * Make sure descriptor is fully written before
 	 * setting ownership bit (because HW can start
diff --git a/drivers/net/mlx4/mlx4_rxtx.h b/drivers/net/mlx4/mlx4_rxtx.h
index 75c98c1..6f33d1c 100644
--- a/drivers/net/mlx4/mlx4_rxtx.h
+++ b/drivers/net/mlx4/mlx4_rxtx.h
@@ -114,6 +114,8 @@ struct txq {
 	uint32_t max_inline; /**< Max inline send size. */
 	uint32_t csum:1; /**< Checksum is supported and enabled */
 	uint32_t csum_l2tun:1; /**< L2 tun Checksum is supported and enabled */
+	uint32_t lb:1;
+	/**< Whether pkts should be looped-back by eswitch or not */
 	char *bounce_buf;
 	/**< memory used for storing the first DWORD of data TXBBs. */
 	struct {
diff --git a/drivers/net/mlx4/mlx4_txq.c b/drivers/net/mlx4/mlx4_txq.c
index 2d776eb..fd1dce0 100644
--- a/drivers/net/mlx4/mlx4_txq.c
+++ b/drivers/net/mlx4/mlx4_txq.c
@@ -415,6 +415,8 @@ struct txq_mp2mr_mbuf_check_data {
 		      (void *)dev, strerror(rte_errno));
 		goto error;
 	}
+	/* If a VF device - need to loopback xmitted packets */
+	tmpl.lb = !!(priv->vf);
 	/* Clean up txq in case we're reinitializing it. */
 	DEBUG("%p: cleaning-up old txq just in case", (void *)txq);
 	mlx4_txq_cleanup(txq);
-- 
1.8.3.1



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