[PATCH net-next,V3, 1/3] net: ethtool: add ethtool COALESCE_RX_CQE_FRAMES/NSECS

[PATCH net-next,V3, 1/3] net: ethtool: add ethtool COALESCE_RX_CQE_FRAMES/NSECS

[Haiyang Zhang]

From: Haiyang Zhang <haiyangz@microsoft.com>

Add two parameters for drivers supporting Rx CQE Coalescing.

ETHTOOL_A_COALESCE_RX_CQE_FRAMES:
Maximum number of frames that can be coalesced into a CQE.

ETHTOOL_A_COALESCE_RX_CQE_NSECS:
Time out value in nanoseconds after the first packet arrival in a
coalesced CQE to be sent.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
---
 Documentation/netlink/specs/ethtool.yaml       |  8 ++++++++
 Documentation/networking/ethtool-netlink.rst   | 10 ++++++++++
 include/linux/ethtool.h                        |  6 +++++-
 include/uapi/linux/ethtool_netlink_generated.h |  2 ++
 net/ethtool/coalesce.c                         | 14 +++++++++++++-
 5 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/Documentation/netlink/specs/ethtool.yaml b/Documentation/netlink/specs/ethtool.yaml
index 4707063af3b4..d254e26c014c 100644
--- a/Documentation/netlink/specs/ethtool.yaml
+++ b/Documentation/netlink/specs/ethtool.yaml
@@ -861,6 +861,12 @@ attribute-sets:
         name: tx-profile
         type: nest
         nested-attributes: profile
+      -
+        name: rx-cqe-frames
+        type: u32
+      -
+        name: rx-cqe-nsecs
+        type: u32
 
   -
     name: pause-stat
@@ -2257,6 +2263,8 @@ operations:
             - tx-aggr-time-usecs
             - rx-profile
             - tx-profile
+            - rx-cqe-frames
+            - rx-cqe-nsecs
       dump: *coalesce-get-op
     -
       name: coalesce-set
diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index 32179168eb73..a9fbb16891fa 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -1076,6 +1076,8 @@ Kernel response contents:
   ``ETHTOOL_A_COALESCE_TX_AGGR_TIME_USECS``    u32     time (us), aggr, Tx
   ``ETHTOOL_A_COALESCE_RX_PROFILE``            nested  profile of DIM, Rx
   ``ETHTOOL_A_COALESCE_TX_PROFILE``            nested  profile of DIM, Tx
+  ``ETHTOOL_A_COALESCE_RX_CQE_FRAMES``         u32     max packets, Rx CQE
+  ``ETHTOOL_A_COALESCE_RX_CQE_NSECS``          u32     delay (ns), Rx CQE
   ===========================================  ======  =======================
 
 Attributes are only included in reply if their value is not zero or the
@@ -1109,6 +1111,12 @@ well with frequent small-sized URBs transmissions.
 to DIM parameters, see `Generic Network Dynamic Interrupt Moderation (Net DIM)
 <https://www.kernel.org/doc/Documentation/networking/net_dim.rst>`_.
 
+Rx CQE coalescing allows multiple received packets to be coalesced into a single
+Completion Queue Entry (CQE). ``ETHTOOL_A_COALESCE_RX_CQE_FRAMES`` describes the
+maximum number of frames that can be coalesced into a CQE.
+``ETHTOOL_A_COALESCE_RX_CQE_NSECS`` describes max time in nanoseconds after the
+first packet arrival in a coalesced CQE to be sent.
+
 COALESCE_SET
 ============
 
@@ -1147,6 +1155,8 @@ Request contents:
   ``ETHTOOL_A_COALESCE_TX_AGGR_TIME_USECS``    u32     time (us), aggr, Tx
   ``ETHTOOL_A_COALESCE_RX_PROFILE``            nested  profile of DIM, Rx
   ``ETHTOOL_A_COALESCE_TX_PROFILE``            nested  profile of DIM, Tx
+  ``ETHTOOL_A_COALESCE_RX_CQE_FRAMES``         u32     max packets, Rx CQE
+  ``ETHTOOL_A_COALESCE_RX_CQE_NSECS``          u32     delay (ns), Rx CQE
   ===========================================  ======  =======================
 
 Request is rejected if it attributes declared as unsupported by driver (i.e.
diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index 83c375840835..656d465bcd06 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -332,6 +332,8 @@ struct kernel_ethtool_coalesce {
 	u32 tx_aggr_max_bytes;
 	u32 tx_aggr_max_frames;
 	u32 tx_aggr_time_usecs;
+	u32 rx_cqe_frames;
+	u32 rx_cqe_nsecs;
 };
 
 /**
@@ -380,7 +382,9 @@ bool ethtool_convert_link_mode_to_legacy_u32(u32 *legacy_u32,
 #define ETHTOOL_COALESCE_TX_AGGR_TIME_USECS	BIT(26)
 #define ETHTOOL_COALESCE_RX_PROFILE		BIT(27)
 #define ETHTOOL_COALESCE_TX_PROFILE		BIT(28)
-#define ETHTOOL_COALESCE_ALL_PARAMS		GENMASK(28, 0)
+#define ETHTOOL_COALESCE_RX_CQE_FRAMES		BIT(29)
+#define ETHTOOL_COALESCE_RX_CQE_NSECS		BIT(30)
+#define ETHTOOL_COALESCE_ALL_PARAMS		GENMASK(30, 0)
 
 #define ETHTOOL_COALESCE_USECS						\
 	(ETHTOOL_COALESCE_RX_USECS | ETHTOOL_COALESCE_TX_USECS)
diff --git a/include/uapi/linux/ethtool_netlink_generated.h b/include/uapi/linux/ethtool_netlink_generated.h
index 114b83017297..8134baf7860f 100644
--- a/include/uapi/linux/ethtool_netlink_generated.h
+++ b/include/uapi/linux/ethtool_netlink_generated.h
@@ -371,6 +371,8 @@ enum {
 	ETHTOOL_A_COALESCE_TX_AGGR_TIME_USECS,
 	ETHTOOL_A_COALESCE_RX_PROFILE,
 	ETHTOOL_A_COALESCE_TX_PROFILE,
+	ETHTOOL_A_COALESCE_RX_CQE_FRAMES,
+	ETHTOOL_A_COALESCE_RX_CQE_NSECS,
 
 	__ETHTOOL_A_COALESCE_CNT,
 	ETHTOOL_A_COALESCE_MAX = (__ETHTOOL_A_COALESCE_CNT - 1)
diff --git a/net/ethtool/coalesce.c b/net/ethtool/coalesce.c
index 3e18ca1ccc5e..349bb02c517a 100644
--- a/net/ethtool/coalesce.c
+++ b/net/ethtool/coalesce.c
@@ -118,6 +118,8 @@ static int coalesce_reply_size(const struct ethnl_req_info *req_base,
 	       nla_total_size(sizeof(u32)) +	/* _TX_AGGR_MAX_BYTES */
 	       nla_total_size(sizeof(u32)) +	/* _TX_AGGR_MAX_FRAMES */
 	       nla_total_size(sizeof(u32)) +	/* _TX_AGGR_TIME_USECS */
+	       nla_total_size(sizeof(u32)) +	/* _RX_CQE_FRAMES */
+	       nla_total_size(sizeof(u32)) +	/* _RX_CQE_NSECS */
 	       total_modersz * 2;		/* _{R,T}X_PROFILE */
 }
 
@@ -269,7 +271,11 @@ static int coalesce_fill_reply(struct sk_buff *skb,
 	    coalesce_put_u32(skb, ETHTOOL_A_COALESCE_TX_AGGR_MAX_FRAMES,
 			     kcoal->tx_aggr_max_frames, supported) ||
 	    coalesce_put_u32(skb, ETHTOOL_A_COALESCE_TX_AGGR_TIME_USECS,
-			     kcoal->tx_aggr_time_usecs, supported))
+			     kcoal->tx_aggr_time_usecs, supported) ||
+	    coalesce_put_u32(skb, ETHTOOL_A_COALESCE_RX_CQE_FRAMES,
+			     kcoal->rx_cqe_frames, supported) ||
+	    coalesce_put_u32(skb, ETHTOOL_A_COALESCE_RX_CQE_NSECS,
+			     kcoal->rx_cqe_nsecs, supported))
 		return -EMSGSIZE;
 
 	if (!req_base->dev || !req_base->dev->irq_moder)
@@ -338,6 +344,8 @@ const struct nla_policy ethnl_coalesce_set_policy[] = {
 	[ETHTOOL_A_COALESCE_TX_AGGR_MAX_BYTES] = { .type = NLA_U32 },
 	[ETHTOOL_A_COALESCE_TX_AGGR_MAX_FRAMES] = { .type = NLA_U32 },
 	[ETHTOOL_A_COALESCE_TX_AGGR_TIME_USECS] = { .type = NLA_U32 },
+	[ETHTOOL_A_COALESCE_RX_CQE_FRAMES] = { .type = NLA_U32 },
+	[ETHTOOL_A_COALESCE_RX_CQE_NSECS] = { .type = NLA_U32 },
 	[ETHTOOL_A_COALESCE_RX_PROFILE] =
 		NLA_POLICY_NESTED(coalesce_profile_policy),
 	[ETHTOOL_A_COALESCE_TX_PROFILE] =
@@ -570,6 +578,10 @@ __ethnl_set_coalesce(struct ethnl_req_info *req_info, struct genl_info *info,
 			 tb[ETHTOOL_A_COALESCE_TX_AGGR_MAX_FRAMES], &mod);
 	ethnl_update_u32(&kernel_coalesce.tx_aggr_time_usecs,
 			 tb[ETHTOOL_A_COALESCE_TX_AGGR_TIME_USECS], &mod);
+	ethnl_update_u32(&kernel_coalesce.rx_cqe_frames,
+			 tb[ETHTOOL_A_COALESCE_RX_CQE_FRAMES], &mod);
+	ethnl_update_u32(&kernel_coalesce.rx_cqe_nsecs,
+			 tb[ETHTOOL_A_COALESCE_RX_CQE_NSECS], &mod);
 
 	if (dev->irq_moder && dev->irq_moder->profile_flags & DIM_PROFILE_RX) {
 		ret = ethnl_update_profile(dev, &dev->irq_moder->rx_profile,
-- 
2.34.1

[PATCH net-next,V3, 2/3] net: mana: Add support for RX CQE Coalescing

[Haiyang Zhang]

From: Haiyang Zhang <haiyangz@microsoft.com>

Our NIC can have up to 4 RX packets on 1 CQE. To support this feature,
check and process the type CQE_RX_COALESCED_4. The default setting is
disabled, to avoid possible regression on latency.

And, add ethtool handler to switch this feature. To turn it on, run:
  ethtool -C <nic> rx-cqe-frames 4
To turn it off:
  ethtool -C <nic> rx-cqe-frames 1

The rx-cqe-nsec is the time out value in nanoseconds after the first
packet arrival in a coalesced CQE to be sent. It's read-only for this
NIC.

Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
---
 drivers/net/ethernet/microsoft/mana/mana_en.c | 72 ++++++++++++-------
 .../ethernet/microsoft/mana/mana_ethtool.c    | 60 +++++++++++++++-
 include/net/mana/mana.h                       |  8 ++-
 3 files changed, 111 insertions(+), 29 deletions(-)

diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index ea71de39f996..c06fec50e51f 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -1365,6 +1365,7 @@ static int mana_cfg_vport_steering(struct mana_port_context *apc,
 			     sizeof(resp));
 
 	req->hdr.req.msg_version = GDMA_MESSAGE_V2;
+	req->hdr.resp.msg_version = GDMA_MESSAGE_V2;
 
 	req->vport = apc->port_handle;
 	req->num_indir_entries = apc->indir_table_sz;
@@ -1376,7 +1377,9 @@ static int mana_cfg_vport_steering(struct mana_port_context *apc,
 	req->update_hashkey = update_key;
 	req->update_indir_tab = update_tab;
 	req->default_rxobj = apc->default_rxobj;
-	req->cqe_coalescing_enable = 0;
+
+	if (rx != TRI_STATE_FALSE)
+		req->cqe_coalescing_enable = apc->cqe_coalescing_enable;
 
 	if (update_key)
 		memcpy(&req->hashkey, apc->hashkey, MANA_HASH_KEY_SIZE);
@@ -1407,6 +1410,10 @@ static int mana_cfg_vport_steering(struct mana_port_context *apc,
 		err = -EPROTO;
 	}
 
+	if (resp.hdr.response.msg_version >= GDMA_MESSAGE_V2)
+		apc->cqe_coalescing_timeout_ns =
+			resp.cqe_coalescing_timeout_ns;
+
 	netdev_info(ndev, "Configured steering vPort %llu entries %u\n",
 		    apc->port_handle, apc->indir_table_sz);
 out:
@@ -1915,11 +1922,12 @@ static struct sk_buff *mana_build_skb(struct mana_rxq *rxq, void *buf_va,
 }
 
 static void mana_rx_skb(void *buf_va, bool from_pool,
-			struct mana_rxcomp_oob *cqe, struct mana_rxq *rxq)
+			struct mana_rxcomp_oob *cqe, struct mana_rxq *rxq,
+			int i)
 {
 	struct mana_stats_rx *rx_stats = &rxq->stats;
 	struct net_device *ndev = rxq->ndev;
-	uint pkt_len = cqe->ppi[0].pkt_len;
+	uint pkt_len = cqe->ppi[i].pkt_len;
 	u16 rxq_idx = rxq->rxq_idx;
 	struct napi_struct *napi;
 	struct xdp_buff xdp = {};
@@ -1963,7 +1971,7 @@ static void mana_rx_skb(void *buf_va, bool from_pool,
 	}
 
 	if (cqe->rx_hashtype != 0 && (ndev->features & NETIF_F_RXHASH)) {
-		hash_value = cqe->ppi[0].pkt_hash;
+		hash_value = cqe->ppi[i].pkt_hash;
 
 		if (cqe->rx_hashtype & MANA_HASH_L4)
 			skb_set_hash(skb, hash_value, PKT_HASH_TYPE_L4);
@@ -2098,9 +2106,11 @@ static void mana_process_rx_cqe(struct mana_rxq *rxq, struct mana_cq *cq,
 	struct mana_recv_buf_oob *rxbuf_oob;
 	struct mana_port_context *apc;
 	struct device *dev = gc->dev;
+	bool coalesced = false;
 	void *old_buf = NULL;
 	u32 curr, pktlen;
 	bool old_fp;
+	int i;
 
 	apc = netdev_priv(ndev);
 
@@ -2112,13 +2122,16 @@ static void mana_process_rx_cqe(struct mana_rxq *rxq, struct mana_cq *cq,
 		++ndev->stats.rx_dropped;
 		rxbuf_oob = &rxq->rx_oobs[rxq->buf_index];
 		netdev_warn_once(ndev, "Dropped a truncated packet\n");
-		goto drop;
 
-	case CQE_RX_COALESCED_4:
-		netdev_err(ndev, "RX coalescing is unsupported\n");
-		apc->eth_stats.rx_coalesced_err++;
+		mana_move_wq_tail(rxq->gdma_rq,
+				  rxbuf_oob->wqe_inf.wqe_size_in_bu);
+		mana_post_pkt_rxq(rxq);
 		return;
 
+	case CQE_RX_COALESCED_4:
+		coalesced = true;
+		break;
+
 	case CQE_RX_OBJECT_FENCE:
 		complete(&rxq->fence_event);
 		return;
@@ -2130,30 +2143,36 @@ static void mana_process_rx_cqe(struct mana_rxq *rxq, struct mana_cq *cq,
 		return;
 	}
 
-	pktlen = oob->ppi[0].pkt_len;
+	for (i = 0; i < MANA_RXCOMP_OOB_NUM_PPI; i++) {
+		pktlen = oob->ppi[i].pkt_len;
+		if (pktlen == 0) {
+			if (i == 0)
+				netdev_err_once(
+					ndev,
+					"RX pkt len=0, rq=%u, cq=%u, rxobj=0x%llx\n",
+					rxq->gdma_id, cq->gdma_id, rxq->rxobj);
+			break;
+		}
 
-	if (pktlen == 0) {
-		/* data packets should never have packetlength of zero */
-		netdev_err(ndev, "RX pkt len=0, rq=%u, cq=%u, rxobj=0x%llx\n",
-			   rxq->gdma_id, cq->gdma_id, rxq->rxobj);
-		return;
-	}
+		curr = rxq->buf_index;
+		rxbuf_oob = &rxq->rx_oobs[curr];
+		WARN_ON_ONCE(rxbuf_oob->wqe_inf.wqe_size_in_bu != 1);
 
-	curr = rxq->buf_index;
-	rxbuf_oob = &rxq->rx_oobs[curr];
-	WARN_ON_ONCE(rxbuf_oob->wqe_inf.wqe_size_in_bu != 1);
+		mana_refill_rx_oob(dev, rxq, rxbuf_oob, &old_buf, &old_fp);
 
-	mana_refill_rx_oob(dev, rxq, rxbuf_oob, &old_buf, &old_fp);
+		/* Unsuccessful refill will have old_buf == NULL.
+		 * In this case, mana_rx_skb() will drop the packet.
+		 */
+		mana_rx_skb(old_buf, old_fp, oob, rxq, i);
 
-	/* Unsuccessful refill will have old_buf == NULL.
-	 * In this case, mana_rx_skb() will drop the packet.
-	 */
-	mana_rx_skb(old_buf, old_fp, oob, rxq);
+		mana_move_wq_tail(rxq->gdma_rq,
+				  rxbuf_oob->wqe_inf.wqe_size_in_bu);
 
-drop:
-	mana_move_wq_tail(rxq->gdma_rq, rxbuf_oob->wqe_inf.wqe_size_in_bu);
+		mana_post_pkt_rxq(rxq);
 
-	mana_post_pkt_rxq(rxq);
+		if (!coalesced)
+			break;
+	}
 }
 
 static void mana_poll_rx_cq(struct mana_cq *cq)
@@ -3332,6 +3351,7 @@ static int mana_probe_port(struct mana_context *ac, int port_idx,
 	apc->port_handle = INVALID_MANA_HANDLE;
 	apc->pf_filter_handle = INVALID_MANA_HANDLE;
 	apc->port_idx = port_idx;
+	apc->cqe_coalescing_enable = 0;
 
 	mutex_init(&apc->vport_mutex);
 	apc->vport_use_count = 0;
diff --git a/drivers/net/ethernet/microsoft/mana/mana_ethtool.c b/drivers/net/ethernet/microsoft/mana/mana_ethtool.c
index f2d220b371b5..4b234b16e57a 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_ethtool.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_ethtool.c
@@ -20,8 +20,6 @@ static const struct mana_stats_desc mana_eth_stats[] = {
 					tx_cqe_unknown_type)},
 	{"tx_linear_pkt_cnt", offsetof(struct mana_ethtool_stats,
 				       tx_linear_pkt_cnt)},
-	{"rx_coalesced_err", offsetof(struct mana_ethtool_stats,
-					rx_coalesced_err)},
 	{"rx_cqe_unknown_type", offsetof(struct mana_ethtool_stats,
 					rx_cqe_unknown_type)},
 };
@@ -390,6 +388,61 @@ static void mana_get_channels(struct net_device *ndev,
 	channel->combined_count = apc->num_queues;
 }
 
+#define MANA_RX_CQE_NSEC_DEF 2048
+static int mana_get_coalesce(struct net_device *ndev,
+			     struct ethtool_coalesce *ec,
+			     struct kernel_ethtool_coalesce *kernel_coal,
+			     struct netlink_ext_ack *extack)
+{
+	struct mana_port_context *apc = netdev_priv(ndev);
+
+	kernel_coal->rx_cqe_frames =
+		apc->cqe_coalescing_enable ? MANA_RXCOMP_OOB_NUM_PPI : 1;
+
+	kernel_coal->rx_cqe_nsecs = apc->cqe_coalescing_timeout_ns;
+
+	/* Return the default timeout value for old FW not providing
+	 * this value.
+	 */
+	if (apc->port_is_up && apc->cqe_coalescing_enable &&
+	    !kernel_coal->rx_cqe_nsecs)
+		kernel_coal->rx_cqe_nsecs = MANA_RX_CQE_NSEC_DEF;
+
+	return 0;
+}
+
+static int mana_set_coalesce(struct net_device *ndev,
+			     struct ethtool_coalesce *ec,
+			     struct kernel_ethtool_coalesce *kernel_coal,
+			     struct netlink_ext_ack *extack)
+{
+	struct mana_port_context *apc = netdev_priv(ndev);
+	u8 saved_cqe_coalescing_enable;
+	int err;
+
+	if (kernel_coal->rx_cqe_frames != 1 &&
+	    kernel_coal->rx_cqe_frames != MANA_RXCOMP_OOB_NUM_PPI) {
+		NL_SET_ERR_MSG_FMT(extack,
+				   "rx-frames must be 1 or %u, got %u",
+				   MANA_RXCOMP_OOB_NUM_PPI,
+				   kernel_coal->rx_cqe_frames);
+		return -EINVAL;
+	}
+
+	saved_cqe_coalescing_enable = apc->cqe_coalescing_enable;
+	apc->cqe_coalescing_enable =
+		kernel_coal->rx_cqe_frames == MANA_RXCOMP_OOB_NUM_PPI;
+
+	if (!apc->port_is_up)
+		return 0;
+
+	err = mana_config_rss(apc, TRI_STATE_TRUE, false, false);
+	if (err)
+		apc->cqe_coalescing_enable = saved_cqe_coalescing_enable;
+
+	return err;
+}
+
 static int mana_set_channels(struct net_device *ndev,
 			     struct ethtool_channels *channels)
 {
@@ -510,6 +563,7 @@ static int mana_get_link_ksettings(struct net_device *ndev,
 }
 
 const struct ethtool_ops mana_ethtool_ops = {
+	.supported_coalesce_params = ETHTOOL_COALESCE_RX_CQE_FRAMES,
 	.get_ethtool_stats	= mana_get_ethtool_stats,
 	.get_sset_count		= mana_get_sset_count,
 	.get_strings		= mana_get_strings,
@@ -520,6 +574,8 @@ const struct ethtool_ops mana_ethtool_ops = {
 	.set_rxfh		= mana_set_rxfh,
 	.get_channels		= mana_get_channels,
 	.set_channels		= mana_set_channels,
+	.get_coalesce		= mana_get_coalesce,
+	.set_coalesce		= mana_set_coalesce,
 	.get_ringparam          = mana_get_ringparam,
 	.set_ringparam          = mana_set_ringparam,
 	.get_link_ksettings	= mana_get_link_ksettings,
diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h
index a078af283bdd..a7f89e7ddc56 100644
--- a/include/net/mana/mana.h
+++ b/include/net/mana/mana.h
@@ -378,7 +378,6 @@ struct mana_ethtool_stats {
 	u64 tx_cqe_err;
 	u64 tx_cqe_unknown_type;
 	u64 tx_linear_pkt_cnt;
-	u64 rx_coalesced_err;
 	u64 rx_cqe_unknown_type;
 };
 
@@ -557,6 +556,9 @@ struct mana_port_context {
 	bool port_is_up;
 	bool port_st_save; /* Saved port state */
 
+	u8 cqe_coalescing_enable;
+	u32 cqe_coalescing_timeout_ns;
+
 	struct mana_ethtool_stats eth_stats;
 
 	struct mana_ethtool_phy_stats phy_stats;
@@ -902,6 +904,10 @@ struct mana_cfg_rx_steer_req_v2 {
 
 struct mana_cfg_rx_steer_resp {
 	struct gdma_resp_hdr hdr;
+
+	/* V2 */
+	u32 cqe_coalescing_timeout_ns;
+	u32 reserved1;
 }; /* HW DATA */
 
 /* Register HW vPort */
-- 
2.34.1

RE: [PATCH net-next,V3, 2/3] net: mana: Add support for RX CQE Coalescing

[Haiyang Zhang]

> -----Original Message-----
> From: Haiyang Zhang <haiyangz@linux.microsoft.com>
> Sent: Friday, March 6, 2026 6:19 PM
> To: linux-hyperv@vger.kernel.org; netdev@vger.kernel.org; KY Srinivasan
> <kys@microsoft.com>; Haiyang Zhang <haiyangz@microsoft.com>; Wei Liu
> <wei.liu@kernel.org>; Dexuan Cui <DECUI@microsoft.com>; Long Li
> <longli@microsoft.com>; Andrew Lunn <andrew+netdev@lunn.ch>; David S.
> Miller <davem@davemloft.net>; Eric Dumazet <edumazet@google.com>; Jakub
> Kicinski <kuba@kernel.org>; Paolo Abeni <pabeni@redhat.com>; Konstantin
> Taranov <kotaranov@microsoft.com>; Simon Horman <horms@kernel.org>; Erni
> Sri Satya Vennela <ernis@linux.microsoft.com>; Shradha Gupta
> <shradhagupta@linux.microsoft.com>; Dipayaan Roy
> <dipayanroy@linux.microsoft.com>; Shiraz Saleem
> <shirazsaleem@microsoft.com>; Kees Cook <kees@kernel.org>; Subbaraya
> Sundeep <sbhatta@marvell.com>; Breno Leitao <leitao@debian.org>; Aditya
> Garg <gargaditya@linux.microsoft.com>; linux-kernel@vger.kernel.org;
> linux-rdma@vger.kernel.org
> Cc: Paul Rosswurm <paulros@microsoft.com>
> Subject: [PATCH net-next,V3, 2/3] net: mana: Add support for RX CQE
> Coalescing
> 
> From: Haiyang Zhang <haiyangz@microsoft.com>

> @@ -2112,13 +2122,16 @@ static void mana_process_rx_cqe(struct mana_rxq
> *rxq, struct mana_cq *cq,
>  		++ndev->stats.rx_dropped;
>  		rxbuf_oob = &rxq->rx_oobs[rxq->buf_index];
>  		netdev_warn_once(ndev, "Dropped a truncated packet\n");
> -		goto drop;
> 
> -	case CQE_RX_COALESCED_4:
> -		netdev_err(ndev, "RX coalescing is unsupported\n");
> -		apc->eth_stats.rx_coalesced_err++;
> +		mana_move_wq_tail(rxq->gdma_rq,
> +				  rxbuf_oob->wqe_inf.wqe_size_in_bu);
> +		mana_post_pkt_rxq(rxq);
>  		return;
> 
> +	case CQE_RX_COALESCED_4:
> +		coalesced = true;
> +		break;
> +
>  	case CQE_RX_OBJECT_FENCE:
>  		complete(&rxq->fence_event);
>  		return;
> @@ -2130,30 +2143,36 @@ static void mana_process_rx_cqe(struct mana_rxq
> *rxq, struct mana_cq *cq,
>  		return;
>  	}
> 
> -	pktlen = oob->ppi[0].pkt_len;
> +	for (i = 0; i < MANA_RXCOMP_OOB_NUM_PPI; i++) {
> +		pktlen = oob->ppi[i].pkt_len;
> +		if (pktlen == 0) {
> +			if (i == 0)
> +				netdev_err_once(
> +					ndev,
> +					"RX pkt len=0, rq=%u, cq=%u,
> rxobj=0x%llx\n",
> +					rxq->gdma_id, cq->gdma_id, rxq->rxobj);
> +			break;
> +		}
> 
> -	if (pktlen == 0) {
> -		/* data packets should never have packetlength of zero */
> -		netdev_err(ndev, "RX pkt len=0, rq=%u, cq=%u, rxobj=0x%llx\n",
> -			   rxq->gdma_id, cq->gdma_id, rxq->rxobj);
> -		return;
> -	}
> +		curr = rxq->buf_index;
> +		rxbuf_oob = &rxq->rx_oobs[curr];
> +		WARN_ON_ONCE(rxbuf_oob->wqe_inf.wqe_size_in_bu != 1);
> 
> -	curr = rxq->buf_index;
> -	rxbuf_oob = &rxq->rx_oobs[curr];
> -	WARN_ON_ONCE(rxbuf_oob->wqe_inf.wqe_size_in_bu != 1);
> +		mana_refill_rx_oob(dev, rxq, rxbuf_oob, &old_buf, &old_fp);
> 
> -	mana_refill_rx_oob(dev, rxq, rxbuf_oob, &old_buf, &old_fp);
> +		/* Unsuccessful refill will have old_buf == NULL.
> +		 * In this case, mana_rx_skb() will drop the packet.
> +		 */
> +		mana_rx_skb(old_buf, old_fp, oob, rxq, i);
> 
> -	/* Unsuccessful refill will have old_buf == NULL.
> -	 * In this case, mana_rx_skb() will drop the packet.
> -	 */
> -	mana_rx_skb(old_buf, old_fp, oob, rxq);
> +		mana_move_wq_tail(rxq->gdma_rq,
> +				  rxbuf_oob->wqe_inf.wqe_size_in_bu);

I will fix this pointed out by AI review:

> The comment says "Unsuccessful refill will have old_buf == NULL" but this is
> only true for the first iteration.
> Should old_buf be set to NULL at the top of the loop, before calling
> mana_refill_rx_oob()?

[PATCH net-next,V3, 3/3] net: mana: Add ethtool counters for RX CQEs in coalesced type

[Haiyang Zhang]

From: Haiyang Zhang <haiyangz@microsoft.com>

For RX CQEs with type CQE_RX_COALESCED_4, to measure the coalescing
efficiency, add counters to count how many contains 2, 3, 4 packets
respectively.
Also, add a counter for the error case of first packet with length == 0.

Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
---
 drivers/net/ethernet/microsoft/mana/mana_en.c | 21 ++++++++++++++++++-
 .../ethernet/microsoft/mana/mana_ethtool.c    | 15 +++++++++++--
 include/net/mana/mana.h                       |  9 +++++---
 3 files changed, 39 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index c06fec50e51f..11ea2b17502d 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -2146,11 +2146,23 @@ static void mana_process_rx_cqe(struct mana_rxq *rxq, struct mana_cq *cq,
 	for (i = 0; i < MANA_RXCOMP_OOB_NUM_PPI; i++) {
 		pktlen = oob->ppi[i].pkt_len;
 		if (pktlen == 0) {
-			if (i == 0)
+			/* Collect coalesced CQE count based on packets processed.
+			 * Coalesced CQEs have at least 2 packets, so index is i - 2.
+			 */
+			if (i > 1) {
+				u64_stats_update_begin(&rxq->stats.syncp);
+				rxq->stats.coalesced_cqe[i - 2]++;
+				u64_stats_update_end(&rxq->stats.syncp);
+			} else if (i == 0) {
+				/* Error case stat */
+				u64_stats_update_begin(&rxq->stats.syncp);
+				rxq->stats.pkt_len0_err++;
+				u64_stats_update_end(&rxq->stats.syncp);
 				netdev_err_once(
 					ndev,
 					"RX pkt len=0, rq=%u, cq=%u, rxobj=0x%llx\n",
 					rxq->gdma_id, cq->gdma_id, rxq->rxobj);
+			}
 			break;
 		}
 
@@ -2173,6 +2185,13 @@ static void mana_process_rx_cqe(struct mana_rxq *rxq, struct mana_cq *cq,
 		if (!coalesced)
 			break;
 	}
+
+	/* Coalesced CQE with all 4 packets */
+	if (coalesced && i == MANA_RXCOMP_OOB_NUM_PPI) {
+		u64_stats_update_begin(&rxq->stats.syncp);
+		rxq->stats.coalesced_cqe[MANA_RXCOMP_OOB_NUM_PPI - 2]++;
+		u64_stats_update_end(&rxq->stats.syncp);
+	}
 }
 
 static void mana_poll_rx_cq(struct mana_cq *cq)
diff --git a/drivers/net/ethernet/microsoft/mana/mana_ethtool.c b/drivers/net/ethernet/microsoft/mana/mana_ethtool.c
index 4b234b16e57a..6a4b42fe0944 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_ethtool.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_ethtool.c
@@ -149,7 +149,7 @@ static void mana_get_strings(struct net_device *ndev, u32 stringset, u8 *data)
 {
 	struct mana_port_context *apc = netdev_priv(ndev);
 	unsigned int num_queues = apc->num_queues;
-	int i;
+	int i, j;
 
 	if (stringset != ETH_SS_STATS)
 		return;
@@ -168,6 +168,9 @@ static void mana_get_strings(struct net_device *ndev, u32 stringset, u8 *data)
 		ethtool_sprintf(&data, "rx_%d_xdp_drop", i);
 		ethtool_sprintf(&data, "rx_%d_xdp_tx", i);
 		ethtool_sprintf(&data, "rx_%d_xdp_redirect", i);
+		ethtool_sprintf(&data, "rx_%d_pkt_len0_err", i);
+		for (j = 0; j < MANA_RXCOMP_OOB_NUM_PPI - 1; j++)
+			ethtool_sprintf(&data, "rx_%d_coalesced_cqe_%d", i, j + 2);
 	}
 
 	for (i = 0; i < num_queues; i++) {
@@ -201,6 +204,8 @@ static void mana_get_ethtool_stats(struct net_device *ndev,
 	u64 xdp_xmit;
 	u64 xdp_drop;
 	u64 xdp_tx;
+	u64 pkt_len0_err;
+	u64 coalesced_cqe[MANA_RXCOMP_OOB_NUM_PPI - 1];
 	u64 tso_packets;
 	u64 tso_bytes;
 	u64 tso_inner_packets;
@@ -209,7 +214,7 @@ static void mana_get_ethtool_stats(struct net_device *ndev,
 	u64 short_pkt_fmt;
 	u64 csum_partial;
 	u64 mana_map_err;
-	int q, i = 0;
+	int q, i = 0, j;
 
 	if (!apc->port_is_up)
 		return;
@@ -239,6 +244,9 @@ static void mana_get_ethtool_stats(struct net_device *ndev,
 			xdp_drop = rx_stats->xdp_drop;
 			xdp_tx = rx_stats->xdp_tx;
 			xdp_redirect = rx_stats->xdp_redirect;
+			pkt_len0_err = rx_stats->pkt_len0_err;
+			for (j = 0; j < MANA_RXCOMP_OOB_NUM_PPI - 1; j++)
+				coalesced_cqe[j] = rx_stats->coalesced_cqe[j];
 		} while (u64_stats_fetch_retry(&rx_stats->syncp, start));
 
 		data[i++] = packets;
@@ -246,6 +254,9 @@ static void mana_get_ethtool_stats(struct net_device *ndev,
 		data[i++] = xdp_drop;
 		data[i++] = xdp_tx;
 		data[i++] = xdp_redirect;
+		data[i++] = pkt_len0_err;
+		for (j = 0; j < MANA_RXCOMP_OOB_NUM_PPI - 1; j++)
+			data[i++] = coalesced_cqe[j];
 	}
 
 	for (q = 0; q < num_queues; q++) {
diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h
index a7f89e7ddc56..3336688fed5e 100644
--- a/include/net/mana/mana.h
+++ b/include/net/mana/mana.h
@@ -61,8 +61,11 @@ enum TRI_STATE {
 
 #define MAX_PORTS_IN_MANA_DEV 256
 
+/* Maximum number of packets per coalesced CQE */
+#define MANA_RXCOMP_OOB_NUM_PPI 4
+
 /* Update this count whenever the respective structures are changed */
-#define MANA_STATS_RX_COUNT 5
+#define MANA_STATS_RX_COUNT (6 + MANA_RXCOMP_OOB_NUM_PPI - 1)
 #define MANA_STATS_TX_COUNT 11
 
 #define MANA_RX_FRAG_ALIGNMENT 64
@@ -73,6 +76,8 @@ struct mana_stats_rx {
 	u64 xdp_drop;
 	u64 xdp_tx;
 	u64 xdp_redirect;
+	u64 pkt_len0_err;
+	u64 coalesced_cqe[MANA_RXCOMP_OOB_NUM_PPI - 1];
 	struct u64_stats_sync syncp;
 };
 
@@ -227,8 +232,6 @@ struct mana_rxcomp_perpkt_info {
 	u32 pkt_hash;
 }; /* HW DATA */
 
-#define MANA_RXCOMP_OOB_NUM_PPI 4
-
 /* Receive completion OOB */
 struct mana_rxcomp_oob {
 	struct mana_cqe_header cqe_hdr;
-- 
2.34.1