[PATCH net,v2, 0/3] net: mana: Fix some TX processing bugs

[PATCH net,v2, 0/3] net: mana: Fix some TX processing bugs

[Haiyang Zhang]

Fix TX processing bugs on error handling, tso_bytes calculation,
and sge0 size.

Haiyang Zhang (3):
  net: mana: Fix TX CQE error handling
  net: mana: Fix the tso_bytes calculation
  net: mana: Fix oversized sge0 for GSO packets

 drivers/net/ethernet/microsoft/mana/mana_en.c | 211 ++++++++++++------
 include/net/mana/mana.h                       |   5 +-
 2 files changed, 149 insertions(+), 67 deletions(-)

-- 
2.25.1

[PATCH net,v2, 1/3] net: mana: Fix TX CQE error handling

[Haiyang Zhang]

For an unknown TX CQE error type (probably from a newer hardware),
still free the SKB, update the queue tail, etc., otherwise the
accounting will be wrong.

Also, TX errors can be triggered by injecting corrupted packets, so
replace the WARN_ONCE to ratelimited error logging.

Cc: stable@vger.kernel.org
Fixes: ca9c54d2d6a5 ("net: mana: Add a driver for Microsoft Azure Network Adapter (MANA)")
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: Simon Horman <horms@kernel.org>
---
 drivers/net/ethernet/microsoft/mana/mana_en.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index 4a16ebff3d1d..5cdcf7561b38 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -1317,19 +1317,23 @@ static void mana_poll_tx_cq(struct mana_cq *cq)
 		case CQE_TX_VPORT_IDX_OUT_OF_RANGE:
 		case CQE_TX_VPORT_DISABLED:
 		case CQE_TX_VLAN_TAGGING_VIOLATION:
-			WARN_ONCE(1, "TX: CQE error %d: ignored.\n",
-				  cqe_oob->cqe_hdr.cqe_type);
+			if (net_ratelimit())
+				netdev_err(ndev, "TX: CQE error %d\n",
+					   cqe_oob->cqe_hdr.cqe_type);
+
 			apc->eth_stats.tx_cqe_err++;
 			break;
 
 		default:
-			/* If the CQE type is unexpected, log an error, assert,
-			 * and go through the error path.
+			/* If the CQE type is unknown, log an error,
+			 * and still free the SKB, update tail, etc.
 			 */
-			WARN_ONCE(1, "TX: Unexpected CQE type %d: HW BUG?\n",
-				  cqe_oob->cqe_hdr.cqe_type);
+			if (net_ratelimit())
+				netdev_err(ndev, "TX: unknown CQE type %d\n",
+					   cqe_oob->cqe_hdr.cqe_type);
+
 			apc->eth_stats.tx_cqe_unknown_type++;
-			return;
+			break;
 		}
 
 		if (WARN_ON_ONCE(txq->gdma_txq_id != completions[i].wq_num))
-- 
2.25.1

Re: [PATCH net,v2, 1/3] net: mana: Fix TX CQE error handling

[Shradha Gupta]

On Fri, Sep 29, 2023 at 01:42:25PM -0700, Haiyang Zhang wrote:
> For an unknown TX CQE error type (probably from a newer hardware),
> still free the SKB, update the queue tail, etc., otherwise the
> accounting will be wrong.
> 
> Also, TX errors can be triggered by injecting corrupted packets, so
> replace the WARN_ONCE to ratelimited error logging.
> 
> Cc: stable@vger.kernel.org
> Fixes: ca9c54d2d6a5 ("net: mana: Add a driver for Microsoft Azure Network Adapter (MANA)")
> Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
> Reviewed-by: Simon Horman <horms@kernel.org>
> ---
>  drivers/net/ethernet/microsoft/mana/mana_en.c | 18 +++++++++++-------
>  1 file changed, 11 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
> index 4a16ebff3d1d..5cdcf7561b38 100644
> --- a/drivers/net/ethernet/microsoft/mana/mana_en.c
> +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
> @@ -1317,19 +1317,23 @@ static void mana_poll_tx_cq(struct mana_cq *cq)
>  		case CQE_TX_VPORT_IDX_OUT_OF_RANGE:
>  		case CQE_TX_VPORT_DISABLED:
>  		case CQE_TX_VLAN_TAGGING_VIOLATION:
> -			WARN_ONCE(1, "TX: CQE error %d: ignored.\n",
> -				  cqe_oob->cqe_hdr.cqe_type);
> +			if (net_ratelimit())
> +				netdev_err(ndev, "TX: CQE error %d\n",
> +					   cqe_oob->cqe_hdr.cqe_type);
> +
>  			apc->eth_stats.tx_cqe_err++;
>  			break;
>  
>  		default:
> -			/* If the CQE type is unexpected, log an error, assert,
> -			 * and go through the error path.
> +			/* If the CQE type is unknown, log an error,
> +			 * and still free the SKB, update tail, etc.
>  			 */
> -			WARN_ONCE(1, "TX: Unexpected CQE type %d: HW BUG?\n",
> -				  cqe_oob->cqe_hdr.cqe_type);
> +			if (net_ratelimit())
> +				netdev_err(ndev, "TX: unknown CQE type %d\n",
> +					   cqe_oob->cqe_hdr.cqe_type);
> +
>  			apc->eth_stats.tx_cqe_unknown_type++;
> -			return;
> +			break;
>  		}
>  
>  		if (WARN_ON_ONCE(txq->gdma_txq_id != completions[i].wq_num))
> -- 
> 2.25.1
Reviewed-by: Shradha Gupta <shradhagupta@linux.microsoft.com>

[PATCH net,v2, 2/3] net: mana: Fix the tso_bytes calculation

[Haiyang Zhang]

sizeof(struct hop_jumbo_hdr) is not part of tso_bytes, so remove
the subtraction from header size.

Cc: stable@vger.kernel.org
Fixes: bd7fc6e1957c ("net: mana: Add new MANA VF performance counters for easier troubleshooting")
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: Simon Horman <horms@kernel.org>
---
 drivers/net/ethernet/microsoft/mana/mana_en.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index 5cdcf7561b38..86e724c3eb89 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -264,8 +264,6 @@ netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 				ihs = skb_transport_offset(skb) + sizeof(struct udphdr);
 			} else {
 				ihs = skb_tcp_all_headers(skb);
-				if (ipv6_has_hopopt_jumbo(skb))
-					ihs -= sizeof(struct hop_jumbo_hdr);
 			}
 
 			u64_stats_update_begin(&tx_stats->syncp);
-- 
2.25.1

Re: [PATCH net,v2, 2/3] net: mana: Fix the tso_bytes calculation

[Shradha Gupta]

On Fri, Sep 29, 2023 at 01:42:26PM -0700, Haiyang Zhang wrote:
> sizeof(struct hop_jumbo_hdr) is not part of tso_bytes, so remove
> the subtraction from header size.
> 
> Cc: stable@vger.kernel.org
> Fixes: bd7fc6e1957c ("net: mana: Add new MANA VF performance counters for easier troubleshooting")
> Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
> Reviewed-by: Simon Horman <horms@kernel.org>
> ---
>  drivers/net/ethernet/microsoft/mana/mana_en.c | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
> index 5cdcf7561b38..86e724c3eb89 100644
> --- a/drivers/net/ethernet/microsoft/mana/mana_en.c
> +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
> @@ -264,8 +264,6 @@ netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev)
>  				ihs = skb_transport_offset(skb) + sizeof(struct udphdr);
>  			} else {
>  				ihs = skb_tcp_all_headers(skb);
> -				if (ipv6_has_hopopt_jumbo(skb))
> -					ihs -= sizeof(struct hop_jumbo_hdr);
>  			}
>  
>  			u64_stats_update_begin(&tx_stats->syncp);
> -- 
> 2.25.1
Reviewed-by:Shradha Gupta <shradhagupta@linux.microsoft.com>

[PATCH net,v2, 3/3] net: mana: Fix oversized sge0 for GSO packets

[Haiyang Zhang]

Handle the case when GSO SKB linear length is too large.

MANA NIC requires GSO packets to put only the header part to SGE0,
otherwise the TX queue may stop at the HW level.

So, use 2 SGEs for the skb linear part which contains more than the
packet header.

Fixes: ca9c54d2d6a5 ("net: mana: Add a driver for Microsoft Azure Network Adapter (MANA)")
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
---
v2: coding style updates suggested by Simon Horman

---
 drivers/net/ethernet/microsoft/mana/mana_en.c | 191 +++++++++++++-----
 include/net/mana/mana.h                       |   5 +-
 2 files changed, 138 insertions(+), 58 deletions(-)

diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index 86e724c3eb89..48ea4aeeea5d 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -91,63 +91,137 @@ static unsigned int mana_checksum_info(struct sk_buff *skb)
 	return 0;
 }
 
+static void mana_add_sge(struct mana_tx_package *tp, struct mana_skb_head *ash,
+			 int sg_i, dma_addr_t da, int sge_len, u32 gpa_mkey)
+{
+	ash->dma_handle[sg_i] = da;
+	ash->size[sg_i] = sge_len;
+
+	tp->wqe_req.sgl[sg_i].address = da;
+	tp->wqe_req.sgl[sg_i].mem_key = gpa_mkey;
+	tp->wqe_req.sgl[sg_i].size = sge_len;
+}
+
 static int mana_map_skb(struct sk_buff *skb, struct mana_port_context *apc,
-			struct mana_tx_package *tp)
+			struct mana_tx_package *tp, int gso_hs)
 {
 	struct mana_skb_head *ash = (struct mana_skb_head *)skb->head;
+	int hsg = 1; /* num of SGEs of linear part */
 	struct gdma_dev *gd = apc->ac->gdma_dev;
+	int skb_hlen = skb_headlen(skb);
+	int sge0_len, sge1_len = 0;
 	struct gdma_context *gc;
 	struct device *dev;
 	skb_frag_t *frag;
 	dma_addr_t da;
+	int sg_i;
 	int i;
 
 	gc = gd->gdma_context;
 	dev = gc->dev;
-	da = dma_map_single(dev, skb->data, skb_headlen(skb), DMA_TO_DEVICE);
 
+	if (gso_hs && gso_hs < skb_hlen) {
+		sge0_len = gso_hs;
+		sge1_len = skb_hlen - gso_hs;
+	} else {
+		sge0_len = skb_hlen;
+	}
+
+	da = dma_map_single(dev, skb->data, sge0_len, DMA_TO_DEVICE);
 	if (dma_mapping_error(dev, da))
 		return -ENOMEM;
 
-	ash->dma_handle[0] = da;
-	ash->size[0] = skb_headlen(skb);
+	mana_add_sge(tp, ash, 0, da, sge0_len, gd->gpa_mkey);
 
-	tp->wqe_req.sgl[0].address = ash->dma_handle[0];
-	tp->wqe_req.sgl[0].mem_key = gd->gpa_mkey;
-	tp->wqe_req.sgl[0].size = ash->size[0];
+	if (sge1_len) {
+		sg_i = 1;
+		da = dma_map_single(dev, skb->data + sge0_len, sge1_len,
+				    DMA_TO_DEVICE);
+		if (dma_mapping_error(dev, da))
+			goto frag_err;
+
+		mana_add_sge(tp, ash, sg_i, da, sge1_len, gd->gpa_mkey);
+		hsg = 2;
+	}
 
 	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+		sg_i = hsg + i;
+
 		frag = &skb_shinfo(skb)->frags[i];
 		da = skb_frag_dma_map(dev, frag, 0, skb_frag_size(frag),
 				      DMA_TO_DEVICE);
-
 		if (dma_mapping_error(dev, da))
 			goto frag_err;
 
-		ash->dma_handle[i + 1] = da;
-		ash->size[i + 1] = skb_frag_size(frag);
-
-		tp->wqe_req.sgl[i + 1].address = ash->dma_handle[i + 1];
-		tp->wqe_req.sgl[i + 1].mem_key = gd->gpa_mkey;
-		tp->wqe_req.sgl[i + 1].size = ash->size[i + 1];
+		mana_add_sge(tp, ash, sg_i, da, skb_frag_size(frag),
+			     gd->gpa_mkey);
 	}
 
 	return 0;
 
 frag_err:
-	for (i = i - 1; i >= 0; i--)
-		dma_unmap_page(dev, ash->dma_handle[i + 1], ash->size[i + 1],
+	for (i = sg_i - 1; i >= hsg; i--)
+		dma_unmap_page(dev, ash->dma_handle[i], ash->size[i],
 			       DMA_TO_DEVICE);
 
-	dma_unmap_single(dev, ash->dma_handle[0], ash->size[0], DMA_TO_DEVICE);
+	for (i = hsg - 1; i >= 0; i--)
+		dma_unmap_single(dev, ash->dma_handle[i], ash->size[i],
+				 DMA_TO_DEVICE);
 
 	return -ENOMEM;
 }
 
+/* Handle the case when GSO SKB linear length is too large.
+ * MANA NIC requires GSO packets to put only the packet header to SGE0.
+ * So, we need 2 SGEs for the skb linear part which contains more than the
+ * header.
+ * Return a positive value for the number of SGEs, or a negative value
+ * for an error.
+ */
+static int mana_fix_skb_head(struct net_device *ndev, struct sk_buff *skb,
+			     int gso_hs)
+{
+	int num_sge = 1 + skb_shinfo(skb)->nr_frags;
+	int skb_hlen = skb_headlen(skb);
+
+	if (gso_hs < skb_hlen) {
+		num_sge++;
+	} else if (gso_hs > skb_hlen) {
+		if (net_ratelimit())
+			netdev_err(ndev,
+				   "TX nonlinear head: hs:%d, skb_hlen:%d\n",
+				   gso_hs, skb_hlen);
+
+		return -EINVAL;
+	}
+
+	return num_sge;
+}
+
+/* Get the GSO packet's header size */
+static int mana_get_gso_hs(struct sk_buff *skb)
+{
+	int gso_hs;
+
+	if (skb->encapsulation) {
+		gso_hs = skb_inner_tcp_all_headers(skb);
+	} else {
+		if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) {
+			gso_hs = skb_transport_offset(skb) +
+				 sizeof(struct udphdr);
+		} else {
+			gso_hs = skb_tcp_all_headers(skb);
+		}
+	}
+
+	return gso_hs;
+}
+
 netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 {
 	enum mana_tx_pkt_format pkt_fmt = MANA_SHORT_PKT_FMT;
 	struct mana_port_context *apc = netdev_priv(ndev);
+	int gso_hs = 0; /* zero for non-GSO pkts */
 	u16 txq_idx = skb_get_queue_mapping(skb);
 	struct gdma_dev *gd = apc->ac->gdma_dev;
 	bool ipv4 = false, ipv6 = false;
@@ -159,7 +233,6 @@ netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 	struct mana_txq *txq;
 	struct mana_cq *cq;
 	int err, len;
-	u16 ihs;
 
 	if (unlikely(!apc->port_is_up))
 		goto tx_drop;
@@ -209,19 +282,6 @@ netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 	pkg.wqe_req.client_data_unit = 0;
 
 	pkg.wqe_req.num_sge = 1 + skb_shinfo(skb)->nr_frags;
-	WARN_ON_ONCE(pkg.wqe_req.num_sge > MAX_TX_WQE_SGL_ENTRIES);
-
-	if (pkg.wqe_req.num_sge <= ARRAY_SIZE(pkg.sgl_array)) {
-		pkg.wqe_req.sgl = pkg.sgl_array;
-	} else {
-		pkg.sgl_ptr = kmalloc_array(pkg.wqe_req.num_sge,
-					    sizeof(struct gdma_sge),
-					    GFP_ATOMIC);
-		if (!pkg.sgl_ptr)
-			goto tx_drop_count;
-
-		pkg.wqe_req.sgl = pkg.sgl_ptr;
-	}
 
 	if (skb->protocol == htons(ETH_P_IP))
 		ipv4 = true;
@@ -229,6 +289,26 @@ netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 		ipv6 = true;
 
 	if (skb_is_gso(skb)) {
+		int num_sge;
+
+		gso_hs = mana_get_gso_hs(skb);
+
+		num_sge = mana_fix_skb_head(ndev, skb, gso_hs);
+		if (num_sge > 0)
+			pkg.wqe_req.num_sge = num_sge;
+		else
+			goto tx_drop_count;
+
+		u64_stats_update_begin(&tx_stats->syncp);
+		if (skb->encapsulation) {
+			tx_stats->tso_inner_packets++;
+			tx_stats->tso_inner_bytes += skb->len - gso_hs;
+		} else {
+			tx_stats->tso_packets++;
+			tx_stats->tso_bytes += skb->len - gso_hs;
+		}
+		u64_stats_update_end(&tx_stats->syncp);
+
 		pkg.tx_oob.s_oob.is_outer_ipv4 = ipv4;
 		pkg.tx_oob.s_oob.is_outer_ipv6 = ipv6;
 
@@ -252,26 +332,6 @@ netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 						 &ipv6_hdr(skb)->daddr, 0,
 						 IPPROTO_TCP, 0);
 		}
-
-		if (skb->encapsulation) {
-			ihs = skb_inner_tcp_all_headers(skb);
-			u64_stats_update_begin(&tx_stats->syncp);
-			tx_stats->tso_inner_packets++;
-			tx_stats->tso_inner_bytes += skb->len - ihs;
-			u64_stats_update_end(&tx_stats->syncp);
-		} else {
-			if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) {
-				ihs = skb_transport_offset(skb) + sizeof(struct udphdr);
-			} else {
-				ihs = skb_tcp_all_headers(skb);
-			}
-
-			u64_stats_update_begin(&tx_stats->syncp);
-			tx_stats->tso_packets++;
-			tx_stats->tso_bytes += skb->len - ihs;
-			u64_stats_update_end(&tx_stats->syncp);
-		}
-
 	} else if (skb->ip_summed == CHECKSUM_PARTIAL) {
 		csum_type = mana_checksum_info(skb);
 
@@ -294,11 +354,25 @@ netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 		} else {
 			/* Can't do offload of this type of checksum */
 			if (skb_checksum_help(skb))
-				goto free_sgl_ptr;
+				goto tx_drop_count;
 		}
 	}
 
-	if (mana_map_skb(skb, apc, &pkg)) {
+	WARN_ON_ONCE(pkg.wqe_req.num_sge > MAX_TX_WQE_SGL_ENTRIES);
+
+	if (pkg.wqe_req.num_sge <= ARRAY_SIZE(pkg.sgl_array)) {
+		pkg.wqe_req.sgl = pkg.sgl_array;
+	} else {
+		pkg.sgl_ptr = kmalloc_array(pkg.wqe_req.num_sge,
+					    sizeof(struct gdma_sge),
+					    GFP_ATOMIC);
+		if (!pkg.sgl_ptr)
+			goto tx_drop_count;
+
+		pkg.wqe_req.sgl = pkg.sgl_ptr;
+	}
+
+	if (mana_map_skb(skb, apc, &pkg, gso_hs)) {
 		u64_stats_update_begin(&tx_stats->syncp);
 		tx_stats->mana_map_err++;
 		u64_stats_update_end(&tx_stats->syncp);
@@ -1256,11 +1330,16 @@ static void mana_unmap_skb(struct sk_buff *skb, struct mana_port_context *apc)
 	struct mana_skb_head *ash = (struct mana_skb_head *)skb->head;
 	struct gdma_context *gc = apc->ac->gdma_dev->gdma_context;
 	struct device *dev = gc->dev;
-	int i;
+	int hsg, i;
+
+	/* Number of SGEs of linear part */
+	hsg = (skb_is_gso(skb) && skb_headlen(skb) > ash->size[0]) ? 2 : 1;
 
-	dma_unmap_single(dev, ash->dma_handle[0], ash->size[0], DMA_TO_DEVICE);
+	for (i = 0; i < hsg; i++)
+		dma_unmap_single(dev, ash->dma_handle[i], ash->size[i],
+				 DMA_TO_DEVICE);
 
-	for (i = 1; i < skb_shinfo(skb)->nr_frags + 1; i++)
+	for (i = hsg; i < skb_shinfo(skb)->nr_frags + hsg; i++)
 		dma_unmap_page(dev, ash->dma_handle[i], ash->size[i],
 			       DMA_TO_DEVICE);
 }
diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h
index 9f70b4332238..4d43adf18606 100644
--- a/include/net/mana/mana.h
+++ b/include/net/mana/mana.h
@@ -103,9 +103,10 @@ struct mana_txq {
 
 /* skb data and frags dma mappings */
 struct mana_skb_head {
-	dma_addr_t dma_handle[MAX_SKB_FRAGS + 1];
+	/* GSO pkts may have 2 SGEs for the linear part*/
+	dma_addr_t dma_handle[MAX_SKB_FRAGS + 2];
 
-	u32 size[MAX_SKB_FRAGS + 1];
+	u32 size[MAX_SKB_FRAGS + 2];
 };
 
 #define MANA_HEADROOM sizeof(struct mana_skb_head)
-- 
2.25.1

Re: [PATCH net,v2, 3/3] net: mana: Fix oversized sge0 for GSO packets

[Simon Horman]

On Fri, Sep 29, 2023 at 01:42:27PM -0700, Haiyang Zhang wrote:
> Handle the case when GSO SKB linear length is too large.
> 
> MANA NIC requires GSO packets to put only the header part to SGE0,
> otherwise the TX queue may stop at the HW level.
> 
> So, use 2 SGEs for the skb linear part which contains more than the
> packet header.
> 
> Fixes: ca9c54d2d6a5 ("net: mana: Add a driver for Microsoft Azure Network Adapter (MANA)")
> Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
> ---
> v2: coding style updates suggested by Simon Horman

Reviewed-by: Simon Horman <horms@kernel.org>

Re: [PATCH net,v2, 3/3] net: mana: Fix oversized sge0 for GSO packets

[Shradha Gupta]

On Fri, Sep 29, 2023 at 01:42:27PM -0700, Haiyang Zhang wrote:
> Handle the case when GSO SKB linear length is too large.
> 
> MANA NIC requires GSO packets to put only the header part to SGE0,
> otherwise the TX queue may stop at the HW level.
> 
> So, use 2 SGEs for the skb linear part which contains more than the
> packet header.
> 
> Fixes: ca9c54d2d6a5 ("net: mana: Add a driver for Microsoft Azure Network Adapter (MANA)")
> Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
> ---
> v2: coding style updates suggested by Simon Horman
> 
> ---
>  drivers/net/ethernet/microsoft/mana/mana_en.c | 191 +++++++++++++-----
>  include/net/mana/mana.h                       |   5 +-
>  2 files changed, 138 insertions(+), 58 deletions(-)
> 
> diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
> index 86e724c3eb89..48ea4aeeea5d 100644
> --- a/drivers/net/ethernet/microsoft/mana/mana_en.c
> +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
> @@ -91,63 +91,137 @@ static unsigned int mana_checksum_info(struct sk_buff *skb)
>  	return 0;
>  }
>  
> +static void mana_add_sge(struct mana_tx_package *tp, struct mana_skb_head *ash,
> +			 int sg_i, dma_addr_t da, int sge_len, u32 gpa_mkey)
> +{
> +	ash->dma_handle[sg_i] = da;
> +	ash->size[sg_i] = sge_len;
> +
> +	tp->wqe_req.sgl[sg_i].address = da;
> +	tp->wqe_req.sgl[sg_i].mem_key = gpa_mkey;
> +	tp->wqe_req.sgl[sg_i].size = sge_len;
> +}
> +
>  static int mana_map_skb(struct sk_buff *skb, struct mana_port_context *apc,
> -			struct mana_tx_package *tp)
> +			struct mana_tx_package *tp, int gso_hs)
>  {
>  	struct mana_skb_head *ash = (struct mana_skb_head *)skb->head;
> +	int hsg = 1; /* num of SGEs of linear part */
>  	struct gdma_dev *gd = apc->ac->gdma_dev;
> +	int skb_hlen = skb_headlen(skb);
> +	int sge0_len, sge1_len = 0;
>  	struct gdma_context *gc;
>  	struct device *dev;
>  	skb_frag_t *frag;
>  	dma_addr_t da;
> +	int sg_i;
>  	int i;
>  
>  	gc = gd->gdma_context;
>  	dev = gc->dev;
> -	da = dma_map_single(dev, skb->data, skb_headlen(skb), DMA_TO_DEVICE);
>  
> +	if (gso_hs && gso_hs < skb_hlen) {
> +		sge0_len = gso_hs;
> +		sge1_len = skb_hlen - gso_hs;
> +	} else {
> +		sge0_len = skb_hlen;
> +	}
> +
> +	da = dma_map_single(dev, skb->data, sge0_len, DMA_TO_DEVICE);
>  	if (dma_mapping_error(dev, da))
>  		return -ENOMEM;
>  
> -	ash->dma_handle[0] = da;
> -	ash->size[0] = skb_headlen(skb);
> +	mana_add_sge(tp, ash, 0, da, sge0_len, gd->gpa_mkey);
>  
> -	tp->wqe_req.sgl[0].address = ash->dma_handle[0];
> -	tp->wqe_req.sgl[0].mem_key = gd->gpa_mkey;
> -	tp->wqe_req.sgl[0].size = ash->size[0];
> +	if (sge1_len) {
> +		sg_i = 1;
> +		da = dma_map_single(dev, skb->data + sge0_len, sge1_len,
> +				    DMA_TO_DEVICE);
> +		if (dma_mapping_error(dev, da))
> +			goto frag_err;
> +
> +		mana_add_sge(tp, ash, sg_i, da, sge1_len, gd->gpa_mkey);
> +		hsg = 2;
> +	}
>  
>  	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
> +		sg_i = hsg + i;
> +
>  		frag = &skb_shinfo(skb)->frags[i];
>  		da = skb_frag_dma_map(dev, frag, 0, skb_frag_size(frag),
>  				      DMA_TO_DEVICE);
> -
>  		if (dma_mapping_error(dev, da))
>  			goto frag_err;
>  
> -		ash->dma_handle[i + 1] = da;
> -		ash->size[i + 1] = skb_frag_size(frag);
> -
> -		tp->wqe_req.sgl[i + 1].address = ash->dma_handle[i + 1];
> -		tp->wqe_req.sgl[i + 1].mem_key = gd->gpa_mkey;
> -		tp->wqe_req.sgl[i + 1].size = ash->size[i + 1];
> +		mana_add_sge(tp, ash, sg_i, da, skb_frag_size(frag),
> +			     gd->gpa_mkey);
>  	}
>  
>  	return 0;
>  
>  frag_err:
> -	for (i = i - 1; i >= 0; i--)
> -		dma_unmap_page(dev, ash->dma_handle[i + 1], ash->size[i + 1],
> +	for (i = sg_i - 1; i >= hsg; i--)
> +		dma_unmap_page(dev, ash->dma_handle[i], ash->size[i],
>  			       DMA_TO_DEVICE);
>  
> -	dma_unmap_single(dev, ash->dma_handle[0], ash->size[0], DMA_TO_DEVICE);
> +	for (i = hsg - 1; i >= 0; i--)
> +		dma_unmap_single(dev, ash->dma_handle[i], ash->size[i],
> +				 DMA_TO_DEVICE);
>  
>  	return -ENOMEM;
>  }
>  
> +/* Handle the case when GSO SKB linear length is too large.
> + * MANA NIC requires GSO packets to put only the packet header to SGE0.
> + * So, we need 2 SGEs for the skb linear part which contains more than the
> + * header.
> + * Return a positive value for the number of SGEs, or a negative value
> + * for an error.
> + */
> +static int mana_fix_skb_head(struct net_device *ndev, struct sk_buff *skb,
> +			     int gso_hs)
> +{
> +	int num_sge = 1 + skb_shinfo(skb)->nr_frags;
> +	int skb_hlen = skb_headlen(skb);
> +
> +	if (gso_hs < skb_hlen) {
> +		num_sge++;
> +	} else if (gso_hs > skb_hlen) {
> +		if (net_ratelimit())
> +			netdev_err(ndev,
> +				   "TX nonlinear head: hs:%d, skb_hlen:%d\n",
> +				   gso_hs, skb_hlen);
> +
> +		return -EINVAL;
> +	}
> +
> +	return num_sge;
> +}
> +
> +/* Get the GSO packet's header size */
> +static int mana_get_gso_hs(struct sk_buff *skb)
> +{
> +	int gso_hs;
> +
> +	if (skb->encapsulation) {
> +		gso_hs = skb_inner_tcp_all_headers(skb);
> +	} else {
> +		if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) {
> +			gso_hs = skb_transport_offset(skb) +
> +				 sizeof(struct udphdr);
> +		} else {
> +			gso_hs = skb_tcp_all_headers(skb);
> +		}
> +	}
> +
> +	return gso_hs;
> +}
> +
>  netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev)
>  {
>  	enum mana_tx_pkt_format pkt_fmt = MANA_SHORT_PKT_FMT;
>  	struct mana_port_context *apc = netdev_priv(ndev);
> +	int gso_hs = 0; /* zero for non-GSO pkts */
>  	u16 txq_idx = skb_get_queue_mapping(skb);
>  	struct gdma_dev *gd = apc->ac->gdma_dev;
>  	bool ipv4 = false, ipv6 = false;
> @@ -159,7 +233,6 @@ netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev)
>  	struct mana_txq *txq;
>  	struct mana_cq *cq;
>  	int err, len;
> -	u16 ihs;
>  
>  	if (unlikely(!apc->port_is_up))
>  		goto tx_drop;
> @@ -209,19 +282,6 @@ netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev)
>  	pkg.wqe_req.client_data_unit = 0;
>  
>  	pkg.wqe_req.num_sge = 1 + skb_shinfo(skb)->nr_frags;
> -	WARN_ON_ONCE(pkg.wqe_req.num_sge > MAX_TX_WQE_SGL_ENTRIES);
> -
> -	if (pkg.wqe_req.num_sge <= ARRAY_SIZE(pkg.sgl_array)) {
> -		pkg.wqe_req.sgl = pkg.sgl_array;
> -	} else {
> -		pkg.sgl_ptr = kmalloc_array(pkg.wqe_req.num_sge,
> -					    sizeof(struct gdma_sge),
> -					    GFP_ATOMIC);
> -		if (!pkg.sgl_ptr)
> -			goto tx_drop_count;
> -
> -		pkg.wqe_req.sgl = pkg.sgl_ptr;
> -	}
>  
>  	if (skb->protocol == htons(ETH_P_IP))
>  		ipv4 = true;
> @@ -229,6 +289,26 @@ netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev)
>  		ipv6 = true;
>  
>  	if (skb_is_gso(skb)) {
> +		int num_sge;
> +
> +		gso_hs = mana_get_gso_hs(skb);
> +
> +		num_sge = mana_fix_skb_head(ndev, skb, gso_hs);
> +		if (num_sge > 0)
> +			pkg.wqe_req.num_sge = num_sge;
> +		else
> +			goto tx_drop_count;
> +
> +		u64_stats_update_begin(&tx_stats->syncp);
> +		if (skb->encapsulation) {
> +			tx_stats->tso_inner_packets++;
> +			tx_stats->tso_inner_bytes += skb->len - gso_hs;
> +		} else {
> +			tx_stats->tso_packets++;
> +			tx_stats->tso_bytes += skb->len - gso_hs;
> +		}
> +		u64_stats_update_end(&tx_stats->syncp);
> +
>  		pkg.tx_oob.s_oob.is_outer_ipv4 = ipv4;
>  		pkg.tx_oob.s_oob.is_outer_ipv6 = ipv6;
>  
> @@ -252,26 +332,6 @@ netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev)
>  						 &ipv6_hdr(skb)->daddr, 0,
>  						 IPPROTO_TCP, 0);
>  		}
> -
> -		if (skb->encapsulation) {
> -			ihs = skb_inner_tcp_all_headers(skb);
> -			u64_stats_update_begin(&tx_stats->syncp);
> -			tx_stats->tso_inner_packets++;
> -			tx_stats->tso_inner_bytes += skb->len - ihs;
> -			u64_stats_update_end(&tx_stats->syncp);
> -		} else {
> -			if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) {
> -				ihs = skb_transport_offset(skb) + sizeof(struct udphdr);
> -			} else {
> -				ihs = skb_tcp_all_headers(skb);
> -			}
> -
> -			u64_stats_update_begin(&tx_stats->syncp);
> -			tx_stats->tso_packets++;
> -			tx_stats->tso_bytes += skb->len - ihs;
> -			u64_stats_update_end(&tx_stats->syncp);
> -		}
> -
>  	} else if (skb->ip_summed == CHECKSUM_PARTIAL) {
>  		csum_type = mana_checksum_info(skb);
>  
> @@ -294,11 +354,25 @@ netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev)
>  		} else {
>  			/* Can't do offload of this type of checksum */
>  			if (skb_checksum_help(skb))
> -				goto free_sgl_ptr;
> +				goto tx_drop_count;
>  		}
>  	}
>  
> -	if (mana_map_skb(skb, apc, &pkg)) {
> +	WARN_ON_ONCE(pkg.wqe_req.num_sge > MAX_TX_WQE_SGL_ENTRIES);
> +
> +	if (pkg.wqe_req.num_sge <= ARRAY_SIZE(pkg.sgl_array)) {
> +		pkg.wqe_req.sgl = pkg.sgl_array;
> +	} else {
> +		pkg.sgl_ptr = kmalloc_array(pkg.wqe_req.num_sge,
> +					    sizeof(struct gdma_sge),
> +					    GFP_ATOMIC);
> +		if (!pkg.sgl_ptr)
> +			goto tx_drop_count;
> +
> +		pkg.wqe_req.sgl = pkg.sgl_ptr;
> +	}
> +
> +	if (mana_map_skb(skb, apc, &pkg, gso_hs)) {
>  		u64_stats_update_begin(&tx_stats->syncp);
>  		tx_stats->mana_map_err++;
>  		u64_stats_update_end(&tx_stats->syncp);
> @@ -1256,11 +1330,16 @@ static void mana_unmap_skb(struct sk_buff *skb, struct mana_port_context *apc)
>  	struct mana_skb_head *ash = (struct mana_skb_head *)skb->head;
>  	struct gdma_context *gc = apc->ac->gdma_dev->gdma_context;
>  	struct device *dev = gc->dev;
> -	int i;
> +	int hsg, i;
> +
> +	/* Number of SGEs of linear part */
> +	hsg = (skb_is_gso(skb) && skb_headlen(skb) > ash->size[0]) ? 2 : 1;
>  
> -	dma_unmap_single(dev, ash->dma_handle[0], ash->size[0], DMA_TO_DEVICE);
> +	for (i = 0; i < hsg; i++)
> +		dma_unmap_single(dev, ash->dma_handle[i], ash->size[i],
> +				 DMA_TO_DEVICE);
>  
> -	for (i = 1; i < skb_shinfo(skb)->nr_frags + 1; i++)
> +	for (i = hsg; i < skb_shinfo(skb)->nr_frags + hsg; i++)
>  		dma_unmap_page(dev, ash->dma_handle[i], ash->size[i],
>  			       DMA_TO_DEVICE);
>  }
> diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h
> index 9f70b4332238..4d43adf18606 100644
> --- a/include/net/mana/mana.h
> +++ b/include/net/mana/mana.h
> @@ -103,9 +103,10 @@ struct mana_txq {
>  
>  /* skb data and frags dma mappings */
>  struct mana_skb_head {
> -	dma_addr_t dma_handle[MAX_SKB_FRAGS + 1];
> +	/* GSO pkts may have 2 SGEs for the linear part*/
> +	dma_addr_t dma_handle[MAX_SKB_FRAGS + 2];
>  
> -	u32 size[MAX_SKB_FRAGS + 1];
> +	u32 size[MAX_SKB_FRAGS + 2];
>  };
>  
>  #define MANA_HEADROOM sizeof(struct mana_skb_head)
> -- 
> 2.25.1
Reviewed-by: Shradha Gupta <shradhagupta@linux.microsoft.com>

Re: [PATCH net,v2, 0/3] net: mana: Fix some TX processing bugs

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net.git (main)
by Paolo Abeni <pabeni@redhat.com>:

On Fri, 29 Sep 2023 13:42:24 -0700 you wrote:
> Fix TX processing bugs on error handling, tso_bytes calculation,
> and sge0 size.
> 
> Haiyang Zhang (3):
>   net: mana: Fix TX CQE error handling
>   net: mana: Fix the tso_bytes calculation
>   net: mana: Fix oversized sge0 for GSO packets
> 
> [...]

Here is the summary with links:
  - [net,v2,1/3] net: mana: Fix TX CQE error handling
    https://git.kernel.org/netdev/net/c/b2b000069a4c
  - [net,v2,2/3] net: mana: Fix the tso_bytes calculation
    https://git.kernel.org/netdev/net/c/7a54de926574
  - [net,v2,3/3] net: mana: Fix oversized sge0 for GSO packets
    https://git.kernel.org/netdev/net/c/a43e8e9ffa0d

You are awesome, thank you!
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