[PATCH net-next V4 0/9] eth: fbnic: Add XDP support for fbnic

[PATCH net-next V4 0/9] eth: fbnic: Add XDP support for fbnic

[Mohsin Bashir]

This patch series introduces basic XDP support for fbnic. To enable this,
it also includes preparatory changes such as making the HDS threshold
configurable via ethtool, updating headroom for fbnic, tracking
frag state in shinfo, and prefetching the first cacheline of data.

---
Changelog:
V4: Update P7 and P8 to address cocci complains about PTR_ERR

V3: https://lore.kernel.org/netdev/20250812220150.161848-1-mohsin.bashr@gmail.com/
V2: https://lore.kernel.org/netdev/20250811211338.857992-1-mohsin.bashr@gmail.com/
V1: https://lore.kernel.org/netdev/20250723145926.4120434-1-mohsin.bashr@gmail.com/

Mohsin Bashir (9):
  eth: fbnic: Add support for HDS configuration
  eth: fbnic: Update Headroom
  eth: fbnic: Use shinfo to track frags state on Rx
  eth: fbnic: Prefetch packet headers on Rx
  eth: fbnic: Add XDP pass, drop, abort support
  eth: fbnic: Add support for XDP queues
  eth: fbnic: Add support for XDP_TX action
  eth: fbnic: Collect packet statistics for XDP
  eth: fbnic: Report XDP stats via ethtool

 .../device_drivers/ethernet/meta/fbnic.rst    |  11 +
 .../net/ethernet/meta/fbnic/fbnic_ethtool.c   |  82 +++-
 .../net/ethernet/meta/fbnic/fbnic_netdev.c    |  75 ++-
 .../net/ethernet/meta/fbnic/fbnic_netdev.h    |   9 +-
 drivers/net/ethernet/meta/fbnic/fbnic_txrx.c  | 458 +++++++++++++++---
 drivers/net/ethernet/meta/fbnic/fbnic_txrx.h  |  23 +-
 6 files changed, 576 insertions(+), 82 deletions(-)

-- 
2.47.3

[PATCH net-next V4 1/9] eth: fbnic: Add support for HDS configuration

[Mohsin Bashir]

Add support for configuring the header data split threshold.
For fbnic, the tcp data split support is enabled all the time.

Fbnic supports a maximum buffer size of 4KB. However, the reservation
for the headroom, tailroom, and padding reduce the max header size
accordingly.

  ethtool_hds -g eth0
  Ring parameters for eth0:
  Pre-set maximums:
  ...
  HDS thresh:		3584
  Current hardware settings:
  ...
  HDS thresh:		1536

Verify hds tests in ksft-net-drv are passing

  ksft-net-drv]# ./drivers/net/hds.py
  TAP version 13
  1..13
  ok 1 hds.get_hds
  ok 2 hds.get_hds_thresh
  ok 3 hds.set_hds_disable # SKIP disabling of HDS not supported by ...
  ...
  ...
  ok 12 hds.ioctl_set_xdp
  ok 13 hds.ioctl_enabled_set_xdp
  \# Totals: pass:12 fail:0 xfail:0 xpass:0 skip:1 error:0

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Mohsin Bashir <mohsin.bashr@gmail.com>
---
 .../net/ethernet/meta/fbnic/fbnic_ethtool.c   | 21 ++++++++++++++++---
 .../net/ethernet/meta/fbnic/fbnic_netdev.c    |  4 ++++
 .../net/ethernet/meta/fbnic/fbnic_netdev.h    |  2 ++
 drivers/net/ethernet/meta/fbnic/fbnic_txrx.c  | 17 +++++++++++----
 drivers/net/ethernet/meta/fbnic/fbnic_txrx.h  |  7 ++++++-
 5 files changed, 43 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c b/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c
index dc7ba8d5fc43..8ae2ecbae06c 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c
@@ -2,6 +2,7 @@
 /* Copyright (c) Meta Platforms, Inc. and affiliates. */
 
 #include <linux/ethtool.h>
+#include <linux/ethtool_netlink.h>
 #include <linux/netdevice.h>
 #include <linux/pci.h>
 #include <net/ipv6.h>
@@ -160,6 +161,7 @@ static void fbnic_clone_swap_cfg(struct fbnic_net *orig,
 	swap(clone->num_rx_queues, orig->num_rx_queues);
 	swap(clone->num_tx_queues, orig->num_tx_queues);
 	swap(clone->num_napi, orig->num_napi);
+	swap(clone->hds_thresh, orig->hds_thresh);
 }
 
 static void fbnic_aggregate_vector_counters(struct fbnic_net *fbn,
@@ -277,15 +279,21 @@ fbnic_get_ringparam(struct net_device *netdev, struct ethtool_ringparam *ring,
 	ring->rx_mini_pending = fbn->hpq_size;
 	ring->rx_jumbo_pending = fbn->ppq_size;
 	ring->tx_pending = fbn->txq_size;
+
+	kernel_ring->tcp_data_split = ETHTOOL_TCP_DATA_SPLIT_ENABLED;
+	kernel_ring->hds_thresh_max = FBNIC_HDS_THRESH_MAX;
+	kernel_ring->hds_thresh = fbn->hds_thresh;
 }
 
 static void fbnic_set_rings(struct fbnic_net *fbn,
-			    struct ethtool_ringparam *ring)
+			    struct ethtool_ringparam *ring,
+			    struct kernel_ethtool_ringparam *kernel_ring)
 {
 	fbn->rcq_size = ring->rx_pending;
 	fbn->hpq_size = ring->rx_mini_pending;
 	fbn->ppq_size = ring->rx_jumbo_pending;
 	fbn->txq_size = ring->tx_pending;
+	fbn->hds_thresh = kernel_ring->hds_thresh;
 }
 
 static int
@@ -316,8 +324,13 @@ fbnic_set_ringparam(struct net_device *netdev, struct ethtool_ringparam *ring,
 		return -EINVAL;
 	}
 
+	if (kernel_ring->tcp_data_split == ETHTOOL_TCP_DATA_SPLIT_DISABLED) {
+		NL_SET_ERR_MSG_MOD(extack, "Cannot disable TCP data split");
+		return -EINVAL;
+	}
+
 	if (!netif_running(netdev)) {
-		fbnic_set_rings(fbn, ring);
+		fbnic_set_rings(fbn, ring, kernel_ring);
 		return 0;
 	}
 
@@ -325,7 +338,7 @@ fbnic_set_ringparam(struct net_device *netdev, struct ethtool_ringparam *ring,
 	if (!clone)
 		return -ENOMEM;
 
-	fbnic_set_rings(clone, ring);
+	fbnic_set_rings(clone, ring, kernel_ring);
 
 	err = fbnic_alloc_napi_vectors(clone);
 	if (err)
@@ -1678,6 +1691,8 @@ fbnic_get_rmon_stats(struct net_device *netdev,
 static const struct ethtool_ops fbnic_ethtool_ops = {
 	.supported_coalesce_params	= ETHTOOL_COALESCE_USECS |
 					  ETHTOOL_COALESCE_RX_MAX_FRAMES,
+	.supported_ring_params		= ETHTOOL_RING_USE_TCP_DATA_SPLIT |
+					  ETHTOOL_RING_USE_HDS_THRS,
 	.rxfh_max_num_contexts		= FBNIC_RPC_RSS_TBL_COUNT,
 	.get_drvinfo			= fbnic_get_drvinfo,
 	.get_regs_len			= fbnic_get_regs_len,
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_netdev.c b/drivers/net/ethernet/meta/fbnic/fbnic_netdev.c
index e67e99487a27..a7eb7a367b98 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_netdev.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_netdev.c
@@ -695,6 +695,10 @@ struct net_device *fbnic_netdev_alloc(struct fbnic_dev *fbd)
 	fbn->rx_usecs = FBNIC_RX_USECS_DEFAULT;
 	fbn->rx_max_frames = FBNIC_RX_FRAMES_DEFAULT;
 
+	/* Initialize the hds_thresh */
+	netdev->cfg->hds_thresh = FBNIC_HDS_THRESH_DEFAULT;
+	fbn->hds_thresh = FBNIC_HDS_THRESH_DEFAULT;
+
 	default_queues = netif_get_num_default_rss_queues();
 	if (default_queues > fbd->max_num_queues)
 		default_queues = fbd->max_num_queues;
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_netdev.h b/drivers/net/ethernet/meta/fbnic/fbnic_netdev.h
index 86576ae04262..04c5c7ed6c3a 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_netdev.h
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_netdev.h
@@ -31,6 +31,8 @@ struct fbnic_net {
 	u32 ppq_size;
 	u32 rcq_size;
 
+	u32 hds_thresh;
+
 	u16 rx_usecs;
 	u16 tx_usecs;
 
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c
index f9543d03485f..7c69f6381d9e 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c
@@ -2232,13 +2232,22 @@ static void fbnic_enable_rcq(struct fbnic_napi_vector *nv,
 {
 	struct fbnic_net *fbn = netdev_priv(nv->napi.dev);
 	u32 log_size = fls(rcq->size_mask);
-	u32 rcq_ctl;
+	u32 hds_thresh = fbn->hds_thresh;
+	u32 rcq_ctl = 0;
 
 	fbnic_config_drop_mode_rcq(nv, rcq);
 
-	rcq_ctl = FIELD_PREP(FBNIC_QUEUE_RDE_CTL1_PADLEN_MASK, FBNIC_RX_PAD) |
-		   FIELD_PREP(FBNIC_QUEUE_RDE_CTL1_MAX_HDR_MASK,
-			      FBNIC_RX_MAX_HDR) |
+	/* Force lower bound on MAX_HEADER_BYTES. Below this, all frames should
+	 * be split at L4. It would also result in the frames being split at
+	 * L2/L3 depending on the frame size.
+	 */
+	if (fbn->hds_thresh < FBNIC_HDR_BYTES_MIN) {
+		rcq_ctl = FBNIC_QUEUE_RDE_CTL0_EN_HDR_SPLIT;
+		hds_thresh = FBNIC_HDR_BYTES_MIN;
+	}
+
+	rcq_ctl |= FIELD_PREP(FBNIC_QUEUE_RDE_CTL1_PADLEN_MASK, FBNIC_RX_PAD) |
+		   FIELD_PREP(FBNIC_QUEUE_RDE_CTL1_MAX_HDR_MASK, hds_thresh) |
 		   FIELD_PREP(FBNIC_QUEUE_RDE_CTL1_PAYLD_OFF_MASK,
 			      FBNIC_RX_PAYLD_OFFSET) |
 		   FIELD_PREP(FBNIC_QUEUE_RDE_CTL1_PAYLD_PG_CL_MASK,
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h
index 34693596e5eb..7d27712d5462 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h
@@ -53,7 +53,6 @@ struct fbnic_net;
 #define FBNIC_RX_HROOM \
 	(ALIGN(FBNIC_RX_TROOM + NET_SKB_PAD, 128) - FBNIC_RX_TROOM)
 #define FBNIC_RX_PAD			0
-#define FBNIC_RX_MAX_HDR		(1536 - FBNIC_RX_PAD)
 #define FBNIC_RX_PAYLD_OFFSET		0
 #define FBNIC_RX_PAYLD_PG_CL		0
 
@@ -61,6 +60,12 @@ struct fbnic_net;
 #define FBNIC_RING_F_CTX		BIT(1)
 #define FBNIC_RING_F_STATS		BIT(2)	/* Ring's stats may be used */
 
+#define FBNIC_HDS_THRESH_MAX \
+	(4096 - FBNIC_RX_HROOM - FBNIC_RX_TROOM - FBNIC_RX_PAD)
+#define FBNIC_HDS_THRESH_DEFAULT \
+	(1536 - FBNIC_RX_PAD)
+#define FBNIC_HDR_BYTES_MIN		128
+
 struct fbnic_pkt_buff {
 	struct xdp_buff buff;
 	ktime_t hwtstamp;
-- 
2.47.3

[PATCH net-next V4 2/9] eth: fbnic: Update Headroom

[Mohsin Bashir]

Fbnic currently reserves a minimum of 64B headroom, but this is
insufficient for inserting additional headers (e.g., IPV6) via XDP, as
only 24 bytes are available for adjustment. To address this limitation,
increase the headroom to a larger value while ensuring better page use.
Although the resulting headroom (192B) is smaller than the recommended
value (256B), forcing the headroom to 256B would require aligning to
256B (as opposed to the current 128B), which can push the max headroom
to 511B.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Mohsin Bashir <mohsin.bashr@gmail.com>
---
 drivers/net/ethernet/meta/fbnic/fbnic_txrx.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h
index 7d27712d5462..66c84375e299 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h
@@ -50,8 +50,9 @@ struct fbnic_net;
 
 #define FBNIC_RX_TROOM \
 	SKB_DATA_ALIGN(sizeof(struct skb_shared_info))
+#define FBNIC_RX_HROOM_PAD		128
 #define FBNIC_RX_HROOM \
-	(ALIGN(FBNIC_RX_TROOM + NET_SKB_PAD, 128) - FBNIC_RX_TROOM)
+	(ALIGN(FBNIC_RX_TROOM + FBNIC_RX_HROOM_PAD, 128) - FBNIC_RX_TROOM)
 #define FBNIC_RX_PAD			0
 #define FBNIC_RX_PAYLD_OFFSET		0
 #define FBNIC_RX_PAYLD_PG_CL		0
-- 
2.47.3

[PATCH net-next V4 3/9] eth: fbnic: Use shinfo to track frags state on Rx

[Mohsin Bashir]

Remove local fields that track frags state and instead store this
information directly in the shinfo struct. This change is necessary
because the current implementation can lead to inaccuracies in certain
scenarios, such as when using XDP multi-buff support. Specifically, the
XDP program may update nr_frags without updating the local variables,
resulting in an inconsistent state.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Mohsin Bashir <mohsin.bashr@gmail.com>
---
 drivers/net/ethernet/meta/fbnic/fbnic_txrx.c | 80 ++++++--------------
 drivers/net/ethernet/meta/fbnic/fbnic_txrx.h |  4 +-
 2 files changed, 26 insertions(+), 58 deletions(-)

diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c
index 7c69f6381d9e..2adbe175ac09 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c
@@ -892,9 +892,8 @@ static void fbnic_pkt_prepare(struct fbnic_napi_vector *nv, u64 rcd,
 	xdp_prepare_buff(&pkt->buff, hdr_start, headroom,
 			 len - FBNIC_RX_PAD, true);
 
-	pkt->data_truesize = 0;
-	pkt->data_len = 0;
-	pkt->nr_frags = 0;
+	pkt->hwtstamp = 0;
+	pkt->add_frag_failed = false;
 }
 
 static void fbnic_add_rx_frag(struct fbnic_napi_vector *nv, u64 rcd,
@@ -905,8 +904,8 @@ static void fbnic_add_rx_frag(struct fbnic_napi_vector *nv, u64 rcd,
 	unsigned int pg_off = FIELD_GET(FBNIC_RCD_AL_BUFF_OFF_MASK, rcd);
 	unsigned int len = FIELD_GET(FBNIC_RCD_AL_BUFF_LEN_MASK, rcd);
 	struct page *page = fbnic_page_pool_get(&qt->sub1, pg_idx);
-	struct skb_shared_info *shinfo;
 	unsigned int truesize;
+	bool added;
 
 	truesize = FIELD_GET(FBNIC_RCD_AL_PAGE_FIN, rcd) ?
 		   FBNIC_BD_FRAG_SIZE - pg_off : ALIGN(len, 128);
@@ -918,34 +917,34 @@ static void fbnic_add_rx_frag(struct fbnic_napi_vector *nv, u64 rcd,
 	dma_sync_single_range_for_cpu(nv->dev, page_pool_get_dma_addr(page),
 				      pg_off, truesize, DMA_BIDIRECTIONAL);
 
-	/* Add page to xdp shared info */
-	shinfo = xdp_get_shared_info_from_buff(&pkt->buff);
-
-	/* We use gso_segs to store truesize */
-	pkt->data_truesize += truesize;
-
-	__skb_fill_page_desc_noacc(shinfo, pkt->nr_frags++, page, pg_off, len);
-
-	/* Store data_len in gso_size */
-	pkt->data_len += len;
+	added = xdp_buff_add_frag(&pkt->buff, page_to_netmem(page), pg_off, len,
+				  truesize);
+	if (unlikely(!added)) {
+		pkt->add_frag_failed = true;
+		netdev_err_once(nv->napi.dev,
+				"Failed to add fragment to xdp_buff\n");
+	}
 }
 
 static void fbnic_put_pkt_buff(struct fbnic_napi_vector *nv,
 			       struct fbnic_pkt_buff *pkt, int budget)
 {
-	struct skb_shared_info *shinfo;
 	struct page *page;
-	int nr_frags;
 
 	if (!pkt->buff.data_hard_start)
 		return;
 
-	shinfo = xdp_get_shared_info_from_buff(&pkt->buff);
-	nr_frags = pkt->nr_frags;
+	if (xdp_buff_has_frags(&pkt->buff)) {
+		struct skb_shared_info *shinfo;
+		int nr_frags;
 
-	while (nr_frags--) {
-		page = skb_frag_page(&shinfo->frags[nr_frags]);
-		page_pool_put_full_page(nv->page_pool, page, !!budget);
+		shinfo = xdp_get_shared_info_from_buff(&pkt->buff);
+		nr_frags = shinfo->nr_frags;
+
+		while (nr_frags--) {
+			page = skb_frag_page(&shinfo->frags[nr_frags]);
+			page_pool_put_full_page(nv->page_pool, page, !!budget);
+		}
 	}
 
 	page = virt_to_page(pkt->buff.data_hard_start);
@@ -955,43 +954,12 @@ static void fbnic_put_pkt_buff(struct fbnic_napi_vector *nv,
 static struct sk_buff *fbnic_build_skb(struct fbnic_napi_vector *nv,
 				       struct fbnic_pkt_buff *pkt)
 {
-	unsigned int nr_frags = pkt->nr_frags;
-	struct skb_shared_info *shinfo;
-	unsigned int truesize;
 	struct sk_buff *skb;
 
-	truesize = xdp_data_hard_end(&pkt->buff) + FBNIC_RX_TROOM -
-		   pkt->buff.data_hard_start;
-
-	/* Build frame around buffer */
-	skb = napi_build_skb(pkt->buff.data_hard_start, truesize);
-	if (unlikely(!skb))
+	skb = xdp_build_skb_from_buff(&pkt->buff);
+	if (!skb)
 		return NULL;
 
-	/* Push data pointer to start of data, put tail to end of data */
-	skb_reserve(skb, pkt->buff.data - pkt->buff.data_hard_start);
-	__skb_put(skb, pkt->buff.data_end - pkt->buff.data);
-
-	/* Add tracking for metadata at the start of the frame */
-	skb_metadata_set(skb, pkt->buff.data - pkt->buff.data_meta);
-
-	/* Add Rx frags */
-	if (nr_frags) {
-		/* Verify that shared info didn't move */
-		shinfo = xdp_get_shared_info_from_buff(&pkt->buff);
-		WARN_ON(skb_shinfo(skb) != shinfo);
-
-		skb->truesize += pkt->data_truesize;
-		skb->data_len += pkt->data_len;
-		shinfo->nr_frags = nr_frags;
-		skb->len += pkt->data_len;
-	}
-
-	skb_mark_for_recycle(skb);
-
-	/* Set MAC header specific fields */
-	skb->protocol = eth_type_trans(skb, nv->napi.dev);
-
 	/* Add timestamp if present */
 	if (pkt->hwtstamp)
 		skb_hwtstamps(skb)->hwtstamp = pkt->hwtstamp;
@@ -1094,7 +1062,9 @@ static int fbnic_clean_rcq(struct fbnic_napi_vector *nv,
 			/* We currently ignore the action table index */
 			break;
 		case FBNIC_RCD_TYPE_META:
-			if (likely(!fbnic_rcd_metadata_err(rcd)))
+			if (unlikely(pkt->add_frag_failed))
+				skb = NULL;
+			else if (likely(!fbnic_rcd_metadata_err(rcd)))
 				skb = fbnic_build_skb(nv, pkt);
 
 			/* Populate skb and invalidate XDP */
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h
index 66c84375e299..d236152bbaaa 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h
@@ -70,9 +70,7 @@ struct fbnic_net;
 struct fbnic_pkt_buff {
 	struct xdp_buff buff;
 	ktime_t hwtstamp;
-	u32 data_truesize;
-	u16 data_len;
-	u16 nr_frags;
+	bool add_frag_failed;
 };
 
 struct fbnic_queue_stats {
-- 
2.47.3

[PATCH net-next V4 4/9] eth: fbnic: Prefetch packet headers on Rx

[Mohsin Bashir]

Issue a prefetch for the start of the buffer on Rx to try to avoid cache
miss on packet headers.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Mohsin Bashir <mohsin.bashr@gmail.com>
---
 drivers/net/ethernet/meta/fbnic/fbnic_txrx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c
index 2adbe175ac09..65d1e40addec 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c
@@ -888,7 +888,7 @@ static void fbnic_pkt_prepare(struct fbnic_napi_vector *nv, u64 rcd,
 
 	/* Build frame around buffer */
 	hdr_start = page_address(page) + hdr_pg_start;
-
+	net_prefetch(pkt->buff.data);
 	xdp_prepare_buff(&pkt->buff, hdr_start, headroom,
 			 len - FBNIC_RX_PAD, true);
 
-- 
2.47.3

[PATCH net-next V4 5/9] eth: fbnic: Add XDP pass, drop, abort support

[Mohsin Bashir]

Add basic support for attaching an XDP program to the device and support
for PASS/DROP/ABORT actions. In fbnic, buffers are always mapped as
DMA_BIDIRECTIONAL.

The BPF program pointer can be read either on a per-packet basis or on a
per-NAPI poll basis. Both approaches are functionally equivalent, in the
current code. Stick to per-packet as it limits number of arguments we need
to pass around.

On the XDP hot path, check that packets with fragments are only allowed
when multi-buffer support is enabled for the XDP program. Ideally, this
check should not be necessary because ndo_bpf verifies that for XDP
programs without multi-buff support, MTU is less than the hds_thresh.
However, the MTU currently does not enforce the receive size which would
require cleaning up the data path and bouncing the link. For practical
reasons, prioritize the ability to enter and exit BPF mode with different
MTU sizes without requiring a full reconfig.

Testing:

Hook a simple XDP program that passes all the packets destined for a
specific port

iperf3 -c 192.168.1.10 -P 5 -p 12345
Connecting to host 192.168.1.10, port 12345
[  5] local 192.168.1.9 port 46702 connected to 192.168.1.10 port 12345
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
- - - - - - - - - - - - - - - - - - - - - - - - -
[SUM]   1.00-2.00   sec  3.86 GBytes  33.2 Gbits/sec    0

XDP_DROP:
Hook an XDP program that drops packets destined for a specific port

 iperf3 -c 192.168.1.10 -P 5 -p 12345
^C- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[SUM]   0.00-0.00   sec  0.00 Bytes  0.00 bits/sec    0       sender
[SUM]   0.00-0.00   sec  0.00 Bytes  0.00 bits/sec            receiver
iperf3: interrupt - the client has terminated

XDP with HDS:

- Validate XDP attachment failure when HDS is low
   ~] ethtool -G eth0 hds-thresh 512
   ~] sudo ip link set eth0 xdpdrv obj xdp_pass_12345.o sec xdp
   ~] Error: fbnic: MTU too high, or HDS threshold is too low for single
      buffer XDP.

- Validate successful XDP attachment when HDS threshold is appropriate
  ~] ethtool -G eth0 hds-thresh 1536
  ~] sudo ip link set eth0 xdpdrv obj xdp_pass_12345.o sec xdp

- Validate when the XDP program is attached, changing HDS thresh to a
  lower value fails
  ~] ethtool -G eth0 hds-thresh 512
  ~] netlink error: fbnic: Use higher HDS threshold or multi-buf capable
     program

- Validate HDS thresh does not matter when xdp frags support is
  available
  ~] ethtool -G eth0 hds-thresh 512
  ~] sudo ip link set eth0 xdpdrv obj xdp_pass_mb_12345.o sec xdp.frags

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Mohsin Bashir <mohsin.bashr@gmail.com>
---
 .../net/ethernet/meta/fbnic/fbnic_ethtool.c   | 11 +++
 .../net/ethernet/meta/fbnic/fbnic_netdev.c    | 35 +++++++
 .../net/ethernet/meta/fbnic/fbnic_netdev.h    |  5 +
 drivers/net/ethernet/meta/fbnic/fbnic_txrx.c  | 96 +++++++++++++++++--
 drivers/net/ethernet/meta/fbnic/fbnic_txrx.h  |  1 +
 5 files changed, 141 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c b/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c
index 8ae2ecbae06c..742b557d0e56 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c
@@ -329,6 +329,17 @@ fbnic_set_ringparam(struct net_device *netdev, struct ethtool_ringparam *ring,
 		return -EINVAL;
 	}
 
+	/* If an XDP program is attached, we should check for potential frame
+	 * splitting. If the new HDS threshold can cause splitting, we should
+	 * only allow if the attached XDP program can handle frags.
+	 */
+	if (fbnic_check_split_frames(fbn->xdp_prog, netdev->mtu,
+				     kernel_ring->hds_thresh)) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Use higher HDS threshold or multi-buf capable program");
+		return -EINVAL;
+	}
+
 	if (!netif_running(netdev)) {
 		fbnic_set_rings(fbn, ring, kernel_ring);
 		return 0;
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_netdev.c b/drivers/net/ethernet/meta/fbnic/fbnic_netdev.c
index a7eb7a367b98..fb81d1a7bc51 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_netdev.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_netdev.c
@@ -508,6 +508,40 @@ static void fbnic_get_stats64(struct net_device *dev,
 	}
 }
 
+bool fbnic_check_split_frames(struct bpf_prog *prog, unsigned int mtu,
+			      u32 hds_thresh)
+{
+	if (!prog)
+		return false;
+
+	if (prog->aux->xdp_has_frags)
+		return false;
+
+	return mtu + ETH_HLEN > hds_thresh;
+}
+
+static int fbnic_bpf(struct net_device *netdev, struct netdev_bpf *bpf)
+{
+	struct bpf_prog *prog = bpf->prog, *prev_prog;
+	struct fbnic_net *fbn = netdev_priv(netdev);
+
+	if (bpf->command != XDP_SETUP_PROG)
+		return -EINVAL;
+
+	if (fbnic_check_split_frames(prog, netdev->mtu,
+				     fbn->hds_thresh)) {
+		NL_SET_ERR_MSG_MOD(bpf->extack,
+				   "MTU too high, or HDS threshold is too low for single buffer XDP");
+		return -EOPNOTSUPP;
+	}
+
+	prev_prog = xchg(&fbn->xdp_prog, prog);
+	if (prev_prog)
+		bpf_prog_put(prev_prog);
+
+	return 0;
+}
+
 static const struct net_device_ops fbnic_netdev_ops = {
 	.ndo_open		= fbnic_open,
 	.ndo_stop		= fbnic_stop,
@@ -517,6 +551,7 @@ static const struct net_device_ops fbnic_netdev_ops = {
 	.ndo_set_mac_address	= fbnic_set_mac,
 	.ndo_set_rx_mode	= fbnic_set_rx_mode,
 	.ndo_get_stats64	= fbnic_get_stats64,
+	.ndo_bpf		= fbnic_bpf,
 	.ndo_hwtstamp_get	= fbnic_hwtstamp_get,
 	.ndo_hwtstamp_set	= fbnic_hwtstamp_set,
 };
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_netdev.h b/drivers/net/ethernet/meta/fbnic/fbnic_netdev.h
index 04c5c7ed6c3a..bfa79ea910d8 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_netdev.h
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_netdev.h
@@ -18,6 +18,8 @@
 #define FBNIC_TUN_GSO_FEATURES		NETIF_F_GSO_IPXIP6
 
 struct fbnic_net {
+	struct bpf_prog *xdp_prog;
+
 	struct fbnic_ring *tx[FBNIC_MAX_TXQS];
 	struct fbnic_ring *rx[FBNIC_MAX_RXQS];
 
@@ -104,4 +106,7 @@ int fbnic_phylink_ethtool_ksettings_get(struct net_device *netdev,
 int fbnic_phylink_get_fecparam(struct net_device *netdev,
 			       struct ethtool_fecparam *fecparam);
 int fbnic_phylink_init(struct net_device *netdev);
+
+bool fbnic_check_split_frames(struct bpf_prog *prog,
+			      unsigned int mtu, u32 hds_threshold);
 #endif /* _FBNIC_NETDEV_H_ */
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c
index 65d1e40addec..a669e169e3ad 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c
@@ -2,17 +2,26 @@
 /* Copyright (c) Meta Platforms, Inc. and affiliates. */
 
 #include <linux/bitfield.h>
+#include <linux/bpf.h>
+#include <linux/bpf_trace.h>
 #include <linux/iopoll.h>
 #include <linux/pci.h>
 #include <net/netdev_queues.h>
 #include <net/page_pool/helpers.h>
 #include <net/tcp.h>
+#include <net/xdp.h>
 
 #include "fbnic.h"
 #include "fbnic_csr.h"
 #include "fbnic_netdev.h"
 #include "fbnic_txrx.h"
 
+enum {
+	FBNIC_XDP_PASS = 0,
+	FBNIC_XDP_CONSUME,
+	FBNIC_XDP_LEN_ERR,
+};
+
 enum {
 	FBNIC_XMIT_CB_TS	= 0x01,
 };
@@ -877,7 +886,7 @@ static void fbnic_pkt_prepare(struct fbnic_napi_vector *nv, u64 rcd,
 
 	headroom = hdr_pg_off - hdr_pg_start + FBNIC_RX_PAD;
 	frame_sz = hdr_pg_end - hdr_pg_start;
-	xdp_init_buff(&pkt->buff, frame_sz, NULL);
+	xdp_init_buff(&pkt->buff, frame_sz, &qt->xdp_rxq);
 	hdr_pg_start += (FBNIC_RCD_AL_BUFF_FRAG_MASK & rcd) *
 			FBNIC_BD_FRAG_SIZE;
 
@@ -967,6 +976,39 @@ static struct sk_buff *fbnic_build_skb(struct fbnic_napi_vector *nv,
 	return skb;
 }
 
+static struct sk_buff *fbnic_run_xdp(struct fbnic_napi_vector *nv,
+				     struct fbnic_pkt_buff *pkt)
+{
+	struct fbnic_net *fbn = netdev_priv(nv->napi.dev);
+	struct bpf_prog *xdp_prog;
+	int act;
+
+	xdp_prog = READ_ONCE(fbn->xdp_prog);
+	if (!xdp_prog)
+		goto xdp_pass;
+
+	/* Should never happen, config paths enforce HDS threshold > MTU */
+	if (xdp_buff_has_frags(&pkt->buff) && !xdp_prog->aux->xdp_has_frags)
+		return ERR_PTR(-FBNIC_XDP_LEN_ERR);
+
+	act = bpf_prog_run_xdp(xdp_prog, &pkt->buff);
+	switch (act) {
+	case XDP_PASS:
+xdp_pass:
+		return fbnic_build_skb(nv, pkt);
+	default:
+		bpf_warn_invalid_xdp_action(nv->napi.dev, xdp_prog, act);
+		fallthrough;
+	case XDP_ABORTED:
+		trace_xdp_exception(nv->napi.dev, xdp_prog, act);
+		fallthrough;
+	case XDP_DROP:
+		break;
+	}
+
+	return ERR_PTR(-FBNIC_XDP_CONSUME);
+}
+
 static enum pkt_hash_types fbnic_skb_hash_type(u64 rcd)
 {
 	return (FBNIC_RCD_META_L4_TYPE_MASK & rcd) ? PKT_HASH_TYPE_L4 :
@@ -1065,7 +1107,7 @@ static int fbnic_clean_rcq(struct fbnic_napi_vector *nv,
 			if (unlikely(pkt->add_frag_failed))
 				skb = NULL;
 			else if (likely(!fbnic_rcd_metadata_err(rcd)))
-				skb = fbnic_build_skb(nv, pkt);
+				skb = fbnic_run_xdp(nv, pkt);
 
 			/* Populate skb and invalidate XDP */
 			if (!IS_ERR_OR_NULL(skb)) {
@@ -1251,6 +1293,7 @@ static void fbnic_free_napi_vector(struct fbnic_net *fbn,
 	}
 
 	for (j = 0; j < nv->rxt_count; j++, i++) {
+		xdp_rxq_info_unreg(&nv->qt[i].xdp_rxq);
 		fbnic_remove_rx_ring(fbn, &nv->qt[i].sub0);
 		fbnic_remove_rx_ring(fbn, &nv->qt[i].sub1);
 		fbnic_remove_rx_ring(fbn, &nv->qt[i].cmpl);
@@ -1423,6 +1466,11 @@ static int fbnic_alloc_napi_vector(struct fbnic_dev *fbd, struct fbnic_net *fbn,
 		fbnic_ring_init(&qt->cmpl, db, rxq_idx, FBNIC_RING_F_STATS);
 		fbn->rx[rxq_idx] = &qt->cmpl;
 
+		err = xdp_rxq_info_reg(&qt->xdp_rxq, fbn->netdev, rxq_idx,
+				       nv->napi.napi_id);
+		if (err)
+			goto free_ring_cur_qt;
+
 		/* Update Rx queue index */
 		rxt_count--;
 		rxq_idx += v_count;
@@ -1433,6 +1481,25 @@ static int fbnic_alloc_napi_vector(struct fbnic_dev *fbd, struct fbnic_net *fbn,
 
 	return 0;
 
+	while (rxt_count < nv->rxt_count) {
+		qt--;
+
+		xdp_rxq_info_unreg(&qt->xdp_rxq);
+free_ring_cur_qt:
+		fbnic_remove_rx_ring(fbn, &qt->sub0);
+		fbnic_remove_rx_ring(fbn, &qt->sub1);
+		fbnic_remove_rx_ring(fbn, &qt->cmpl);
+		rxt_count++;
+	}
+	while (txt_count < nv->txt_count) {
+		qt--;
+
+		fbnic_remove_tx_ring(fbn, &qt->sub0);
+		fbnic_remove_tx_ring(fbn, &qt->cmpl);
+
+		txt_count++;
+	}
+	fbnic_napi_free_irq(fbd, nv);
 pp_destroy:
 	page_pool_destroy(nv->page_pool);
 napi_del:
@@ -1709,8 +1776,10 @@ static void fbnic_free_nv_resources(struct fbnic_net *fbn,
 	for (i = 0; i < nv->txt_count; i++)
 		fbnic_free_qt_resources(fbn, &nv->qt[i]);
 
-	for (j = 0; j < nv->rxt_count; j++, i++)
+	for (j = 0; j < nv->rxt_count; j++, i++) {
 		fbnic_free_qt_resources(fbn, &nv->qt[i]);
+		xdp_rxq_info_unreg_mem_model(&nv->qt[i].xdp_rxq);
+	}
 }
 
 static int fbnic_alloc_nv_resources(struct fbnic_net *fbn,
@@ -1722,19 +1791,32 @@ static int fbnic_alloc_nv_resources(struct fbnic_net *fbn,
 	for (i = 0; i < nv->txt_count; i++) {
 		err = fbnic_alloc_tx_qt_resources(fbn, &nv->qt[i]);
 		if (err)
-			goto free_resources;
+			goto free_qt_resources;
 	}
 
 	/* Allocate Rx Resources */
 	for (j = 0; j < nv->rxt_count; j++, i++) {
+		/* Register XDP memory model for completion queue */
+		err = xdp_reg_mem_model(&nv->qt[i].xdp_rxq.mem,
+					MEM_TYPE_PAGE_POOL,
+					nv->page_pool);
+		if (err)
+			goto xdp_unreg_mem_model;
+
 		err = fbnic_alloc_rx_qt_resources(fbn, &nv->qt[i]);
 		if (err)
-			goto free_resources;
+			goto xdp_unreg_cur_model;
 	}
 
 	return 0;
 
-free_resources:
+xdp_unreg_mem_model:
+	while (j-- && i--) {
+		fbnic_free_qt_resources(fbn, &nv->qt[i]);
+xdp_unreg_cur_model:
+		xdp_rxq_info_unreg_mem_model(&nv->qt[i].xdp_rxq);
+	}
+free_qt_resources:
 	while (i--)
 		fbnic_free_qt_resources(fbn, &nv->qt[i]);
 	return err;
@@ -2026,7 +2108,7 @@ void fbnic_flush(struct fbnic_net *fbn)
 			memset(qt->cmpl.desc, 0, qt->cmpl.size);
 
 			fbnic_put_pkt_buff(nv, qt->cmpl.pkt, 0);
-			qt->cmpl.pkt->buff.data_hard_start = NULL;
+			memset(qt->cmpl.pkt, 0, sizeof(struct fbnic_pkt_buff));
 		}
 	}
 }
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h
index d236152bbaaa..5536f72a1c85 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h
@@ -128,6 +128,7 @@ struct fbnic_ring {
 
 struct fbnic_q_triad {
 	struct fbnic_ring sub0, sub1, cmpl;
+	struct xdp_rxq_info xdp_rxq;
 };
 
 struct fbnic_napi_vector {
-- 
2.47.3

Re: [PATCH net-next V4 5/9] eth: fbnic: Add XDP pass, drop, abort support

[Dan Carpenter]

On Wed, Aug 13, 2025 at 03:13:15PM -0700, Mohsin Bashir wrote:
> @@ -1251,6 +1293,7 @@ static void fbnic_free_napi_vector(struct fbnic_net *fbn,
>  	}
>  
>  	for (j = 0; j < nv->rxt_count; j++, i++) {
> +		xdp_rxq_info_unreg(&nv->qt[i].xdp_rxq);
>  		fbnic_remove_rx_ring(fbn, &nv->qt[i].sub0);
>  		fbnic_remove_rx_ring(fbn, &nv->qt[i].sub1);
>  		fbnic_remove_rx_ring(fbn, &nv->qt[i].cmpl);
> @@ -1423,6 +1466,11 @@ static int fbnic_alloc_napi_vector(struct fbnic_dev *fbd, struct fbnic_net *fbn,
>  		fbnic_ring_init(&qt->cmpl, db, rxq_idx, FBNIC_RING_F_STATS);
>  		fbn->rx[rxq_idx] = &qt->cmpl;
>  
> +		err = xdp_rxq_info_reg(&qt->xdp_rxq, fbn->netdev, rxq_idx,
> +				       nv->napi.napi_id);
> +		if (err)
> +			goto free_ring_cur_qt;
> +
>  		/* Update Rx queue index */
>  		rxt_count--;
>  		rxq_idx += v_count;
> @@ -1433,6 +1481,25 @@ static int fbnic_alloc_napi_vector(struct fbnic_dev *fbd, struct fbnic_net *fbn,
>  
>  	return 0;
>  
> +	while (rxt_count < nv->rxt_count) {
               ^^^^^^^^^^^^^^^^^^^^^^^^^
This should be <= otherwise it won't free enough.  Then qt will point to
the wrong thing and the next loop will crash.

The loops in this function are mind bendingly complicated.  It might be
easiter to write them as:

	for (i = 0; i < nv->txt_count; i++) {
		qt = &nv->qt[i];
		...
	}

	for (i = 0; i < nv->rxt_count; i++) {
		qt = &nv->qt[txt_count + i];
		...
	}

Generally, I would just unwind the partial loop before the goto instead
of doing a jump to the middle of the goto.  It's more lines of code, but
I'm stupid, so I prefer code which is easy even if it's longer.

regards,
dan carpenter

> +		qt--;
> +
> +		xdp_rxq_info_unreg(&qt->xdp_rxq);
> +free_ring_cur_qt:
> +		fbnic_remove_rx_ring(fbn, &qt->sub0);
> +		fbnic_remove_rx_ring(fbn, &qt->sub1);
> +		fbnic_remove_rx_ring(fbn, &qt->cmpl);
> +		rxt_count++;
> +	}
> +	while (txt_count < nv->txt_count) {
> +		qt--;
> +
> +		fbnic_remove_tx_ring(fbn, &qt->sub0);
> +		fbnic_remove_tx_ring(fbn, &qt->cmpl);
> +
> +		txt_count++;
> +	}
> +	fbnic_napi_free_irq(fbd, nv);
>  pp_destroy:
>  	page_pool_destroy(nv->page_pool);
>  napi_del:

[PATCH net-next V4 6/9] eth: fbnic: Add support for XDP queues

[Mohsin Bashir]

Add support for allocating XDP_TX queues and configuring ring support.
FBNIC has been designed with XDP support in mind. Each Tx queue has 2
submission queues and one completion queue, with the expectation that
one of the submission queues will be used by the stack, and the other
by XDP. XDP queues are populated by XDP_TX and start from index 128
in the TX queue array.
The support for XDP_TX is added in the next patch.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Mohsin Bashir <mohsin.bashr@gmail.com>
---
 .../net/ethernet/meta/fbnic/fbnic_netdev.h    |   2 +-
 drivers/net/ethernet/meta/fbnic/fbnic_txrx.c  | 139 +++++++++++++++++-
 drivers/net/ethernet/meta/fbnic/fbnic_txrx.h  |   7 +
 3 files changed, 142 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_netdev.h b/drivers/net/ethernet/meta/fbnic/fbnic_netdev.h
index bfa79ea910d8..0a6347f28210 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_netdev.h
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_netdev.h
@@ -20,7 +20,7 @@
 struct fbnic_net {
 	struct bpf_prog *xdp_prog;
 
-	struct fbnic_ring *tx[FBNIC_MAX_TXQS];
+	struct fbnic_ring *tx[FBNIC_MAX_TXQS + FBNIC_MAX_XDPQS];
 	struct fbnic_ring *rx[FBNIC_MAX_RXQS];
 
 	struct fbnic_napi_vector *napi[FBNIC_MAX_NAPI_VECTORS];
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c
index a669e169e3ad..8c7709f707e6 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c
@@ -615,6 +615,37 @@ static void fbnic_clean_twq0(struct fbnic_napi_vector *nv, int napi_budget,
 	}
 }
 
+static void fbnic_clean_twq1(struct fbnic_napi_vector *nv, bool pp_allow_direct,
+			     struct fbnic_ring *ring, bool discard,
+			     unsigned int hw_head)
+{
+	unsigned int head = ring->head;
+	u64 total_bytes = 0;
+
+	while (hw_head != head) {
+		struct page *page;
+		u64 twd;
+
+		if (unlikely(!(ring->desc[head] & FBNIC_TWD_TYPE(AL))))
+			goto next_desc;
+
+		twd = le64_to_cpu(ring->desc[head]);
+		page = ring->tx_buf[head];
+
+		total_bytes += FIELD_GET(FBNIC_TWD_LEN_MASK, twd);
+
+		page_pool_put_page(nv->page_pool, page, -1, pp_allow_direct);
+next_desc:
+		head++;
+		head &= ring->size_mask;
+	}
+
+	if (!total_bytes)
+		return;
+
+	ring->head = head;
+}
+
 static void fbnic_clean_tsq(struct fbnic_napi_vector *nv,
 			    struct fbnic_ring *ring,
 			    u64 tcd, int *ts_head, int *head0)
@@ -698,12 +729,21 @@ static void fbnic_page_pool_drain(struct fbnic_ring *ring, unsigned int idx,
 }
 
 static void fbnic_clean_twq(struct fbnic_napi_vector *nv, int napi_budget,
-			    struct fbnic_q_triad *qt, s32 ts_head, s32 head0)
+			    struct fbnic_q_triad *qt, s32 ts_head, s32 head0,
+			    s32 head1)
 {
 	if (head0 >= 0)
 		fbnic_clean_twq0(nv, napi_budget, &qt->sub0, false, head0);
 	else if (ts_head >= 0)
 		fbnic_clean_twq0(nv, napi_budget, &qt->sub0, false, ts_head);
+
+	if (head1 >= 0) {
+		qt->cmpl.deferred_head = -1;
+		if (napi_budget)
+			fbnic_clean_twq1(nv, true, &qt->sub1, false, head1);
+		else
+			qt->cmpl.deferred_head = head1;
+	}
 }
 
 static void
@@ -711,6 +751,7 @@ fbnic_clean_tcq(struct fbnic_napi_vector *nv, struct fbnic_q_triad *qt,
 		int napi_budget)
 {
 	struct fbnic_ring *cmpl = &qt->cmpl;
+	s32 head1 = cmpl->deferred_head;
 	s32 head0 = -1, ts_head = -1;
 	__le64 *raw_tcd, done;
 	u32 head = cmpl->head;
@@ -728,7 +769,10 @@ fbnic_clean_tcq(struct fbnic_napi_vector *nv, struct fbnic_q_triad *qt,
 
 		switch (FIELD_GET(FBNIC_TCD_TYPE_MASK, tcd)) {
 		case FBNIC_TCD_TYPE_0:
-			if (!(tcd & FBNIC_TCD_TWQ1))
+			if (tcd & FBNIC_TCD_TWQ1)
+				head1 = FIELD_GET(FBNIC_TCD_TYPE0_HEAD1_MASK,
+						  tcd);
+			else
 				head0 = FIELD_GET(FBNIC_TCD_TYPE0_HEAD0_MASK,
 						  tcd);
 			/* Currently all err status bits are related to
@@ -761,7 +805,7 @@ fbnic_clean_tcq(struct fbnic_napi_vector *nv, struct fbnic_q_triad *qt,
 	}
 
 	/* Unmap and free processed buffers */
-	fbnic_clean_twq(nv, napi_budget, qt, ts_head, head0);
+	fbnic_clean_twq(nv, napi_budget, qt, ts_head, head0, head1);
 }
 
 static void fbnic_clean_bdq(struct fbnic_napi_vector *nv, int napi_budget,
@@ -1268,6 +1312,17 @@ static void fbnic_remove_tx_ring(struct fbnic_net *fbn,
 	fbn->tx[txr->q_idx] = NULL;
 }
 
+static void fbnic_remove_xdp_ring(struct fbnic_net *fbn,
+				  struct fbnic_ring *xdpr)
+{
+	if (!(xdpr->flags & FBNIC_RING_F_STATS))
+		return;
+
+	/* Remove pointer to the Tx ring */
+	WARN_ON(fbn->tx[xdpr->q_idx] && fbn->tx[xdpr->q_idx] != xdpr);
+	fbn->tx[xdpr->q_idx] = NULL;
+}
+
 static void fbnic_remove_rx_ring(struct fbnic_net *fbn,
 				 struct fbnic_ring *rxr)
 {
@@ -1289,6 +1344,7 @@ static void fbnic_free_napi_vector(struct fbnic_net *fbn,
 
 	for (i = 0; i < nv->txt_count; i++) {
 		fbnic_remove_tx_ring(fbn, &nv->qt[i].sub0);
+		fbnic_remove_xdp_ring(fbn, &nv->qt[i].sub1);
 		fbnic_remove_tx_ring(fbn, &nv->qt[i].cmpl);
 	}
 
@@ -1363,6 +1419,7 @@ static void fbnic_ring_init(struct fbnic_ring *ring, u32 __iomem *doorbell,
 	ring->doorbell = doorbell;
 	ring->q_idx = q_idx;
 	ring->flags = flags;
+	ring->deferred_head = -1;
 }
 
 static int fbnic_alloc_napi_vector(struct fbnic_dev *fbd, struct fbnic_net *fbn,
@@ -1372,11 +1429,18 @@ static int fbnic_alloc_napi_vector(struct fbnic_dev *fbd, struct fbnic_net *fbn,
 {
 	int txt_count = txq_count, rxt_count = rxq_count;
 	u32 __iomem *uc_addr = fbd->uc_addr0;
+	int xdp_count = 0, qt_count, err;
 	struct fbnic_napi_vector *nv;
 	struct fbnic_q_triad *qt;
-	int qt_count, err;
 	u32 __iomem *db;
 
+	/* We need to reserve at least one Tx Queue Triad for an XDP ring */
+	if (rxq_count) {
+		xdp_count = 1;
+		if (!txt_count)
+			txt_count = 1;
+	}
+
 	qt_count = txt_count + rxq_count;
 	if (!qt_count)
 		return -EINVAL;
@@ -1425,12 +1489,13 @@ static int fbnic_alloc_napi_vector(struct fbnic_dev *fbd, struct fbnic_net *fbn,
 	qt = nv->qt;
 
 	while (txt_count) {
+		u8 flags = FBNIC_RING_F_CTX | FBNIC_RING_F_STATS;
+
 		/* Configure Tx queue */
 		db = &uc_addr[FBNIC_QUEUE(txq_idx) + FBNIC_QUEUE_TWQ0_TAIL];
 
 		/* Assign Tx queue to netdev if applicable */
 		if (txq_count > 0) {
-			u8 flags = FBNIC_RING_F_CTX | FBNIC_RING_F_STATS;
 
 			fbnic_ring_init(&qt->sub0, db, txq_idx, flags);
 			fbn->tx[txq_idx] = &qt->sub0;
@@ -1440,6 +1505,28 @@ static int fbnic_alloc_napi_vector(struct fbnic_dev *fbd, struct fbnic_net *fbn,
 					FBNIC_RING_F_DISABLED);
 		}
 
+		/* Configure XDP queue */
+		db = &uc_addr[FBNIC_QUEUE(txq_idx) + FBNIC_QUEUE_TWQ1_TAIL];
+
+		/* Assign XDP queue to netdev if applicable
+		 *
+		 * The setup for this is in itself a bit different.
+		 * 1. We only need one XDP Tx queue per NAPI vector.
+		 * 2. We associate it to the first Rx queue index.
+		 * 3. The hardware side is associated based on the Tx Queue.
+		 * 4. The netdev queue is offset by FBNIC_MAX_TXQs.
+		 */
+		if (xdp_count > 0) {
+			unsigned int xdp_idx = FBNIC_MAX_TXQS + rxq_idx;
+
+			fbnic_ring_init(&qt->sub1, db, xdp_idx, flags);
+			fbn->tx[xdp_idx] = &qt->sub1;
+			xdp_count--;
+		} else {
+			fbnic_ring_init(&qt->sub1, db, 0,
+					FBNIC_RING_F_DISABLED);
+		}
+
 		/* Configure Tx completion queue */
 		db = &uc_addr[FBNIC_QUEUE(txq_idx) + FBNIC_QUEUE_TCQ_HEAD];
 		fbnic_ring_init(&qt->cmpl, db, 0, 0);
@@ -1495,6 +1582,7 @@ static int fbnic_alloc_napi_vector(struct fbnic_dev *fbd, struct fbnic_net *fbn,
 		qt--;
 
 		fbnic_remove_tx_ring(fbn, &qt->sub0);
+		fbnic_remove_xdp_ring(fbn, &qt->sub1);
 		fbnic_remove_tx_ring(fbn, &qt->cmpl);
 
 		txt_count++;
@@ -1729,6 +1817,10 @@ static int fbnic_alloc_tx_qt_resources(struct fbnic_net *fbn,
 	if (err)
 		return err;
 
+	err = fbnic_alloc_tx_ring_resources(fbn, &qt->sub1);
+	if (err)
+		goto free_sub0;
+
 	err = fbnic_alloc_tx_ring_resources(fbn, &qt->cmpl);
 	if (err)
 		goto free_sub1;
@@ -1736,6 +1828,8 @@ static int fbnic_alloc_tx_qt_resources(struct fbnic_net *fbn,
 	return 0;
 
 free_sub1:
+	fbnic_free_ring_resources(dev, &qt->sub1);
+free_sub0:
 	fbnic_free_ring_resources(dev, &qt->sub0);
 	return err;
 }
@@ -1923,6 +2017,15 @@ static void fbnic_disable_twq0(struct fbnic_ring *txr)
 	fbnic_ring_wr32(txr, FBNIC_QUEUE_TWQ0_CTL, twq_ctl);
 }
 
+static void fbnic_disable_twq1(struct fbnic_ring *txr)
+{
+	u32 twq_ctl = fbnic_ring_rd32(txr, FBNIC_QUEUE_TWQ1_CTL);
+
+	twq_ctl &= ~FBNIC_QUEUE_TWQ_CTL_ENABLE;
+
+	fbnic_ring_wr32(txr, FBNIC_QUEUE_TWQ1_CTL, twq_ctl);
+}
+
 static void fbnic_disable_tcq(struct fbnic_ring *txr)
 {
 	fbnic_ring_wr32(txr, FBNIC_QUEUE_TCQ_CTL, 0);
@@ -1968,6 +2071,7 @@ void fbnic_disable(struct fbnic_net *fbn)
 			struct fbnic_q_triad *qt = &nv->qt[t];
 
 			fbnic_disable_twq0(&qt->sub0);
+			fbnic_disable_twq1(&qt->sub1);
 			fbnic_disable_tcq(&qt->cmpl);
 		}
 
@@ -2082,6 +2186,8 @@ void fbnic_flush(struct fbnic_net *fbn)
 
 			/* Clean the work queues of unprocessed work */
 			fbnic_clean_twq0(nv, 0, &qt->sub0, true, qt->sub0.tail);
+			fbnic_clean_twq1(nv, false, &qt->sub1, true,
+					 qt->sub1.tail);
 
 			/* Reset completion queue descriptor ring */
 			memset(qt->cmpl.desc, 0, qt->cmpl.size);
@@ -2156,6 +2262,28 @@ static void fbnic_enable_twq0(struct fbnic_ring *twq)
 	fbnic_ring_wr32(twq, FBNIC_QUEUE_TWQ0_CTL, FBNIC_QUEUE_TWQ_CTL_ENABLE);
 }
 
+static void fbnic_enable_twq1(struct fbnic_ring *twq)
+{
+	u32 log_size = fls(twq->size_mask);
+
+	if (!twq->size_mask)
+		return;
+
+	/* Reset head/tail */
+	fbnic_ring_wr32(twq, FBNIC_QUEUE_TWQ1_CTL, FBNIC_QUEUE_TWQ_CTL_RESET);
+	twq->tail = 0;
+	twq->head = 0;
+
+	/* Store descriptor ring address and size */
+	fbnic_ring_wr32(twq, FBNIC_QUEUE_TWQ1_BAL, lower_32_bits(twq->dma));
+	fbnic_ring_wr32(twq, FBNIC_QUEUE_TWQ1_BAH, upper_32_bits(twq->dma));
+
+	/* Write lower 4 bits of log size as 64K ring size is 0 */
+	fbnic_ring_wr32(twq, FBNIC_QUEUE_TWQ1_SIZE, log_size & 0xf);
+
+	fbnic_ring_wr32(twq, FBNIC_QUEUE_TWQ1_CTL, FBNIC_QUEUE_TWQ_CTL_ENABLE);
+}
+
 static void fbnic_enable_tcq(struct fbnic_napi_vector *nv,
 			     struct fbnic_ring *tcq)
 {
@@ -2341,6 +2469,7 @@ void fbnic_enable(struct fbnic_net *fbn)
 			struct fbnic_q_triad *qt = &nv->qt[t];
 
 			fbnic_enable_twq0(&qt->sub0);
+			fbnic_enable_twq1(&qt->sub1);
 			fbnic_enable_tcq(nv, &qt->cmpl);
 		}
 
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h
index 5536f72a1c85..0e92d11115a6 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h
@@ -35,6 +35,7 @@ struct fbnic_net;
 
 #define FBNIC_MAX_TXQS			128u
 #define FBNIC_MAX_RXQS			128u
+#define FBNIC_MAX_XDPQS			128u
 
 /* These apply to TWQs, TCQ, RCQ */
 #define FBNIC_QUEUE_SIZE_MIN		16u
@@ -119,6 +120,12 @@ struct fbnic_ring {
 
 	u32 head, tail;			/* Head/Tail of ring */
 
+	/* Deferred_head is used to cache the head for TWQ1 if an attempt
+	 * is made to clean TWQ1 with zero napi_budget. We do not use it for
+	 * any other ring.
+	 */
+	s32 deferred_head;
+
 	struct fbnic_queue_stats stats;
 
 	/* Slow path fields follow */
-- 
2.47.3

[PATCH net-next V4 7/9] eth: fbnic: Add support for XDP_TX action

[Mohsin Bashir]

Add support for XDP_TX action and cleaning the associated work.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Mohsin Bashir <mohsin.bashr@gmail.com>
---
 drivers/net/ethernet/meta/fbnic/fbnic_txrx.c | 85 +++++++++++++++++++-
 1 file changed, 84 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c
index 8c7709f707e6..de3610a7491a 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c
@@ -19,6 +19,7 @@
 enum {
 	FBNIC_XDP_PASS = 0,
 	FBNIC_XDP_CONSUME,
+	FBNIC_XDP_TX,
 	FBNIC_XDP_LEN_ERR,
 };
 
@@ -1020,6 +1021,80 @@ static struct sk_buff *fbnic_build_skb(struct fbnic_napi_vector *nv,
 	return skb;
 }
 
+static long fbnic_pkt_tx(struct fbnic_napi_vector *nv,
+			 struct fbnic_pkt_buff *pkt)
+{
+	struct fbnic_ring *ring = &nv->qt[0].sub1;
+	int size, offset, nsegs = 1, data_len = 0;
+	unsigned int tail = ring->tail;
+	struct skb_shared_info *shinfo;
+	skb_frag_t *frag = NULL;
+	struct page *page;
+	dma_addr_t dma;
+	__le64 *twd;
+
+	if (unlikely(xdp_buff_has_frags(&pkt->buff))) {
+		shinfo = xdp_get_shared_info_from_buff(&pkt->buff);
+		nsegs += shinfo->nr_frags;
+		data_len = shinfo->xdp_frags_size;
+		frag = &shinfo->frags[0];
+	}
+
+	if (fbnic_desc_unused(ring) < nsegs)
+		return -FBNIC_XDP_CONSUME;
+
+	page = virt_to_page(pkt->buff.data_hard_start);
+	offset = offset_in_page(pkt->buff.data);
+	dma = page_pool_get_dma_addr(page);
+
+	size = pkt->buff.data_end - pkt->buff.data;
+
+	while (nsegs--) {
+		dma_sync_single_range_for_device(nv->dev, dma, offset, size,
+						 DMA_BIDIRECTIONAL);
+		dma += offset;
+
+		ring->tx_buf[tail] = page;
+
+		twd = &ring->desc[tail];
+		*twd = cpu_to_le64(FIELD_PREP(FBNIC_TWD_ADDR_MASK, dma) |
+				   FIELD_PREP(FBNIC_TWD_LEN_MASK, size) |
+				   FIELD_PREP(FBNIC_TWD_TYPE_MASK,
+					      FBNIC_TWD_TYPE_AL));
+
+		tail++;
+		tail &= ring->size_mask;
+
+		if (!data_len)
+			break;
+
+		offset = skb_frag_off(frag);
+		page = skb_frag_page(frag);
+		dma = page_pool_get_dma_addr(page);
+
+		size = skb_frag_size(frag);
+		data_len -= size;
+		frag++;
+	}
+
+	*twd |= FBNIC_TWD_TYPE(LAST_AL);
+
+	ring->tail = tail;
+
+	return -FBNIC_XDP_TX;
+}
+
+static void fbnic_pkt_commit_tail(struct fbnic_napi_vector *nv,
+				  unsigned int pkt_tail)
+{
+	struct fbnic_ring *ring = &nv->qt[0].sub1;
+
+	/* Force DMA writes to flush before writing to tail */
+	dma_wmb();
+
+	writel(pkt_tail, ring->doorbell);
+}
+
 static struct sk_buff *fbnic_run_xdp(struct fbnic_napi_vector *nv,
 				     struct fbnic_pkt_buff *pkt)
 {
@@ -1040,6 +1115,8 @@ static struct sk_buff *fbnic_run_xdp(struct fbnic_napi_vector *nv,
 	case XDP_PASS:
 xdp_pass:
 		return fbnic_build_skb(nv, pkt);
+	case XDP_TX:
+		return ERR_PTR(fbnic_pkt_tx(nv, pkt));
 	default:
 		bpf_warn_invalid_xdp_action(nv->napi.dev, xdp_prog, act);
 		fallthrough;
@@ -1104,10 +1181,10 @@ static int fbnic_clean_rcq(struct fbnic_napi_vector *nv,
 			   struct fbnic_q_triad *qt, int budget)
 {
 	unsigned int packets = 0, bytes = 0, dropped = 0, alloc_failed = 0;
+	s32 head0 = -1, head1 = -1, pkt_tail = -1;
 	u64 csum_complete = 0, csum_none = 0;
 	struct fbnic_ring *rcq = &qt->cmpl;
 	struct fbnic_pkt_buff *pkt;
-	s32 head0 = -1, head1 = -1;
 	__le64 *raw_rcd, done;
 	u32 head = rcq->head;
 
@@ -1163,6 +1240,9 @@ static int fbnic_clean_rcq(struct fbnic_napi_vector *nv,
 				bytes += skb->len;
 
 				napi_gro_receive(&nv->napi, skb);
+			} else if (skb == ERR_PTR(-FBNIC_XDP_TX)) {
+				pkt_tail = nv->qt[0].sub1.tail;
+				bytes += xdp_get_buff_len(&pkt->buff);
 			} else {
 				if (!skb) {
 					alloc_failed++;
@@ -1198,6 +1278,9 @@ static int fbnic_clean_rcq(struct fbnic_napi_vector *nv,
 	rcq->stats.rx.csum_none += csum_none;
 	u64_stats_update_end(&rcq->stats.syncp);
 
+	if (pkt_tail >= 0)
+		fbnic_pkt_commit_tail(nv, pkt_tail);
+
 	/* Unmap and free processed buffers */
 	if (head0 >= 0)
 		fbnic_clean_bdq(nv, budget, &qt->sub0, head0);
-- 
2.47.3

[PATCH net-next V4 8/9] eth: fbnic: Collect packet statistics for XDP

[Mohsin Bashir]

Add support for XDP statistics collection and reporting via rtnl_link
and netdev_queue API.

For XDP programs without frags support, fbnic requires MTU to be less
than the HDS threshold. If an over-sized frame is received, the frame
is dropped and recorded as rx_length_errors reported via ip stats to
highlight that this is an error.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Mohsin Bashir <mohsin.bashr@gmail.com>
---
 .../device_drivers/ethernet/meta/fbnic.rst    | 11 ++++
 .../net/ethernet/meta/fbnic/fbnic_netdev.c    | 36 ++++++++++++-
 drivers/net/ethernet/meta/fbnic/fbnic_txrx.c  | 51 +++++++++++++++++--
 drivers/net/ethernet/meta/fbnic/fbnic_txrx.h  |  1 +
 4 files changed, 94 insertions(+), 5 deletions(-)

diff --git a/Documentation/networking/device_drivers/ethernet/meta/fbnic.rst b/Documentation/networking/device_drivers/ethernet/meta/fbnic.rst
index afb8353daefd..fb6559fa4be4 100644
--- a/Documentation/networking/device_drivers/ethernet/meta/fbnic.rst
+++ b/Documentation/networking/device_drivers/ethernet/meta/fbnic.rst
@@ -160,3 +160,14 @@ behavior and potential performance bottlenecks.
 	  credit exhaustion
         - ``pcie_ob_rd_no_np_cred``: Read requests dropped due to non-posted
 	  credit exhaustion
+
+XDP Length Error:
+~~~~~~~~~~~~~~~~~
+
+For XDP programs without frags support, fbnic tries to make sure that MTU fits
+into a single buffer. If an oversized frame is received and gets fragmented,
+it is dropped and the following netlink counters are updated
+
+   - ``rx-length``: number of frames dropped due to lack of fragmentation
+     support in the attached XDP program
+   - ``rx-errors``: total number of packets with errors received on the interface
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_netdev.c b/drivers/net/ethernet/meta/fbnic/fbnic_netdev.c
index fb81d1a7bc51..b8b684ad376b 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_netdev.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_netdev.c
@@ -407,11 +407,12 @@ static void fbnic_get_stats64(struct net_device *dev,
 			      struct rtnl_link_stats64 *stats64)
 {
 	u64 rx_bytes, rx_packets, rx_dropped = 0, rx_errors = 0;
+	u64 rx_over = 0, rx_missed = 0, rx_length = 0;
 	u64 tx_bytes, tx_packets, tx_dropped = 0;
 	struct fbnic_net *fbn = netdev_priv(dev);
 	struct fbnic_dev *fbd = fbn->fbd;
 	struct fbnic_queue_stats *stats;
-	u64 rx_over = 0, rx_missed = 0;
+
 	unsigned int start, i;
 
 	fbnic_get_hw_stats(fbd);
@@ -489,6 +490,7 @@ static void fbnic_get_stats64(struct net_device *dev,
 	stats64->rx_missed_errors = rx_missed;
 
 	for (i = 0; i < fbn->num_rx_queues; i++) {
+		struct fbnic_ring *xdpr = fbn->tx[FBNIC_MAX_TXQS + i];
 		struct fbnic_ring *rxr = fbn->rx[i];
 
 		if (!rxr)
@@ -500,11 +502,29 @@ static void fbnic_get_stats64(struct net_device *dev,
 			rx_bytes = stats->bytes;
 			rx_packets = stats->packets;
 			rx_dropped = stats->dropped;
+			rx_length = stats->rx.length_errors;
 		} while (u64_stats_fetch_retry(&stats->syncp, start));
 
 		stats64->rx_bytes += rx_bytes;
 		stats64->rx_packets += rx_packets;
 		stats64->rx_dropped += rx_dropped;
+		stats64->rx_errors += rx_length;
+		stats64->rx_length_errors += rx_length;
+
+		if (!xdpr)
+			continue;
+
+		stats = &xdpr->stats;
+		do {
+			start = u64_stats_fetch_begin(&stats->syncp);
+			tx_bytes = stats->bytes;
+			tx_packets = stats->packets;
+			tx_dropped = stats->dropped;
+		} while (u64_stats_fetch_retry(&stats->syncp, start));
+
+		stats64->tx_bytes += tx_bytes;
+		stats64->tx_packets += tx_packets;
+		stats64->tx_dropped += tx_dropped;
 	}
 }
 
@@ -603,6 +623,7 @@ static void fbnic_get_queue_stats_tx(struct net_device *dev, int idx,
 	struct fbnic_ring *txr = fbn->tx[idx];
 	struct fbnic_queue_stats *stats;
 	u64 stop, wake, csum, lso;
+	struct fbnic_ring *xdpr;
 	unsigned int start;
 	u64 bytes, packets;
 
@@ -626,6 +647,19 @@ static void fbnic_get_queue_stats_tx(struct net_device *dev, int idx,
 	tx->hw_gso_wire_packets = lso;
 	tx->stop = stop;
 	tx->wake = wake;
+
+	xdpr = fbn->tx[FBNIC_MAX_TXQS + idx];
+	if (xdpr) {
+		stats = &xdpr->stats;
+		do {
+			start = u64_stats_fetch_begin(&stats->syncp);
+			bytes = stats->bytes;
+			packets = stats->packets;
+		} while (u64_stats_fetch_retry(&stats->syncp, start));
+
+		tx->bytes += bytes;
+		tx->packets += packets;
+	}
 }
 
 static void fbnic_get_base_stats(struct net_device *dev,
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c
index de3610a7491a..fea4577e38d4 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.c
@@ -620,8 +620,8 @@ static void fbnic_clean_twq1(struct fbnic_napi_vector *nv, bool pp_allow_direct,
 			     struct fbnic_ring *ring, bool discard,
 			     unsigned int hw_head)
 {
+	u64 total_bytes = 0, total_packets = 0;
 	unsigned int head = ring->head;
-	u64 total_bytes = 0;
 
 	while (hw_head != head) {
 		struct page *page;
@@ -633,6 +633,11 @@ static void fbnic_clean_twq1(struct fbnic_napi_vector *nv, bool pp_allow_direct,
 		twd = le64_to_cpu(ring->desc[head]);
 		page = ring->tx_buf[head];
 
+		/* TYPE_AL is 2, TYPE_LAST_AL is 3. So this trick gives
+		 * us one increment per packet, with no branches.
+		 */
+		total_packets += FIELD_GET(FBNIC_TWD_TYPE_MASK, twd) -
+				 FBNIC_TWD_TYPE_AL;
 		total_bytes += FIELD_GET(FBNIC_TWD_LEN_MASK, twd);
 
 		page_pool_put_page(nv->page_pool, page, -1, pp_allow_direct);
@@ -645,6 +650,18 @@ static void fbnic_clean_twq1(struct fbnic_napi_vector *nv, bool pp_allow_direct,
 		return;
 
 	ring->head = head;
+
+	if (discard) {
+		u64_stats_update_begin(&ring->stats.syncp);
+		ring->stats.dropped += total_packets;
+		u64_stats_update_end(&ring->stats.syncp);
+		return;
+	}
+
+	u64_stats_update_begin(&ring->stats.syncp);
+	ring->stats.bytes += total_bytes;
+	ring->stats.packets += total_packets;
+	u64_stats_update_end(&ring->stats.syncp);
 }
 
 static void fbnic_clean_tsq(struct fbnic_napi_vector *nv,
@@ -1040,8 +1057,12 @@ static long fbnic_pkt_tx(struct fbnic_napi_vector *nv,
 		frag = &shinfo->frags[0];
 	}
 
-	if (fbnic_desc_unused(ring) < nsegs)
+	if (fbnic_desc_unused(ring) < nsegs) {
+		u64_stats_update_begin(&ring->stats.syncp);
+		ring->stats.dropped++;
+		u64_stats_update_end(&ring->stats.syncp);
 		return -FBNIC_XDP_CONSUME;
+	}
 
 	page = virt_to_page(pkt->buff.data_hard_start);
 	offset = offset_in_page(pkt->buff.data);
@@ -1181,8 +1202,8 @@ static int fbnic_clean_rcq(struct fbnic_napi_vector *nv,
 			   struct fbnic_q_triad *qt, int budget)
 {
 	unsigned int packets = 0, bytes = 0, dropped = 0, alloc_failed = 0;
+	u64 csum_complete = 0, csum_none = 0, length_errors = 0;
 	s32 head0 = -1, head1 = -1, pkt_tail = -1;
-	u64 csum_complete = 0, csum_none = 0;
 	struct fbnic_ring *rcq = &qt->cmpl;
 	struct fbnic_pkt_buff *pkt;
 	__le64 *raw_rcd, done;
@@ -1247,6 +1268,8 @@ static int fbnic_clean_rcq(struct fbnic_napi_vector *nv,
 				if (!skb) {
 					alloc_failed++;
 					dropped++;
+				} else if (skb == ERR_PTR(-FBNIC_XDP_LEN_ERR)) {
+					length_errors++;
 				} else {
 					dropped++;
 				}
@@ -1276,6 +1299,7 @@ static int fbnic_clean_rcq(struct fbnic_napi_vector *nv,
 	rcq->stats.rx.alloc_failed += alloc_failed;
 	rcq->stats.rx.csum_complete += csum_complete;
 	rcq->stats.rx.csum_none += csum_none;
+	rcq->stats.rx.length_errors += length_errors;
 	u64_stats_update_end(&rcq->stats.syncp);
 
 	if (pkt_tail >= 0)
@@ -1359,8 +1383,9 @@ void fbnic_aggregate_ring_rx_counters(struct fbnic_net *fbn,
 	fbn->rx_stats.rx.alloc_failed += stats->rx.alloc_failed;
 	fbn->rx_stats.rx.csum_complete += stats->rx.csum_complete;
 	fbn->rx_stats.rx.csum_none += stats->rx.csum_none;
+	fbn->rx_stats.rx.length_errors += stats->rx.length_errors;
 	/* Remember to add new stats here */
-	BUILD_BUG_ON(sizeof(fbn->rx_stats.rx) / 8 != 3);
+	BUILD_BUG_ON(sizeof(fbn->rx_stats.rx) / 8 != 4);
 }
 
 void fbnic_aggregate_ring_tx_counters(struct fbnic_net *fbn,
@@ -1382,6 +1407,22 @@ void fbnic_aggregate_ring_tx_counters(struct fbnic_net *fbn,
 	BUILD_BUG_ON(sizeof(fbn->tx_stats.twq) / 8 != 6);
 }
 
+static void fbnic_aggregate_ring_xdp_counters(struct fbnic_net *fbn,
+					      struct fbnic_ring *xdpr)
+{
+	struct fbnic_queue_stats *stats = &xdpr->stats;
+
+	if (!(xdpr->flags & FBNIC_RING_F_STATS))
+		return;
+
+	/* Capture stats from queues before dissasociating them */
+	fbn->rx_stats.bytes += stats->bytes;
+	fbn->rx_stats.packets += stats->packets;
+	fbn->rx_stats.dropped += stats->dropped;
+	fbn->tx_stats.bytes += stats->bytes;
+	fbn->tx_stats.packets += stats->packets;
+}
+
 static void fbnic_remove_tx_ring(struct fbnic_net *fbn,
 				 struct fbnic_ring *txr)
 {
@@ -1401,6 +1442,8 @@ static void fbnic_remove_xdp_ring(struct fbnic_net *fbn,
 	if (!(xdpr->flags & FBNIC_RING_F_STATS))
 		return;
 
+	fbnic_aggregate_ring_xdp_counters(fbn, xdpr);
+
 	/* Remove pointer to the Tx ring */
 	WARN_ON(fbn->tx[xdpr->q_idx] && fbn->tx[xdpr->q_idx] != xdpr);
 	fbn->tx[xdpr->q_idx] = NULL;
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h
index 0e92d11115a6..873440ca6a31 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_txrx.h
@@ -90,6 +90,7 @@ struct fbnic_queue_stats {
 			u64 alloc_failed;
 			u64 csum_complete;
 			u64 csum_none;
+			u64 length_errors;
 		} rx;
 	};
 	u64 dropped;
-- 
2.47.3

[PATCH net-next V4 9/9] eth: fbnic: Report XDP stats via ethtool

[Mohsin Bashir]

Add support to collect XDP stats via ethtool API. We record
packets and bytes sent, and packets dropped on the XDP_TX path.

ethtool -S eth0 | grep xdp | grep -v "0"
     xdp_tx_queue_13_packets: 2
     xdp_tx_queue_13_bytes: 16126

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Mohsin Bashir <mohsin.bashr@gmail.com>
---
 .../net/ethernet/meta/fbnic/fbnic_ethtool.c   | 50 ++++++++++++++++++-
 1 file changed, 49 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c b/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c
index 742b557d0e56..ceb8f88ae41c 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c
@@ -112,6 +112,20 @@ static const struct fbnic_stat fbnic_gstrings_hw_q_stats[] = {
 	 FBNIC_HW_RXB_DEQUEUE_STATS_LEN * FBNIC_RXB_DEQUEUE_INDICES + \
 	 FBNIC_HW_Q_STATS_LEN * FBNIC_MAX_QUEUES)
 
+#define FBNIC_QUEUE_STAT(name, stat) \
+	FBNIC_STAT_FIELDS(fbnic_ring, name, stat)
+
+static const struct fbnic_stat fbnic_gstrings_xdp_stats[] = {
+	FBNIC_QUEUE_STAT("xdp_tx_queue_%u_packets", stats.packets),
+	FBNIC_QUEUE_STAT("xdp_tx_queue_%u_bytes", stats.bytes),
+	FBNIC_QUEUE_STAT("xdp_tx_queue_%u_dropped", stats.dropped),
+};
+
+#define FBNIC_XDP_STATS_LEN ARRAY_SIZE(fbnic_gstrings_xdp_stats)
+
+#define FBNIC_STATS_LEN \
+	(FBNIC_HW_STATS_LEN + FBNIC_XDP_STATS_LEN * FBNIC_MAX_XDPQS)
+
 static void
 fbnic_get_drvinfo(struct net_device *netdev, struct ethtool_drvinfo *drvinfo)
 {
@@ -422,6 +436,16 @@ static void fbnic_get_rxb_dequeue_strings(u8 **data, unsigned int idx)
 		ethtool_sprintf(data, stat->string, idx);
 }
 
+static void fbnic_get_xdp_queue_strings(u8 **data, unsigned int idx)
+{
+	const struct fbnic_stat *stat;
+	int i;
+
+	stat = fbnic_gstrings_xdp_stats;
+	for (i = 0; i < FBNIC_XDP_STATS_LEN; i++, stat++)
+		ethtool_sprintf(data, stat->string, idx);
+}
+
 static void fbnic_get_strings(struct net_device *dev, u32 sset, u8 *data)
 {
 	const struct fbnic_stat *stat;
@@ -447,6 +471,9 @@ static void fbnic_get_strings(struct net_device *dev, u32 sset, u8 *data)
 			for (i = 0; i < FBNIC_HW_Q_STATS_LEN; i++, stat++)
 				ethtool_sprintf(&data, stat->string, idx);
 		}
+
+		for (i = 0; i < FBNIC_MAX_XDPQS; i++)
+			fbnic_get_xdp_queue_strings(&data, i);
 		break;
 	}
 }
@@ -464,6 +491,24 @@ static void fbnic_report_hw_stats(const struct fbnic_stat *stat,
 	}
 }
 
+static void fbnic_get_xdp_queue_stats(struct fbnic_ring *ring, u64 **data)
+{
+	const struct fbnic_stat *stat;
+	int i;
+
+	if (!ring) {
+		*data += FBNIC_XDP_STATS_LEN;
+		return;
+	}
+
+	stat = fbnic_gstrings_xdp_stats;
+	for (i = 0; i < FBNIC_XDP_STATS_LEN; i++, stat++, (*data)++) {
+		u8 *p = (u8 *)ring + stat->offset;
+
+		**data = *(u64 *)p;
+	}
+}
+
 static void fbnic_get_ethtool_stats(struct net_device *dev,
 				    struct ethtool_stats *stats, u64 *data)
 {
@@ -511,13 +556,16 @@ static void fbnic_get_ethtool_stats(struct net_device *dev,
 				      FBNIC_HW_Q_STATS_LEN, &data);
 	}
 	spin_unlock(&fbd->hw_stats_lock);
+
+	for (i = 0; i < FBNIC_MAX_XDPQS; i++)
+		fbnic_get_xdp_queue_stats(fbn->tx[i + FBNIC_MAX_TXQS], &data);
 }
 
 static int fbnic_get_sset_count(struct net_device *dev, int sset)
 {
 	switch (sset) {
 	case ETH_SS_STATS:
-		return FBNIC_HW_STATS_LEN;
+		return FBNIC_STATS_LEN;
 	default:
 		return -EOPNOTSUPP;
 	}
-- 
2.47.3

Re: [PATCH net-next V4 0/9] eth: fbnic: Add XDP support for fbnic

[patchwork-bot+netdevbpf]

Hello:

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

On Wed, 13 Aug 2025 15:13:10 -0700 you wrote:
> This patch series introduces basic XDP support for fbnic. To enable this,
> it also includes preparatory changes such as making the HDS threshold
> configurable via ethtool, updating headroom for fbnic, tracking
> frag state in shinfo, and prefetching the first cacheline of data.
> 
> ---
> Changelog:
> V4: Update P7 and P8 to address cocci complains about PTR_ERR
> 
> [...]

Here is the summary with links:
  - [net-next,V4,1/9] eth: fbnic: Add support for HDS configuration
    https://git.kernel.org/netdev/net-next/c/2b30fc01a6c7
  - [net-next,V4,2/9] eth: fbnic: Update Headroom
    https://git.kernel.org/netdev/net-next/c/0cf5a39720d0
  - [net-next,V4,3/9] eth: fbnic: Use shinfo to track frags state on Rx
    https://git.kernel.org/netdev/net-next/c/61f9a066c309
  - [net-next,V4,4/9] eth: fbnic: Prefetch packet headers on Rx
    https://git.kernel.org/netdev/net-next/c/9064ab485f04
  - [net-next,V4,5/9] eth: fbnic: Add XDP pass, drop, abort support
    https://git.kernel.org/netdev/net-next/c/1b0a3950dbd4
  - [net-next,V4,6/9] eth: fbnic: Add support for XDP queues
    https://git.kernel.org/netdev/net-next/c/cf4facfb132a
  - [net-next,V4,7/9] eth: fbnic: Add support for XDP_TX action
    https://git.kernel.org/netdev/net-next/c/168deb7b31b2
  - [net-next,V4,8/9] eth: fbnic: Collect packet statistics for XDP
    https://git.kernel.org/netdev/net-next/c/5213ff086344
  - [net-next,V4,9/9] eth: fbnic: Report XDP stats via ethtool
    https://git.kernel.org/netdev/net-next/c/7fedb8f2677e

You are awesome, thank you!
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