[Intel-wired-lan] [PATCH iwl-next 05/10] ixgbevf: support XDP multi-buffer on Rx path

Larysa Zaremba
2026-02-23T10:23:02Z

Implement XDP support for received fragmented packets, this requires using
some helpers from libeth_xdp.

Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
---
drivers/net/ethernet/intel/ixgbevf/ixgbevf.h | 3 +-
.../net/ethernet/intel/ixgbevf/ixgbevf_main.c | 88 ++++++-------------
2 files changed, 31 insertions(+), 60 deletions(-)

diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h b/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h
index 698091d42dbd..eada53c57fcf 100644
--- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h
+++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h
@@ -11,6 +11,7 @@
#include <linux/netdevice.h>
#include <linux/if_vlan.h>
#include <linux/u64_stats_sync.h>
+#include <net/libeth/types.h>
#include <net/xdp.h>

#include "vf.h"
@@ -106,7 +107,6 @@ struct ixgbevf_ring {
struct xdp_rxq_info xdp_rxq;
u64 hw_csum_rx_error;
u8 __iomem *tail;
- struct sk_buff *skb;

/* holds the special value that gets the hardware register offset
* associated with this ring, which is different for DCB and RSS modes
@@ -114,6 +114,7 @@ struct ixgbevf_ring {
u16 reg_idx;
int queue_index; /* needed for multiqueue queue management */
u32 rx_buf_len;
+ struct libeth_xdp_buff_stash xdp_stash;
} ____cacheline_internodealigned_in_smp;

/* How many Rx Buffers do we bundle into one write to the hardware ? */
diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
index 39124c430537..558a4fad543a 100644
--- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
+++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
@@ -84,6 +84,7 @@ MODULE_DEVICE_TABLE(pci, ixgbevf_pci_tbl);

MODULE_DESCRIPTION("Intel(R) 10 Gigabit Virtual Function Network Driver");
MODULE_IMPORT_NS("LIBETH");
+MODULE_IMPORT_NS("LIBETH_XDP");
MODULE_LICENSE("GPL v2");

#define DEFAULT_MSG_ENABLE (NETIF_MSG_DRV|NETIF_MSG_PROBE|NETIF_MSG_LINK)
@@ -647,26 +648,6 @@ static bool ixgbevf_cleanup_headers(struct ixgbevf_ring *rx_ring,
return false;
}

-/**
- * ixgbevf_add_rx_frag - Add contents of Rx buffer to sk_buff
- * @rx_ring: rx descriptor ring to transact packets on
- * @rx_buffer: buffer containing page to add
- * @skb: sk_buff to place the data into
- * @size: size of buffer to be added
- *
- * This function will add the data contained in rx_buffer->page to the skb.
- **/
-static void ixgbevf_add_rx_frag(const struct libeth_fqe *rx_buffer,
- struct sk_buff *skb,
- unsigned int size)
-{
- u32 hr = netmem_get_pp(rx_buffer->netmem)->p.offset;
-
- skb_add_rx_frag_netmem(skb, skb_shinfo(skb)->nr_frags,
- rx_buffer->netmem, rx_buffer->offset + hr,
- size, rx_buffer->truesize);
-}
-
static inline void ixgbevf_irq_enable_queues(struct ixgbevf_adapter *adapter,
u32 qmask)
{
@@ -803,16 +784,16 @@ static int ixgbevf_clean_rx_irq(struct ixgbevf_q_vector *q_vector,
unsigned int total_rx_bytes = 0, total_rx_packets = 0;
struct ixgbevf_adapter *adapter = q_vector->adapter;
u16 cleaned_count = ixgbevf_desc_unused(rx_ring);
- struct sk_buff *skb = rx_ring->skb;
LIBETH_XDP_ONSTACK_BUFF(xdp);
bool xdp_xmit = false;
int xdp_res = 0;

- xdp->base.rxq = &rx_ring->xdp_rxq;
+ libeth_xdp_init_buff(xdp, &rx_ring->xdp_stash, &rx_ring->xdp_rxq);

while (likely(total_rx_packets < budget)) {
union ixgbe_adv_rx_desc *rx_desc;
struct libeth_fqe *rx_buffer;
+ struct sk_buff *skb;
unsigned int size;

/* return some buffers to hardware, one at a time is too slow */
@@ -833,42 +814,34 @@ static int ixgbevf_clean_rx_irq(struct ixgbevf_q_vector *q_vector,
rmb();

rx_buffer = &rx_ring->rx_fqes[rx_ring->next_to_clean];
- libeth_rx_sync_for_cpu(rx_buffer, size);
+ libeth_xdp_process_buff(xdp, rx_buffer, size);

- /* retrieve a buffer from the ring */
- if (!skb) {
- libeth_xdp_prepare_buff(xdp, rx_buffer, size);
- prefetch(xdp->data);
- xdp_res = ixgbevf_run_xdp(adapter, rx_ring, xdp);
- }
+ cleaned_count++;
+ /* fetch next buffer in frame if non-eop */
+ if (ixgbevf_is_non_eop(rx_ring, rx_desc))
+ continue;

+ xdp_res = ixgbevf_run_xdp(adapter, rx_ring, xdp);
if (xdp_res) {
if (xdp_res == IXGBEVF_XDP_TX)
xdp_xmit = true;

total_rx_packets++;
total_rx_bytes += size;
- } else if (skb) {
- ixgbevf_add_rx_frag(rx_buffer, skb, size);
- } else {
- skb = xdp_build_skb_from_buff(&xdp->base);
+ continue;
}

+ skb = xdp_build_skb_from_buff(&xdp->base);
+ xdp->data = NULL;
+
/* exit if we failed to retrieve a buffer */
- if (unlikely(!xdp_res && !skb)) {
+ if (unlikely(!skb)) {
rx_ring->rx_stats.alloc_rx_buff_failed++;
break;
}

- cleaned_count++;
-
- /* fetch next buffer in frame if non-eop */
- if (ixgbevf_is_non_eop(rx_ring, rx_desc))
- continue;
-
/* verify the packet layout is correct */
- if (xdp_res ||
- unlikely(ixgbevf_cleanup_headers(rx_ring, rx_desc, skb))) {
+ if (unlikely(ixgbevf_cleanup_headers(rx_ring, rx_desc, skb))) {
skb = NULL;
continue;
}
@@ -892,13 +865,10 @@ static int ixgbevf_clean_rx_irq(struct ixgbevf_q_vector *q_vector,
total_rx_packets++;

ixgbevf_rx_skb(q_vector, skb);
-
- /* reset skb pointer */
- skb = NULL;
}

/* place incomplete frames back on ring for completion */
- rx_ring->skb = skb;
+ libeth_xdp_save_buff(&rx_ring->xdp_stash, xdp);

if (xdp_xmit) {
struct ixgbevf_ring *xdp_ring =
@@ -2018,10 +1988,7 @@ void ixgbevf_up(struct ixgbevf_adapter *adapter)
static void ixgbevf_clean_rx_ring(struct ixgbevf_ring *rx_ring)
{
/* Free Rx ring sk_buff */
- if (rx_ring->skb) {
- dev_kfree_skb(rx_ring->skb);
- rx_ring->skb = NULL;
- }
+ libeth_xdp_return_stash(&rx_ring->xdp_stash);

/* Free all the Rx ring pages */
for (u32 i = rx_ring->next_to_clean; i != rx_ring->next_to_use; ) {
@@ -4101,16 +4068,19 @@ ixgbevf_features_check(struct sk_buff *skb, struct net_device *dev,
return features;
}

-static int ixgbevf_xdp_setup(struct net_device *dev, struct bpf_prog *prog)
+static int ixgbevf_xdp_setup(struct net_device *dev, struct bpf_prog *prog,
+ struct netlink_ext_ack *extack)
{
- int i, frame_size = dev->mtu + ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN;
+ u32 frame_size = READ_ONCE(dev->mtu) + LIBETH_RX_LL_LEN;
struct ixgbevf_adapter *adapter = netdev_priv(dev);
struct bpf_prog *old_prog;
+ bool requires_mbuf;

- /* verify ixgbevf ring attributes are sufficient for XDP */
- for (i = 0; i < adapter->num_rx_queues; i++) {
- if (frame_size > IXGBEVF_RXBUFFER_3072)
- return -EINVAL;
+ requires_mbuf = frame_size > IXGBEVF_RX_PAGE_LEN(LIBETH_XDP_HEADROOM);
+ if (prog && !prog->aux->xdp_has_frags && requires_mbuf) {
+ NL_SET_ERR_MSG_MOD(extack,
+ "Configured MTU requires non-linear frames and XDP prog does not support frags");
+ return -EOPNOTSUPP;
}

old_prog = xchg(&adapter->xdp_prog, prog);
@@ -4130,7 +4100,7 @@ static int ixgbevf_xdp_setup(struct net_device *dev, struct bpf_prog *prog)
if (netif_running(dev))
ixgbevf_open(dev);
} else {
- for (i = 0; i < adapter->num_rx_queues; i++)
+ for (int i = 0; i < adapter->num_rx_queues; i++)
xchg(&adapter->rx_ring[i]->xdp_prog, adapter->xdp_prog);
}

@@ -4144,7 +4114,7 @@ static int ixgbevf_xdp(struct net_device *dev, struct netdev_bpf *xdp)
{
switch (xdp->command) {
case XDP_SETUP_PROG:
- return ixgbevf_xdp_setup(dev, xdp->prog);
+ return ixgbevf_xdp_setup(dev, xdp->prog, xdp->extack);
default:
return -EINVAL;
}
@@ -4296,7 +4266,7 @@ static int ixgbevf_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
NETIF_F_HW_VLAN_CTAG_TX;

netdev->priv_flags |= IFF_UNICAST_FLT;
- netdev->xdp_features = NETDEV_XDP_ACT_BASIC;
+ netdev->xdp_features = NETDEV_XDP_ACT_BASIC | NETDEV_XDP_ACT_RX_SG;

/* MTU range: 68 - 1504 or 9710 */
netdev->min_mtu = ETH_MIN_MTU;
--
2.52.0