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ixgbe: convert Rx to libeth and page_pool #6

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973e36d
ixgbe: remove legacy rx
Magda-Pytel Apr 13, 2026
1ed40c0
ixgbe: do not share pages between packets
Magda-Pytel May 7, 2026
bb94122
ixgbe: use libeth in Rx processing
Magda-Pytel May 7, 2026
077bdc0
ixgbe: branch prediction and cleanup
Magda-Pytel May 28, 2026
f38e292
ixgbe: support XDP multi-buffer on Rx path
Magda-Pytel Jun 1, 2026
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1 change: 1 addition & 0 deletions drivers/net/ethernet/intel/Kconfig
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Original file line number Diff line number Diff line change
Expand Up @@ -146,6 +146,7 @@ config IXGBE
tristate "Intel(R) 10GbE PCI Express adapters support"
depends on PCI
depends on PTP_1588_CLOCK_OPTIONAL
select LIBETH_XDP
select LIBIE_FWLOG if DEBUG_FS
select MDIO
select NET_DEVLINK
Expand Down
141 changes: 23 additions & 118 deletions drivers/net/ethernet/intel/ixgbe/ixgbe.h
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Original file line number Diff line number Diff line change
Expand Up @@ -33,6 +33,8 @@
#include "ixgbe_ipsec.h"

#include <net/xdp.h>
#include <net/libeth/rx.h>
#include <net/libeth/types.h>

/* common prefix used by pr_<> macros */
#undef pr_fmt
Expand Down Expand Up @@ -69,73 +71,16 @@

/* Supported Rx Buffer Sizes */
#define IXGBE_RXBUFFER_256 256 /* Used for skb receive header */
#define IXGBE_RXBUFFER_1536 1536
#define IXGBE_RXBUFFER_2K 2048
#define IXGBE_RXBUFFER_3K 3072
#define IXGBE_RXBUFFER_4K 4096
#define IXGBE_MAX_RXBUFFER 16384 /* largest size for a single descriptor */

#define IXGBE_PKT_HDR_PAD (ETH_HLEN + ETH_FCS_LEN + (VLAN_HLEN * 2))

/* Attempt to maximize the headroom available for incoming frames. We
* use a 2K buffer for receives and need 1536/1534 to store the data for
* the frame. This leaves us with 512 bytes of room. From that we need
* to deduct the space needed for the shared info and the padding needed
* to IP align the frame.
*
* Note: For cache line sizes 256 or larger this value is going to end
* up negative. In these cases we should fall back to the 3K
* buffers.
*/
#if (PAGE_SIZE < 8192)
#define IXGBE_MAX_2K_FRAME_BUILD_SKB (IXGBE_RXBUFFER_1536 - NET_IP_ALIGN)
#define IXGBE_2K_TOO_SMALL_WITH_PADDING \
((NET_SKB_PAD + IXGBE_RXBUFFER_1536) > SKB_WITH_OVERHEAD(IXGBE_RXBUFFER_2K))

static inline int ixgbe_compute_pad(int rx_buf_len)
{
int page_size, pad_size;

page_size = ALIGN(rx_buf_len, PAGE_SIZE / 2);
pad_size = SKB_WITH_OVERHEAD(page_size) - rx_buf_len;

return pad_size;
}

static inline int ixgbe_skb_pad(void)
{
int rx_buf_len;

/* If a 2K buffer cannot handle a standard Ethernet frame then
* optimize padding for a 3K buffer instead of a 1.5K buffer.
*
* For a 3K buffer we need to add enough padding to allow for
* tailroom due to NET_IP_ALIGN possibly shifting us out of
* cache-line alignment.
*/
if (IXGBE_2K_TOO_SMALL_WITH_PADDING)
rx_buf_len = IXGBE_RXBUFFER_3K + SKB_DATA_ALIGN(NET_IP_ALIGN);
else
rx_buf_len = IXGBE_RXBUFFER_1536;

/* if needed make room for NET_IP_ALIGN */
rx_buf_len -= NET_IP_ALIGN;

return ixgbe_compute_pad(rx_buf_len);
}

#define IXGBE_SKB_PAD ixgbe_skb_pad()
#else
#define IXGBE_SKB_PAD (NET_SKB_PAD + NET_IP_ALIGN)
#endif
#define IXGBE_RX_PAGE_LEN(hr) (ALIGN_DOWN(LIBETH_RX_PAGE_LEN(hr), \
IXGBE_SRRCTL_BSIZEPKT_STEP))

/*
* NOTE: netdev_alloc_skb reserves up to 64 bytes, NET_IP_ALIGN means we
* reserve 64 more, and skb_shared_info adds an additional 320 bytes more,
* this adds up to 448 bytes of extra data.
*
* Since netdev_alloc_skb now allocates a page fragment we can use a value
* of 256 and the resultant skb will have a truesize of 960 or less.
* RX header buffer size for page-based allocation using napi_build_skb.
* Allows efficient header/data split without excessive overhead.

@walking-machine walking-machine Jul 30, 2026

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This updated comment does not make much sense to me. You can probably get rid of ixgbe_pull_tail() in this patch, because it does not make much sense with build_skb. This way this define can just serve as just a default HW header buffer size.

*/
#define IXGBE_RX_HDR_SIZE IXGBE_RXBUFFER_256

Expand Down Expand Up @@ -271,20 +216,9 @@ struct ixgbe_tx_buffer {
u32 tx_flags;
};

struct ixgbe_rx_buffer {
union {
struct {
struct sk_buff *skb;
dma_addr_t dma;
struct page *page;
__u32 page_offset;
__u16 pagecnt_bias;
};
struct {
bool discard;
struct xdp_buff *xdp;
};
};
struct ixgbe_xsk_rx_buffer {
bool discard;
struct xdp_buff *xdp;
};

struct ixgbe_queue_stats {
Expand All @@ -311,8 +245,6 @@ struct ixgbe_rx_queue_stats {
#define IXGBE_TS_HDR_LEN 8

enum ixgbe_ring_state_t {
__IXGBE_RX_3K_BUFFER,
__IXGBE_RX_BUILD_SKB_ENABLED,
__IXGBE_RX_RSC_ENABLED,
__IXGBE_RX_CSUM_UDP_ZERO_ERR,
__IXGBE_RX_FCOE,
Expand All @@ -324,9 +256,6 @@ enum ixgbe_ring_state_t {
__IXGBE_TX_DISABLED,
};

#define ring_uses_build_skb(ring) \
test_bit(__IXGBE_RX_BUILD_SKB_ENABLED, &(ring)->state)

struct ixgbe_fwd_adapter {
unsigned long active_vlans[BITS_TO_LONGS(VLAN_N_VID)];
struct net_device *netdev;
Expand Down Expand Up @@ -357,17 +286,22 @@ struct ixgbe_ring {
struct ixgbe_ring *next; /* pointer to next ring in q_vector */
struct ixgbe_q_vector *q_vector; /* backpointer to host q_vector */
struct net_device *netdev; /* netdev ring belongs to */
struct bpf_prog *xdp_prog;
struct device *dev; /* device for DMA mapping */
struct bpf_prog __rcu *xdp_prog;

@walking-machine walking-machine Jul 21, 2026

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ring->xdp_prog is still accessed though xdp_prog = READ_ONCE(rx_ring->xdp_prog);, but rcu_dereference() should be used.
rx_ring->xdp_prog = NULL; could also utilize rcu_assign_pointer() for consistency, although AFAIK sparse does not compain about that. Neither it complains about accesses like !!rx_ring->xdp_prog, so those can stay as-is, although I think rcu_access_pointer() can be used there (rcu_dereference() is only for NAPI and other high priority contexts).

union {
struct page_pool *pp; /* Rx ring */
struct device *dev; /* Tx ring */
};
void *desc; /* descriptor ring memory */
union {
struct libeth_fqe *rx_fqes;
struct ixgbe_xsk_rx_buffer *rx_xsk_buffer_info;
struct ixgbe_tx_buffer *tx_buffer_info;
struct ixgbe_rx_buffer *rx_buffer_info;
};
Comment on lines 295 to 299
unsigned long state;
u8 __iomem *tail;
dma_addr_t dma; /* phys. address of descriptor ring */
unsigned int size; /* length in bytes */
u32 truesize;

u16 count; /* amount of descriptors */

Expand All @@ -382,12 +316,9 @@ struct ixgbe_ring {

unsigned long last_rx_timestamp;

union {
u16 next_to_alloc;
struct {
u8 atr_sample_rate;
u8 atr_count;
};
struct {
u8 atr_sample_rate;
u8 atr_count;
};

u8 dcb_tc;
Expand All @@ -397,12 +328,12 @@ struct ixgbe_ring {
struct ixgbe_tx_queue_stats tx_stats;
struct ixgbe_rx_queue_stats rx_stats;
};
u16 rx_offset;
struct xdp_rxq_info xdp_rxq;
spinlock_t tx_lock; /* used in XDP mode */
struct xsk_buff_pool *xsk_pool;
u16 ring_idx; /* {rx,tx,xdp}_ring back reference idx */
u16 rx_buf_len;
u32 rx_buf_len;
struct libeth_xdp_buff_stash xdp_stash;
} ____cacheline_internodealigned_in_smp;

enum ixgbe_ring_f_enum {
Expand Down Expand Up @@ -446,31 +377,6 @@ struct ixgbe_ring_feature {
#define IXGBE_82599_VMDQ_4Q_MASK 0x7C
#define IXGBE_82599_VMDQ_2Q_MASK 0x7E

/*
* FCoE requires that all Rx buffers be over 2200 bytes in length. Since
* this is twice the size of a half page we need to double the page order
* for FCoE enabled Rx queues.
*/
static inline unsigned int ixgbe_rx_bufsz(struct ixgbe_ring *ring)
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{
if (test_bit(__IXGBE_RX_3K_BUFFER, &ring->state))
return IXGBE_RXBUFFER_3K;
#if (PAGE_SIZE < 8192)
if (ring_uses_build_skb(ring))
return IXGBE_MAX_2K_FRAME_BUILD_SKB;
#endif
return IXGBE_RXBUFFER_2K;
}

static inline unsigned int ixgbe_rx_pg_order(struct ixgbe_ring *ring)
{
#if (PAGE_SIZE < 8192)
if (test_bit(__IXGBE_RX_3K_BUFFER, &ring->state))
return 1;
#endif
return 0;
}
#define ixgbe_rx_pg_size(_ring) (PAGE_SIZE << ixgbe_rx_pg_order(_ring))

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@walking-machine walking-machine Jul 30, 2026

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Rogue change

#define IXGBE_ITR_ADAPTIVE_MIN_INC 2
#define IXGBE_ITR_ADAPTIVE_MIN_USECS 10
Expand Down Expand Up @@ -672,7 +578,7 @@ struct ixgbe_adapter {
#define IXGBE_FLAG2_VLAN_PROMISC BIT(13)
#define IXGBE_FLAG2_EEE_CAPABLE BIT(14)
#define IXGBE_FLAG2_EEE_ENABLED BIT(15)
#define IXGBE_FLAG2_RX_LEGACY BIT(16)
/* BIT16 used to be reserved for legacy RX flag */
#define IXGBE_FLAG2_IPSEC_ENABLED BIT(17)
#define IXGBE_FLAG2_VF_IPSEC_ENABLED BIT(18)
#define IXGBE_FLAG2_AUTO_DISABLE_VF BIT(19)
Expand Down Expand Up @@ -919,7 +825,6 @@ struct ixgbe_cb {
};
dma_addr_t dma;
u16 append_cnt;
bool page_released;
};
#define IXGBE_CB(skb) ((struct ixgbe_cb *)(skb)->cb)

Expand Down
40 changes: 15 additions & 25 deletions drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
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Original file line number Diff line number Diff line change
Expand Up @@ -132,11 +132,9 @@ static const char ixgbe_gstrings_test[][ETH_GSTRING_LEN] = {
#define IXGBE_TEST_LEN sizeof(ixgbe_gstrings_test) / ETH_GSTRING_LEN

static const char ixgbe_priv_flags_strings[][ETH_GSTRING_LEN] = {
#define IXGBE_PRIV_FLAGS_LEGACY_RX BIT(0)
"legacy-rx",
#define IXGBE_PRIV_FLAGS_VF_IPSEC_EN BIT(1)
#define IXGBE_PRIV_FLAGS_VF_IPSEC_EN BIT(0)
"vf-ipsec",
#define IXGBE_PRIV_FLAGS_AUTO_DISABLE_VF BIT(2)
#define IXGBE_PRIV_FLAGS_AUTO_DISABLE_VF BIT(1)
"mdd-disable-vf",
};

Expand Down Expand Up @@ -1951,7 +1949,6 @@ static int ixgbe_setup_desc_rings(struct ixgbe_adapter *adapter)
/* Setup Rx Descriptor ring and Rx buffers */
rx_ring->count = IXGBE_DEFAULT_RXD;
rx_ring->queue_index = 0;
rx_ring->dev = &adapter->pdev->dev;

@walking-machine walking-machine Jul 21, 2026

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There is still ring->dev = ... for an Rx ring in ixgbe_alloc_q_vector(). This is a mistake that you have admittedly inherited from me ;)

rx_ring->netdev = adapter->netdev;
rx_ring->reg_idx = adapter->rx_ring[0]->reg_idx;

Expand All @@ -1963,6 +1960,10 @@ static int ixgbe_setup_desc_rings(struct ixgbe_adapter *adapter)

hw->mac.ops.disable_rx(hw);

clear_ring_rsc_enabled(rx_ring);
if (adapter->flags2 & IXGBE_FLAG2_RSC_ENABLED)
set_ring_rsc_enabled(rx_ring);

ixgbe_configure_rx_ring(adapter, rx_ring);

rctl = IXGBE_READ_REG(&adapter->hw, IXGBE_RXCTRL);
Expand Down Expand Up @@ -2058,14 +2059,16 @@ static void ixgbe_create_lbtest_frame(struct sk_buff *skb,
skb->data[frame_size + 12] = 0xAF;
}

static bool ixgbe_check_lbtest_frame(struct ixgbe_rx_buffer *rx_buffer,
static bool ixgbe_check_lbtest_frame(const struct libeth_fqe *rx_buffer,
unsigned int frame_size)
{
u32 hr = netmem_get_pp(rx_buffer->netmem)->p.offset;
unsigned char *data;

frame_size >>= 1;

data = page_address(rx_buffer->page) + rx_buffer->page_offset;
data = page_address(__netmem_to_page(rx_buffer->netmem)) +
rx_buffer->offset + hr;

return data[3] == 0xFF && data[frame_size + 10] == 0xBE &&
data[frame_size + 12] == 0xAF;
Expand Down Expand Up @@ -2113,28 +2116,22 @@ static u16 ixgbe_clean_test_rings(struct ixgbe_ring *rx_ring,
}

while (rx_desc->wb.upper.length) {
struct ixgbe_rx_buffer *rx_buffer;
struct libeth_fqe *rx_buffer;

/* check Rx buffer */
rx_buffer = &rx_ring->rx_buffer_info[rx_ntc];
rx_buffer = &rx_ring->rx_fqes[rx_ntc];

/* sync Rx buffer for CPU read */
dma_sync_single_for_cpu(rx_ring->dev,
rx_buffer->dma,
ixgbe_rx_bufsz(rx_ring),
DMA_FROM_DEVICE);
libeth_rx_sync_for_cpu(rx_buffer, rx_ring->rx_buf_len);

/* verify contents of skb */
if (ixgbe_check_lbtest_frame(rx_buffer, size))
count++;
else
break;

/* sync Rx buffer for device write */
dma_sync_single_for_device(rx_ring->dev,
rx_buffer->dma,
ixgbe_rx_bufsz(rx_ring),
DMA_FROM_DEVICE);
/* recycle the page back to the pool */
libeth_rx_recycle_slow(rx_buffer->netmem);

/* increment Rx next to clean counter */
rx_ntc++;
Expand Down Expand Up @@ -3667,9 +3664,6 @@ static u32 ixgbe_get_priv_flags(struct net_device *netdev)
struct ixgbe_adapter *adapter = ixgbe_from_netdev(netdev);
u32 priv_flags = 0;

if (adapter->flags2 & IXGBE_FLAG2_RX_LEGACY)
priv_flags |= IXGBE_PRIV_FLAGS_LEGACY_RX;

if (adapter->flags2 & IXGBE_FLAG2_VF_IPSEC_ENABLED)
priv_flags |= IXGBE_PRIV_FLAGS_VF_IPSEC_EN;

Expand All @@ -3685,10 +3679,6 @@ static int ixgbe_set_priv_flags(struct net_device *netdev, u32 priv_flags)
unsigned int flags2 = adapter->flags2;
unsigned int i;

flags2 &= ~IXGBE_FLAG2_RX_LEGACY;
if (priv_flags & IXGBE_PRIV_FLAGS_LEGACY_RX)
flags2 |= IXGBE_FLAG2_RX_LEGACY;

flags2 &= ~IXGBE_FLAG2_VF_IPSEC_ENABLED;
if (priv_flags & IXGBE_PRIV_FLAGS_VF_IPSEC_EN)
flags2 |= IXGBE_FLAG2_VF_IPSEC_ENABLED;
Expand Down
1 change: 0 additions & 1 deletion drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c
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Expand Up @@ -965,7 +965,6 @@ static int ixgbe_alloc_q_vector(struct ixgbe_adapter *adapter,

while (rxr_count) {
/* assign generic ring traits */
ring->dev = &adapter->pdev->dev;
ring->netdev = adapter->netdev;

/* configure backlink on ring */
Expand Down
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