On 18/04/2023 06.34, Song, Yoong Siang wrote:
On Monday, April 17, 2023 10:57 PM, Jesper Dangaard Brouer <brouer@xxxxxxxxxx> wrote:
Driver specific metadata data for XDP-hints kfuncs are propagated via tail
extending the struct xdp_buff with a locally scoped driver struct.
Zero-Copy AF_XDP/XSK does similar tricks via struct xdp_buff_xsk. This
xdp_buff_xsk struct contains a CB area (24 bytes) that can be used for extending
the locally scoped driver into. The XSK_CHECK_PRIV_TYPE define catch size
violations build time.
Since the main purpose of this patch is to introduce igc_xdp_buff, and
you have another two patches for timestamp and hash,
thus, suggest to move timestamp and hash related code into respective patches.
Signed-off-by: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
---
drivers/net/ethernet/intel/igc/igc.h | 6 ++++++
drivers/net/ethernet/intel/igc/igc_main.c | 30 ++++++++++++++++++++++-------
2 files changed, 29 insertions(+), 7 deletions(-)
diff --git a/drivers/net/ethernet/intel/igc/igc.h
b/drivers/net/ethernet/intel/igc/igc.h
index f7f9e217e7b4..c609a2e648f8 100644
--- a/drivers/net/ethernet/intel/igc/igc.h
+++ b/drivers/net/ethernet/intel/igc/igc.h
@@ -499,6 +499,12 @@ struct igc_rx_buffer {
};
};
+/* context wrapper around xdp_buff to provide access to descriptor
+metadata */ struct igc_xdp_buff {
+ struct xdp_buff xdp;
+ union igc_adv_rx_desc *rx_desc;
Move rx_desc to 4th patch (Rx hash patch)
Hmm, rx_desc is also needed by 3rd patch (Rx timestamp), so that would
break...
I can reorder patches, and have "Rx hash patch" come before "Rx
timestamp" patch.
+};
+
struct igc_q_vector {
struct igc_adapter *adapter; /* backlink */
void __iomem *itr_register;
diff --git a/drivers/net/ethernet/intel/igc/igc_main.c
b/drivers/net/ethernet/intel/igc/igc_main.c
index bfa9768d447f..3a844cf5be3f 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -2236,6 +2236,8 @@ static bool igc_alloc_rx_buffers_zc(struct igc_ring
*ring, u16 count)
if (!count)
return ok;
+ XSK_CHECK_PRIV_TYPE(struct igc_xdp_buff);
+
desc = IGC_RX_DESC(ring, i);
bi = &ring->rx_buffer_info[i];
i -= ring->count;
@@ -2520,8 +2522,8 @@ static int igc_clean_rx_irq(struct igc_q_vector
*q_vector, const int budget)
union igc_adv_rx_desc *rx_desc;
struct igc_rx_buffer *rx_buffer;
unsigned int size, truesize;
+ struct igc_xdp_buff ctx;
ktime_t timestamp = 0;
- struct xdp_buff xdp;
int pkt_offset = 0;
void *pktbuf;
@@ -2555,13 +2557,14 @@ static int igc_clean_rx_irq(struct igc_q_vector
*q_vector, const int budget)
}
if (!skb) {
- xdp_init_buff(&xdp, truesize, &rx_ring->xdp_rxq);
- xdp_prepare_buff(&xdp, pktbuf - igc_rx_offset(rx_ring),
+ xdp_init_buff(&ctx.xdp, truesize, &rx_ring->xdp_rxq);
+ xdp_prepare_buff(&ctx.xdp, pktbuf - igc_rx_offset(rx_ring),
igc_rx_offset(rx_ring) + pkt_offset,
size, true);
- xdp_buff_clear_frags_flag(&xdp);
+ xdp_buff_clear_frags_flag(&ctx.xdp);
+ ctx.rx_desc = rx_desc;
Move rx_desc to 4th patch (Rx hash patch)
Again would break 3rd patch.
- skb = igc_xdp_run_prog(adapter, &xdp);
+ skb = igc_xdp_run_prog(adapter, &ctx.xdp);
}
if (IS_ERR(skb)) {
@@ -2583,9 +2586,9 @@ static int igc_clean_rx_irq(struct igc_q_vector
*q_vector, const int budget)
} else if (skb)
igc_add_rx_frag(rx_ring, rx_buffer, skb, size);
else if (ring_uses_build_skb(rx_ring))
- skb = igc_build_skb(rx_ring, rx_buffer, &xdp);
+ skb = igc_build_skb(rx_ring, rx_buffer, &ctx.xdp);
else
- skb = igc_construct_skb(rx_ring, rx_buffer, &xdp,
+ skb = igc_construct_skb(rx_ring, rx_buffer, &ctx.xdp,
timestamp);
/* exit if we failed to retrieve a buffer */ @@ -2686,6 +2689,15
@@ static void igc_dispatch_skb_zc(struct igc_q_vector *q_vector,
napi_gro_receive(&q_vector->napi, skb); }
+static struct igc_xdp_buff *xsk_buff_to_igc_ctx(struct xdp_buff *xdp) {
+ /* xdp_buff pointer used by ZC code path is alloc as xdp_buff_xsk. The
+ * igc_xdp_buff shares its layout with xdp_buff_xsk and private
+ * igc_xdp_buff fields fall into xdp_buff_xsk->cb
+ */
+ return (struct igc_xdp_buff *)xdp; }
+
Move xsk_buff_to_igc_ctx to 3th patch (timestamp patch), which is first patch
adding xdp_metadata_ops support to igc.
Hmm, maybe, but that make the "wrapper" patch incomplete and then it
gets "completed" in the first patch that adds a xdp_metadata_ops.
static int igc_clean_rx_irq_zc(struct igc_q_vector *q_vector, const int budget) {
struct igc_adapter *adapter = q_vector->adapter; @@ -2704,6 +2716,7
@@ static int igc_clean_rx_irq_zc(struct igc_q_vector *q_vector, const int
budget)
while (likely(total_packets < budget)) {
union igc_adv_rx_desc *desc;
struct igc_rx_buffer *bi;
+ struct igc_xdp_buff *ctx;
ktime_t timestamp = 0;
unsigned int size;
int res;
@@ -2721,6 +2734,9 @@ static int igc_clean_rx_irq_zc(struct igc_q_vector
*q_vector, const int budget)
bi = &ring->rx_buffer_info[ntc];
+ ctx = xsk_buff_to_igc_ctx(bi->xdp);
Move xsk_buff_to_igc_ctx to 3th patch (timestamp patch), which is first patch
adding xdp_metadata_ops support to igc.
Sure, but it feels wrong to no "complete" the wrapper work in the
wrapper patch.
+ ctx->rx_desc = desc;
Move rx_desc to 4th patch (Rx hash patch)
I'll reorder patch 3 and 4, else it doesn't make any sense to gradually
introduce the members in wrapper struct igc_xdp_buff.
--Jesper
