[PATCH v9 bpf-next 04/14] xdp: add multi-buff support to xdp_return_{buff/frame}

Lorenzo Bianconi
2021-06-14T12:50:52Z

Take into account if the received xdp_buff/xdp_frame is non-linear
recycling/returning the frame memory to the allocator or into
xdp_frame_bulk.
Introduce xdp_return_num_frags_from_buff to return a given number of
fragments from a xdp multi-buff starting from the tail.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
include/net/xdp.h | 18 ++++++++++++++--
net/core/xdp.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 69 insertions(+), 3 deletions(-)

diff --git a/include/net/xdp.h b/include/net/xdp.h
index de11d981fa44..935a6f83115f 100644
--- a/include/net/xdp.h
+++ b/include/net/xdp.h
@@ -275,10 +275,24 @@ void __xdp_release_frame(void *data, struct xdp_mem_info *mem);
static inline void xdp_release_frame(struct xdp_frame *xdpf)
{
struct xdp_mem_info *mem = &xdpf->mem;
+ struct skb_shared_info *sinfo;
+ int i;

/* Curr only page_pool needs this */
- if (mem->type == MEM_TYPE_PAGE_POOL)
- __xdp_release_frame(xdpf->data, mem);
+ if (mem->type != MEM_TYPE_PAGE_POOL)
+ return;
+
+ if (likely(!xdp_frame_is_mb(xdpf)))
+ goto out;
+
+ sinfo = xdp_get_shared_info_from_frame(xdpf);
+ for (i = 0; i < sinfo->nr_frags; i++) {
+ struct page *page = skb_frag_page(&sinfo->frags[i]);
+
+ __xdp_release_frame(page_address(page), mem);
+ }
+out:
+ __xdp_release_frame(xdpf->data, mem);
}

int xdp_rxq_info_reg(struct xdp_rxq_info *xdp_rxq,
diff --git a/net/core/xdp.c b/net/core/xdp.c
index 725d20f1b100..f61c63115c95 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -375,12 +375,38 @@ static void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct,

void xdp_return_frame(struct xdp_frame *xdpf)
{
+ struct skb_shared_info *sinfo;
+ int i;
+
+ if (likely(!xdp_frame_is_mb(xdpf)))
+ goto out;
+
+ sinfo = xdp_get_shared_info_from_frame(xdpf);
+ for (i = 0; i < sinfo->nr_frags; i++) {
+ struct page *page = skb_frag_page(&sinfo->frags[i]);
+
+ __xdp_return(page_address(page), &xdpf->mem, false, NULL);
+ }
+out:
__xdp_return(xdpf->data, &xdpf->mem, false, NULL);
}
EXPORT_SYMBOL_GPL(xdp_return_frame);

void xdp_return_frame_rx_napi(struct xdp_frame *xdpf)
{
+ struct skb_shared_info *sinfo;
+ int i;
+
+ if (likely(!xdp_frame_is_mb(xdpf)))
+ goto out;
+
+ sinfo = xdp_get_shared_info_from_frame(xdpf);
+ for (i = 0; i < sinfo->nr_frags; i++) {
+ struct page *page = skb_frag_page(&sinfo->frags[i]);
+
+ __xdp_return(page_address(page), &xdpf->mem, true, NULL);
+ }
+out:
__xdp_return(xdpf->data, &xdpf->mem, true, NULL);
}
EXPORT_SYMBOL_GPL(xdp_return_frame_rx_napi);
@@ -416,7 +442,7 @@ void xdp_return_frame_bulk(struct xdp_frame *xdpf,
struct xdp_mem_allocator *xa;

if (mem->type != MEM_TYPE_PAGE_POOL) {
- __xdp_return(xdpf->data, &xdpf->mem, false, NULL);
+ xdp_return_frame(xdpf);
return;
}

@@ -435,12 +461,38 @@ void xdp_return_frame_bulk(struct xdp_frame *xdpf,
bq->xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params);
}

+ if (unlikely(xdp_frame_is_mb(xdpf))) {
+ struct skb_shared_info *sinfo;
+ int i;
+
+ sinfo = xdp_get_shared_info_from_frame(xdpf);
+ for (i = 0; i < sinfo->nr_frags; i++) {
+ skb_frag_t *frag = &sinfo->frags[i];
+
+ bq->q[bq->count++] = skb_frag_address(frag);
+ if (bq->count == XDP_BULK_QUEUE_SIZE)
+ xdp_flush_frame_bulk(bq);
+ }
+ }
bq->q[bq->count++] = xdpf->data;
}
EXPORT_SYMBOL_GPL(xdp_return_frame_bulk);

void xdp_return_buff(struct xdp_buff *xdp)
{
+ struct skb_shared_info *sinfo;
+ int i;
+
+ if (likely(!xdp_buff_is_mb(xdp)))
+ goto out;
+
+ sinfo = xdp_get_shared_info_from_buff(xdp);
+ for (i = 0; i < sinfo->nr_frags; i++) {
+ struct page *page = skb_frag_page(&sinfo->frags[i]);
+
+ __xdp_return(page_address(page), &xdp->rxq->mem, true, xdp);
+ }
+out:
__xdp_return(xdp->data, &xdp->rxq->mem, true, xdp);
}

--
2.31.1