[PATCH v4 bpf-next 13/13] bpf: cpumap: introduce xdp multi-buff support
From: Lorenzo Bianconi <lorenzo@kernel.org>
Date: 2020-10-02 14:43:20
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), networking [general], the rest, xdp (express data path) · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, David S. Miller, Jesper Dangaard Brouer, John Fastabend
Introduce __xdp_build_skb_from_frame and xdp_build_skb_from_frame utility routines to build the skb from xdp_frame. Add xdp multi-buff support to cpumap Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> --- include/net/xdp.h | 5 ++++ kernel/bpf/cpumap.c | 45 +------------------------------ net/core/xdp.c | 64 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 70 insertions(+), 44 deletions(-)
diff --git a/include/net/xdp.h b/include/net/xdp.h
index 4d47076546ff..8d9224ef75ee 100644
--- a/include/net/xdp.h
+++ b/include/net/xdp.h@@ -134,6 +134,11 @@ void xdp_warn(const char *msg, const char *func, const int line); #define XDP_WARN(msg) xdp_warn(msg, __func__, __LINE__) struct xdp_frame *xdp_convert_zc_to_xdp_frame(struct xdp_buff *xdp); +struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf, + struct sk_buff *skb, + struct net_device *dev); +struct sk_buff *xdp_build_skb_from_frame(struct xdp_frame *xdpf, + struct net_device *dev); static inline void xdp_convert_frame_to_buff(struct xdp_frame *frame, struct xdp_buff *xdp)
diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c
index c61a23b564aa..fa07b4226836 100644
--- a/kernel/bpf/cpumap.c
+++ b/kernel/bpf/cpumap.c@@ -155,49 +155,6 @@ static void cpu_map_kthread_stop(struct work_struct *work) kthread_stop(rcpu->kthread); } -static struct sk_buff *cpu_map_build_skb(struct xdp_frame *xdpf, - struct sk_buff *skb) -{ - unsigned int hard_start_headroom; - unsigned int frame_size; - void *pkt_data_start; - - /* Part of headroom was reserved to xdpf */ - hard_start_headroom = sizeof(struct xdp_frame) + xdpf->headroom; - - /* Memory size backing xdp_frame data already have reserved - * room for build_skb to place skb_shared_info in tailroom. - */ - frame_size = xdpf->frame_sz; - - pkt_data_start = xdpf->data - hard_start_headroom; - skb = build_skb_around(skb, pkt_data_start, frame_size); - if (unlikely(!skb)) - return NULL; - - skb_reserve(skb, hard_start_headroom); - __skb_put(skb, xdpf->len); - if (xdpf->metasize) - skb_metadata_set(skb, xdpf->metasize); - - /* Essential SKB info: protocol and skb->dev */ - skb->protocol = eth_type_trans(skb, xdpf->dev_rx); - - /* Optional SKB info, currently missing: - * - HW checksum info (skb->ip_summed) - * - HW RX hash (skb_set_hash) - * - RX ring dev queue index (skb_record_rx_queue) - */ - - /* Until page_pool get SKB return path, release DMA here */ - xdp_release_frame(xdpf); - - /* Allow SKB to reuse area used by xdp_frame */ - xdp_scrub_frame(xdpf); - - return skb; -} - static void __cpu_map_ring_cleanup(struct ptr_ring *ring) { /* The tear-down procedure should have made sure that queue is
@@ -364,7 +321,7 @@ static int cpu_map_kthread_run(void *data) struct sk_buff *skb = skbs[i]; int ret; - skb = cpu_map_build_skb(xdpf, skb); + skb = __xdp_build_skb_from_frame(xdpf, skb, xdpf->dev_rx); if (!skb) { xdp_return_frame(xdpf); continue;
diff --git a/net/core/xdp.c b/net/core/xdp.c
index 6d4fd4dddb00..a6bdefed92e6 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c@@ -507,3 +507,67 @@ void xdp_warn(const char *msg, const char *func, const int line) WARN(1, "XDP_WARN: %s(line:%d): %s\n", func, line, msg); }; EXPORT_SYMBOL_GPL(xdp_warn); + +struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf, + struct sk_buff *skb, + struct net_device *dev) +{ + struct skb_shared_info *sinfo = xdp_get_shared_info_from_frame(xdpf); + unsigned int headroom = sizeof(*xdpf) + xdpf->headroom; + int i, num_frags = xdpf->mb ? sinfo->nr_frags : 0; + void *hard_start = xdpf->data - headroom; + + skb = build_skb_around(skb, hard_start, xdpf->frame_sz); + if (unlikely(!skb)) + return NULL; + + skb_reserve(skb, headroom); + __skb_put(skb, xdpf->len); + if (xdpf->metasize) + skb_metadata_set(skb, xdpf->metasize); + + if (likely(!num_frags)) + goto out; + + for (i = 0; i < num_frags; i++) { + skb_frag_t *frag = &sinfo->frags[i]; + + skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, + skb_frag_page(frag), skb_frag_off(frag), + skb_frag_size(frag), xdpf->frame_sz); + } + +out: + /* Essential SKB info: protocol and skb->dev */ + skb->protocol = eth_type_trans(skb, dev); + + /* Optional SKB info, currently missing: + * - HW checksum info (skb->ip_summed) + * - HW RX hash (skb_set_hash) + * - RX ring dev queue index (skb_record_rx_queue) + */ + + /* Until page_pool get SKB return path, release DMA here */ + xdp_release_frame(xdpf); + + /* Allow SKB to reuse area used by xdp_frame */ + xdp_scrub_frame(xdpf); + + return skb; +} +EXPORT_SYMBOL_GPL(__xdp_build_skb_from_frame); + +struct sk_buff *xdp_build_skb_from_frame(struct xdp_frame *xdpf, + struct net_device *dev) +{ + struct sk_buff *skb; + + skb = kmem_cache_alloc(skbuff_head_cache, GFP_ATOMIC); + if (unlikely(!skb)) + return NULL; + + memset(skb, 0, offsetof(struct sk_buff, tail)); + + return __xdp_build_skb_from_frame(xdpf, skb, dev); +} +EXPORT_SYMBOL_GPL(xdp_build_skb_from_frame);
--
2.26.2