From: Lorenzo Bianconi <lorenzo@kernel.org>
To: bpf@vger.kernel.org, netdev@vger.kernel.org
Cc: davem@davemloft.net, kuba@kernel.org, ast@kernel.org,
daniel@iogearbox.net, shayagr@amazon.com, sameehj@amazon.com,
john.fastabend@gmail.com, dsahern@kernel.org, brouer@redhat.com,
echaudro@redhat.com, lorenzo.bianconi@redhat.com,
jasowang@redhat.com
Subject: [PATCH v5 bpf-next 12/14] bpf: add multi-buff support to the bpf_xdp_adjust_tail() API
Date: Mon, 7 Dec 2020 17:32:41 +0100 [thread overview]
Message-ID: <45d9ac7cd5895fa7af1ff54472257662ba25b877.1607349924.git.lorenzo@kernel.org> (raw)
In-Reply-To: <cover.1607349924.git.lorenzo@kernel.org>
From: Eelco Chaudron <echaudro@redhat.com>
This change adds support for tail growing and shrinking for XDP multi-buff.
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
include/net/xdp.h | 5 ++++
net/core/filter.c | 63 +++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 68 insertions(+)
diff --git a/include/net/xdp.h b/include/net/xdp.h
index 76cfee6a40f7..09078ab6644c 100644
--- a/include/net/xdp.h
+++ b/include/net/xdp.h
@@ -137,6 +137,11 @@ static inline void xdp_set_frag_size(skb_frag_t *frag, u32 size)
frag->bv_len = size;
}
+static inline unsigned int xdp_get_frag_tailroom(const skb_frag_t *frag)
+{
+ return PAGE_SIZE - xdp_get_frag_size(frag) - xdp_get_frag_offset(frag);
+}
+
struct xdp_frame {
void *data;
u16 len;
diff --git a/net/core/filter.c b/net/core/filter.c
index 77001a35768f..4c4882d4d92c 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -3860,11 +3860,74 @@ static const struct bpf_func_proto bpf_xdp_adjust_head_proto = {
.arg2_type = ARG_ANYTHING,
};
+static int bpf_xdp_mb_adjust_tail(struct xdp_buff *xdp, int offset)
+{
+ struct xdp_shared_info *xdp_sinfo = xdp_get_shared_info_from_buff(xdp);
+
+ if (unlikely(xdp_sinfo->nr_frags == 0))
+ return -EINVAL;
+
+ if (offset >= 0) {
+ skb_frag_t *frag = &xdp_sinfo->frags[xdp_sinfo->nr_frags - 1];
+ int size;
+
+ if (unlikely(offset > xdp_get_frag_tailroom(frag)))
+ return -EINVAL;
+
+ size = xdp_get_frag_size(frag);
+ memset(xdp_get_frag_address(frag) + size, 0, offset);
+ xdp_set_frag_size(frag, size + offset);
+ xdp_sinfo->data_length += offset;
+ } else {
+ int i, frags_to_free = 0;
+
+ offset = abs(offset);
+
+ if (unlikely(offset > ((int)(xdp->data_end - xdp->data) +
+ xdp_sinfo->data_length -
+ ETH_HLEN)))
+ return -EINVAL;
+
+ for (i = xdp_sinfo->nr_frags - 1; i >= 0 && offset > 0; i--) {
+ skb_frag_t *frag = &xdp_sinfo->frags[i];
+ int size = xdp_get_frag_size(frag);
+ int shrink = min_t(int, offset, size);
+
+ offset -= shrink;
+ if (likely(size - shrink > 0)) {
+ /* When updating the final fragment we have
+ * to adjust the data_length in line.
+ */
+ xdp_sinfo->data_length -= shrink;
+ xdp_set_frag_size(frag, size - shrink);
+ break;
+ }
+
+ /* When we free the fragments,
+ * xdp_return_frags_from_buff() will take care
+ * of updating the xdp share info data_length.
+ */
+ frags_to_free++;
+ }
+
+ if (unlikely(frags_to_free))
+ xdp_return_num_frags_from_buff(xdp, frags_to_free);
+
+ if (unlikely(offset > 0))
+ xdp->data_end -= offset;
+ }
+
+ return 0;
+}
+
BPF_CALL_2(bpf_xdp_adjust_tail, struct xdp_buff *, xdp, int, offset)
{
void *data_hard_end = xdp_data_hard_end(xdp); /* use xdp->frame_sz */
void *data_end = xdp->data_end + offset;
+ if (unlikely(xdp->mb))
+ return bpf_xdp_mb_adjust_tail(xdp, offset);
+
/* Notice that xdp_data_hard_end have reserved some tailroom */
if (unlikely(data_end > data_hard_end))
return -EINVAL;
--
2.28.0
next prev parent reply other threads:[~2020-12-07 16:34 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-07 16:32 [PATCH v5 bpf-next 00/14] mvneta: introduce XDP multi-buffer support Lorenzo Bianconi
2020-12-07 16:32 ` [PATCH v5 bpf-next 01/14] xdp: introduce mb in xdp_buff/xdp_frame Lorenzo Bianconi
2020-12-07 21:16 ` Alexander Duyck
2020-12-07 23:03 ` Saeed Mahameed
2020-12-08 3:16 ` Alexander Duyck
2020-12-08 6:49 ` Saeed Mahameed
2020-12-08 9:47 ` Jesper Dangaard Brouer
2020-12-07 16:32 ` [PATCH v5 bpf-next 02/14] xdp: initialize xdp_buff mb bit to 0 in all XDP drivers Lorenzo Bianconi
2020-12-07 21:15 ` Alexander Duyck
2020-12-07 21:37 ` Maciej Fijalkowski
2020-12-07 23:20 ` Saeed Mahameed
2020-12-08 10:31 ` Lorenzo Bianconi
2020-12-08 13:29 ` Jesper Dangaard Brouer
2020-12-07 16:32 ` [PATCH v5 bpf-next 03/14] xdp: add xdp_shared_info data structure Lorenzo Bianconi
2020-12-08 0:22 ` Saeed Mahameed
2020-12-08 11:01 ` Lorenzo Bianconi
2020-12-19 14:53 ` Shay Agroskin
2020-12-19 15:30 ` Jamal Hadi Salim
2020-12-21 9:01 ` Jesper Dangaard Brouer
2020-12-21 13:00 ` Jamal Hadi Salim
2020-12-20 17:52 ` Lorenzo Bianconi
2020-12-21 20:55 ` Shay Agroskin
2020-12-07 16:32 ` [PATCH v5 bpf-next 04/14] net: mvneta: update mb bit before passing the xdp buffer to eBPF layer Lorenzo Bianconi
2020-12-07 16:32 ` [PATCH v5 bpf-next 05/14] xdp: add multi-buff support to xdp_return_{buff/frame} Lorenzo Bianconi
2020-12-07 16:32 ` [PATCH v5 bpf-next 06/14] net: mvneta: add multi buffer support to XDP_TX Lorenzo Bianconi
2020-12-19 15:56 ` Shay Agroskin
2020-12-20 18:06 ` Lorenzo Bianconi
2020-12-07 16:32 ` [PATCH v5 bpf-next 07/14] bpf: move user_size out of bpf_test_init Lorenzo Bianconi
2020-12-07 16:32 ` [PATCH v5 bpf-next 08/14] bpf: introduce multibuff support to bpf_prog_test_run_xdp() Lorenzo Bianconi
2020-12-07 16:32 ` [PATCH v5 bpf-next 09/14] bpf: test_run: add xdp_shared_info pointer in bpf_test_finish signature Lorenzo Bianconi
2020-12-07 16:32 ` [PATCH v5 bpf-next 10/14] net: mvneta: enable jumbo frames for XDP Lorenzo Bianconi
2020-12-07 16:32 ` [PATCH v5 bpf-next 11/14] bpf: cpumap: introduce xdp multi-buff support Lorenzo Bianconi
2020-12-19 17:46 ` Shay Agroskin
2020-12-20 17:56 ` Lorenzo Bianconi
2020-12-07 16:32 ` Lorenzo Bianconi [this message]
2020-12-07 16:32 ` [PATCH v5 bpf-next 13/14] bpf: add new frame_length field to the XDP ctx Lorenzo Bianconi
2020-12-08 22:17 ` Maciej Fijalkowski
2020-12-09 10:35 ` Eelco Chaudron
2020-12-09 11:10 ` Maciej Fijalkowski
2020-12-09 12:07 ` Eelco Chaudron
2020-12-15 13:28 ` Eelco Chaudron
2020-12-15 18:06 ` Maciej Fijalkowski
2020-12-16 14:08 ` Eelco Chaudron
2021-01-15 16:36 ` Eelco Chaudron
2021-01-18 16:48 ` Maciej Fijalkowski
2021-01-20 13:20 ` Eelco Chaudron
2021-02-01 16:00 ` Eelco Chaudron
2020-12-07 16:32 ` [PATCH v5 bpf-next 14/14] bpf: update xdp_adjust_tail selftest to include multi-buffer Lorenzo Bianconi
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