[PATCH v17 bpf-next 00/23] mvneta: introduce XDP multi-buffer support

[PATCH v17 bpf-next 00/23] mvneta: introduce XDP multi-buffer support

[Lorenzo Bianconi]

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This series introduce XDP multi-buffer support. The mvneta driver is
the first to support these new "non-linear" xdp_{buff,frame}. Reviewers
please focus on how these new types of xdp_{buff,frame} packets
traverse the different layers and the layout design. It is on purpose
that BPF-helpers are kept simple, as we don't want to expose the
internal layout to allow later changes.

The main idea for the new multi-buffer layout is to reuse the same
structure used for non-linear SKB. This rely on the "skb_shared_info"
struct at the end of the first buffer to link together subsequent
buffers. Keeping the layout compatible with SKBs is also done to ease
and speedup creating a SKB from an xdp_{buff,frame}.
Converting xdp_frame to SKB and deliver it to the network stack is shown
in patch 05/18 (e.g. cpumaps).

A multi-buffer bit (mb) has been introduced in the flags field of xdp_{buff,frame}
structure to notify the bpf/network layer if this is a xdp multi-buffer frame
(mb = 1) or not (mb = 0).
The mb bit will be set by a xdp multi-buffer capable driver only for
non-linear frames maintaining the capability to receive linear frames
without any extra cost since the skb_shared_info structure at the end
of the first buffer will be initialized only if mb is set.
Moreover the flags field in xdp_{buff,frame} will be reused even for
xdp rx csum offloading in future series.

Typical use cases for this series are:
- Jumbo-frames
- Packet header split (please see Google’s use-case @ NetDevConf 0x14, [0])
- TSO/GRO for XDP_REDIRECT

The three following ebpf helpers (and related selftests) has been introduced:
- bpf_xdp_load_bytes:
  This helper is provided as an easy way to load data from a xdp buffer. It
  can be used to load len bytes from offset from the frame associated to
  xdp_md, into the buffer pointed by buf.
- bpf_xdp_store_bytes:
  Store len bytes from buffer buf into the frame associated to xdp_md, at
  offset.
- bpf_xdp_get_buff_len:
  Return the total frame size (linear + paged parts)

bpf_xdp_adjust_tail and bpf_xdp_copy helpers have been modified to take into
account xdp multi-buff frames.
Moreover, similar to skb_header_pointer, we introduced bpf_xdp_pointer utility
routine to return a pointer to a given position in the xdp_buff if the
requested area (offset + len) is contained in a contiguous memory area
otherwise it will be copied in a bounce buffer provided by the caller.

BPF_F_XDP_MB flag for bpf_attr has been introduced to notify the kernel the
eBPF program fully support xdp multi-buffer.
SEC("xdp_mb/"), SEC_DEF("xdp_devmap_mb/") and SEC_DEF("xdp_cpumap_mb/" have been
introduced to declare xdp multi-buffer support.
The NIC driver is expected to reject an eBPF program if it is running in XDP
multi-buffer mode and the program does not support XDP multi-buffer.
In the same way it is not possible to mix xdp multi-buffer and xdp legacy
programs in a CPUMAP/DEVMAP or tailcall a xdp multi-buffer/legacy program from
a legacy/multi-buff one.

More info about the main idea behind this approach can be found here [1][2].

Changes since v16:
- do not allow tailcalling a xdp multi-buffer/legacy program from a
  legacy/multi-buff one.
- do not allow mixing xdp multi-buffer and xdp legacy programs in a
  CPUMAP/DEVMAP
- add selftests for CPUMAP/DEVMAP xdp mb compatibility
- disable XDP_REDIRECT for xdp multi-buff for the moment
- set max offset value to 0xffff in bpf_xdp_pointer
- use ARG_PTR_TO_UNINIT_MEM and ARG_CONST_SIZE for arg3_type and arg4_type
  of bpf_xdp_store_bytes/bpf_xdp_load_bytes

Changes since v15:
- let the verifier check buf is not NULL in
  bpf_xdp_load_bytes/bpf_xdp_store_bytes helpers
- return an error if offset + length is over frame boundaries in
  bpf_xdp_pointer routine
- introduce BPF_F_XDP_MB flag for bpf_attr to notify the kernel the eBPF
  program fully supports xdp multi-buffer.
- reject a non XDP multi-buffer program if the driver is running in
  XDP multi-buffer mode.

Changes since v14:
- intrudce bpf_xdp_pointer utility routine and
  bpf_xdp_load_bytes/bpf_xdp_store_bytes helpers
- drop bpf_xdp_adjust_data helper
- drop xdp_frags_truesize in skb_shared_info
- explode bpf_xdp_mb_adjust_tail in bpf_xdp_mb_increase_tail and
  bpf_xdp_mb_shrink_tail

Changes since v13:
- use u32 for xdp_buff/xdp_frame flags field
- rename xdp_frags_tsize in xdp_frags_truesize
- fixed comments

Changes since v12:
- fix bpf_xdp_adjust_data helper for single-buffer use case
- return -EFAULT in bpf_xdp_adjust_{head,tail} in case the data pointers are not
  properly reset
- collect ACKs from John

Changes since v11:
- add missing static to bpf_xdp_get_buff_len_proto structure
- fix bpf_xdp_adjust_data helper when offset is smaller than linear area length.

Changes since v10:
- move xdp->data to the requested payload offset instead of to the beginning of
  the fragment in bpf_xdp_adjust_data()

Changes since v9:
- introduce bpf_xdp_adjust_data helper and related selftest
- add xdp_frags_size and xdp_frags_tsize fields in skb_shared_info
- introduce xdp_update_skb_shared_info utility routine in ordere to not reset
  frags array in skb_shared_info converting from a xdp_buff/xdp_frame to a skb 
- simplify bpf_xdp_copy routine

Changes since v8:
- add proper dma unmapping if XDP_TX fails on mvneta for a xdp multi-buff
- switch back to skb_shared_info implementation from previous xdp_shared_info
  one
- avoid using a bietfield in xdp_buff/xdp_frame since it introduces performance
  regressions. Tested now on 10G NIC (ixgbe) to verify there are no performance
  penalties for regular codebase
- add bpf_xdp_get_buff_len helper and remove frame_length field in xdp ctx
- add data_len field in skb_shared_info struct
- introduce XDP_FLAGS_FRAGS_PF_MEMALLOC flag

Changes since v7:
- rebase on top of bpf-next
- fix sparse warnings
- improve comments for frame_length in include/net/xdp.h

Changes since v6:
- the main difference respect to previous versions is the new approach proposed
  by Eelco to pass full length of the packet to eBPF layer in XDP context
- reintroduce multi-buff support to eBPF kself-tests
- reintroduce multi-buff support to bpf_xdp_adjust_tail helper
- introduce multi-buffer support to bpf_xdp_copy helper
- rebase on top of bpf-next

Changes since v5:
- rebase on top of bpf-next
- initialize mb bit in xdp_init_buff() and drop per-driver initialization
- drop xdp->mb initialization in xdp_convert_zc_to_xdp_frame()
- postpone introduction of frame_length field in XDP ctx to another series
- minor changes

Changes since v4:
- rebase ontop of bpf-next
- introduce xdp_shared_info to build xdp multi-buff instead of using the
  skb_shared_info struct
- introduce frame_length in xdp ctx
- drop previous bpf helpers
- fix bpf_xdp_adjust_tail for xdp multi-buff
- introduce xdp multi-buff self-tests for bpf_xdp_adjust_tail
- fix xdp_return_frame_bulk for xdp multi-buff

Changes since v3:
- rebase ontop of bpf-next
- add patch 10/13 to copy back paged data from a xdp multi-buff frame to
  userspace buffer for xdp multi-buff selftests

Changes since v2:
- add throughput measurements
- drop bpf_xdp_adjust_mb_header bpf helper
- introduce selftest for xdp multibuffer
- addressed comments on bpf_xdp_get_frags_count
- introduce xdp multi-buff support to cpumaps

Changes since v1:
- Fix use-after-free in xdp_return_{buff/frame}
- Introduce bpf helpers
- Introduce xdp_mb sample program
- access skb_shared_info->nr_frags only on the last fragment

Changes since RFC:
- squash multi-buffer bit initialization in a single patch
- add mvneta non-linear XDP buff support for tx side

[0] https://netdevconf.info/0x14/session.html?talk-the-path-to-tcp-4k-mtu-and-rx-zerocopy
[1] https://github.com/xdp-project/xdp-project/blob/master/areas/core/xdp-multi-buffer01-design.org
[2] https://netdevconf.info/0x14/session.html?tutorial-add-XDP-support-to-a-NIC-driver (XDPmulti-buffers section)

Eelco Chaudron (3):
  bpf: add multi-buff support to the bpf_xdp_adjust_tail() API
  bpf: add multi-buffer support to xdp copy helpers
  bpf: selftests: update xdp_adjust_tail selftest to include
    multi-buffer

Lorenzo Bianconi (19):
  net: skbuff: add size metadata to skb_shared_info for xdp
  xdp: introduce flags field in xdp_buff/xdp_frame
  net: mvneta: update mb bit before passing the xdp buffer to eBPF layer
  net: mvneta: simplify mvneta_swbm_add_rx_fragment management
  net: xdp: add xdp_update_skb_shared_info utility routine
  net: marvell: rely on xdp_update_skb_shared_info utility routine
  xdp: add multi-buff support to xdp_return_{buff/frame}
  net: mvneta: add multi buffer support to XDP_TX
  bpf: introduce BPF_F_XDP_MB flag in prog_flags loading the ebpf
    program
  net: mvneta: enable jumbo frames if the loaded XDP program support mb
  bpf: introduce bpf_xdp_get_buff_len helper
  bpf: move user_size out of bpf_test_init
  bpf: introduce multibuff support to bpf_prog_test_run_xdp()
  bpf: test_run: add xdp_shared_info pointer in bpf_test_finish
    signature
  libbpf: Add SEC name for xdp_mb programs
  net: xdp: introduce bpf_xdp_pointer utility routine
  bpf: selftests: introduce bpf_xdp_{load,store}_bytes selftest
  bpf: selftests: add CPUMAP/DEVMAP selftests for xdp multi-buff
  xdp: disable XDP_REDIRECT for xdp multi-buff

Toke Hoiland-Jorgensen (1):
  bpf: generalise tail call map compatibility check

 drivers/net/ethernet/marvell/mvneta.c         | 201 ++++++++-----
 include/linux/bpf.h                           |  32 +-
 include/linux/skbuff.h                        |   1 +
 include/net/xdp.h                             |  94 +++++-
 include/uapi/linux/bpf.h                      |  30 ++
 kernel/bpf/arraymap.c                         |   4 +-
 kernel/bpf/core.c                             |  28 +-
 kernel/bpf/cpumap.c                           |   8 +-
 kernel/bpf/devmap.c                           |   3 +-
 kernel/bpf/syscall.c                          |  25 +-
 kernel/trace/bpf_trace.c                      |   3 +
 net/bpf/test_run.c                            | 111 +++++--
 net/core/filter.c                             | 280 +++++++++++++++++-
 net/core/xdp.c                                |  71 ++++-
 tools/include/uapi/linux/bpf.h                |  30 ++
 tools/lib/bpf/libbpf.c                        |   8 +
 .../bpf/prog_tests/xdp_adjust_frags.c         |  81 +++++
 .../bpf/prog_tests/xdp_adjust_tail.c          | 118 ++++++++
 .../selftests/bpf/prog_tests/xdp_bpf2bpf.c    | 151 +++++++---
 .../bpf/prog_tests/xdp_cpumap_attach.c        |  65 +++-
 .../bpf/prog_tests/xdp_devmap_attach.c        |  56 ++++
 .../bpf/progs/test_xdp_adjust_tail_grow.c     |  10 +-
 .../bpf/progs/test_xdp_adjust_tail_shrink.c   |  32 +-
 .../selftests/bpf/progs/test_xdp_bpf2bpf.c    |   2 +-
 .../bpf/progs/test_xdp_update_frags.c         |  42 +++
 .../bpf/progs/test_xdp_with_cpumap_helpers.c  |   6 +
 .../progs/test_xdp_with_cpumap_mb_helpers.c   |  27 ++
 .../bpf/progs/test_xdp_with_devmap_helpers.c  |   7 +
 .../progs/test_xdp_with_devmap_mb_helpers.c   |  27 ++
 29 files changed, 1349 insertions(+), 204 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/xdp_adjust_frags.c
 create mode 100644 tools/testing/selftests/bpf/progs/test_xdp_update_frags.c
 create mode 100644 tools/testing/selftests/bpf/progs/test_xdp_with_cpumap_mb_helpers.c
 create mode 100644 tools/testing/selftests/bpf/progs/test_xdp_with_devmap_mb_helpers.c

-- 
2.31.1

[PATCH v17 bpf-next 01/23] net: skbuff: add size metadata to skb_shared_info for xdp

[Lorenzo Bianconi]

Introduce xdp_frags_size field in skb_shared_info data structure
to store xdp_buff/xdp_frame frame paged size (xdp_frags_size will
be used in xdp multi-buff support). In order to not increase
skb_shared_info size we will use a hole due to skb_shared_info
alignment.

Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 include/linux/skbuff.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 0bd6520329f6..de85a76afbc1 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -529,6 +529,7 @@ struct skb_shared_info {
 	 * Warning : all fields before dataref are cleared in __alloc_skb()
 	 */
 	atomic_t	dataref;
+	unsigned int	xdp_frags_size;
 
 	/* Intermediate layers must ensure that destructor_arg
 	 * remains valid until skb destructor */
-- 
2.31.1

[PATCH v17 bpf-next 02/23] xdp: introduce flags field in xdp_buff/xdp_frame

[Lorenzo Bianconi]

Introduce flags field in xdp_frame and xdp_buffer data structures
to define additional buffer features. At the moment the only
supported buffer feature is multi-buffer bit (mb). Multi-buffer bit
is used to specify if this is a linear buffer (mb = 0) or a multi-buffer
frame (mb = 1). In the latter case the driver is expected to initialize
the skb_shared_info structure at the end of the first buffer to link
together subsequent buffers belonging to the same frame.

Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 include/net/xdp.h | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/include/net/xdp.h b/include/net/xdp.h
index 447f9b1578f3..4ec7bdf0d937 100644
--- a/include/net/xdp.h
+++ b/include/net/xdp.h
@@ -66,6 +66,10 @@ struct xdp_txq_info {
 	struct net_device *dev;
 };
 
+enum xdp_buff_flags {
+	XDP_FLAGS_MULTI_BUFF	= BIT(0), /* non-linear xdp buff */
+};
+
 struct xdp_buff {
 	void *data;
 	void *data_end;
@@ -74,13 +78,30 @@ struct xdp_buff {
 	struct xdp_rxq_info *rxq;
 	struct xdp_txq_info *txq;
 	u32 frame_sz; /* frame size to deduce data_hard_end/reserved tailroom*/
+	u32 flags; /* supported values defined in xdp_buff_flags */
 };
 
+static __always_inline bool xdp_buff_is_mb(struct xdp_buff *xdp)
+{
+	return !!(xdp->flags & XDP_FLAGS_MULTI_BUFF);
+}
+
+static __always_inline void xdp_buff_set_mb(struct xdp_buff *xdp)
+{
+	xdp->flags |= XDP_FLAGS_MULTI_BUFF;
+}
+
+static __always_inline void xdp_buff_clear_mb(struct xdp_buff *xdp)
+{
+	xdp->flags &= ~XDP_FLAGS_MULTI_BUFF;
+}
+
 static __always_inline void
 xdp_init_buff(struct xdp_buff *xdp, u32 frame_sz, struct xdp_rxq_info *rxq)
 {
 	xdp->frame_sz = frame_sz;
 	xdp->rxq = rxq;
+	xdp->flags = 0;
 }
 
 static __always_inline void
@@ -122,8 +143,14 @@ struct xdp_frame {
 	 */
 	struct xdp_mem_info mem;
 	struct net_device *dev_rx; /* used by cpumap */
+	u32 flags; /* supported values defined in xdp_buff_flags */
 };
 
+static __always_inline bool xdp_frame_is_mb(struct xdp_frame *frame)
+{
+	return !!(frame->flags & XDP_FLAGS_MULTI_BUFF);
+}
+
 #define XDP_BULK_QUEUE_SIZE	16
 struct xdp_frame_bulk {
 	int count;
@@ -180,6 +207,7 @@ void xdp_convert_frame_to_buff(struct xdp_frame *frame, struct xdp_buff *xdp)
 	xdp->data_end = frame->data + frame->len;
 	xdp->data_meta = frame->data - frame->metasize;
 	xdp->frame_sz = frame->frame_sz;
+	xdp->flags = frame->flags;
 }
 
 static inline
@@ -206,6 +234,7 @@ int xdp_update_frame_from_buff(struct xdp_buff *xdp,
 	xdp_frame->headroom = headroom - sizeof(*xdp_frame);
 	xdp_frame->metasize = metasize;
 	xdp_frame->frame_sz = xdp->frame_sz;
+	xdp_frame->flags = xdp->flags;
 
 	return 0;
 }
-- 
2.31.1

[PATCH v17 bpf-next 03/23] net: mvneta: update mb bit before passing the xdp buffer to eBPF layer

[Lorenzo Bianconi]

Update multi-buffer bit (mb) in xdp_buff to notify XDP/eBPF layer and
XDP remote drivers if this is a "non-linear" XDP buffer. Access
skb_shared_info only if xdp_buff mb is set in order to avoid possible
cache-misses.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 drivers/net/ethernet/marvell/mvneta.c | 23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index 5a7bdca22a63..f3f8c32750b8 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -2037,9 +2037,14 @@ mvneta_xdp_put_buff(struct mvneta_port *pp, struct mvneta_rx_queue *rxq,
 {
 	int i;
 
+	if (likely(!xdp_buff_is_mb(xdp)))
+		goto out;
+
 	for (i = 0; i < sinfo->nr_frags; i++)
 		page_pool_put_full_page(rxq->page_pool,
 					skb_frag_page(&sinfo->frags[i]), true);
+
+out:
 	page_pool_put_page(rxq->page_pool, virt_to_head_page(xdp->data),
 			   sync_len, true);
 }
@@ -2241,7 +2246,6 @@ mvneta_swbm_rx_frame(struct mvneta_port *pp,
 	int data_len = -MVNETA_MH_SIZE, len;
 	struct net_device *dev = pp->dev;
 	enum dma_data_direction dma_dir;
-	struct skb_shared_info *sinfo;
 
 	if (*size > MVNETA_MAX_RX_BUF_SIZE) {
 		len = MVNETA_MAX_RX_BUF_SIZE;
@@ -2261,11 +2265,9 @@ mvneta_swbm_rx_frame(struct mvneta_port *pp,
 
 	/* Prefetch header */
 	prefetch(data);
+	xdp_buff_clear_mb(xdp);
 	xdp_prepare_buff(xdp, data, pp->rx_offset_correction + MVNETA_MH_SIZE,
 			 data_len, false);
-
-	sinfo = xdp_get_shared_info_from_buff(xdp);
-	sinfo->nr_frags = 0;
 }
 
 static void
@@ -2299,6 +2301,9 @@ mvneta_swbm_add_rx_fragment(struct mvneta_port *pp,
 		skb_frag_off_set(frag, pp->rx_offset_correction);
 		skb_frag_size_set(frag, data_len);
 		__skb_frag_set_page(frag, page);
+
+		if (!xdp_buff_is_mb(xdp))
+			xdp_buff_set_mb(xdp);
 	} else {
 		page_pool_put_full_page(rxq->page_pool, page, true);
 	}
@@ -2320,8 +2325,12 @@ mvneta_swbm_build_skb(struct mvneta_port *pp, struct page_pool *pool,
 		      struct xdp_buff *xdp, u32 desc_status)
 {
 	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
-	int i, num_frags = sinfo->nr_frags;
 	struct sk_buff *skb;
+	u8 num_frags;
+	int i;
+
+	if (unlikely(xdp_buff_is_mb(xdp)))
+		num_frags = sinfo->nr_frags;
 
 	skb = build_skb(xdp->data_hard_start, PAGE_SIZE);
 	if (!skb)
@@ -2333,6 +2342,9 @@ mvneta_swbm_build_skb(struct mvneta_port *pp, struct page_pool *pool,
 	skb_put(skb, xdp->data_end - xdp->data);
 	skb->ip_summed = mvneta_rx_csum(pp, desc_status);
 
+	if (likely(!xdp_buff_is_mb(xdp)))
+		goto out;
+
 	for (i = 0; i < num_frags; i++) {
 		skb_frag_t *frag = &sinfo->frags[i];
 
@@ -2341,6 +2353,7 @@ mvneta_swbm_build_skb(struct mvneta_port *pp, struct page_pool *pool,
 				skb_frag_size(frag), PAGE_SIZE);
 	}
 
+out:
 	return skb;
 }
 
-- 
2.31.1

[PATCH v17 bpf-next 04/23] net: mvneta: simplify mvneta_swbm_add_rx_fragment management

[Lorenzo Bianconi]

Relying on xdp mb bit, remove skb_shared_info structure allocated on the
stack in mvneta_rx_swbm routine and simplify mvneta_swbm_add_rx_fragment
accessing skb_shared_info in the xdp_buff structure directly. There is no
performance penalty in this approach since mvneta_swbm_add_rx_fragment
is run just for multi-buff use-case.

Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 drivers/net/ethernet/marvell/mvneta.c | 42 ++++++++++-----------------
 1 file changed, 15 insertions(+), 27 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index f3f8c32750b8..d57ca55b1c60 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -2032,9 +2032,9 @@ int mvneta_rx_refill_queue(struct mvneta_port *pp, struct mvneta_rx_queue *rxq)
 
 static void
 mvneta_xdp_put_buff(struct mvneta_port *pp, struct mvneta_rx_queue *rxq,
-		    struct xdp_buff *xdp, struct skb_shared_info *sinfo,
-		    int sync_len)
+		    struct xdp_buff *xdp, int sync_len)
 {
+	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
 	int i;
 
 	if (likely(!xdp_buff_is_mb(xdp)))
@@ -2182,7 +2182,6 @@ mvneta_run_xdp(struct mvneta_port *pp, struct mvneta_rx_queue *rxq,
 	       struct bpf_prog *prog, struct xdp_buff *xdp,
 	       u32 frame_sz, struct mvneta_stats *stats)
 {
-	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
 	unsigned int len, data_len, sync;
 	u32 ret, act;
 
@@ -2203,7 +2202,7 @@ mvneta_run_xdp(struct mvneta_port *pp, struct mvneta_rx_queue *rxq,
 
 		err = xdp_do_redirect(pp->dev, xdp, prog);
 		if (unlikely(err)) {
-			mvneta_xdp_put_buff(pp, rxq, xdp, sinfo, sync);
+			mvneta_xdp_put_buff(pp, rxq, xdp, sync);
 			ret = MVNETA_XDP_DROPPED;
 		} else {
 			ret = MVNETA_XDP_REDIR;
@@ -2214,7 +2213,7 @@ mvneta_run_xdp(struct mvneta_port *pp, struct mvneta_rx_queue *rxq,
 	case XDP_TX:
 		ret = mvneta_xdp_xmit_back(pp, xdp);
 		if (ret != MVNETA_XDP_TX)
-			mvneta_xdp_put_buff(pp, rxq, xdp, sinfo, sync);
+			mvneta_xdp_put_buff(pp, rxq, xdp, sync);
 		break;
 	default:
 		bpf_warn_invalid_xdp_action(act);
@@ -2223,7 +2222,7 @@ mvneta_run_xdp(struct mvneta_port *pp, struct mvneta_rx_queue *rxq,
 		trace_xdp_exception(pp->dev, prog, act);
 		fallthrough;
 	case XDP_DROP:
-		mvneta_xdp_put_buff(pp, rxq, xdp, sinfo, sync);
+		mvneta_xdp_put_buff(pp, rxq, xdp, sync);
 		ret = MVNETA_XDP_DROPPED;
 		stats->xdp_drop++;
 		break;
@@ -2275,9 +2274,9 @@ mvneta_swbm_add_rx_fragment(struct mvneta_port *pp,
 			    struct mvneta_rx_desc *rx_desc,
 			    struct mvneta_rx_queue *rxq,
 			    struct xdp_buff *xdp, int *size,
-			    struct skb_shared_info *xdp_sinfo,
 			    struct page *page)
 {
+	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
 	struct net_device *dev = pp->dev;
 	enum dma_data_direction dma_dir;
 	int data_len, len;
@@ -2295,8 +2294,11 @@ mvneta_swbm_add_rx_fragment(struct mvneta_port *pp,
 				len, dma_dir);
 	rx_desc->buf_phys_addr = 0;
 
-	if (data_len > 0 && xdp_sinfo->nr_frags < MAX_SKB_FRAGS) {
-		skb_frag_t *frag = &xdp_sinfo->frags[xdp_sinfo->nr_frags++];
+	if (!xdp_buff_is_mb(xdp))
+		sinfo->nr_frags = 0;
+
+	if (data_len > 0 && sinfo->nr_frags < MAX_SKB_FRAGS) {
+		skb_frag_t *frag = &sinfo->frags[sinfo->nr_frags++];
 
 		skb_frag_off_set(frag, pp->rx_offset_correction);
 		skb_frag_size_set(frag, data_len);
@@ -2307,16 +2309,6 @@ mvneta_swbm_add_rx_fragment(struct mvneta_port *pp,
 	} else {
 		page_pool_put_full_page(rxq->page_pool, page, true);
 	}
-
-	/* last fragment */
-	if (len == *size) {
-		struct skb_shared_info *sinfo;
-
-		sinfo = xdp_get_shared_info_from_buff(xdp);
-		sinfo->nr_frags = xdp_sinfo->nr_frags;
-		memcpy(sinfo->frags, xdp_sinfo->frags,
-		       sinfo->nr_frags * sizeof(skb_frag_t));
-	}
 	*size -= len;
 }
 
@@ -2364,7 +2356,6 @@ static int mvneta_rx_swbm(struct napi_struct *napi,
 {
 	int rx_proc = 0, rx_todo, refill, size = 0;
 	struct net_device *dev = pp->dev;
-	struct skb_shared_info sinfo;
 	struct mvneta_stats ps = {};
 	struct bpf_prog *xdp_prog;
 	u32 desc_status, frame_sz;
@@ -2373,8 +2364,6 @@ static int mvneta_rx_swbm(struct napi_struct *napi,
 	xdp_init_buff(&xdp_buf, PAGE_SIZE, &rxq->xdp_rxq);
 	xdp_buf.data_hard_start = NULL;
 
-	sinfo.nr_frags = 0;
-
 	/* Get number of received packets */
 	rx_todo = mvneta_rxq_busy_desc_num_get(pp, rxq);
 
@@ -2416,7 +2405,7 @@ static int mvneta_rx_swbm(struct napi_struct *napi,
 			}
 
 			mvneta_swbm_add_rx_fragment(pp, rx_desc, rxq, &xdp_buf,
-						    &size, &sinfo, page);
+						    &size, page);
 		} /* Middle or Last descriptor */
 
 		if (!(rx_status & MVNETA_RXD_LAST_DESC))
@@ -2424,7 +2413,7 @@ static int mvneta_rx_swbm(struct napi_struct *napi,
 			continue;
 
 		if (size) {
-			mvneta_xdp_put_buff(pp, rxq, &xdp_buf, &sinfo, -1);
+			mvneta_xdp_put_buff(pp, rxq, &xdp_buf, -1);
 			goto next;
 		}
 
@@ -2436,7 +2425,7 @@ static int mvneta_rx_swbm(struct napi_struct *napi,
 		if (IS_ERR(skb)) {
 			struct mvneta_pcpu_stats *stats = this_cpu_ptr(pp->stats);
 
-			mvneta_xdp_put_buff(pp, rxq, &xdp_buf, &sinfo, -1);
+			mvneta_xdp_put_buff(pp, rxq, &xdp_buf, -1);
 
 			u64_stats_update_begin(&stats->syncp);
 			stats->es.skb_alloc_error++;
@@ -2453,11 +2442,10 @@ static int mvneta_rx_swbm(struct napi_struct *napi,
 		napi_gro_receive(napi, skb);
 next:
 		xdp_buf.data_hard_start = NULL;
-		sinfo.nr_frags = 0;
 	}
 
 	if (xdp_buf.data_hard_start)
-		mvneta_xdp_put_buff(pp, rxq, &xdp_buf, &sinfo, -1);
+		mvneta_xdp_put_buff(pp, rxq, &xdp_buf, -1);
 
 	if (ps.xdp_redirect)
 		xdp_do_flush_map();
-- 
2.31.1

[PATCH v17 bpf-next 05/23] net: xdp: add xdp_update_skb_shared_info utility routine

[Lorenzo Bianconi]

Introduce xdp_update_skb_shared_info routine to update frags array
metadata in skb_shared_info data structure converting to a skb from
a xdp_buff or xdp_frame.
According to the current skb_shared_info architecture in
xdp_frame/xdp_buff and to the xdp multi-buff support, there is
no need to run skb_add_rx_frag() and reset frags array converting the buffer
to a skb since the frag array will be in the same position for xdp_buff/xdp_frame
and for the skb, we just need to update memory metadata.
Introduce XDP_FLAGS_PF_MEMALLOC flag in xdp_buff_flags in order to mark
the xdp_buff or xdp_frame as under memory-pressure if pages of the frags array
are under memory pressure. Doing so we can avoid looping over all fragments in
xdp_update_skb_shared_info routine. The driver is expected to set the
flag constructing the xdp_buffer using xdp_buff_set_frag_pfmemalloc
utility routine.
Rely on xdp_update_skb_shared_info in __xdp_build_skb_from_frame routine
converting the multi-buff xdp_frame to a skb after performing a XDP_REDIRECT.

Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 include/net/xdp.h | 33 ++++++++++++++++++++++++++++++++-
 net/core/xdp.c    | 12 ++++++++++++
 2 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/include/net/xdp.h b/include/net/xdp.h
index 4ec7bdf0d937..e594016eb193 100644
--- a/include/net/xdp.h
+++ b/include/net/xdp.h
@@ -67,7 +67,10 @@ struct xdp_txq_info {
 };
 
 enum xdp_buff_flags {
-	XDP_FLAGS_MULTI_BUFF	= BIT(0), /* non-linear xdp buff */
+	XDP_FLAGS_MULTI_BUFF		= BIT(0), /* non-linear xdp buff */
+	XDP_FLAGS_FRAGS_PF_MEMALLOC	= BIT(1), /* xdp multi-buff paged memory
+						   * is under pressure
+						   */
 };
 
 struct xdp_buff {
@@ -96,6 +99,16 @@ static __always_inline void xdp_buff_clear_mb(struct xdp_buff *xdp)
 	xdp->flags &= ~XDP_FLAGS_MULTI_BUFF;
 }
 
+static __always_inline bool xdp_buff_is_frag_pfmemalloc(struct xdp_buff *xdp)
+{
+	return !!(xdp->flags & XDP_FLAGS_FRAGS_PF_MEMALLOC);
+}
+
+static __always_inline void xdp_buff_set_frag_pfmemalloc(struct xdp_buff *xdp)
+{
+	xdp->flags |= XDP_FLAGS_FRAGS_PF_MEMALLOC;
+}
+
 static __always_inline void
 xdp_init_buff(struct xdp_buff *xdp, u32 frame_sz, struct xdp_rxq_info *rxq)
 {
@@ -151,6 +164,11 @@ static __always_inline bool xdp_frame_is_mb(struct xdp_frame *frame)
 	return !!(frame->flags & XDP_FLAGS_MULTI_BUFF);
 }
 
+static __always_inline bool xdp_frame_is_frag_pfmemalloc(struct xdp_frame *frame)
+{
+	return !!(frame->flags & XDP_FLAGS_FRAGS_PF_MEMALLOC);
+}
+
 #define XDP_BULK_QUEUE_SIZE	16
 struct xdp_frame_bulk {
 	int count;
@@ -186,6 +204,19 @@ static inline void xdp_scrub_frame(struct xdp_frame *frame)
 	frame->dev_rx = NULL;
 }
 
+static inline void
+xdp_update_skb_shared_info(struct sk_buff *skb, u8 nr_frags,
+			   unsigned int size, unsigned int truesize,
+			   bool pfmemalloc)
+{
+	skb_shinfo(skb)->nr_frags = nr_frags;
+
+	skb->len += size;
+	skb->data_len += size;
+	skb->truesize += truesize;
+	skb->pfmemalloc |= pfmemalloc;
+}
+
 /* Avoids inlining WARN macro in fast-path */
 void xdp_warn(const char *msg, const char *func, const int line);
 #define XDP_WARN(msg) xdp_warn(msg, __func__, __LINE__)
diff --git a/net/core/xdp.c b/net/core/xdp.c
index 5ddc29f29bad..89183b2e3c07 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -529,8 +529,14 @@ 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, frame_size;
 	void *hard_start;
+	u8 nr_frags;
+
+	/* xdp multi-buff frame */
+	if (unlikely(xdp_frame_is_mb(xdpf)))
+		nr_frags = sinfo->nr_frags;
 
 	/* Part of headroom was reserved to xdpf */
 	headroom = sizeof(*xdpf) + xdpf->headroom;
@@ -550,6 +556,12 @@ struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf,
 	if (xdpf->metasize)
 		skb_metadata_set(skb, xdpf->metasize);
 
+	if (unlikely(xdp_frame_is_mb(xdpf)))
+		xdp_update_skb_shared_info(skb, nr_frags,
+					   sinfo->xdp_frags_size,
+					   nr_frags * xdpf->frame_sz,
+					   xdp_frame_is_frag_pfmemalloc(xdpf));
+
 	/* Essential SKB info: protocol and skb->dev */
 	skb->protocol = eth_type_trans(skb, dev);
 
-- 
2.31.1

[PATCH v17 bpf-next 06/23] net: marvell: rely on xdp_update_skb_shared_info utility routine

[Lorenzo Bianconi]

Rely on xdp_update_skb_shared_info routine in order to avoid
resetting frags array in skb_shared_info structure building
the skb in mvneta_swbm_build_skb(). Frags array is expected to
be initialized by the receiving driver building the xdp_buff
and here we just need to update memory metadata.

Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 drivers/net/ethernet/marvell/mvneta.c | 23 ++++++++++-------------
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index d57ca55b1c60..9da75a6d51a2 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -2304,8 +2304,12 @@ mvneta_swbm_add_rx_fragment(struct mvneta_port *pp,
 		skb_frag_size_set(frag, data_len);
 		__skb_frag_set_page(frag, page);
 
-		if (!xdp_buff_is_mb(xdp))
+		if (!xdp_buff_is_mb(xdp)) {
+			sinfo->xdp_frags_size = *size;
 			xdp_buff_set_mb(xdp);
+		}
+		if (page_is_pfmemalloc(page))
+			xdp_buff_set_frag_pfmemalloc(xdp);
 	} else {
 		page_pool_put_full_page(rxq->page_pool, page, true);
 	}
@@ -2319,7 +2323,6 @@ mvneta_swbm_build_skb(struct mvneta_port *pp, struct page_pool *pool,
 	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
 	struct sk_buff *skb;
 	u8 num_frags;
-	int i;
 
 	if (unlikely(xdp_buff_is_mb(xdp)))
 		num_frags = sinfo->nr_frags;
@@ -2334,18 +2337,12 @@ mvneta_swbm_build_skb(struct mvneta_port *pp, struct page_pool *pool,
 	skb_put(skb, xdp->data_end - xdp->data);
 	skb->ip_summed = mvneta_rx_csum(pp, desc_status);
 
-	if (likely(!xdp_buff_is_mb(xdp)))
-		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), PAGE_SIZE);
-	}
+	if (unlikely(xdp_buff_is_mb(xdp)))
+		xdp_update_skb_shared_info(skb, num_frags,
+					   sinfo->xdp_frags_size,
+					   num_frags * xdp->frame_sz,
+					   xdp_buff_is_frag_pfmemalloc(xdp));
 
-out:
 	return skb;
 }
 
-- 
2.31.1

[PATCH v17 bpf-next 07/23] xdp: add multi-buff support to xdp_return_{buff/frame}

[Lorenzo Bianconi]

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.

Acked-by: John Fastabend <john.fastabend@gmail.com>
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 e594016eb193..798b84d86d97 100644
--- a/include/net/xdp.h
+++ b/include/net/xdp.h
@@ -306,10 +306,24 @@ 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 89183b2e3c07..7cfcc93116d7 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -374,12 +374,38 @@ 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);
@@ -415,7 +441,7 @@ 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;
 	}
 
@@ -434,12 +460,38 @@ 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

[PATCH v17 bpf-next 08/23] net: mvneta: add multi buffer support to XDP_TX

[Lorenzo Bianconi]

Introduce the capability to map non-linear xdp buffer running
mvneta_xdp_submit_frame() for XDP_TX and XDP_REDIRECT

Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 drivers/net/ethernet/marvell/mvneta.c | 112 +++++++++++++++++---------
 1 file changed, 76 insertions(+), 36 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index 9da75a6d51a2..8842c9c8c665 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -1856,8 +1856,8 @@ static void mvneta_txq_bufs_free(struct mvneta_port *pp,
 			bytes_compl += buf->skb->len;
 			pkts_compl++;
 			dev_kfree_skb_any(buf->skb);
-		} else if (buf->type == MVNETA_TYPE_XDP_TX ||
-			   buf->type == MVNETA_TYPE_XDP_NDO) {
+		} else if ((buf->type == MVNETA_TYPE_XDP_TX ||
+			    buf->type == MVNETA_TYPE_XDP_NDO) && buf->xdpf) {
 			if (napi && buf->type == MVNETA_TYPE_XDP_TX)
 				xdp_return_frame_rx_napi(buf->xdpf);
 			else
@@ -2051,47 +2051,87 @@ mvneta_xdp_put_buff(struct mvneta_port *pp, struct mvneta_rx_queue *rxq,
 
 static int
 mvneta_xdp_submit_frame(struct mvneta_port *pp, struct mvneta_tx_queue *txq,
-			struct xdp_frame *xdpf, bool dma_map)
+			struct xdp_frame *xdpf, int *nxmit_byte, bool dma_map)
 {
-	struct mvneta_tx_desc *tx_desc;
-	struct mvneta_tx_buf *buf;
-	dma_addr_t dma_addr;
+	struct skb_shared_info *sinfo = xdp_get_shared_info_from_frame(xdpf);
+	struct device *dev = pp->dev->dev.parent;
+	struct mvneta_tx_desc *tx_desc = NULL;
+	int i, num_frames = 1;
+	struct page *page;
+
+	if (unlikely(xdp_frame_is_mb(xdpf)))
+		num_frames += sinfo->nr_frags;
 
-	if (txq->count >= txq->tx_stop_threshold)
+	if (txq->count + num_frames >= txq->size)
 		return MVNETA_XDP_DROPPED;
 
-	tx_desc = mvneta_txq_next_desc_get(txq);
+	for (i = 0; i < num_frames; i++) {
+		struct mvneta_tx_buf *buf = &txq->buf[txq->txq_put_index];
+		skb_frag_t *frag = NULL;
+		int len = xdpf->len;
+		dma_addr_t dma_addr;
 
-	buf = &txq->buf[txq->txq_put_index];
-	if (dma_map) {
-		/* ndo_xdp_xmit */
-		dma_addr = dma_map_single(pp->dev->dev.parent, xdpf->data,
-					  xdpf->len, DMA_TO_DEVICE);
-		if (dma_mapping_error(pp->dev->dev.parent, dma_addr)) {
-			mvneta_txq_desc_put(txq);
-			return MVNETA_XDP_DROPPED;
+		if (unlikely(i)) { /* paged area */
+			frag = &sinfo->frags[i - 1];
+			len = skb_frag_size(frag);
 		}
-		buf->type = MVNETA_TYPE_XDP_NDO;
-	} else {
-		struct page *page = virt_to_page(xdpf->data);
 
-		dma_addr = page_pool_get_dma_addr(page) +
-			   sizeof(*xdpf) + xdpf->headroom;
-		dma_sync_single_for_device(pp->dev->dev.parent, dma_addr,
-					   xdpf->len, DMA_BIDIRECTIONAL);
-		buf->type = MVNETA_TYPE_XDP_TX;
+		tx_desc = mvneta_txq_next_desc_get(txq);
+		if (dma_map) {
+			/* ndo_xdp_xmit */
+			void *data;
+
+			data = unlikely(frag) ? skb_frag_address(frag)
+					      : xdpf->data;
+			dma_addr = dma_map_single(dev, data, len,
+						  DMA_TO_DEVICE);
+			if (dma_mapping_error(dev, dma_addr)) {
+				mvneta_txq_desc_put(txq);
+				goto unmap;
+			}
+
+			buf->type = MVNETA_TYPE_XDP_NDO;
+		} else {
+			page = unlikely(frag) ? skb_frag_page(frag)
+					      : virt_to_page(xdpf->data);
+			dma_addr = page_pool_get_dma_addr(page);
+			if (unlikely(frag))
+				dma_addr += skb_frag_off(frag);
+			else
+				dma_addr += sizeof(*xdpf) + xdpf->headroom;
+			dma_sync_single_for_device(dev, dma_addr, len,
+						   DMA_BIDIRECTIONAL);
+			buf->type = MVNETA_TYPE_XDP_TX;
+		}
+		buf->xdpf = unlikely(i) ? NULL : xdpf;
+
+		tx_desc->command = unlikely(i) ? 0 : MVNETA_TXD_F_DESC;
+		tx_desc->buf_phys_addr = dma_addr;
+		tx_desc->data_size = len;
+		*nxmit_byte += len;
+
+		mvneta_txq_inc_put(txq);
 	}
-	buf->xdpf = xdpf;
 
-	tx_desc->command = MVNETA_TXD_FLZ_DESC;
-	tx_desc->buf_phys_addr = dma_addr;
-	tx_desc->data_size = xdpf->len;
+	/*last descriptor */
+	if (likely(tx_desc))
+		tx_desc->command |= MVNETA_TXD_L_DESC | MVNETA_TXD_Z_PAD;
 
-	mvneta_txq_inc_put(txq);
-	txq->pending++;
-	txq->count++;
+	txq->pending += num_frames;
+	txq->count += num_frames;
 
 	return MVNETA_XDP_TX;
+
+unmap:
+	for (i--; i >= 0; i--) {
+		mvneta_txq_desc_put(txq);
+		tx_desc = txq->descs + txq->next_desc_to_proc;
+		dma_unmap_single(dev, tx_desc->buf_phys_addr,
+				 tx_desc->data_size,
+				 DMA_TO_DEVICE);
+	}
+
+	return MVNETA_XDP_DROPPED;
 }
 
 static int
@@ -2100,8 +2140,8 @@ mvneta_xdp_xmit_back(struct mvneta_port *pp, struct xdp_buff *xdp)
 	struct mvneta_pcpu_stats *stats = this_cpu_ptr(pp->stats);
 	struct mvneta_tx_queue *txq;
 	struct netdev_queue *nq;
+	int cpu, nxmit_byte = 0;
 	struct xdp_frame *xdpf;
-	int cpu;
 	u32 ret;
 
 	xdpf = xdp_convert_buff_to_frame(xdp);
@@ -2113,10 +2153,10 @@ mvneta_xdp_xmit_back(struct mvneta_port *pp, struct xdp_buff *xdp)
 	nq = netdev_get_tx_queue(pp->dev, txq->id);
 
 	__netif_tx_lock(nq, cpu);
-	ret = mvneta_xdp_submit_frame(pp, txq, xdpf, false);
+	ret = mvneta_xdp_submit_frame(pp, txq, xdpf, &nxmit_byte, false);
 	if (ret == MVNETA_XDP_TX) {
 		u64_stats_update_begin(&stats->syncp);
-		stats->es.ps.tx_bytes += xdpf->len;
+		stats->es.ps.tx_bytes += nxmit_byte;
 		stats->es.ps.tx_packets++;
 		stats->es.ps.xdp_tx++;
 		u64_stats_update_end(&stats->syncp);
@@ -2155,11 +2195,11 @@ mvneta_xdp_xmit(struct net_device *dev, int num_frame,
 
 	__netif_tx_lock(nq, cpu);
 	for (i = 0; i < num_frame; i++) {
-		ret = mvneta_xdp_submit_frame(pp, txq, frames[i], true);
+		ret = mvneta_xdp_submit_frame(pp, txq, frames[i], &nxmit_byte,
+					      true);
 		if (ret != MVNETA_XDP_TX)
 			break;
 
-		nxmit_byte += frames[i]->len;
 		nxmit++;
 	}
 
-- 
2.31.1

[PATCH v17 bpf-next 09/23] bpf: introduce BPF_F_XDP_MB flag in prog_flags loading the ebpf program

[Lorenzo Bianconi]

Introduce BPF_F_XDP_MB and the related field in bpf_prog_aux in order to
notify the driver the loaded program support xdp multi-buffer.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 include/linux/bpf.h            | 1 +
 include/uapi/linux/bpf.h       | 5 +++++
 kernel/bpf/syscall.c           | 4 +++-
 tools/include/uapi/linux/bpf.h | 5 +++++
 4 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 2be6dfd68df9..ba31c22ad839 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -869,6 +869,7 @@ struct bpf_prog_aux {
 	bool func_proto_unreliable;
 	bool sleepable;
 	bool tail_call_reachable;
+	bool xdp_mb;
 	struct hlist_node tramp_hlist;
 	/* BTF_KIND_FUNC_PROTO for valid attach_btf_id */
 	const struct btf_type *attach_func_proto;
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index ba5af15e25f5..d2abb7cff9b5 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -1111,6 +1111,11 @@ enum bpf_link_type {
  */
 #define BPF_F_SLEEPABLE		(1U << 4)
 
+/* If BPF_F_XDP_MB is used in BPF_PROG_LOAD command, the loaded program
+ * fully support xdp multi-buffer
+ */
+#define BPF_F_XDP_MB		(1U << 5)
+
 /* When BPF ldimm64's insn[0].src_reg != 0 then this can have
  * the following extensions:
  *
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 50f96ea4452a..fbae37d5b329 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -2202,7 +2202,8 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr)
 				 BPF_F_ANY_ALIGNMENT |
 				 BPF_F_TEST_STATE_FREQ |
 				 BPF_F_SLEEPABLE |
-				 BPF_F_TEST_RND_HI32))
+				 BPF_F_TEST_RND_HI32 |
+				 BPF_F_XDP_MB))
 		return -EINVAL;
 
 	if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
@@ -2288,6 +2289,7 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr)
 	prog->aux->dst_prog = dst_prog;
 	prog->aux->offload_requested = !!attr->prog_ifindex;
 	prog->aux->sleepable = attr->prog_flags & BPF_F_SLEEPABLE;
+	prog->aux->xdp_mb = attr->prog_flags & BPF_F_XDP_MB;
 
 	err = security_bpf_prog_alloc(prog->aux);
 	if (err)
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index ba5af15e25f5..d2abb7cff9b5 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -1111,6 +1111,11 @@ enum bpf_link_type {
  */
 #define BPF_F_SLEEPABLE		(1U << 4)
 
+/* If BPF_F_XDP_MB is used in BPF_PROG_LOAD command, the loaded program
+ * fully support xdp multi-buffer
+ */
+#define BPF_F_XDP_MB		(1U << 5)
+
 /* When BPF ldimm64's insn[0].src_reg != 0 then this can have
  * the following extensions:
  *
-- 
2.31.1

[PATCH v17 bpf-next 10/23] net: mvneta: enable jumbo frames if the loaded XDP program support mb

[Lorenzo Bianconi]

Enable the capability to receive jumbo frames even if the interface is
running in XDP mode if the loaded program declare to properly support
xdp multi-buff. At same time reject a xdp program not supporting xdp
multi-buffer if the driver is running in xdp multi-buffer mode.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 drivers/net/ethernet/marvell/mvneta.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index 8842c9c8c665..8b26d733b3cd 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -3750,6 +3750,7 @@ static void mvneta_percpu_disable(void *arg)
 static int mvneta_change_mtu(struct net_device *dev, int mtu)
 {
 	struct mvneta_port *pp = netdev_priv(dev);
+	struct bpf_prog *prog = pp->xdp_prog;
 	int ret;
 
 	if (!IS_ALIGNED(MVNETA_RX_PKT_SIZE(mtu), 8)) {
@@ -3758,8 +3759,11 @@ static int mvneta_change_mtu(struct net_device *dev, int mtu)
 		mtu = ALIGN(MVNETA_RX_PKT_SIZE(mtu), 8);
 	}
 
-	if (pp->xdp_prog && mtu > MVNETA_MAX_RX_BUF_SIZE) {
-		netdev_info(dev, "Illegal MTU value %d for XDP mode\n", mtu);
+	if (prog && !prog->aux->xdp_mb && mtu > MVNETA_MAX_RX_BUF_SIZE) {
+		netdev_info(dev,
+			    "Illegal MTU %d for XDP prog without multi-buf\n",
+			    mtu);
+
 		return -EINVAL;
 	}
 
@@ -4457,8 +4461,9 @@ static int mvneta_xdp_setup(struct net_device *dev, struct bpf_prog *prog,
 	struct mvneta_port *pp = netdev_priv(dev);
 	struct bpf_prog *old_prog;
 
-	if (prog && dev->mtu > MVNETA_MAX_RX_BUF_SIZE) {
-		NL_SET_ERR_MSG_MOD(extack, "MTU too large for XDP");
+	if (prog && !prog->aux->xdp_mb && dev->mtu > MVNETA_MAX_RX_BUF_SIZE) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "prog does not support XDP multi-buff");
 		return -EOPNOTSUPP;
 	}
 
-- 
2.31.1

[PATCH v17 bpf-next 11/23] bpf: introduce bpf_xdp_get_buff_len helper

[Lorenzo Bianconi]

Introduce bpf_xdp_get_buff_len helper in order to return the xdp buffer
total size (linear and paged area)

Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 include/net/xdp.h              | 14 ++++++++++++++
 include/uapi/linux/bpf.h       |  7 +++++++
 net/core/filter.c              | 15 +++++++++++++++
 tools/include/uapi/linux/bpf.h |  7 +++++++
 4 files changed, 43 insertions(+)

diff --git a/include/net/xdp.h b/include/net/xdp.h
index 798b84d86d97..067716d38ebc 100644
--- a/include/net/xdp.h
+++ b/include/net/xdp.h
@@ -145,6 +145,20 @@ xdp_get_shared_info_from_buff(struct xdp_buff *xdp)
 	return (struct skb_shared_info *)xdp_data_hard_end(xdp);
 }
 
+static __always_inline unsigned int xdp_get_buff_len(struct xdp_buff *xdp)
+{
+	unsigned int len = xdp->data_end - xdp->data;
+	struct skb_shared_info *sinfo;
+
+	if (likely(!xdp_buff_is_mb(xdp)))
+		goto out;
+
+	sinfo = xdp_get_shared_info_from_buff(xdp);
+	len += sinfo->xdp_frags_size;
+out:
+	return len;
+}
+
 struct xdp_frame {
 	void *data;
 	u16 len;
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index d2abb7cff9b5..c643be066700 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -4943,6 +4943,12 @@ union bpf_attr {
  *		**-ENOENT** if symbol is not found.
  *
  *		**-EPERM** if caller does not have permission to obtain kernel address.
+ *
+ * u64 bpf_xdp_get_buff_len(struct xdp_buff *xdp_md)
+ *	Description
+ *		Get the total size of a given xdp buff (linear and paged area)
+ *	Return
+ *		The total size of a given xdp buffer.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -5125,6 +5131,7 @@ union bpf_attr {
 	FN(trace_vprintk),		\
 	FN(skc_to_unix_sock),		\
 	FN(kallsyms_lookup_name),	\
+	FN(xdp_get_buff_len),		\
 	/* */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
diff --git a/net/core/filter.c b/net/core/filter.c
index 8e8d3b49c297..1b8bb44ef03f 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -3784,6 +3784,19 @@ static const struct bpf_func_proto sk_skb_change_head_proto = {
 	.arg2_type	= ARG_ANYTHING,
 	.arg3_type	= ARG_ANYTHING,
 };
+
+BPF_CALL_1(bpf_xdp_get_buff_len, struct  xdp_buff*, xdp)
+{
+	return xdp_get_buff_len(xdp);
+}
+
+static const struct bpf_func_proto bpf_xdp_get_buff_len_proto = {
+	.func		= bpf_xdp_get_buff_len,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+};
+
 static unsigned long xdp_get_metalen(const struct xdp_buff *xdp)
 {
 	return xdp_data_meta_unsupported(xdp) ? 0 :
@@ -7471,6 +7484,8 @@ xdp_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 		return &bpf_xdp_redirect_map_proto;
 	case BPF_FUNC_xdp_adjust_tail:
 		return &bpf_xdp_adjust_tail_proto;
+	case BPF_FUNC_xdp_get_buff_len:
+		return &bpf_xdp_get_buff_len_proto;
 	case BPF_FUNC_fib_lookup:
 		return &bpf_xdp_fib_lookup_proto;
 	case BPF_FUNC_check_mtu:
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index d2abb7cff9b5..c643be066700 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -4943,6 +4943,12 @@ union bpf_attr {
  *		**-ENOENT** if symbol is not found.
  *
  *		**-EPERM** if caller does not have permission to obtain kernel address.
+ *
+ * u64 bpf_xdp_get_buff_len(struct xdp_buff *xdp_md)
+ *	Description
+ *		Get the total size of a given xdp buff (linear and paged area)
+ *	Return
+ *		The total size of a given xdp buffer.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -5125,6 +5131,7 @@ union bpf_attr {
 	FN(trace_vprintk),		\
 	FN(skc_to_unix_sock),		\
 	FN(kallsyms_lookup_name),	\
+	FN(xdp_get_buff_len),		\
 	/* */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
-- 
2.31.1

[PATCH v17 bpf-next 12/23] bpf: add multi-buff support to the bpf_xdp_adjust_tail() API

[Lorenzo Bianconi]

From: Eelco Chaudron <echaudro@redhat.com>

This change adds support for tail growing and shrinking for XDP multi-buff.

When called on a multi-buffer packet with a grow request, it will always
work on the last fragment of the packet. So the maximum grow size is the
last fragments tailroom, i.e. no new buffer will be allocated.

When shrinking, it will work from the last fragment, all the way down to
the base buffer depending on the shrinking size. It's important to mention
that once you shrink down the fragment(s) are freed, so you can not grow
again to the original size.

Acked-by: John Fastabend <john.fastabend@gmail.com>
Co-developed-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
---
 include/net/xdp.h |  2 ++
 net/core/filter.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++
 net/core/xdp.c    |  5 ++--
 3 files changed, 69 insertions(+), 2 deletions(-)

diff --git a/include/net/xdp.h b/include/net/xdp.h
index 067716d38ebc..4b1cdc4a8a17 100644
--- a/include/net/xdp.h
+++ b/include/net/xdp.h
@@ -304,6 +304,8 @@ struct xdp_frame *xdp_convert_buff_to_frame(struct xdp_buff *xdp)
 	return xdp_frame;
 }
 
+void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct,
+		  struct xdp_buff *xdp);
 void xdp_return_frame(struct xdp_frame *xdpf);
 void xdp_return_frame_rx_napi(struct xdp_frame *xdpf);
 void xdp_return_buff(struct xdp_buff *xdp);
diff --git a/net/core/filter.c b/net/core/filter.c
index 1b8bb44ef03f..36d8e14b32ec 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -3831,11 +3831,75 @@ static const struct bpf_func_proto bpf_xdp_adjust_head_proto = {
 	.arg2_type	= ARG_ANYTHING,
 };
 
+static int bpf_xdp_mb_increase_tail(struct xdp_buff *xdp, int offset)
+{
+	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
+	skb_frag_t *frag = &sinfo->frags[sinfo->nr_frags - 1];
+	int size, tailroom;
+
+	tailroom = xdp->frame_sz - skb_frag_size(frag) - skb_frag_off(frag);
+	if (unlikely(offset > tailroom))
+		return -EINVAL;
+
+	size = skb_frag_size(frag);
+	memset(skb_frag_address(frag) + size, 0, offset);
+	skb_frag_size_set(frag, size + offset);
+	sinfo->xdp_frags_size += offset;
+
+	return 0;
+}
+
+static int bpf_xdp_mb_shrink_tail(struct xdp_buff *xdp, int offset)
+{
+	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
+	int i, n_frags_free = 0, len_free = 0, tlen_free = 0;
+
+	if (unlikely(offset > ((int)xdp_get_buff_len(xdp) - ETH_HLEN)))
+		return -EINVAL;
+
+	for (i = sinfo->nr_frags - 1; i >= 0 && offset > 0; i--) {
+		skb_frag_t *frag = &sinfo->frags[i];
+		int size = skb_frag_size(frag);
+		int shrink = min_t(int, offset, size);
+
+		len_free += shrink;
+		offset -= shrink;
+
+		if (unlikely(size == shrink)) {
+			struct page *page = skb_frag_page(frag);
+
+			__xdp_return(page_address(page), &xdp->rxq->mem,
+				     false, NULL);
+			tlen_free += page_size(page);
+			n_frags_free++;
+		} else {
+			skb_frag_size_set(frag, size - shrink);
+			break;
+		}
+	}
+	sinfo->nr_frags -= n_frags_free;
+	sinfo->xdp_frags_size -= len_free;
+
+	if (unlikely(offset > 0)) {
+		xdp_buff_clear_mb(xdp);
+		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_buff_is_mb(xdp))) { /* xdp multi-buffer */
+		if (offset < 0)
+			return bpf_xdp_mb_shrink_tail(xdp, -offset);
+
+		return bpf_xdp_mb_increase_tail(xdp, offset);
+	}
+
 	/* Notice that xdp_data_hard_end have reserved some tailroom */
 	if (unlikely(data_end > data_hard_end))
 		return -EINVAL;
diff --git a/net/core/xdp.c b/net/core/xdp.c
index 7cfcc93116d7..c1b0919203b7 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -337,8 +337,8 @@ EXPORT_SYMBOL_GPL(xdp_rxq_info_reg_mem_model);
  * is used for those calls sites.  Thus, allowing for faster recycling
  * of xdp_frames/pages in those cases.
  */
-static void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct,
-			 struct xdp_buff *xdp)
+void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct,
+		  struct xdp_buff *xdp)
 {
 	struct xdp_mem_allocator *xa;
 	struct page *page;
@@ -371,6 +371,7 @@ static void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct,
 		break;
 	}
 }
+EXPORT_SYMBOL_GPL(__xdp_return);
 
 void xdp_return_frame(struct xdp_frame *xdpf)
 {
-- 
2.31.1

[PATCH v17 bpf-next 13/23] bpf: add multi-buffer support to xdp copy helpers

[Lorenzo Bianconi]

From: Eelco Chaudron <echaudro@redhat.com>

This patch adds support for multi-buffer for the following helpers:
  - bpf_xdp_output()
  - bpf_perf_event_output()

Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 kernel/trace/bpf_trace.c                      |   3 +
 net/core/filter.c                             |  61 ++++++-
 .../selftests/bpf/prog_tests/xdp_bpf2bpf.c    | 151 +++++++++++++-----
 .../selftests/bpf/progs/test_xdp_bpf2bpf.c    |   2 +-
 4 files changed, 172 insertions(+), 45 deletions(-)

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 7396488793ff..84fa48bb0f66 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1519,6 +1519,7 @@ static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = {
 
 extern const struct bpf_func_proto bpf_skb_output_proto;
 extern const struct bpf_func_proto bpf_xdp_output_proto;
+extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto;
 
 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args,
 	   struct bpf_map *, map, u64, flags)
@@ -1618,6 +1619,8 @@ tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 		return &bpf_sock_from_file_proto;
 	case BPF_FUNC_get_socket_cookie:
 		return &bpf_get_socket_ptr_cookie_proto;
+	case BPF_FUNC_xdp_get_buff_len:
+		return &bpf_xdp_get_buff_len_trace_proto;
 #endif
 	case BPF_FUNC_seq_printf:
 		return prog->expected_attach_type == BPF_TRACE_ITER ?
diff --git a/net/core/filter.c b/net/core/filter.c
index 36d8e14b32ec..386dd2fffded 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -3797,6 +3797,15 @@ static const struct bpf_func_proto bpf_xdp_get_buff_len_proto = {
 	.arg1_type	= ARG_PTR_TO_CTX,
 };
 
+BTF_ID_LIST_SINGLE(bpf_xdp_get_buff_len_bpf_ids, struct, xdp_buff)
+
+const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto = {
+	.func		= bpf_xdp_get_buff_len,
+	.gpl_only	= false,
+	.arg1_type	= ARG_PTR_TO_BTF_ID,
+	.arg1_btf_id	= &bpf_xdp_get_buff_len_bpf_ids[0],
+};
+
 static unsigned long xdp_get_metalen(const struct xdp_buff *xdp)
 {
 	return xdp_data_meta_unsupported(xdp) ? 0 :
@@ -4615,10 +4624,52 @@ static const struct bpf_func_proto bpf_sk_ancestor_cgroup_id_proto = {
 };
 #endif
 
-static unsigned long bpf_xdp_copy(void *dst_buff, const void *src_buff,
+static unsigned long bpf_xdp_copy(void *dst_buff, const void *ctx,
 				  unsigned long off, unsigned long len)
 {
-	memcpy(dst_buff, src_buff + off, len);
+	unsigned long base_len, copy_len, frag_off_total;
+	struct xdp_buff *xdp = (struct xdp_buff *)ctx;
+	struct skb_shared_info *sinfo;
+	int i;
+
+	if (likely(!xdp_buff_is_mb(xdp))) {
+		memcpy(dst_buff, xdp->data + off, len);
+		return 0;
+	}
+
+	base_len = xdp->data_end - xdp->data;
+	frag_off_total = base_len;
+	sinfo = xdp_get_shared_info_from_buff(xdp);
+
+	/* If we need to copy data from the base buffer do it */
+	if (off < base_len) {
+		copy_len = min(len, base_len - off);
+		memcpy(dst_buff, xdp->data + off, copy_len);
+
+		off += copy_len;
+		len -= copy_len;
+		dst_buff += copy_len;
+	}
+
+	/* Copy any remaining data from the fragments */
+	for (i = 0; len && i < sinfo->nr_frags; i++) {
+		skb_frag_t *frag = &sinfo->frags[i];
+		unsigned long frag_len, frag_off;
+
+		frag_len = skb_frag_size(frag);
+		frag_off = off - frag_off_total;
+		if (frag_off < frag_len) {
+			copy_len = min(len, frag_len - frag_off);
+			memcpy(dst_buff,
+			       skb_frag_address(frag) + frag_off, copy_len);
+
+			off += copy_len;
+			len -= copy_len;
+			dst_buff += copy_len;
+		}
+		frag_off_total += frag_len;
+	}
+
 	return 0;
 }
 
@@ -4629,11 +4680,11 @@ BPF_CALL_5(bpf_xdp_event_output, struct xdp_buff *, xdp, struct bpf_map *, map,
 
 	if (unlikely(flags & ~(BPF_F_CTXLEN_MASK | BPF_F_INDEX_MASK)))
 		return -EINVAL;
-	if (unlikely(!xdp ||
-		     xdp_size > (unsigned long)(xdp->data_end - xdp->data)))
+
+	if (unlikely(!xdp || xdp_size > xdp_get_buff_len(xdp)))
 		return -EFAULT;
 
-	return bpf_event_output(map, flags, meta, meta_size, xdp->data,
+	return bpf_event_output(map, flags, meta, meta_size, xdp,
 				xdp_size, bpf_xdp_copy);
 }
 
diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c b/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c
index 3bd5904b4db5..fe279c1c0e48 100644
--- a/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c
@@ -10,11 +10,20 @@ struct meta {
 	int pkt_len;
 };
 
+struct test_ctx_s {
+	bool passed;
+	int pkt_size;
+};
+
+struct test_ctx_s test_ctx;
+
 static void on_sample(void *ctx, int cpu, void *data, __u32 size)
 {
-	int duration = 0;
 	struct meta *meta = (struct meta *)data;
 	struct ipv4_packet *trace_pkt_v4 = data + sizeof(*meta);
+	unsigned char *raw_pkt = data + sizeof(*meta);
+	struct test_ctx_s *tst_ctx = ctx;
+	int duration = 0;
 
 	if (CHECK(size < sizeof(pkt_v4) + sizeof(*meta),
 		  "check_size", "size %u < %zu\n",
@@ -25,25 +34,114 @@ static void on_sample(void *ctx, int cpu, void *data, __u32 size)
 		  "meta->ifindex = %d\n", meta->ifindex))
 		return;
 
-	if (CHECK(meta->pkt_len != sizeof(pkt_v4), "check_meta_pkt_len",
-		  "meta->pkt_len = %zd\n", sizeof(pkt_v4)))
+	if (CHECK(meta->pkt_len != tst_ctx->pkt_size, "check_meta_pkt_len",
+		  "meta->pkt_len = %d\n", tst_ctx->pkt_size))
 		return;
 
 	if (CHECK(memcmp(trace_pkt_v4, &pkt_v4, sizeof(pkt_v4)),
 		  "check_packet_content", "content not the same\n"))
 		return;
 
-	*(bool *)ctx = true;
+	if (meta->pkt_len > sizeof(pkt_v4)) {
+		for (int i = 0; i < (meta->pkt_len - sizeof(pkt_v4)); i++) {
+			if (raw_pkt[i + sizeof(pkt_v4)] != (unsigned char)i) {
+				CHECK(true, "check_packet_content",
+				      "byte %zu does not match %u != %u\n",
+				      i + sizeof(pkt_v4),
+				      raw_pkt[i + sizeof(pkt_v4)],
+				      (unsigned char)i);
+				break;
+			}
+		}
+	}
+
+	tst_ctx->passed = true;
 }
 
-void test_xdp_bpf2bpf(void)
+#define BUF_SZ	9000
+
+static int run_xdp_bpf2bpf_pkt_size(int pkt_fd, struct perf_buffer *pb,
+				    struct test_xdp_bpf2bpf *ftrace_skel,
+				    int pkt_size)
 {
 	__u32 duration = 0, retval, size;
-	char buf[128];
+	__u8 *buf, *buf_in;
+	int err, ret = 0;
+
+	if (pkt_size > BUF_SZ || pkt_size < sizeof(pkt_v4))
+		return -EINVAL;
+
+	buf_in = malloc(BUF_SZ);
+	if (CHECK(!buf_in, "buf_in malloc()", "error:%s\n", strerror(errno)))
+		return -ENOMEM;
+
+	buf = malloc(BUF_SZ);
+	if (CHECK(!buf, "buf malloc()", "error:%s\n", strerror(errno))) {
+		ret = -ENOMEM;
+		goto free_buf_in;
+	}
+
+	test_ctx.passed = false;
+	test_ctx.pkt_size = pkt_size;
+
+	memcpy(buf_in, &pkt_v4, sizeof(pkt_v4));
+	if (pkt_size > sizeof(pkt_v4)) {
+		for (int i = 0; i < (pkt_size - sizeof(pkt_v4)); i++)
+			buf_in[i + sizeof(pkt_v4)] = i;
+	}
+
+	/* Run test program */
+	err = bpf_prog_test_run(pkt_fd, 1, buf_in, pkt_size,
+				buf, &size, &retval, &duration);
+
+	if (CHECK(err || retval != XDP_PASS || size != pkt_size,
+		  "ipv4", "err %d errno %d retval %d size %d\n",
+		  err, errno, retval, size)) {
+		ret = err ? err : -EINVAL;
+		goto free_buf;
+	}
+
+	/* Make sure bpf_xdp_output() was triggered and it sent the expected
+	 * data to the perf ring buffer.
+	 */
+	err = perf_buffer__poll(pb, 100);
+	if (CHECK(err <= 0, "perf_buffer__poll", "err %d\n", err)) {
+		ret = -EINVAL;
+		goto free_buf;
+	}
+
+	if (CHECK_FAIL(!test_ctx.passed)) {
+		ret = -EINVAL;
+		goto free_buf;
+	}
+
+	/* Verify test results */
+	if (CHECK(ftrace_skel->bss->test_result_fentry != if_nametoindex("lo"),
+		  "result", "fentry failed err %llu\n",
+		  ftrace_skel->bss->test_result_fentry)) {
+		ret = -EINVAL;
+		goto free_buf;
+	}
+
+	if (CHECK(ftrace_skel->bss->test_result_fexit != XDP_PASS, "result",
+		  "fexit failed err %llu\n",
+		  ftrace_skel->bss->test_result_fexit))
+		ret = -EINVAL;
+
+free_buf:
+	free(buf);
+free_buf_in:
+	free(buf_in);
+
+	return ret;
+}
+
+void test_xdp_bpf2bpf(void)
+{
 	int err, pkt_fd, map_fd;
-	bool passed = false;
-	struct iphdr *iph = (void *)buf + sizeof(struct ethhdr);
-	struct iptnl_info value4 = {.family = AF_INET};
+	__u32 duration = 0;
+	int pkt_sizes[] = {sizeof(pkt_v4), 1024, 4100, 8200};
+	struct iptnl_info value4 = {.family = AF_INET6};
 	struct test_xdp *pkt_skel = NULL;
 	struct test_xdp_bpf2bpf *ftrace_skel = NULL;
 	struct vip key4 = {.protocol = 6, .family = AF_INET};
@@ -87,40 +185,15 @@ void test_xdp_bpf2bpf(void)
 
 	/* Set up perf buffer */
 	pb_opts.sample_cb = on_sample;
-	pb_opts.ctx = &passed;
+	pb_opts.ctx = &test_ctx;
 	pb = perf_buffer__new(bpf_map__fd(ftrace_skel->maps.perf_buf_map),
-			      1, &pb_opts);
+			      8, &pb_opts);
 	if (!ASSERT_OK_PTR(pb, "perf_buf__new"))
 		goto out;
 
-	/* Run test program */
-	err = bpf_prog_test_run(pkt_fd, 1, &pkt_v4, sizeof(pkt_v4),
-				buf, &size, &retval, &duration);
-
-	if (CHECK(err || retval != XDP_TX || size != 74 ||
-		  iph->protocol != IPPROTO_IPIP, "ipv4",
-		  "err %d errno %d retval %d size %d\n",
-		  err, errno, retval, size))
-		goto out;
-
-	/* Make sure bpf_xdp_output() was triggered and it sent the expected
-	 * data to the perf ring buffer.
-	 */
-	err = perf_buffer__poll(pb, 100);
-	if (CHECK(err < 0, "perf_buffer__poll", "err %d\n", err))
-		goto out;
-
-	CHECK_FAIL(!passed);
-
-	/* Verify test results */
-	if (CHECK(ftrace_skel->bss->test_result_fentry != if_nametoindex("lo"),
-		  "result", "fentry failed err %llu\n",
-		  ftrace_skel->bss->test_result_fentry))
-		goto out;
-
-	CHECK(ftrace_skel->bss->test_result_fexit != XDP_TX, "result",
-	      "fexit failed err %llu\n", ftrace_skel->bss->test_result_fexit);
-
+	for (int i = 0; i < ARRAY_SIZE(pkt_sizes); i++)
+		run_xdp_bpf2bpf_pkt_size(pkt_fd, pb, ftrace_skel,
+					 pkt_sizes[i]);
 out:
 	if (pb)
 		perf_buffer__free(pb);
diff --git a/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c b/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c
index 58cf4345f5cc..3379d303f41a 100644
--- a/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c
+++ b/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c
@@ -49,7 +49,7 @@ int BPF_PROG(trace_on_entry, struct xdp_buff *xdp)
 	void *data = (void *)(long)xdp->data;
 
 	meta.ifindex = xdp->rxq->dev->ifindex;
-	meta.pkt_len = data_end - data;
+	meta.pkt_len = bpf_xdp_get_buff_len((struct xdp_md *)xdp);
 	bpf_xdp_output(xdp, &perf_buf_map,
 		       ((__u64) meta.pkt_len << 32) |
 		       BPF_F_CURRENT_CPU,
-- 
2.31.1

[PATCH v17 bpf-next 14/23] bpf: move user_size out of bpf_test_init

[Lorenzo Bianconi]

Rely on data_size_in in bpf_test_init routine signature. This is a
preliminary patch to introduce xdp multi-buff selftest

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 net/bpf/test_run.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index 46dd95755967..dbf1227f437c 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -249,11 +249,10 @@ bool bpf_prog_test_check_kfunc_call(u32 kfunc_id, struct module *owner)
 	return bpf_check_mod_kfunc_call(&prog_test_kfunc_list, kfunc_id, owner);
 }
 
-static void *bpf_test_init(const union bpf_attr *kattr, u32 size,
-			   u32 headroom, u32 tailroom)
+static void *bpf_test_init(const union bpf_attr *kattr, u32 user_size,
+			   u32 size, u32 headroom, u32 tailroom)
 {
 	void __user *data_in = u64_to_user_ptr(kattr->test.data_in);
-	u32 user_size = kattr->test.data_size_in;
 	void *data;
 
 	if (size < ETH_HLEN || size > PAGE_SIZE - headroom - tailroom)
@@ -581,7 +580,8 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
 	if (kattr->test.flags || kattr->test.cpu)
 		return -EINVAL;
 
-	data = bpf_test_init(kattr, size, NET_SKB_PAD + NET_IP_ALIGN,
+	data = bpf_test_init(kattr, kattr->test.data_size_in,
+			     size, NET_SKB_PAD + NET_IP_ALIGN,
 			     SKB_DATA_ALIGN(sizeof(struct skb_shared_info)));
 	if (IS_ERR(data))
 		return PTR_ERR(data);
@@ -790,7 +790,8 @@ int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
 	/* XDP have extra tailroom as (most) drivers use full page */
 	max_data_sz = 4096 - headroom - tailroom;
 
-	data = bpf_test_init(kattr, max_data_sz, headroom, tailroom);
+	data = bpf_test_init(kattr, kattr->test.data_size_in,
+			     max_data_sz, headroom, tailroom);
 	if (IS_ERR(data)) {
 		ret = PTR_ERR(data);
 		goto free_ctx;
@@ -876,7 +877,7 @@ int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog,
 	if (size < ETH_HLEN)
 		return -EINVAL;
 
-	data = bpf_test_init(kattr, size, 0, 0);
+	data = bpf_test_init(kattr, kattr->test.data_size_in, size, 0, 0);
 	if (IS_ERR(data))
 		return PTR_ERR(data);
 
-- 
2.31.1

[PATCH v17 bpf-next 15/23] bpf: introduce multibuff support to bpf_prog_test_run_xdp()

[Lorenzo Bianconi]

Introduce the capability to allocate a xdp multi-buff in
bpf_prog_test_run_xdp routine. This is a preliminary patch to introduce
the selftests for new xdp multi-buff ebpf helpers

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 net/bpf/test_run.c | 54 ++++++++++++++++++++++++++++++++++++----------
 1 file changed, 43 insertions(+), 11 deletions(-)

diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index dbf1227f437c..69cf012985a2 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -758,16 +758,16 @@ int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
 			  union bpf_attr __user *uattr)
 {
 	u32 tailroom = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
-	u32 headroom = XDP_PACKET_HEADROOM;
 	u32 size = kattr->test.data_size_in;
+	u32 headroom = XDP_PACKET_HEADROOM;
+	u32 retval, duration, max_data_sz;
 	u32 repeat = kattr->test.repeat;
 	struct netdev_rx_queue *rxqueue;
+	struct skb_shared_info *sinfo;
 	struct xdp_buff xdp = {};
-	u32 retval, duration;
+	int i, ret = -EINVAL;
 	struct xdp_md *ctx;
-	u32 max_data_sz;
 	void *data;
-	int ret = -EINVAL;
 
 	if (prog->expected_attach_type == BPF_XDP_DEVMAP ||
 	    prog->expected_attach_type == BPF_XDP_CPUMAP)
@@ -787,11 +787,10 @@ int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
 		headroom -= ctx->data;
 	}
 
-	/* XDP have extra tailroom as (most) drivers use full page */
 	max_data_sz = 4096 - headroom - tailroom;
+	size = min_t(u32, size, max_data_sz);
 
-	data = bpf_test_init(kattr, kattr->test.data_size_in,
-			     max_data_sz, headroom, tailroom);
+	data = bpf_test_init(kattr, size, max_data_sz, headroom, tailroom);
 	if (IS_ERR(data)) {
 		ret = PTR_ERR(data);
 		goto free_ctx;
@@ -801,13 +800,47 @@ int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
 	xdp_init_buff(&xdp, headroom + max_data_sz + tailroom,
 		      &rxqueue->xdp_rxq);
 	xdp_prepare_buff(&xdp, data, headroom, size, true);
+	sinfo = xdp_get_shared_info_from_buff(&xdp);
 
 	ret = xdp_convert_md_to_buff(ctx, &xdp);
 	if (ret)
 		goto free_data;
 
+	if (unlikely(kattr->test.data_size_in > size)) {
+		void __user *data_in = u64_to_user_ptr(kattr->test.data_in);
+
+		while (size < kattr->test.data_size_in) {
+			struct page *page;
+			skb_frag_t *frag;
+			int data_len;
+
+			page = alloc_page(GFP_KERNEL);
+			if (!page) {
+				ret = -ENOMEM;
+				goto out;
+			}
+
+			frag = &sinfo->frags[sinfo->nr_frags++];
+			__skb_frag_set_page(frag, page);
+
+			data_len = min_t(int, kattr->test.data_size_in - size,
+					 PAGE_SIZE);
+			skb_frag_size_set(frag, data_len);
+
+			if (copy_from_user(page_address(page), data_in + size,
+					   data_len)) {
+				ret = -EFAULT;
+				goto out;
+			}
+			sinfo->xdp_frags_size += data_len;
+			size += data_len;
+		}
+		xdp_buff_set_mb(&xdp);
+	}
+
 	if (repeat > 1)
 		bpf_prog_change_xdp(NULL, prog);
+
 	ret = bpf_test_run(prog, &xdp, repeat, &retval, &duration, true);
 	/* We convert the xdp_buff back to an xdp_md before checking the return
 	 * code so the reference count of any held netdevice will be decremented
@@ -817,10 +850,7 @@ int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
 	if (ret)
 		goto out;
 
-	if (xdp.data_meta != data + headroom ||
-	    xdp.data_end != xdp.data_meta + size)
-		size = xdp.data_end - xdp.data_meta;
-
+	size = xdp.data_end - xdp.data_meta + sinfo->xdp_frags_size;
 	ret = bpf_test_finish(kattr, uattr, xdp.data_meta, size, retval,
 			      duration);
 	if (!ret)
@@ -831,6 +861,8 @@ int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
 	if (repeat > 1)
 		bpf_prog_change_xdp(prog, NULL);
 free_data:
+	for (i = 0; i < sinfo->nr_frags; i++)
+		__free_page(skb_frag_page(&sinfo->frags[i]));
 	kfree(data);
 free_ctx:
 	kfree(ctx);
-- 
2.31.1

[PATCH v17 bpf-next 16/23] bpf: test_run: add xdp_shared_info pointer in bpf_test_finish signature

[Lorenzo Bianconi]

introduce xdp_shared_info pointer in bpf_test_finish signature in order
to copy back paged data from a xdp multi-buff frame to userspace buffer

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 net/bpf/test_run.c | 48 +++++++++++++++++++++++++++++++++++++---------
 1 file changed, 39 insertions(+), 9 deletions(-)

diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index 69cf012985a2..50245396d3ff 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -130,7 +130,8 @@ static int bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat,
 
 static int bpf_test_finish(const union bpf_attr *kattr,
 			   union bpf_attr __user *uattr, const void *data,
-			   u32 size, u32 retval, u32 duration)
+			   struct skb_shared_info *sinfo, u32 size,
+			   u32 retval, u32 duration)
 {
 	void __user *data_out = u64_to_user_ptr(kattr->test.data_out);
 	int err = -EFAULT;
@@ -145,8 +146,36 @@ static int bpf_test_finish(const union bpf_attr *kattr,
 		err = -ENOSPC;
 	}
 
-	if (data_out && copy_to_user(data_out, data, copy_size))
-		goto out;
+	if (data_out) {
+		int len = sinfo ? copy_size - sinfo->xdp_frags_size : copy_size;
+
+		if (copy_to_user(data_out, data, len))
+			goto out;
+
+		if (sinfo) {
+			int i, offset = len, data_len;
+
+			for (i = 0; i < sinfo->nr_frags; i++) {
+				skb_frag_t *frag = &sinfo->frags[i];
+
+				if (offset >= copy_size) {
+					err = -ENOSPC;
+					break;
+				}
+
+				data_len = min_t(int, copy_size - offset,
+						 skb_frag_size(frag));
+
+				if (copy_to_user(data_out + offset,
+						 skb_frag_address(frag),
+						 data_len))
+					goto out;
+
+				offset += data_len;
+			}
+		}
+	}
+
 	if (copy_to_user(&uattr->test.data_size_out, &size, sizeof(size)))
 		goto out;
 	if (copy_to_user(&uattr->test.retval, &retval, sizeof(retval)))
@@ -683,7 +712,8 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
 	/* bpf program can never convert linear skb to non-linear */
 	if (WARN_ON_ONCE(skb_is_nonlinear(skb)))
 		size = skb_headlen(skb);
-	ret = bpf_test_finish(kattr, uattr, skb->data, size, retval, duration);
+	ret = bpf_test_finish(kattr, uattr, skb->data, NULL, size, retval,
+			      duration);
 	if (!ret)
 		ret = bpf_ctx_finish(kattr, uattr, ctx,
 				     sizeof(struct __sk_buff));
@@ -851,8 +881,8 @@ int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
 		goto out;
 
 	size = xdp.data_end - xdp.data_meta + sinfo->xdp_frags_size;
-	ret = bpf_test_finish(kattr, uattr, xdp.data_meta, size, retval,
-			      duration);
+	ret = bpf_test_finish(kattr, uattr, xdp.data_meta, sinfo, size,
+			      retval, duration);
 	if (!ret)
 		ret = bpf_ctx_finish(kattr, uattr, ctx,
 				     sizeof(struct xdp_md));
@@ -944,8 +974,8 @@ int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog,
 	if (ret < 0)
 		goto out;
 
-	ret = bpf_test_finish(kattr, uattr, &flow_keys, sizeof(flow_keys),
-			      retval, duration);
+	ret = bpf_test_finish(kattr, uattr, &flow_keys, NULL,
+			      sizeof(flow_keys), retval, duration);
 	if (!ret)
 		ret = bpf_ctx_finish(kattr, uattr, user_ctx,
 				     sizeof(struct bpf_flow_keys));
@@ -1049,7 +1079,7 @@ int bpf_prog_test_run_sk_lookup(struct bpf_prog *prog, const union bpf_attr *kat
 		user_ctx->cookie = sock_gen_cookie(ctx.selected_sk);
 	}
 
-	ret = bpf_test_finish(kattr, uattr, NULL, 0, retval, duration);
+	ret = bpf_test_finish(kattr, uattr, NULL, NULL, 0, retval, duration);
 	if (!ret)
 		ret = bpf_ctx_finish(kattr, uattr, user_ctx, sizeof(*user_ctx));
 
-- 
2.31.1

[PATCH v17 bpf-next 17/23] bpf: selftests: update xdp_adjust_tail selftest to include multi-buffer

[Lorenzo Bianconi]

From: Eelco Chaudron <echaudro@redhat.com>

This change adds test cases for the multi-buffer scenarios when shrinking
and growing.

Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 .../bpf/prog_tests/xdp_adjust_tail.c          | 118 ++++++++++++++++++
 .../bpf/progs/test_xdp_adjust_tail_grow.c     |  10 +-
 .../bpf/progs/test_xdp_adjust_tail_shrink.c   |  32 ++++-
 3 files changed, 153 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_adjust_tail.c b/tools/testing/selftests/bpf/prog_tests/xdp_adjust_tail.c
index f529e3c923ae..250078893479 100644
--- a/tools/testing/selftests/bpf/prog_tests/xdp_adjust_tail.c
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_adjust_tail.c
@@ -130,6 +130,120 @@ static void test_xdp_adjust_tail_grow2(void)
 	bpf_object__close(obj);
 }
 
+void test_xdp_adjust_mb_tail_shrink(void)
+{
+	const char *file = "./test_xdp_adjust_tail_shrink.o";
+	__u32 duration, retval, size, exp_size;
+	struct bpf_object *obj;
+	int err, prog_fd;
+	__u8 *buf;
+
+	/* For the individual test cases, the first byte in the packet
+	 * indicates which test will be run.
+	 */
+
+	err = bpf_prog_load(file, BPF_PROG_TYPE_XDP, &obj, &prog_fd);
+	if (CHECK_FAIL(err))
+		return;
+
+	buf = malloc(9000);
+	if (CHECK(!buf, "malloc()", "error:%s\n", strerror(errno)))
+		return;
+
+	memset(buf, 0, 9000);
+
+	/* Test case removing 10 bytes from last frag, NOT freeing it */
+	exp_size = 8990; /* 9000 - 10 */
+	err = bpf_prog_test_run(prog_fd, 1, buf, 9000,
+				buf, &size, &retval, &duration);
+
+	CHECK(err || retval != XDP_TX || size != exp_size,
+	      "9k-10b", "err %d errno %d retval %d[%d] size %d[%u]\n",
+	      err, errno, retval, XDP_TX, size, exp_size);
+
+	/* Test case removing one of two pages, assuming 4K pages */
+	buf[0] = 1;
+	exp_size = 4900; /* 9000 - 4100 */
+	err = bpf_prog_test_run(prog_fd, 1, buf, 9000,
+				buf, &size, &retval, &duration);
+
+	CHECK(err || retval != XDP_TX || size != exp_size,
+	      "9k-1p", "err %d errno %d retval %d[%d] size %d[%u]\n",
+	      err, errno, retval, XDP_TX, size, exp_size);
+
+	/* Test case removing two pages resulting in a non mb xdp_buff */
+	buf[0] = 2;
+	exp_size = 800; /* 9000 - 8200 */
+	err = bpf_prog_test_run(prog_fd, 1, buf, 9000,
+				buf, &size, &retval, &duration);
+
+	CHECK(err || retval != XDP_TX || size != exp_size,
+	      "9k-2p", "err %d errno %d retval %d[%d] size %d[%u]\n",
+	      err, errno, retval, XDP_TX, size, exp_size);
+
+	free(buf);
+
+	bpf_object__close(obj);
+}
+
+void test_xdp_adjust_mb_tail_grow(void)
+{
+	const char *file = "./test_xdp_adjust_tail_grow.o";
+	__u32 duration, retval, size, exp_size;
+	struct bpf_object *obj;
+	int err, i, prog_fd;
+	__u8 *buf;
+
+	err = bpf_prog_load(file, BPF_PROG_TYPE_XDP, &obj, &prog_fd);
+	if (CHECK_FAIL(err))
+		return;
+
+	buf = malloc(16384);
+	if (CHECK(!buf, "malloc()", "error:%s\n", strerror(errno)))
+		return;
+
+	/* Test case add 10 bytes to last frag */
+	memset(buf, 1, 16384);
+	size = 9000;
+	exp_size = size + 10;
+	err = bpf_prog_test_run(prog_fd, 1, buf, size,
+				buf, &size, &retval, &duration);
+
+	CHECK(err || retval != XDP_TX || size != exp_size,
+	      "9k+10b", "err %d retval %d[%d] size %d[%u]\n",
+	      err, retval, XDP_TX, size, exp_size);
+
+	for (i = 0; i < 9000; i++)
+		CHECK(buf[i] != 1, "9k+10b-old",
+		      "Old data not all ok, offset %i is failing [%u]!\n",
+		      i, buf[i]);
+
+	for (i = 9000; i < 9010; i++)
+		CHECK(buf[i] != 0, "9k+10b-new",
+		      "New data not all ok, offset %i is failing [%u]!\n",
+		      i, buf[i]);
+
+	for (i = 9010; i < 16384; i++)
+		CHECK(buf[i] != 1, "9k+10b-untouched",
+		      "Unused data not all ok, offset %i is failing [%u]!\n",
+		      i, buf[i]);
+
+	/* Test a too large grow */
+	memset(buf, 1, 16384);
+	size = 9001;
+	exp_size = size;
+	err = bpf_prog_test_run(prog_fd, 1, buf, size,
+				buf, &size, &retval, &duration);
+
+	CHECK(err || retval != XDP_DROP || size != exp_size,
+	      "9k+10b", "err %d retval %d[%d] size %d[%u]\n",
+	      err, retval, XDP_TX, size, exp_size);
+
+	free(buf);
+
+	bpf_object__close(obj);
+}
+
 void test_xdp_adjust_tail(void)
 {
 	if (test__start_subtest("xdp_adjust_tail_shrink"))
@@ -138,4 +252,8 @@ void test_xdp_adjust_tail(void)
 		test_xdp_adjust_tail_grow();
 	if (test__start_subtest("xdp_adjust_tail_grow2"))
 		test_xdp_adjust_tail_grow2();
+	if (test__start_subtest("xdp_adjust_mb_tail_shrink"))
+		test_xdp_adjust_mb_tail_shrink();
+	if (test__start_subtest("xdp_adjust_mb_tail_grow"))
+		test_xdp_adjust_mb_tail_grow();
 }
diff --git a/tools/testing/selftests/bpf/progs/test_xdp_adjust_tail_grow.c b/tools/testing/selftests/bpf/progs/test_xdp_adjust_tail_grow.c
index 199c61b7d062..53b64c999450 100644
--- a/tools/testing/selftests/bpf/progs/test_xdp_adjust_tail_grow.c
+++ b/tools/testing/selftests/bpf/progs/test_xdp_adjust_tail_grow.c
@@ -7,11 +7,10 @@ int _xdp_adjust_tail_grow(struct xdp_md *xdp)
 {
 	void *data_end = (void *)(long)xdp->data_end;
 	void *data = (void *)(long)xdp->data;
-	unsigned int data_len;
+	int data_len = bpf_xdp_get_buff_len(xdp);
 	int offset = 0;
 
 	/* Data length determine test case */
-	data_len = data_end - data;
 
 	if (data_len == 54) { /* sizeof(pkt_v4) */
 		offset = 4096; /* test too large offset */
@@ -20,7 +19,12 @@ int _xdp_adjust_tail_grow(struct xdp_md *xdp)
 	} else if (data_len == 64) {
 		offset = 128;
 	} else if (data_len == 128) {
-		offset = 4096 - 256 - 320 - data_len; /* Max tail grow 3520 */
+		/* Max tail grow 3520 */
+		offset = 4096 - 256 - 320 - data_len;
+	} else if (data_len == 9000) {
+		offset = 10;
+	} else if (data_len == 9001) {
+		offset = 4096;
 	} else {
 		return XDP_ABORTED; /* No matching test */
 	}
diff --git a/tools/testing/selftests/bpf/progs/test_xdp_adjust_tail_shrink.c b/tools/testing/selftests/bpf/progs/test_xdp_adjust_tail_shrink.c
index b7448253d135..eeff48997b6e 100644
--- a/tools/testing/selftests/bpf/progs/test_xdp_adjust_tail_shrink.c
+++ b/tools/testing/selftests/bpf/progs/test_xdp_adjust_tail_shrink.c
@@ -12,14 +12,38 @@
 SEC("xdp")
 int _xdp_adjust_tail_shrink(struct xdp_md *xdp)
 {
-	void *data_end = (void *)(long)xdp->data_end;
-	void *data = (void *)(long)xdp->data;
+	__u8 *data_end = (void *)(long)xdp->data_end;
+	__u8 *data = (void *)(long)xdp->data;
 	int offset = 0;
 
-	if (data_end - data == 54) /* sizeof(pkt_v4) */
+	switch (bpf_xdp_get_buff_len(xdp)) {
+	case 54:
+		/* sizeof(pkt_v4) */
 		offset = 256; /* shrink too much */
-	else
+		break;
+	case 9000:
+		/* Multi-buffer test cases */
+		if (data + 1 > data_end)
+			return XDP_DROP;
+
+		switch (data[0]) {
+		case 0:
+			offset = 10;
+			break;
+		case 1:
+			offset = 4100;
+			break;
+		case 2:
+			offset = 8200;
+			break;
+		default:
+			return XDP_DROP;
+		}
+		break;
+	default:
 		offset = 20;
+		break;
+	}
 	if (bpf_xdp_adjust_tail(xdp, 0 - offset))
 		return XDP_DROP;
 	return XDP_TX;
-- 
2.31.1

[PATCH v17 bpf-next 18/23] libbpf: Add SEC name for xdp_mb programs

[Lorenzo Bianconi]

Introduce support for the following SEC entries for XDP multi-buff
property:
- SEC("xdp_mb/")
- SEC("xdp_devmap_mb/")
- SEC("xdp_cpumap_mb/")

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 tools/lib/bpf/libbpf.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 7fcea11ecaa9..e5c668dc685c 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -244,6 +244,8 @@ enum sec_def_flags {
 	SEC_SLEEPABLE = 8,
 	/* allow non-strict prefix matching */
 	SEC_SLOPPY_PFX = 16,
+	/* BPF program support XDP multi-buff */
+	SEC_XDP_MB = 32,
 };
 
 struct bpf_sec_def {
@@ -6402,6 +6404,9 @@ static int libbpf_preload_prog(struct bpf_program *prog,
 	if (def & SEC_SLEEPABLE)
 		attr->prog_flags |= BPF_F_SLEEPABLE;
 
+	if (prog->type == BPF_PROG_TYPE_XDP && (def & SEC_XDP_MB))
+		attr->prog_flags |= BPF_F_XDP_MB;
+
 	if ((prog->type == BPF_PROG_TYPE_TRACING ||
 	     prog->type == BPF_PROG_TYPE_LSM ||
 	     prog->type == BPF_PROG_TYPE_EXT) && !prog->attach_btf_id) {
@@ -8351,8 +8356,11 @@ static const struct bpf_sec_def section_defs[] = {
 	SEC_DEF("lsm.s/",		LSM, BPF_LSM_MAC, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_lsm),
 	SEC_DEF("iter/",		TRACING, BPF_TRACE_ITER, SEC_ATTACH_BTF, attach_iter),
 	SEC_DEF("syscall",		SYSCALL, 0, SEC_SLEEPABLE),
+	SEC_DEF("xdp_devmap_mb/",	XDP, BPF_XDP_DEVMAP, SEC_ATTACHABLE | SEC_XDP_MB),
 	SEC_DEF("xdp_devmap/",		XDP, BPF_XDP_DEVMAP, SEC_ATTACHABLE),
+	SEC_DEF("xdp_cpumap_mb/",	XDP, BPF_XDP_CPUMAP, SEC_ATTACHABLE | SEC_XDP_MB),
 	SEC_DEF("xdp_cpumap/",		XDP, BPF_XDP_CPUMAP, SEC_ATTACHABLE),
+	SEC_DEF("xdp_mb/",		XDP, BPF_XDP, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX | SEC_XDP_MB),
 	SEC_DEF("xdp",			XDP, BPF_XDP, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
 	SEC_DEF("perf_event",		PERF_EVENT, 0, SEC_NONE | SEC_SLOPPY_PFX),
 	SEC_DEF("lwt_in",		LWT_IN, 0, SEC_NONE | SEC_SLOPPY_PFX),
-- 
2.31.1

[PATCH v17 bpf-next 19/23] bpf: generalise tail call map

[Lorenzo Bianconi]

From: Toke Hoiland-Jorgensen <toke@redhat.com>

The check for tail call map compatibility ensures that tail calls only
happen between maps of the same type. To ensure backwards compatibility for
XDP multi-buffer we need a similar type of check for cpumap and devmap
programs, so move the state from bpf_array_aux into bpf_map, add xdp_mb to
the check, and apply the same check to cpumap and devmap.

Co-developed-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Toke Hoiland-Jorgensen <toke@redhat.com>
---
 include/linux/bpf.h   | 31 ++++++++++++++++++++-----------
 kernel/bpf/arraymap.c |  4 +---
 kernel/bpf/core.c     | 28 ++++++++++++++--------------
 kernel/bpf/cpumap.c   |  8 +++++---
 kernel/bpf/devmap.c   |  3 ++-
 kernel/bpf/syscall.c  | 21 +++++++++++----------
 6 files changed, 53 insertions(+), 42 deletions(-)

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index ba31c22ad839..09f0422d7fcd 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -194,6 +194,18 @@ struct bpf_map {
 	struct work_struct work;
 	struct mutex freeze_mutex;
 	u64 writecnt; /* writable mmap cnt; protected by freeze_mutex */
+
+	/* 'Ownership' of program-containing map is claimed by the first program
+	 * that is going to use this map or by the first program which FD is
+	 * stored in the map to make sure that all callers and callees have the
+	 * same prog type, JITed flag and xdp_mb flag.
+	 */
+	struct {
+		spinlock_t lock;
+		enum bpf_prog_type type;
+		bool jited;
+		bool xdp_mb;
+	} owner;
 };
 
 static inline bool map_value_has_spin_lock(const struct bpf_map *map)
@@ -930,16 +942,6 @@ struct bpf_prog_aux {
 };
 
 struct bpf_array_aux {
-	/* 'Ownership' of prog array is claimed by the first program that
-	 * is going to use this map or by the first program which FD is
-	 * stored in the map to make sure that all callers and callees have
-	 * the same prog type and JITed flag.
-	 */
-	struct {
-		spinlock_t lock;
-		enum bpf_prog_type type;
-		bool jited;
-	} owner;
 	/* Programs with direct jumps into programs part of this array. */
 	struct list_head poke_progs;
 	struct bpf_map *map;
@@ -1114,7 +1116,14 @@ struct bpf_event_entry {
 	struct rcu_head rcu;
 };
 
-bool bpf_prog_array_compatible(struct bpf_array *array, const struct bpf_prog *fp);
+static inline bool map_type_contains_progs(struct bpf_map *map)
+{
+	return map->map_type == BPF_MAP_TYPE_PROG_ARRAY ||
+	       map->map_type == BPF_MAP_TYPE_DEVMAP ||
+	       map->map_type == BPF_MAP_TYPE_CPUMAP;
+}
+
+bool bpf_prog_map_compatible(struct bpf_map *map, const struct bpf_prog *fp);
 int bpf_prog_calc_tag(struct bpf_prog *fp);
 
 const struct bpf_func_proto *bpf_get_trace_printk_proto(void);
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index c7a5be3bf8be..7f145aefbff8 100644
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -837,13 +837,12 @@ static int fd_array_map_delete_elem(struct bpf_map *map, void *key)
 static void *prog_fd_array_get_ptr(struct bpf_map *map,
 				   struct file *map_file, int fd)
 {
-	struct bpf_array *array = container_of(map, struct bpf_array, map);
 	struct bpf_prog *prog = bpf_prog_get(fd);
 
 	if (IS_ERR(prog))
 		return prog;
 
-	if (!bpf_prog_array_compatible(array, prog)) {
+	if (!bpf_prog_map_compatible(map, prog)) {
 		bpf_prog_put(prog);
 		return ERR_PTR(-EINVAL);
 	}
@@ -1071,7 +1070,6 @@ static struct bpf_map *prog_array_map_alloc(union bpf_attr *attr)
 	INIT_WORK(&aux->work, prog_array_map_clear_deferred);
 	INIT_LIST_HEAD(&aux->poke_progs);
 	mutex_init(&aux->poke_mutex);
-	spin_lock_init(&aux->owner.lock);
 
 	map = array_map_alloc(attr);
 	if (IS_ERR(map)) {
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 327e3996eadb..bd24cc30d3bd 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -1821,28 +1821,30 @@ static unsigned int __bpf_prog_ret0_warn(const void *ctx,
 }
 #endif
 
-bool bpf_prog_array_compatible(struct bpf_array *array,
-			       const struct bpf_prog *fp)
+bool bpf_prog_map_compatible(struct bpf_map *map,
+			     const struct bpf_prog *fp)
 {
 	bool ret;
 
 	if (fp->kprobe_override)
 		return false;
 
-	spin_lock(&array->aux->owner.lock);
-
-	if (!array->aux->owner.type) {
+	spin_lock(&map->owner.lock);
+	if (!map->owner.type) {
 		/* There's no owner yet where we could check for
 		 * compatibility.
 		 */
-		array->aux->owner.type  = fp->type;
-		array->aux->owner.jited = fp->jited;
+		map->owner.type  = fp->type;
+		map->owner.jited = fp->jited;
+		map->owner.xdp_mb = fp->aux->xdp_mb;
 		ret = true;
 	} else {
-		ret = array->aux->owner.type  == fp->type &&
-		      array->aux->owner.jited == fp->jited;
+		ret = map->owner.type  == fp->type &&
+		      map->owner.jited == fp->jited &&
+		      map->owner.xdp_mb == fp->aux->xdp_mb;
 	}
-	spin_unlock(&array->aux->owner.lock);
+	spin_unlock(&map->owner.lock);
+
 	return ret;
 }
 
@@ -1854,13 +1856,11 @@ static int bpf_check_tail_call(const struct bpf_prog *fp)
 	mutex_lock(&aux->used_maps_mutex);
 	for (i = 0; i < aux->used_map_cnt; i++) {
 		struct bpf_map *map = aux->used_maps[i];
-		struct bpf_array *array;
 
-		if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY)
+		if (!map_type_contains_progs(map))
 			continue;
 
-		array = container_of(map, struct bpf_array, map);
-		if (!bpf_prog_array_compatible(array, fp)) {
+		if (!bpf_prog_map_compatible(map, fp)) {
 			ret = -EINVAL;
 			goto out;
 		}
diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c
index 585b2b77ccc4..7f9984e7ba1d 100644
--- a/kernel/bpf/cpumap.c
+++ b/kernel/bpf/cpumap.c
@@ -397,7 +397,8 @@ static int cpu_map_kthread_run(void *data)
 	return 0;
 }
 
-static int __cpu_map_load_bpf_program(struct bpf_cpu_map_entry *rcpu, int fd)
+static int __cpu_map_load_bpf_program(struct bpf_cpu_map_entry *rcpu,
+				      struct bpf_map *map, int fd)
 {
 	struct bpf_prog *prog;
 
@@ -405,7 +406,8 @@ static int __cpu_map_load_bpf_program(struct bpf_cpu_map_entry *rcpu, int fd)
 	if (IS_ERR(prog))
 		return PTR_ERR(prog);
 
-	if (prog->expected_attach_type != BPF_XDP_CPUMAP) {
+	if (prog->expected_attach_type != BPF_XDP_CPUMAP ||
+	    !bpf_prog_map_compatible(map, prog)) {
 		bpf_prog_put(prog);
 		return -EINVAL;
 	}
@@ -457,7 +459,7 @@ __cpu_map_entry_alloc(struct bpf_map *map, struct bpf_cpumap_val *value,
 	rcpu->map_id = map->id;
 	rcpu->value.qsize  = value->qsize;
 
-	if (fd > 0 && __cpu_map_load_bpf_program(rcpu, fd))
+	if (fd > 0 && __cpu_map_load_bpf_program(rcpu, map, fd))
 		goto free_ptr_ring;
 
 	/* Setup kthread */
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index f02d04540c0c..a35edd4a2bf1 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -868,7 +868,8 @@ static struct bpf_dtab_netdev *__dev_map_alloc_node(struct net *net,
 					     BPF_PROG_TYPE_XDP, false);
 		if (IS_ERR(prog))
 			goto err_put_dev;
-		if (prog->expected_attach_type != BPF_XDP_DEVMAP)
+		if (prog->expected_attach_type != BPF_XDP_DEVMAP ||
+		    !bpf_prog_map_compatible(&dtab->map, prog))
 			goto err_put_prog;
 	}
 
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index fbae37d5b329..ba78d3490491 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -540,16 +540,15 @@ static unsigned long bpf_map_memory_footprint(const struct bpf_map *map)
 
 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
 {
-	const struct bpf_map *map = filp->private_data;
-	const struct bpf_array *array;
-	u32 type = 0, jited = 0;
-
-	if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY) {
-		array = container_of(map, struct bpf_array, map);
-		spin_lock(&array->aux->owner.lock);
-		type  = array->aux->owner.type;
-		jited = array->aux->owner.jited;
-		spin_unlock(&array->aux->owner.lock);
+	struct bpf_map *map = filp->private_data;
+	u32 type = 0, jited = 0, xdp_mb = 0;
+
+	if (map_type_contains_progs(map)) {
+		spin_lock(&map->owner.lock);
+		type  = map->owner.type;
+		jited = map->owner.jited;
+		xdp_mb = map->owner.xdp_mb;
+		spin_unlock(&map->owner.lock);
 	}
 
 	seq_printf(m,
@@ -574,6 +573,7 @@ static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
 	if (type) {
 		seq_printf(m, "owner_prog_type:\t%u\n", type);
 		seq_printf(m, "owner_jited:\t%u\n", jited);
+		seq_printf(m, "owner_xdp_mb:\t%u\n", xdp_mb);
 	}
 }
 #endif
@@ -864,6 +864,7 @@ static int map_create(union bpf_attr *attr)
 	atomic64_set(&map->refcnt, 1);
 	atomic64_set(&map->usercnt, 1);
 	mutex_init(&map->freeze_mutex);
+	spin_lock_init(&map->owner.lock);
 
 	map->spin_lock_off = -EINVAL;
 	map->timer_off = -EINVAL;
-- 
2.31.1

[PATCH v17 bpf-next 20/23] net: xdp: introduce bpf_xdp_pointer utility routine

[Lorenzo Bianconi]

Similar to skb_header_pointer, introduce bpf_xdp_pointer utility routine
to return a pointer to a given position in the xdp_buff if the requested
area (offset + len) is contained in a contiguous memory area otherwise it
will be copied in a bounce buffer provided by the caller.
Similar to the tc counterpart, introduce the two following xdp helpers:
- bpf_xdp_load_bytes
- bpf_xdp_store_bytes

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 include/uapi/linux/bpf.h       |  18 +++++
 net/core/filter.c              | 133 +++++++++++++++++++++++++++++++++
 tools/include/uapi/linux/bpf.h |  18 +++++
 3 files changed, 169 insertions(+)

diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index c643be066700..a63c7080b74d 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -4949,6 +4949,22 @@ union bpf_attr {
  *		Get the total size of a given xdp buff (linear and paged area)
  *	Return
  *		The total size of a given xdp buffer.
+ *
+ * long bpf_xdp_load_bytes(struct xdp_buff *xdp_md, u32 offset, void *buf, u32 len)
+ *	Description
+ *		This helper is provided as an easy way to load data from a
+ *		xdp buffer. It can be used to load *len* bytes from *offset* from
+ *		the frame associated to *xdp_md*, into the buffer pointed by
+ *		*buf*.
+ *	Return
+ *		0 on success, or a negative error in case of failure.
+ *
+ * long bpf_xdp_store_bytes(struct xdp_buff *xdp_md, u32 offset, void *buf, u32 len)
+ *	Description
+ *		Store *len* bytes from buffer *buf* into the frame
+ *		associated to *xdp_md*, at *offset*.
+ *	Return
+ *		0 on success, or a negative error in case of failure.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -5132,6 +5148,8 @@ union bpf_attr {
 	FN(skc_to_unix_sock),		\
 	FN(kallsyms_lookup_name),	\
 	FN(xdp_get_buff_len),		\
+	FN(xdp_load_bytes),		\
+	FN(xdp_store_bytes),		\
 	/* */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
diff --git a/net/core/filter.c b/net/core/filter.c
index 386dd2fffded..534305037ad7 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -3840,6 +3840,135 @@ static const struct bpf_func_proto bpf_xdp_adjust_head_proto = {
 	.arg2_type	= ARG_ANYTHING,
 };
 
+static void bpf_xdp_copy_buf(struct xdp_buff *xdp, u32 offset,
+			     u32 len, void *buf, bool flush)
+{
+	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
+	u32 headsize = xdp->data_end - xdp->data;
+	u32 count = 0, frame_offset = headsize;
+	int i = 0;
+
+	if (offset < headsize) {
+		int size = min_t(int, headsize - offset, len);
+		void *src = flush ? buf : xdp->data + offset;
+		void *dst = flush ? xdp->data + offset : buf;
+
+		memcpy(dst, src, size);
+		count = size;
+		offset = 0;
+	}
+
+	while (count < len && i < sinfo->nr_frags) {
+		skb_frag_t *frag = &sinfo->frags[i++];
+		u32 frag_size = skb_frag_size(frag);
+
+		if  (offset < frame_offset + frag_size) {
+			int size = min_t(int, frag_size - offset, len - count);
+			void *addr = skb_frag_address(frag);
+			void *src = flush ? buf + count : addr + offset;
+			void *dst = flush ? addr + offset : buf + count;
+
+			memcpy(dst, src, size);
+			count += size;
+			offset = 0;
+		}
+		frame_offset += frag_size;
+	}
+}
+
+static void *bpf_xdp_pointer(struct xdp_buff *xdp, u32 offset,
+			     u32 len, void *buf)
+{
+	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
+	u32 size = xdp->data_end - xdp->data;
+	void *addr = xdp->data;
+	int i;
+
+	if (unlikely(offset > 0xffff))
+		return ERR_PTR(-EFAULT);
+
+	if (offset + len > xdp_get_buff_len(xdp))
+		return ERR_PTR(-EINVAL);
+
+	if (offset < size) /* linear area */
+		goto out;
+
+	offset -= size;
+	for (i = 0; i < sinfo->nr_frags; i++) { /* paged area */
+		u32 frag_size = skb_frag_size(&sinfo->frags[i]);
+
+		if  (offset < frag_size) {
+			addr = skb_frag_address(&sinfo->frags[i]);
+			size = frag_size;
+			break;
+		}
+		offset -= frag_size;
+	}
+
+out:
+	if (offset + len < size)
+		return addr + offset; /* fast path - no need to copy */
+
+	if (!buf) /* no copy to the bounce buffer */
+		return NULL;
+
+	/* slow path - we need to copy data into the bounce buffer */
+	bpf_xdp_copy_buf(xdp, offset, len, buf, false);
+	return buf;
+}
+
+BPF_CALL_4(bpf_xdp_load_bytes, struct xdp_buff *, xdp, u32, offset,
+	   void *, buf, u32, len)
+{
+	void *ptr;
+
+	ptr = bpf_xdp_pointer(xdp, offset, len, buf);
+	if (IS_ERR(ptr))
+		return PTR_ERR(ptr);
+
+	if (ptr != buf)
+		memcpy(buf, ptr, len);
+
+	return 0;
+}
+
+static const struct bpf_func_proto bpf_xdp_load_bytes_proto = {
+	.func		= bpf_xdp_load_bytes,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg2_type	= ARG_ANYTHING,
+	.arg3_type	= ARG_PTR_TO_UNINIT_MEM,
+	.arg4_type	= ARG_CONST_SIZE,
+};
+
+BPF_CALL_4(bpf_xdp_store_bytes, struct xdp_buff *, xdp, u32, offset,
+	   void *, buf, u32, len)
+{
+	void *ptr;
+
+	ptr = bpf_xdp_pointer(xdp, offset, len, NULL);
+	if (IS_ERR(ptr))
+		return PTR_ERR(ptr);
+
+	if (!ptr)
+		bpf_xdp_copy_buf(xdp, offset, len, buf, true);
+	else
+		memcpy(ptr, buf, len);
+
+	return 0;
+}
+
+static const struct bpf_func_proto bpf_xdp_store_bytes_proto = {
+	.func		= bpf_xdp_store_bytes,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg2_type	= ARG_ANYTHING,
+	.arg3_type	= ARG_PTR_TO_UNINIT_MEM,
+	.arg4_type	= ARG_CONST_SIZE,
+};
+
 static int bpf_xdp_mb_increase_tail(struct xdp_buff *xdp, int offset)
 {
 	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
@@ -7601,6 +7730,10 @@ xdp_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 		return &bpf_xdp_adjust_tail_proto;
 	case BPF_FUNC_xdp_get_buff_len:
 		return &bpf_xdp_get_buff_len_proto;
+	case BPF_FUNC_xdp_load_bytes:
+		return &bpf_xdp_load_bytes_proto;
+	case BPF_FUNC_xdp_store_bytes:
+		return &bpf_xdp_store_bytes_proto;
 	case BPF_FUNC_fib_lookup:
 		return &bpf_xdp_fib_lookup_proto;
 	case BPF_FUNC_check_mtu:
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index c643be066700..a63c7080b74d 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -4949,6 +4949,22 @@ union bpf_attr {
  *		Get the total size of a given xdp buff (linear and paged area)
  *	Return
  *		The total size of a given xdp buffer.
+ *
+ * long bpf_xdp_load_bytes(struct xdp_buff *xdp_md, u32 offset, void *buf, u32 len)
+ *	Description
+ *		This helper is provided as an easy way to load data from a
+ *		xdp buffer. It can be used to load *len* bytes from *offset* from
+ *		the frame associated to *xdp_md*, into the buffer pointed by
+ *		*buf*.
+ *	Return
+ *		0 on success, or a negative error in case of failure.
+ *
+ * long bpf_xdp_store_bytes(struct xdp_buff *xdp_md, u32 offset, void *buf, u32 len)
+ *	Description
+ *		Store *len* bytes from buffer *buf* into the frame
+ *		associated to *xdp_md*, at *offset*.
+ *	Return
+ *		0 on success, or a negative error in case of failure.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -5132,6 +5148,8 @@ union bpf_attr {
 	FN(skc_to_unix_sock),		\
 	FN(kallsyms_lookup_name),	\
 	FN(xdp_get_buff_len),		\
+	FN(xdp_load_bytes),		\
+	FN(xdp_store_bytes),		\
 	/* */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
-- 
2.31.1

[PATCH v17 bpf-next 21/23] bpf: selftests: introduce bpf_xdp_{load,store}_bytes selftest

[Lorenzo Bianconi]

Introduce kernel selftest for new bpf_xdp_{load,store}_bytes helpers.
and bpf_xdp_pointer/bpf_xdp_copy_buf utility routines.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 .../bpf/prog_tests/xdp_adjust_frags.c         | 81 +++++++++++++++++++
 .../bpf/progs/test_xdp_update_frags.c         | 42 ++++++++++
 2 files changed, 123 insertions(+)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/xdp_adjust_frags.c
 create mode 100644 tools/testing/selftests/bpf/progs/test_xdp_update_frags.c

diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_adjust_frags.c b/tools/testing/selftests/bpf/prog_tests/xdp_adjust_frags.c
new file mode 100644
index 000000000000..53febbcb8fd4
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_adjust_frags.c
@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <test_progs.h>
+#include <network_helpers.h>
+
+void test_xdp_update_frags(void)
+{
+	const char *file = "./test_xdp_update_frags.o";
+	__u32 duration, retval, size;
+	struct bpf_object *obj;
+	int err, prog_fd;
+	__u32 *offset;
+	__u8 *buf;
+
+	err = bpf_prog_load(file, BPF_PROG_TYPE_XDP, &obj, &prog_fd);
+	if (CHECK_FAIL(err))
+		return;
+
+	buf = malloc(128);
+	if (CHECK(!buf, "malloc()", "error:%s\n", strerror(errno)))
+		return;
+
+	memset(buf, 0, 128);
+	offset = (__u32 *)buf;
+	*offset = 16;
+	buf[*offset] = 0xaa;		/* marker at offset 16 */
+	buf[*offset + 15] = 0xaa;	/* marker at offset 31 */
+
+	err = bpf_prog_test_run(prog_fd, 1, buf, 128,
+				buf, &size, &retval, &duration);
+
+	/* test_xdp_update_frags: buf[16,31]: 0xaa -> 0xbb */
+	CHECK(err || retval != XDP_PASS || buf[16] != 0xbb || buf[31] != 0xbb,
+	      "128b", "err %d errno %d retval %d size %d\n",
+	      err, errno, retval, size);
+
+	free(buf);
+
+	buf = malloc(9000);
+	if (CHECK(!buf, "malloc()", "error:%s\n", strerror(errno)))
+		return;
+
+	memset(buf, 0, 9000);
+	offset = (__u32 *)buf;
+	*offset = 5000;
+	buf[*offset] = 0xaa;		/* marker at offset 5000 (frag0) */
+	buf[*offset + 15] = 0xaa;	/* marker at offset 5015 (frag0) */
+
+	err = bpf_prog_test_run(prog_fd, 1, buf, 9000,
+				buf, &size, &retval, &duration);
+
+	/* test_xdp_update_frags: buf[5000,5015]: 0xaa -> 0xbb */
+	CHECK(err || retval != XDP_PASS ||
+	      buf[5000] != 0xbb || buf[5015] != 0xbb,
+	      "9000b", "err %d errno %d retval %d size %d\n",
+	      err, errno, retval, size);
+
+	memset(buf, 0, 9000);
+	offset = (__u32 *)buf;
+	*offset = 3510;
+	buf[*offset] = 0xaa;		/* marker at offset 3510 (head) */
+	buf[*offset + 15] = 0xaa;	/* marker at offset 3525 (frag0) */
+
+	err = bpf_prog_test_run(prog_fd, 1, buf, 9000,
+				buf, &size, &retval, &duration);
+
+	/* test_xdp_update_frags: buf[3510,3525]: 0xaa -> 0xbb */
+	CHECK(err || retval != XDP_PASS ||
+	      buf[3510] != 0xbb || buf[3525] != 0xbb,
+	      "9000b", "err %d errno %d retval %d size %d\n",
+	      err, errno, retval, size);
+
+	free(buf);
+
+	bpf_object__close(obj);
+}
+
+void test_xdp_adjust_frags(void)
+{
+	if (test__start_subtest("xdp_adjust_frags"))
+		test_xdp_update_frags();
+}
diff --git a/tools/testing/selftests/bpf/progs/test_xdp_update_frags.c b/tools/testing/selftests/bpf/progs/test_xdp_update_frags.c
new file mode 100644
index 000000000000..5801f05219db
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_xdp_update_frags.c
@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <linux/bpf.h>
+#include <linux/if_ether.h>
+#include <bpf/bpf_helpers.h>
+
+int _version SEC("version") = 1;
+
+SEC("xdp_mb/xdp_adjust_frags")
+int _xdp_adjust_frags(struct xdp_md *xdp)
+{
+	__u8 *data_end = (void *)(long)xdp->data_end;
+	__u8 *data = (void *)(long)xdp->data;
+	__u8 val[16] = {};
+	__u32 offset;
+	int err;
+
+	if (data + sizeof(__u32) > data_end)
+		return XDP_DROP;
+
+	offset = *(__u32 *)data;
+	err = bpf_xdp_load_bytes(xdp, offset, val, sizeof(val));
+	if (err < 0)
+		return XDP_DROP;
+
+	if (val[0] != 0xaa || val[15] != 0xaa) /* marker */
+		return XDP_DROP;
+
+	val[0] = 0xbb; /* update the marker */
+	val[15] = 0xbb;
+	err = bpf_xdp_store_bytes(xdp, offset, val, sizeof(val));
+	if (err < 0)
+		return XDP_DROP;
+
+	return XDP_PASS;
+}
+
+char _license[] SEC("license") = "GPL";
-- 
2.31.1

[PATCH v17 bpf-next 22/23] bpf: selftests: add CPUMAP/DEVMAP selftests for xdp multi-buff

[Lorenzo Bianconi]

Verify compatibility checks attaching a XDP multi-buff program to a
CPUMAP/DEVMAP

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 .../bpf/prog_tests/xdp_cpumap_attach.c        | 65 ++++++++++++++++++-
 .../bpf/prog_tests/xdp_devmap_attach.c        | 56 ++++++++++++++++
 .../bpf/progs/test_xdp_with_cpumap_helpers.c  |  6 ++
 .../progs/test_xdp_with_cpumap_mb_helpers.c   | 27 ++++++++
 .../bpf/progs/test_xdp_with_devmap_helpers.c  |  7 ++
 .../progs/test_xdp_with_devmap_mb_helpers.c   | 27 ++++++++
 6 files changed, 187 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/bpf/progs/test_xdp_with_cpumap_mb_helpers.c
 create mode 100644 tools/testing/selftests/bpf/progs/test_xdp_with_devmap_mb_helpers.c

diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_cpumap_attach.c b/tools/testing/selftests/bpf/prog_tests/xdp_cpumap_attach.c
index fd812bd43600..ee580b50a945 100644
--- a/tools/testing/selftests/bpf/prog_tests/xdp_cpumap_attach.c
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_cpumap_attach.c
@@ -3,11 +3,12 @@
 #include <linux/if_link.h>
 #include <test_progs.h>
 
+#include "test_xdp_with_cpumap_mb_helpers.skel.h"
 #include "test_xdp_with_cpumap_helpers.skel.h"
 
 #define IFINDEX_LO	1
 
-void serial_test_xdp_cpumap_attach(void)
+void test_xdp_with_cpumap_helpers(void)
 {
 	struct test_xdp_with_cpumap_helpers *skel;
 	struct bpf_prog_info info = {};
@@ -54,6 +55,68 @@ void serial_test_xdp_cpumap_attach(void)
 	err = bpf_map_update_elem(map_fd, &idx, &val, 0);
 	ASSERT_NEQ(err, 0, "Add non-BPF_XDP_CPUMAP program to cpumap entry");
 
+	/* try to attach BPF_XDP_CPUMAP multi-buff program when we have already
+	 * loaded a legacy XDP program on the map
+	 */
+	idx = 1;
+	val.qsize = 192;
+	val.bpf_prog.fd = bpf_program__fd(skel->progs.xdp_dummy_cm_mb);
+	err = bpf_map_update_elem(map_fd, &idx, &val, 0);
+	ASSERT_NEQ(err, 0,
+		   "Add BPF_XDP_CPUMAP multi-buff program to cpumap entry");
+
 out_close:
 	test_xdp_with_cpumap_helpers__destroy(skel);
 }
+
+void test_xdp_with_cpumap_mb_helpers(void)
+{
+	struct test_xdp_with_cpumap_mb_helpers *skel;
+	struct bpf_prog_info info = {};
+	__u32 len = sizeof(info);
+	struct bpf_cpumap_val val = {
+		.qsize = 192,
+	};
+	int err, mb_prog_fd, map_fd;
+	__u32 idx = 0;
+
+	skel = test_xdp_with_cpumap_mb_helpers__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "test_xdp_with_cpumap_helpers__open_and_load"))
+		return;
+
+	mb_prog_fd = bpf_program__fd(skel->progs.xdp_dummy_cm_mb);
+	map_fd = bpf_map__fd(skel->maps.cpu_map);
+	err = bpf_obj_get_info_by_fd(mb_prog_fd, &info, &len);
+	if (!ASSERT_OK(err, "bpf_obj_get_info_by_fd"))
+		goto out_close;
+
+	val.bpf_prog.fd = mb_prog_fd;
+	err = bpf_map_update_elem(map_fd, &idx, &val, 0);
+	ASSERT_OK(err, "Add program to cpumap entry");
+
+	err = bpf_map_lookup_elem(map_fd, &idx, &val);
+	ASSERT_OK(err, "Read cpumap entry");
+	ASSERT_EQ(info.id, val.bpf_prog.id,
+		  "Match program id to cpumap entry prog_id");
+
+	/* try to attach BPF_XDP_CPUMAP program when we have already
+	 * loaded a multi-buff XDP program on the map
+	 */
+	idx = 1;
+	val.qsize = 192;
+	val.bpf_prog.fd = bpf_program__fd(skel->progs.xdp_dummy_cm);
+	err = bpf_map_update_elem(map_fd, &idx, &val, 0);
+	ASSERT_NEQ(err, 0, "Add BPF_XDP_CPUMAP program to cpumap entry");
+
+out_close:
+	test_xdp_with_cpumap_mb_helpers__destroy(skel);
+}
+
+void serial_test_xdp_cpumap_attach(void)
+{
+	if (test__start_subtest("CPUMAP with programs in entries"))
+		test_xdp_with_cpumap_helpers();
+
+	if (test__start_subtest("CPUMAP with multi-buff programs in entries"))
+		test_xdp_with_cpumap_mb_helpers();
+}
diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_devmap_attach.c b/tools/testing/selftests/bpf/prog_tests/xdp_devmap_attach.c
index 3079d5568f8f..5c0dc3c20fc9 100644
--- a/tools/testing/selftests/bpf/prog_tests/xdp_devmap_attach.c
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_devmap_attach.c
@@ -4,6 +4,7 @@
 #include <test_progs.h>
 
 #include "test_xdp_devmap_helpers.skel.h"
+#include "test_xdp_with_devmap_mb_helpers.skel.h"
 #include "test_xdp_with_devmap_helpers.skel.h"
 
 #define IFINDEX_LO 1
@@ -56,6 +57,16 @@ static void test_xdp_with_devmap_helpers(void)
 	err = bpf_map_update_elem(map_fd, &idx, &val, 0);
 	ASSERT_NEQ(err, 0, "Add non-BPF_XDP_DEVMAP program to devmap entry");
 
+	/* try to attach BPF_XDP_DEVMAP multi-buff program when we have already
+	 * loaded a legacy XDP program on the map
+	 */
+	idx = 1;
+	val.ifindex = 1;
+	val.bpf_prog.fd = bpf_program__fd(skel->progs.xdp_dummy_dm_mb);
+	err = bpf_map_update_elem(map_fd, &idx, &val, 0);
+	ASSERT_NEQ(err, 0,
+		   "Add BPF_XDP_DEVMAP multi-buff program to devmap entry");
+
 out_close:
 	test_xdp_with_devmap_helpers__destroy(skel);
 }
@@ -71,12 +82,57 @@ static void test_neg_xdp_devmap_helpers(void)
 	}
 }
 
+void test_xdp_with_devmap_mb_helpers(void)
+{
+	struct test_xdp_with_devmap_mb_helpers *skel;
+	struct bpf_prog_info info = {};
+	struct bpf_devmap_val val = {
+		.ifindex = IFINDEX_LO,
+	};
+	__u32 len = sizeof(info);
+	int err, dm_fd_mb, map_fd;
+	__u32 idx = 0;
+
+	skel = test_xdp_with_devmap_mb_helpers__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "test_xdp_with_devmap_helpers__open_and_load"))
+		return;
+
+	dm_fd_mb = bpf_program__fd(skel->progs.xdp_dummy_dm_mb);
+	map_fd = bpf_map__fd(skel->maps.dm_ports);
+	err = bpf_obj_get_info_by_fd(dm_fd_mb, &info, &len);
+	if (!ASSERT_OK(err, "bpf_obj_get_info_by_fd"))
+		goto out_close;
+
+	val.bpf_prog.fd = dm_fd_mb;
+	err = bpf_map_update_elem(map_fd, &idx, &val, 0);
+	ASSERT_OK(err, "Add multi-buff program to devmap entry");
+
+	err = bpf_map_lookup_elem(map_fd, &idx, &val);
+	ASSERT_OK(err, "Read devmap entry");
+	ASSERT_EQ(info.id, val.bpf_prog.id,
+		  "Match program id to devmap entry prog_id");
+
+	/* try to attach BPF_XDP_DEVMAP program when we have already loaded a
+	 * multi-buff XDP program on the map
+	 */
+	idx = 1;
+	val.ifindex = 1;
+	val.bpf_prog.fd = bpf_program__fd(skel->progs.xdp_dummy_dm);
+	err = bpf_map_update_elem(map_fd, &idx, &val, 0);
+	ASSERT_NEQ(err, 0, "Add BPF_XDP_DEVMAP program to devmap entry");
+
+out_close:
+	test_xdp_with_devmap_mb_helpers__destroy(skel);
+}
 
 void serial_test_xdp_devmap_attach(void)
 {
 	if (test__start_subtest("DEVMAP with programs in entries"))
 		test_xdp_with_devmap_helpers();
 
+	if (test__start_subtest("DEVMAP with multi-buff programs in entries"))
+		test_xdp_with_devmap_mb_helpers();
+
 	if (test__start_subtest("Verifier check of DEVMAP programs"))
 		test_neg_xdp_devmap_helpers();
 }
diff --git a/tools/testing/selftests/bpf/progs/test_xdp_with_cpumap_helpers.c b/tools/testing/selftests/bpf/progs/test_xdp_with_cpumap_helpers.c
index 532025057711..f32e4dab1751 100644
--- a/tools/testing/selftests/bpf/progs/test_xdp_with_cpumap_helpers.c
+++ b/tools/testing/selftests/bpf/progs/test_xdp_with_cpumap_helpers.c
@@ -33,4 +33,10 @@ int xdp_dummy_cm(struct xdp_md *ctx)
 	return XDP_PASS;
 }
 
+SEC("xdp_cpumap_mb/mb_dummy_cm")
+int xdp_dummy_cm_mb(struct xdp_md *ctx)
+{
+	return XDP_PASS;
+}
+
 char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/test_xdp_with_cpumap_mb_helpers.c b/tools/testing/selftests/bpf/progs/test_xdp_with_cpumap_mb_helpers.c
new file mode 100644
index 000000000000..96eedbaef71b
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_xdp_with_cpumap_mb_helpers.c
@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+#define IFINDEX_LO	1
+
+struct {
+	__uint(type, BPF_MAP_TYPE_CPUMAP);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(struct bpf_cpumap_val));
+	__uint(max_entries, 4);
+} cpu_map SEC(".maps");
+
+SEC("xdp_cpumap/dummy_cm")
+int xdp_dummy_cm(struct xdp_md *ctx)
+{
+	return XDP_PASS;
+}
+
+SEC("xdp_cpumap_mb/mb_dummy_cm")
+int xdp_dummy_cm_mb(struct xdp_md *ctx)
+{
+	return XDP_PASS;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/test_xdp_with_devmap_helpers.c b/tools/testing/selftests/bpf/progs/test_xdp_with_devmap_helpers.c
index 1e6b9c38ea6d..691f2d70dedc 100644
--- a/tools/testing/selftests/bpf/progs/test_xdp_with_devmap_helpers.c
+++ b/tools/testing/selftests/bpf/progs/test_xdp_with_devmap_helpers.c
@@ -40,4 +40,11 @@ int xdp_dummy_dm(struct xdp_md *ctx)
 
 	return XDP_PASS;
 }
+
+SEC("xdp_devmap_mb/mp_map_prog")
+int xdp_dummy_dm_mb(struct xdp_md *ctx)
+{
+	return XDP_PASS;
+}
+
 char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/test_xdp_with_devmap_mb_helpers.c b/tools/testing/selftests/bpf/progs/test_xdp_with_devmap_mb_helpers.c
new file mode 100644
index 000000000000..05221b1fd9f2
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_xdp_with_devmap_mb_helpers.c
@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+struct {
+	__uint(type, BPF_MAP_TYPE_DEVMAP);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(struct bpf_devmap_val));
+	__uint(max_entries, 4);
+} dm_ports SEC(".maps");
+
+/* valid program on DEVMAP entry via SEC name;
+ * has access to egress and ingress ifindex
+ */
+SEC("xdp_devmap/map_prog")
+int xdp_dummy_dm(struct xdp_md *ctx)
+{
+	return XDP_PASS;
+}
+
+SEC("xdp_devmap_mb/mp_map_prog")
+int xdp_dummy_dm_mb(struct xdp_md *ctx)
+{
+	return XDP_PASS;
+}
+
+char _license[] SEC("license") = "GPL";
-- 
2.31.1

[PATCH v17 bpf-next 23/23] xdp: disable XDP_REDIRECT for xdp multi-buff

[Lorenzo Bianconi]

XDP_REDIRECT is not fully supported yet for xdp multi-buff since not
all XDP capable drivers can map non-linear xdp_frame in ndo_xdp_xmit
so disable it for the moment.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 net/core/filter.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/net/core/filter.c b/net/core/filter.c
index 534305037ad7..00e08bdeb5f2 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4183,6 +4183,13 @@ int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp,
 	struct bpf_map *map;
 	int err;
 
+	/* XDP_REDIRECT is not fully supported yet for xdp multi-buff since
+	 * not all XDP capable drivers can map non-linear xdp_frame in
+	 * ndo_xdp_xmit.
+	 */
+	if (unlikely(xdp_buff_is_mb(xdp)))
+		return -EOPNOTSUPP;
+
 	ri->map_id = 0; /* Valid map id idr range: [1,INT_MAX[ */
 	ri->map_type = BPF_MAP_TYPE_UNSPEC;
 
-- 
2.31.1

Re: [PATCH v17 bpf-next 12/23] bpf: add multi-buff support to the bpf_xdp_adjust_tail() API

[Jakub Kicinski]

On Thu,  4 Nov 2021 18:35:32 +0100 Lorenzo Bianconi wrote:
> +static int bpf_xdp_mb_shrink_tail(struct xdp_buff *xdp, int offset)
> +{
> +	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
> +	int i, n_frags_free = 0, len_free = 0, tlen_free = 0;

clang says tlen_free set but not used.

Re: [PATCH v17 bpf-next 12/23] bpf: add multi-buff support to the bpf_xdp_adjust_tail() API

[Lorenzo Bianconi]

[-- Attachment #1: Type: text/plain, Size: 470 bytes --]

> On Thu,  4 Nov 2021 18:35:32 +0100 Lorenzo Bianconi wrote:
> > +static int bpf_xdp_mb_shrink_tail(struct xdp_buff *xdp, int offset)
> > +{
> > +	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
> > +	int i, n_frags_free = 0, len_free = 0, tlen_free = 0;
> 
> clang says tlen_free set but not used.

ack, right. It is a leftover of a previous refactor. I will wait for other
feedbacks and then I will repost. Thanks :)

Regards,
Lorenzo

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]

Re: [PATCH v17 bpf-next 13/23] bpf: add multi-buffer support to xdp copy helpers

[Jakub Kicinski]

On Thu,  4 Nov 2021 18:35:33 +0100 Lorenzo Bianconi wrote:
> -static unsigned long bpf_xdp_copy(void *dst_buff, const void *src_buff,
> +static unsigned long bpf_xdp_copy(void *dst_buff, const void *ctx,
>  				  unsigned long off, unsigned long len)
>  {
> -	memcpy(dst_buff, src_buff + off, len);
> +	unsigned long base_len, copy_len, frag_off_total;
> +	struct xdp_buff *xdp = (struct xdp_buff *)ctx;
> +	struct skb_shared_info *sinfo;
> +	int i;
> +
> +	if (likely(!xdp_buff_is_mb(xdp))) {

Would it be better to do

	if (xdp->data_end - xdp->data >= off + len)

?

> +		memcpy(dst_buff, xdp->data + off, len);
> +		return 0;
> +	}
> +
> +	base_len = xdp->data_end - xdp->data;
> +	frag_off_total = base_len;
> +	sinfo = xdp_get_shared_info_from_buff(xdp);
> +
> +	/* If we need to copy data from the base buffer do it */
> +	if (off < base_len) {
> +		copy_len = min(len, base_len - off);
> +		memcpy(dst_buff, xdp->data + off, copy_len);
> +
> +		off += copy_len;
> +		len -= copy_len;
> +		dst_buff += copy_len;
> +	}
> +
> +	/* Copy any remaining data from the fragments */
> +	for (i = 0; len && i < sinfo->nr_frags; i++) {
> +		skb_frag_t *frag = &sinfo->frags[i];
> +		unsigned long frag_len, frag_off;
> +
> +		frag_len = skb_frag_size(frag);
> +		frag_off = off - frag_off_total;
> +		if (frag_off < frag_len) {
> +			copy_len = min(len, frag_len - frag_off);
> +			memcpy(dst_buff,
> +			       skb_frag_address(frag) + frag_off, copy_len);
> +
> +			off += copy_len;
> +			len -= copy_len;
> +			dst_buff += copy_len;
> +		}
> +		frag_off_total += frag_len;
> +	}
> +

nit: can't help but feel that you can merge base copy and frag copy:

	sinfo = xdp_get_shared_info_from_buff(xdp);
	next_frag = &sinfo->frags[0];
	end_frag = &sinfo->frags[sinfo->nr_frags];

	ptr_off = 0;
	ptr_buf = xdp->data;
	ptr_len = xdp->data_end - xdp->data;

	while (true) {
		if (off < ptr_off + ptr_len) {
			copy_off = ptr_off - off;
			copy_len = min(len, ptr_len - copy_off);
			memcpy(dst_buff, ptr_buf + copy_off, copy_len);

			off += copy_len;
			len -= copy_len;
			dst_buff += copy_len;
		}

		if (!len || next_frag == end_frag)
			break;
	
		ptr_off += ptr_len;
		ptr_buf = skb_frag_address(next_frag);
		ptr_len = skb_frag_size(next_frag);
		next_frag++;
	}

Up to you.

Re: [PATCH v17 bpf-next 12/23] bpf: add multi-buff support to the bpf_xdp_adjust_tail() API

[Jakub Kicinski]

On Thu,  4 Nov 2021 18:35:32 +0100 Lorenzo Bianconi wrote:
> This change adds support for tail growing and shrinking for XDP multi-buff.
> 
> When called on a multi-buffer packet with a grow request, it will always
> work on the last fragment of the packet. So the maximum grow size is the
> last fragments tailroom, i.e. no new buffer will be allocated.
> 
> When shrinking, it will work from the last fragment, all the way down to
> the base buffer depending on the shrinking size. It's important to mention
> that once you shrink down the fragment(s) are freed, so you can not grow
> again to the original size.

> +static int bpf_xdp_mb_increase_tail(struct xdp_buff *xdp, int offset)
> +{
> +	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
> +	skb_frag_t *frag = &sinfo->frags[sinfo->nr_frags - 1];
> +	int size, tailroom;
> +
> +	tailroom = xdp->frame_sz - skb_frag_size(frag) - skb_frag_off(frag);

I know I complained about this before but the assumption that we can
use all the space up to xdp->frame_sz makes me uneasy.

Drivers may not expect the idea that core may decide to extend the 
last frag.. I don't think the skb path would ever do this.

How do you feel about any of these options: 
 - dropping this part for now (return an error for increase)
 - making this an rxq flag or reading the "reserved frag size"
   from rxq (so that drivers explicitly opt-in)
 - adding a test that can be run on real NICs
?

> +static int bpf_xdp_mb_shrink_tail(struct xdp_buff *xdp, int offset)
> +{
> +	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
> +	int i, n_frags_free = 0, len_free = 0, tlen_free = 0;
> +
> +	if (unlikely(offset > ((int)xdp_get_buff_len(xdp) - ETH_HLEN)))

nit: outer parens unnecessary

> +		return -EINVAL;


> @@ -371,6 +371,7 @@ static void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct,
>  		break;
>  	}
>  }
> +EXPORT_SYMBOL_GPL(__xdp_return);

Why the export?

Re: [PATCH v17 bpf-next 20/23] net: xdp: introduce bpf_xdp_pointer utility routine

[Jakub Kicinski]

On Thu,  4 Nov 2021 18:35:40 +0100 Lorenzo Bianconi wrote:
> Similar to skb_header_pointer, introduce bpf_xdp_pointer utility routine
> to return a pointer to a given position in the xdp_buff if the requested
> area (offset + len) is contained in a contiguous memory area otherwise it
> will be copied in a bounce buffer provided by the caller.
> Similar to the tc counterpart, introduce the two following xdp helpers:
> - bpf_xdp_load_bytes
> - bpf_xdp_store_bytes
> 
> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>

> diff --git a/net/core/filter.c b/net/core/filter.c
> index 386dd2fffded..534305037ad7 100644
> --- a/net/core/filter.c
> +++ b/net/core/filter.c
> @@ -3840,6 +3840,135 @@ static const struct bpf_func_proto bpf_xdp_adjust_head_proto = {
>  	.arg2_type	= ARG_ANYTHING,
>  };
>  
> +static void bpf_xdp_copy_buf(struct xdp_buff *xdp, u32 offset,
> +			     u32 len, void *buf, bool flush)
> +{
> +	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
> +	u32 headsize = xdp->data_end - xdp->data;
> +	u32 count = 0, frame_offset = headsize;
> +	int i = 0;
> +
> +	if (offset < headsize) {
> +		int size = min_t(int, headsize - offset, len);
> +		void *src = flush ? buf : xdp->data + offset;
> +		void *dst = flush ? xdp->data + offset : buf;
> +
> +		memcpy(dst, src, size);
> +		count = size;
> +		offset = 0;
> +	}
> +
> +	while (count < len && i < sinfo->nr_frags) {

nit: for (i = 0; ...; i++) ?

> +		skb_frag_t *frag = &sinfo->frags[i++];
> +		u32 frag_size = skb_frag_size(frag);
> +
> +		if  (offset < frame_offset + frag_size) {

nit: double space after if

> +			int size = min_t(int, frag_size - offset, len - count);
> +			void *addr = skb_frag_address(frag);
> +			void *src = flush ? buf + count : addr + offset;
> +			void *dst = flush ? addr + offset : buf + count;
> +
> +			memcpy(dst, src, size);
> +			count += size;
> +			offset = 0;
> +		}
> +		frame_offset += frag_size;
> +	}
> +}
> +
> +static void *bpf_xdp_pointer(struct xdp_buff *xdp, u32 offset,
> +			     u32 len, void *buf)
> +{
> +	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
> +	u32 size = xdp->data_end - xdp->data;
> +	void *addr = xdp->data;
> +	int i;
> +
> +	if (unlikely(offset > 0xffff))
> +		return ERR_PTR(-EFAULT);
> +
> +	if (offset + len > xdp_get_buff_len(xdp))
> +		return ERR_PTR(-EINVAL);

I don't think it breaks anything but should we sanity check len?
Maybe make the test above (offset | len) > 0xffff -> EFAULT?

> +	if (offset < size) /* linear area */
> +		goto out;
> +
> +	offset -= size;
> +	for (i = 0; i < sinfo->nr_frags; i++) { /* paged area */
> +		u32 frag_size = skb_frag_size(&sinfo->frags[i]);
> +
> +		if  (offset < frag_size) {
> +			addr = skb_frag_address(&sinfo->frags[i]);
> +			size = frag_size;
> +			break;
> +		}
> +		offset -= frag_size;
> +	}
> +
> +out:
> +	if (offset + len < size)
> +		return addr + offset; /* fast path - no need to copy */
> +
> +	if (!buf) /* no copy to the bounce buffer */
> +		return NULL;
> +
> +	/* slow path - we need to copy data into the bounce buffer */
> +	bpf_xdp_copy_buf(xdp, offset, len, buf, false);
> +	return buf;
> +}
> +
> +BPF_CALL_4(bpf_xdp_load_bytes, struct xdp_buff *, xdp, u32, offset,
> +	   void *, buf, u32, len)
> +{
> +	void *ptr;
> +
> +	ptr = bpf_xdp_pointer(xdp, offset, len, buf);
> +	if (IS_ERR(ptr))
> +		return PTR_ERR(ptr);
> +
> +	if (ptr != buf)
> +		memcpy(buf, ptr, len);

Maybe we should just call out to bpf_xdp_copy_buf() like store does
instead of putting one but not the other inside bpf_xdp_pointer().

We'll have to refactor this later for the real bpf_xdp_pointer,
I'd lean on the side of keeping things symmetric for now.

> +	return 0;
> +}

> +BPF_CALL_4(bpf_xdp_store_bytes, struct xdp_buff *, xdp, u32, offset,
> +	   void *, buf, u32, len)
> +{
> +	void *ptr;
> +
> +	ptr = bpf_xdp_pointer(xdp, offset, len, NULL);
> +	if (IS_ERR(ptr))
> +		return PTR_ERR(ptr);
> +
> +	if (!ptr)
> +		bpf_xdp_copy_buf(xdp, offset, len, buf, true);
> +	else
> +		memcpy(ptr, buf, len);
> +
> +	return 0;
> +}

Re: [PATCH v17 bpf-next 13/23] bpf: add multi-buffer support to xdp copy helpers

[Lorenzo Bianconi]

[-- Attachment #1: Type: text/plain, Size: 2809 bytes --]

> On Thu,  4 Nov 2021 18:35:33 +0100 Lorenzo Bianconi wrote:
> > -static unsigned long bpf_xdp_copy(void *dst_buff, const void *src_buff,
> > +static unsigned long bpf_xdp_copy(void *dst_buff, const void *ctx,
> >  				  unsigned long off, unsigned long len)
> >  {
> > -	memcpy(dst_buff, src_buff + off, len);
> > +	unsigned long base_len, copy_len, frag_off_total;
> > +	struct xdp_buff *xdp = (struct xdp_buff *)ctx;
> > +	struct skb_shared_info *sinfo;
> > +	int i;
> > +
> > +	if (likely(!xdp_buff_is_mb(xdp))) {
> 
> Would it be better to do
> 
> 	if (xdp->data_end - xdp->data >= off + len)
> 
> ?

Hi Jakub,

I am fine with the patch (just a typo inline), thx :)
I will let Eelco to comment since he wrote the original code.
If there is no objections, I will integrate it in v18.

Regards,
Lorenzo

> 
> > +		memcpy(dst_buff, xdp->data + off, len);
> > +		return 0;
> > +	}
> > +
> > +	base_len = xdp->data_end - xdp->data;
> > +	frag_off_total = base_len;
> > +	sinfo = xdp_get_shared_info_from_buff(xdp);
> > +
> > +	/* If we need to copy data from the base buffer do it */
> > +	if (off < base_len) {
> > +		copy_len = min(len, base_len - off);
> > +		memcpy(dst_buff, xdp->data + off, copy_len);
> > +
> > +		off += copy_len;
> > +		len -= copy_len;
> > +		dst_buff += copy_len;
> > +	}
> > +
> > +	/* Copy any remaining data from the fragments */
> > +	for (i = 0; len && i < sinfo->nr_frags; i++) {
> > +		skb_frag_t *frag = &sinfo->frags[i];
> > +		unsigned long frag_len, frag_off;
> > +
> > +		frag_len = skb_frag_size(frag);
> > +		frag_off = off - frag_off_total;
> > +		if (frag_off < frag_len) {
> > +			copy_len = min(len, frag_len - frag_off);
> > +			memcpy(dst_buff,
> > +			       skb_frag_address(frag) + frag_off, copy_len);
> > +
> > +			off += copy_len;
> > +			len -= copy_len;
> > +			dst_buff += copy_len;
> > +		}
> > +		frag_off_total += frag_len;
> > +	}
> > +
> 
> nit: can't help but feel that you can merge base copy and frag copy:
> 
> 	sinfo = xdp_get_shared_info_from_buff(xdp);
> 	next_frag = &sinfo->frags[0];
> 	end_frag = &sinfo->frags[sinfo->nr_frags];
> 
> 	ptr_off = 0;
> 	ptr_buf = xdp->data;
> 	ptr_len = xdp->data_end - xdp->data;
> 
> 	while (true) {
> 		if (off < ptr_off + ptr_len) {
> 			copy_off = ptr_off - off;

I guess here should be:
			copy_off = off - ptr_off;

> 			copy_len = min(len, ptr_len - copy_off);
> 			memcpy(dst_buff, ptr_buf + copy_off, copy_len);
> 
> 			off += copy_len;
> 			len -= copy_len;
> 			dst_buff += copy_len;
> 		}
> 
> 		if (!len || next_frag == end_frag)
> 			break;
> 	
> 		ptr_off += ptr_len;
> 		ptr_buf = skb_frag_address(next_frag);
> 		ptr_len = skb_frag_size(next_frag);
> 		next_frag++;
> 	}
> 
> Up to you.

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Re: [PATCH v17 bpf-next 20/23] net: xdp: introduce bpf_xdp_pointer utility routine

[Lorenzo Bianconi]

[-- Attachment #1: Type: text/plain, Size: 4735 bytes --]

> On Thu,  4 Nov 2021 18:35:40 +0100 Lorenzo Bianconi wrote:
> > Similar to skb_header_pointer, introduce bpf_xdp_pointer utility routine
> > to return a pointer to a given position in the xdp_buff if the requested
> > area (offset + len) is contained in a contiguous memory area otherwise it
> > will be copied in a bounce buffer provided by the caller.
> > Similar to the tc counterpart, introduce the two following xdp helpers:
> > - bpf_xdp_load_bytes
> > - bpf_xdp_store_bytes
> > 
> > Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
> 
> > diff --git a/net/core/filter.c b/net/core/filter.c
> > index 386dd2fffded..534305037ad7 100644
> > --- a/net/core/filter.c
> > +++ b/net/core/filter.c
> > @@ -3840,6 +3840,135 @@ static const struct bpf_func_proto bpf_xdp_adjust_head_proto = {
> >  	.arg2_type	= ARG_ANYTHING,
> >  };
> >  
> > +static void bpf_xdp_copy_buf(struct xdp_buff *xdp, u32 offset,
> > +			     u32 len, void *buf, bool flush)
> > +{
> > +	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
> > +	u32 headsize = xdp->data_end - xdp->data;
> > +	u32 count = 0, frame_offset = headsize;
> > +	int i = 0;
> > +
> > +	if (offset < headsize) {
> > +		int size = min_t(int, headsize - offset, len);
> > +		void *src = flush ? buf : xdp->data + offset;
> > +		void *dst = flush ? xdp->data + offset : buf;
> > +
> > +		memcpy(dst, src, size);
> > +		count = size;
> > +		offset = 0;
> > +	}
> > +
> > +	while (count < len && i < sinfo->nr_frags) {
> 
> nit: for (i = 0; ...; i++) ?

ack, I will fix it in v18

> 
> > +		skb_frag_t *frag = &sinfo->frags[i++];
> > +		u32 frag_size = skb_frag_size(frag);
> > +
> > +		if  (offset < frame_offset + frag_size) {
> 
> nit: double space after if

ack, I will fix it in v18
> 
> > +			int size = min_t(int, frag_size - offset, len - count);
> > +			void *addr = skb_frag_address(frag);
> > +			void *src = flush ? buf + count : addr + offset;
> > +			void *dst = flush ? addr + offset : buf + count;
> > +
> > +			memcpy(dst, src, size);
> > +			count += size;
> > +			offset = 0;
> > +		}
> > +		frame_offset += frag_size;
> > +	}
> > +}
> > +
> > +static void *bpf_xdp_pointer(struct xdp_buff *xdp, u32 offset,
> > +			     u32 len, void *buf)
> > +{
> > +	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
> > +	u32 size = xdp->data_end - xdp->data;
> > +	void *addr = xdp->data;
> > +	int i;
> > +
> > +	if (unlikely(offset > 0xffff))
> > +		return ERR_PTR(-EFAULT);
> > +
> > +	if (offset + len > xdp_get_buff_len(xdp))
> > +		return ERR_PTR(-EINVAL);
> 
> I don't think it breaks anything but should we sanity check len?
> Maybe make the test above (offset | len) > 0xffff -> EFAULT?

ack, I will add it in v18

> 
> > +	if (offset < size) /* linear area */
> > +		goto out;
> > +
> > +	offset -= size;
> > +	for (i = 0; i < sinfo->nr_frags; i++) { /* paged area */
> > +		u32 frag_size = skb_frag_size(&sinfo->frags[i]);
> > +
> > +		if  (offset < frag_size) {
> > +			addr = skb_frag_address(&sinfo->frags[i]);
> > +			size = frag_size;
> > +			break;
> > +		}
> > +		offset -= frag_size;
> > +	}
> > +
> > +out:
> > +	if (offset + len < size)
> > +		return addr + offset; /* fast path - no need to copy */
> > +
> > +	if (!buf) /* no copy to the bounce buffer */
> > +		return NULL;
> > +
> > +	/* slow path - we need to copy data into the bounce buffer */
> > +	bpf_xdp_copy_buf(xdp, offset, len, buf, false);
> > +	return buf;
> > +}
> > +
> > +BPF_CALL_4(bpf_xdp_load_bytes, struct xdp_buff *, xdp, u32, offset,
> > +	   void *, buf, u32, len)
> > +{
> > +	void *ptr;
> > +
> > +	ptr = bpf_xdp_pointer(xdp, offset, len, buf);
> > +	if (IS_ERR(ptr))
> > +		return PTR_ERR(ptr);
> > +
> > +	if (ptr != buf)
> > +		memcpy(buf, ptr, len);
> 
> Maybe we should just call out to bpf_xdp_copy_buf() like store does
> instead of putting one but not the other inside bpf_xdp_pointer().
> 
> We'll have to refactor this later for the real bpf_xdp_pointer,
> I'd lean on the side of keeping things symmetric for now.

ack, I agree. I will move bpf_xdp_copy_buf out of bpf_xdp_pointer so
bpf_xdp_load_bytes and bpf_xdp_store_bytes are symmetric

Regards,
Lorenzo

> 
> > +	return 0;
> > +}
> 
> > +BPF_CALL_4(bpf_xdp_store_bytes, struct xdp_buff *, xdp, u32, offset,
> > +	   void *, buf, u32, len)
> > +{
> > +	void *ptr;
> > +
> > +	ptr = bpf_xdp_pointer(xdp, offset, len, NULL);
> > +	if (IS_ERR(ptr))
> > +		return PTR_ERR(ptr);
> > +
> > +	if (!ptr)
> > +		bpf_xdp_copy_buf(xdp, offset, len, buf, true);
> > +	else
> > +		memcpy(ptr, buf, len);
> > +
> > +	return 0;
> > +}

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Re: [PATCH v17 bpf-next 12/23] bpf: add multi-buff support to the bpf_xdp_adjust_tail() API

[Lorenzo Bianconi]

[-- Attachment #1: Type: text/plain, Size: 2405 bytes --]

> On Thu,  4 Nov 2021 18:35:32 +0100 Lorenzo Bianconi wrote:
> > This change adds support for tail growing and shrinking for XDP multi-buff.
> > 
> > When called on a multi-buffer packet with a grow request, it will always
> > work on the last fragment of the packet. So the maximum grow size is the
> > last fragments tailroom, i.e. no new buffer will be allocated.
> > 
> > When shrinking, it will work from the last fragment, all the way down to
> > the base buffer depending on the shrinking size. It's important to mention
> > that once you shrink down the fragment(s) are freed, so you can not grow
> > again to the original size.
> 
> > +static int bpf_xdp_mb_increase_tail(struct xdp_buff *xdp, int offset)
> > +{
> > +	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
> > +	skb_frag_t *frag = &sinfo->frags[sinfo->nr_frags - 1];
> > +	int size, tailroom;
> > +
> > +	tailroom = xdp->frame_sz - skb_frag_size(frag) - skb_frag_off(frag);
> 
> I know I complained about this before but the assumption that we can
> use all the space up to xdp->frame_sz makes me uneasy.
> 
> Drivers may not expect the idea that core may decide to extend the 
> last frag.. I don't think the skb path would ever do this.
> 
> How do you feel about any of these options: 
>  - dropping this part for now (return an error for increase)
>  - making this an rxq flag or reading the "reserved frag size"
>    from rxq (so that drivers explicitly opt-in)
>  - adding a test that can be run on real NICs
> ?

I think this has been added to be symmetric with bpf_xdp_adjust_tail().
I do think there is a real use-case for it so far so I am fine to just
support the shrink part.

@Eelco, Jesper, Toke: any comments on it?

> 
> > +static int bpf_xdp_mb_shrink_tail(struct xdp_buff *xdp, int offset)
> > +{
> > +	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
> > +	int i, n_frags_free = 0, len_free = 0, tlen_free = 0;
> > +
> > +	if (unlikely(offset > ((int)xdp_get_buff_len(xdp) - ETH_HLEN)))
> 
> nit: outer parens unnecessary

ack, I will fix it.

> 
> > +		return -EINVAL;
> 
> 
> > @@ -371,6 +371,7 @@ static void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct,
> >  		break;
> >  	}
> >  }
> > +EXPORT_SYMBOL_GPL(__xdp_return);
> 
> Why the export?

ack, I will remove it

Regards,
Lorenzo

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Re: [PATCH v17 bpf-next 12/23] bpf: add multi-buff support to the bpf_xdp_adjust_tail() API

[Toke Høiland-Jørgensen]

Lorenzo Bianconi <lorenzo@kernel.org> writes:

>> On Thu,  4 Nov 2021 18:35:32 +0100 Lorenzo Bianconi wrote:
>> > This change adds support for tail growing and shrinking for XDP multi-buff.
>> > 
>> > When called on a multi-buffer packet with a grow request, it will always
>> > work on the last fragment of the packet. So the maximum grow size is the
>> > last fragments tailroom, i.e. no new buffer will be allocated.
>> > 
>> > When shrinking, it will work from the last fragment, all the way down to
>> > the base buffer depending on the shrinking size. It's important to mention
>> > that once you shrink down the fragment(s) are freed, so you can not grow
>> > again to the original size.
>> 
>> > +static int bpf_xdp_mb_increase_tail(struct xdp_buff *xdp, int offset)
>> > +{
>> > +	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
>> > +	skb_frag_t *frag = &sinfo->frags[sinfo->nr_frags - 1];
>> > +	int size, tailroom;
>> > +
>> > +	tailroom = xdp->frame_sz - skb_frag_size(frag) - skb_frag_off(frag);
>> 
>> I know I complained about this before but the assumption that we can
>> use all the space up to xdp->frame_sz makes me uneasy.
>> 
>> Drivers may not expect the idea that core may decide to extend the 
>> last frag.. I don't think the skb path would ever do this.
>> 
>> How do you feel about any of these options: 
>>  - dropping this part for now (return an error for increase)
>>  - making this an rxq flag or reading the "reserved frag size"
>>    from rxq (so that drivers explicitly opt-in)
>>  - adding a test that can be run on real NICs
>> ?
>
> I think this has been added to be symmetric with bpf_xdp_adjust_tail().
> I do think there is a real use-case for it so far so I am fine to just
> support the shrink part.
>
> @Eelco, Jesper, Toke: any comments on it?

Well, tail adjust is useful for things like encapsulations that need to
add a trailer. Don't see why that wouldn't be something people would
want to do for jumboframes as well?

Not sure I get what the issue is with this either? But having a test
that can be run to validate this on hardware would be great in any case,
I suppose - we've been discussing more general "compliance tests" for
XDP before...

-Toke

Re: [PATCH v17 bpf-next 12/23] bpf: add multi-buff support to the bpf_xdp_adjust_tail() API

[Lorenzo Bianconi]

[-- Attachment #1: Type: text/plain, Size: 3150 bytes --]

> Lorenzo Bianconi <lorenzo@kernel.org> writes:
> 
> >> On Thu,  4 Nov 2021 18:35:32 +0100 Lorenzo Bianconi wrote:
> >> > This change adds support for tail growing and shrinking for XDP multi-buff.
> >> > 
> >> > When called on a multi-buffer packet with a grow request, it will always
> >> > work on the last fragment of the packet. So the maximum grow size is the
> >> > last fragments tailroom, i.e. no new buffer will be allocated.
> >> > 
> >> > When shrinking, it will work from the last fragment, all the way down to
> >> > the base buffer depending on the shrinking size. It's important to mention
> >> > that once you shrink down the fragment(s) are freed, so you can not grow
> >> > again to the original size.
> >> 
> >> > +static int bpf_xdp_mb_increase_tail(struct xdp_buff *xdp, int offset)
> >> > +{
> >> > +	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
> >> > +	skb_frag_t *frag = &sinfo->frags[sinfo->nr_frags - 1];
> >> > +	int size, tailroom;
> >> > +
> >> > +	tailroom = xdp->frame_sz - skb_frag_size(frag) - skb_frag_off(frag);
> >> 
> >> I know I complained about this before but the assumption that we can
> >> use all the space up to xdp->frame_sz makes me uneasy.
> >> 
> >> Drivers may not expect the idea that core may decide to extend the 
> >> last frag.. I don't think the skb path would ever do this.
> >> 
> >> How do you feel about any of these options: 
> >>  - dropping this part for now (return an error for increase)
> >>  - making this an rxq flag or reading the "reserved frag size"
> >>    from rxq (so that drivers explicitly opt-in)
> >>  - adding a test that can be run on real NICs
> >> ?
> >
> > I think this has been added to be symmetric with bpf_xdp_adjust_tail().
> > I do think there is a real use-case for it so far so I am fine to just
> > support the shrink part.
> >
> > @Eelco, Jesper, Toke: any comments on it?
> 
> Well, tail adjust is useful for things like encapsulations that need to
> add a trailer. Don't see why that wouldn't be something people would
> want to do for jumboframes as well?
> 

I agree this would be useful for protocols that add a trailer.

> Not sure I get what the issue is with this either? But having a test
> that can be run to validate this on hardware would be great in any case,
> I suppose - we've been discussing more general "compliance tests" for
> XDP before...

what about option 2? We can add a frag_size field to rxq [0] that is set by
the driver initializing the xdp_buff. frag_size set to 0 means we can use
all the buffer.

Regards,
Lorenzo

[0] pahole -C xdp_rxq_info vmlinux
struct xdp_rxq_info {
	struct net_device *        dev;                  /*     0     8 */
	u32                        queue_index;          /*     8     4 */
	u32                        reg_state;            /*    12     4 */
	struct xdp_mem_info        mem;                  /*    16     8 */
	unsigned int               napi_id;              /*    24     4 */

	/* size: 64, cachelines: 1, members: 5 */
	/* padding: 36 */
} __attribute__((__aligned__(64)));

> 
> -Toke
> 

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Re: [PATCH v17 bpf-next 12/23] bpf: add multi-buff support to the bpf_xdp_adjust_tail() API

[Toke Høiland-Jørgensen]

Lorenzo Bianconi <lorenzo@kernel.org> writes:

>> Lorenzo Bianconi <lorenzo@kernel.org> writes:
>> 
>> >> On Thu,  4 Nov 2021 18:35:32 +0100 Lorenzo Bianconi wrote:
>> >> > This change adds support for tail growing and shrinking for XDP multi-buff.
>> >> > 
>> >> > When called on a multi-buffer packet with a grow request, it will always
>> >> > work on the last fragment of the packet. So the maximum grow size is the
>> >> > last fragments tailroom, i.e. no new buffer will be allocated.
>> >> > 
>> >> > When shrinking, it will work from the last fragment, all the way down to
>> >> > the base buffer depending on the shrinking size. It's important to mention
>> >> > that once you shrink down the fragment(s) are freed, so you can not grow
>> >> > again to the original size.
>> >> 
>> >> > +static int bpf_xdp_mb_increase_tail(struct xdp_buff *xdp, int offset)
>> >> > +{
>> >> > +	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
>> >> > +	skb_frag_t *frag = &sinfo->frags[sinfo->nr_frags - 1];
>> >> > +	int size, tailroom;
>> >> > +
>> >> > +	tailroom = xdp->frame_sz - skb_frag_size(frag) - skb_frag_off(frag);
>> >> 
>> >> I know I complained about this before but the assumption that we can
>> >> use all the space up to xdp->frame_sz makes me uneasy.
>> >> 
>> >> Drivers may not expect the idea that core may decide to extend the 
>> >> last frag.. I don't think the skb path would ever do this.
>> >> 
>> >> How do you feel about any of these options: 
>> >>  - dropping this part for now (return an error for increase)
>> >>  - making this an rxq flag or reading the "reserved frag size"
>> >>    from rxq (so that drivers explicitly opt-in)
>> >>  - adding a test that can be run on real NICs
>> >> ?
>> >
>> > I think this has been added to be symmetric with bpf_xdp_adjust_tail().
>> > I do think there is a real use-case for it so far so I am fine to just
>> > support the shrink part.
>> >
>> > @Eelco, Jesper, Toke: any comments on it?
>> 
>> Well, tail adjust is useful for things like encapsulations that need to
>> add a trailer. Don't see why that wouldn't be something people would
>> want to do for jumboframes as well?
>> 
>
> I agree this would be useful for protocols that add a trailer.
>
>> Not sure I get what the issue is with this either? But having a test
>> that can be run to validate this on hardware would be great in any case,
>> I suppose - we've been discussing more general "compliance tests" for
>> XDP before...
>
> what about option 2? We can add a frag_size field to rxq [0] that is set by
> the driver initializing the xdp_buff. frag_size set to 0 means we can use
> all the buffer.
>
> Regards,
> Lorenzo
>
> [0] pahole -C xdp_rxq_info vmlinux
> struct xdp_rxq_info {
> 	struct net_device *        dev;                  /*     0     8 */
> 	u32                        queue_index;          /*     8     4 */
> 	u32                        reg_state;            /*    12     4 */
> 	struct xdp_mem_info        mem;                  /*    16     8 */
> 	unsigned int               napi_id;              /*    24     4 */
>
> 	/* size: 64, cachelines: 1, members: 5 */
> 	/* padding: 36 */
> } __attribute__((__aligned__(64)));

Works for me :)

-Toke

Re: [PATCH v17 bpf-next 12/23] bpf: add multi-buff support to the bpf_xdp_adjust_tail() API

[Jakub Kicinski]

On Mon, 8 Nov 2021 20:06:39 +0100 Lorenzo Bianconi wrote:
> > Not sure I get what the issue is with this either? But having a test
> > that can be run to validate this on hardware would be great in any case,
> > I suppose - we've been discussing more general "compliance tests" for
> > XDP before...  
> 
> what about option 2? We can add a frag_size field to rxq [0] that is set by
> the driver initializing the xdp_buff. frag_size set to 0 means we can use
> all the buffer.

So 0 would mean xdp->frame_sz can be used for extending frags?

I was expecting that we'd used rxq->frag_size in place of xdp->frame_sz.

For devices doing payload packing we will not be able to extend the
last frag at all. Wouldn't it be better to keep 0 for the case where
extending is not allowed?

Re: [PATCH v17 bpf-next 12/23] bpf: add multi-buff support to the bpf_xdp_adjust_tail() API

[Lorenzo Bianconi]

[-- Attachment #1: Type: text/plain, Size: 914 bytes --]

> On Mon, 8 Nov 2021 20:06:39 +0100 Lorenzo Bianconi wrote:
> > > Not sure I get what the issue is with this either? But having a test
> > > that can be run to validate this on hardware would be great in any case,
> > > I suppose - we've been discussing more general "compliance tests" for
> > > XDP before...  
> > 
> > what about option 2? We can add a frag_size field to rxq [0] that is set by
> > the driver initializing the xdp_buff. frag_size set to 0 means we can use
> > all the buffer.
> 
> So 0 would mean xdp->frame_sz can be used for extending frags?
> 
> I was expecting that we'd used rxq->frag_size in place of xdp->frame_sz.
> 
> For devices doing payload packing we will not be able to extend the
> last frag at all. Wouldn't it be better to keep 0 for the case where
> extending is not allowed?

ack, I am fine with it. I will integrate it in v18. Thanks.

Regards,
Lorenzo

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Re: [PATCH v17 bpf-next 13/23] bpf: add multi-buffer support to xdp copy helpers

[Eelco Chaudron]

On 8 Nov 2021, at 14:59, Lorenzo Bianconi wrote:

>> On Thu,  4 Nov 2021 18:35:33 +0100 Lorenzo Bianconi wrote:
>>> -static unsigned long bpf_xdp_copy(void *dst_buff, const void *src_buff,
>>> +static unsigned long bpf_xdp_copy(void *dst_buff, const void *ctx,
>>>  				  unsigned long off, unsigned long len)
>>>  {
>>> -	memcpy(dst_buff, src_buff + off, len);
>>> +	unsigned long base_len, copy_len, frag_off_total;
>>> +	struct xdp_buff *xdp = (struct xdp_buff *)ctx;
>>> +	struct skb_shared_info *sinfo;
>>> +	int i;
>>> +
>>> +	if (likely(!xdp_buff_is_mb(xdp))) {
>>
>> Would it be better to do
>>
>> 	if (xdp->data_end - xdp->data >= off + len)
>>
>> ?
>
> Hi Jakub,
>
> I am fine with the patch (just a typo inline), thx :)
> I will let Eelco to comment since he wrote the original code.
> If there is no objections, I will integrate it in v18.

Sorry for the late response, but both suggestions look fine to me.

>>
>>> +		memcpy(dst_buff, xdp->data + off, len);
>>> +		return 0;
>>> +	}
>>> +
>>> +	base_len = xdp->data_end - xdp->data;
>>> +	frag_off_total = base_len;
>>> +	sinfo = xdp_get_shared_info_from_buff(xdp);
>>> +
>>> +	/* If we need to copy data from the base buffer do it */
>>> +	if (off < base_len) {
>>> +		copy_len = min(len, base_len - off);
>>> +		memcpy(dst_buff, xdp->data + off, copy_len);
>>> +
>>> +		off += copy_len;
>>> +		len -= copy_len;
>>> +		dst_buff += copy_len;
>>> +	}
>>> +
>>> +	/* Copy any remaining data from the fragments */
>>> +	for (i = 0; len && i < sinfo->nr_frags; i++) {
>>> +		skb_frag_t *frag = &sinfo->frags[i];
>>> +		unsigned long frag_len, frag_off;
>>> +
>>> +		frag_len = skb_frag_size(frag);
>>> +		frag_off = off - frag_off_total;
>>> +		if (frag_off < frag_len) {
>>> +			copy_len = min(len, frag_len - frag_off);
>>> +			memcpy(dst_buff,
>>> +			       skb_frag_address(frag) + frag_off, copy_len);
>>> +
>>> +			off += copy_len;
>>> +			len -= copy_len;
>>> +			dst_buff += copy_len;
>>> +		}
>>> +		frag_off_total += frag_len;
>>> +	}
>>> +
>>
>> nit: can't help but feel that you can merge base copy and frag copy:
>>
>> 	sinfo = xdp_get_shared_info_from_buff(xdp);
>> 	next_frag = &sinfo->frags[0];
>> 	end_frag = &sinfo->frags[sinfo->nr_frags];
>>
>> 	ptr_off = 0;
>> 	ptr_buf = xdp->data;
>> 	ptr_len = xdp->data_end - xdp->data;
>>
>> 	while (true) {
>> 		if (off < ptr_off + ptr_len) {
>> 			copy_off = ptr_off - off;
>
> I guess here should be:
> 			copy_off = off - ptr_off;
>
>> 			copy_len = min(len, ptr_len - copy_off);
>> 			memcpy(dst_buff, ptr_buf + copy_off, copy_len);
>>
>> 			off += copy_len;
>> 			len -= copy_len;
>> 			dst_buff += copy_len;
>> 		}
>>
>> 		if (!len || next_frag == end_frag)
>> 			break;
>> 	
>> 		ptr_off += ptr_len;
>> 		ptr_buf = skb_frag_address(next_frag);
>> 		ptr_len = skb_frag_size(next_frag);
>> 		next_frag++;
>> 	}
>>
>> Up to you.