mvneta: introduce XDP multi-buffer support
Subsystems (11)
v13 cover mvneta: introduce XDP multi-buffer support
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 two following ebpf helpers (and related selftests) has been introduced:
- bpf_xdp_adjust_data:
Move xdp_md->data and xdp_md->data_end pointers in subsequent fragments according to the offset provided by the ebpf program. This helper can be used to read/write values in frame payload.
- 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.
A multi-buffer enabled NIC may receive XDP frames with multiple frags. If a BPF program does not understand mb layouts its possible to contrive a BPF program that incorrectly views data_end as the end of data when there is more data in the payload. Note helpers will generally due the correct thing, for example perf_output will consume entire payload. But, it is still possible some programs could do the wrong thing even if in an edge case. Although we expect most BPF programs not to be impacted we can't rule out, you've been warned.
More info about the main idea behind this approach can be found here [1][2].
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: update xdp_adjust_tail selftest to include multi-buffer
Lorenzo Bianconi (15):
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
net: mvneta: enable jumbo frames for XDP
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
net: xdp: introduce bpf_xdp_adjust_data helper
bpf: add bpf_xdp_adjust_data selftest
drivers/net/ethernet/marvell/mvneta.c | 204 ++++++++++------- include/linux/skbuff.h | 6 +- include/net/xdp.h | 95 +++++++- include/uapi/linux/bpf.h | 39 ++++ kernel/trace/bpf_trace.c | 3 + net/bpf/test_run.c | 117 ++++++++-- net/core/filter.c | 216 +++++++++++++++++- net/core/xdp.c | 76 +++++- tools/include/uapi/linux/bpf.h | 39 ++++ .../bpf/prog_tests/xdp_adjust_data.c | 63 +++++ .../bpf/prog_tests/xdp_adjust_tail.c | 118 ++++++++++ .../selftests/bpf/prog_tests/xdp_bpf2bpf.c | 151 ++++++++---- .../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 | 45 ++++ 16 files changed, 1051 insertions(+), 165 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/xdp_adjust_data.c create mode 100644 tools/testing/selftests/bpf/progs/test_xdp_update_frags.c
Signature · 1 line
2.31.1
PATCH v13 1/18 net: skbuff: add size metadata to skb_shared_info for xdp
Introduce xdp_frags_tsize field in skb_shared_info data structure to store xdp_buff/xdp_frame truesize (xdp_frags_tsize 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. Introduce xdp_frags_size field in skb_shared_info data structure reusing gso_type field in order to store xdp_buff/xdp_frame paged size. xdp_frags_size will be used in xdp multi-buff support.
--- include/linux/skbuff.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
include/linux/skbuff.h +5 -1
@@ -522,13 +522,17 @@ struct skb_shared_info {unsigned short gso_segs;struct sk_buff *frag_list;struct skb_shared_hwtstamps hwtstamps; -unsigned int gso_type; +union { +unsigned int gso_type; +unsigned int xdp_frags_size; + };u32 tskey;/* * Warning : all fields before dataref are cleared in __alloc_skb() */ atomic_t dataref; +unsigned int xdp_frags_tsize;/* Intermediate layers must ensure that destructor_arg * remains valid until skb destructor */
Signature · 1 line
2.31.1
Re: [PATCH v13 bpf-next 01/18] net: skbuff: add size metadata to skb_shared_info for xdp
Quoted 24 lines · Lorenzo Bianconi
Introduce
xdp_frags_tsizefield inskb_shared_infodata structure to store xdp_buff/xdp_frame truesize (xdp_frags_tsizewill be used in xdp multi-buff support). In order to not increaseskb_shared_infosize we will use a hole due toskb_shared_infoalignment. Introducexdp_frags_sizefield inskb_shared_infodata structure reusinggso_typefield in order to store xdp_buff/xdp_frame paged size.xdp_frags_sizewill be used in xdp multi-buff support.Acked-by John Fastabend <[email protected]>Signed-off-by Lorenzo Bianconi <[email protected]>--- include/linux/skbuff.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)include/linux/skbuff.h +1
-1@@ -522,13 +522,17 @@ struct skb_shared_info {unsigned short gso_segs;struct sk_buff *frag_list;struct skb_shared_hwtstamps hwtstamps; -unsigned int gso_type; +union {
include/linux/skbuff.h struct skb_shared_info { · line 535
Quoted 10 lines
include/linux/skbuff.h +4
-0+unsigned int gso_type; +unsigned int xdp_frags_size; + };u32 tskey;/* * Warning : all fields before dataref are cleared in __alloc_skb() */ atomic_t dataref; +unsigned int xdp_frags_tsize;
I wonder if we could call this variable: xdp_frags_truesize.
As while reviewing patches I had to focus my eyes extra hard to tell the variables xdp_frags_size and xdp_frags_tsize from each-other.
--Jesper
Re: [PATCH v13 bpf-next 01/18] net: skbuff: add size metadata to skb_shared_info for xdp
Quoted 39 lines · Lorenzo Bianconi
Quoted 23 lines
Introduce
xdp_frags_tsizefield inskb_shared_infodata structure to store xdp_buff/xdp_frame truesize (xdp_frags_tsizewill be used in xdp multi-buff support). In order to not increaseskb_shared_infosize we will use a hole due toskb_shared_infoalignment. Introducexdp_frags_sizefield inskb_shared_infodata structure reusinggso_typefield in order to store xdp_buff/xdp_frame paged size.xdp_frags_sizewill be used in xdp multi-buff support.Acked-by John Fastabend <[email protected]>Signed-off-by Lorenzo Bianconi <[email protected]>--- include/linux/skbuff.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)include/linux/skbuff.h +0
-1@@ -522,13 +522,17 @@ struct skb_shared_info {unsigned short gso_segs;struct sk_buff *frag_list;struct skb_shared_hwtstamps hwtstamps; -unsigned int gso_type;include/linux/skbuff.h struct skb_shared_info { · line 534
Quoted 10 lines
include/linux/skbuff.h +5
-0+union { +unsigned int gso_type; +unsigned int xdp_frags_size; + };u32 tskey;/* * Warning : all fields before dataref are cleared in __alloc_skb() */ atomic_t dataref; +unsigned int xdp_frags_tsize;I wonder if we could call this variable:
xdp_frags_truesize.
Quoted 2 lines
As while reviewing patches I had to focus my eyes extra hard to tell the variables
xdp_frags_sizeandxdp_frags_tsizefrom each-other.
sure, I will fix it in v14.
Regards,
Lorenzo
Quoted 3 lines
--Jesper
PATCH v13 2/18 xdp: introduce flags field in xdp_buff/xdp_frame
In reply to Lorenzo BianconiIntroduce 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.
--- include/net/xdp.h | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+)
include/net/xdp.h +29 -0
@@ -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*/ +u16 flags;/* supported values defined in xdp_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 voidxdp_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 */ +u16 flags;/* supported values defined in xdp_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 16struct 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 ; }
Signature · 1 line
2.31.1
Re: [PATCH v13 bpf-next 02/18] xdp: introduce flags field in xdp_buff/xdp_frame
(Minor changes requested below)
Quoted 30 lines · Lorenzo Bianconi
Introduce flags field in
xdp_frameandxdp_bufferdata 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 theskb_shared_infostructure at the end of the first buffer to link together subsequent buffers belonging to the same frame.Acked-by John Fastabend <[email protected]>Signed-off-by Lorenzo Bianconi <[email protected]>--- include/net/xdp.h | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+)include/net/xdp.h +4
-0@@ -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;
include/net/xdp.h struct xdp_buff { · line 81
Quoted 4 lines
include/net/xdp.h +1
-0@@ -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*/ +u16 flags;/* supported values defined in xdp_flags */
^^^^^^^^^
Variable/enum is named "xdp_buff_flags", but comment says "xdp_flags".
I think we should change flags to use u32, because xdp_buff already contain 4 byte padding. (pahole output provided as help below)
Quoted 27 lines
include/net/xdp.h +16
-0}; +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 voidxdp_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
include/net/xdp.h struct xdp_frame { · line 146
Quoted 4 lines
include/net/xdp.h +1
-0@@ -122,8 +143,14 @@ struct xdp_frame {*/ struct xdp_mem_info mem;struct net_device *dev_rx;/* used by cpumap */ +u16 flags;/* supported values defined in xdp_flags */
^^^^^^^^^
Variable/enum is named "xdp_buff_flags", but comment says "xdp_flags".
Here (for xdp_frame) I also think we should change flags to u32, because adding this u16 cause extra padding anyhow. (pahole output provided as help below).
Quoted 20 lines
include/net/xdp.h +6
-0}; +static __always_inline bool xdp_frame_is_mb(struct xdp_frame *frame) +{ +return !!(frame->flags &XDP_FLAGS_MULTI_BUFF ); +} +#define XDP_BULK_QUEUE_SIZE 16struct 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
include/net/xdp.h int xdp_update_frame_from_buff(struct xdp_buff *xdp, · line 240
Quoted 7 lines
include/net/xdp.h +1
-0@@ -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 ; }
Details below... no need to read any further
Investigating struct xdp_frame with pahole:
$ pahole -C xdp_frame net/core/xdp.o
struct xdp_frame {
void * data; /* 0 8 */
u16 len; /* 8 2 */
u16 headroom; /* 10 2 */
u32 metasize:8; /* 12: 0 4 */
u32 frame_sz:24; /* 12: 8 4 */
struct xdp_mem_info mem; /* 16 8 */
struct net_device * dev_rx; /* 24 8 *//* size: 32, cachelines: 1, members: 7 */ /* last cacheline: 32 bytes */ };
pahole -C xdp_frame net/core/xdp.o
struct xdp_frame {
void * data; /* 0 8 */ u16 len; /* 8 2 */ u16 headroom; /* 10 2 */ u32 metasize:8; /* 12: 0 4 */ u32 frame_sz:24; /* 12: 8 4 */ struct xdp_mem_info mem; /* 16 8 */ struct net_device * dev_rx; /* 24 8 */ u16 flags; /* 32 2 */
/* size: 40, cachelines: 1, members: 8 */ /* padding: 6 */ /* last cacheline: 40 bytes */ };
$ pahole -C xdp_frame net/core/xdp.o
struct xdp_frame {
void * data; /* 0 8 */
u16 len; /* 8 2 */
u16 headroom; /* 10 2 */
u32 metasize:8; /* 12: 0 4 */
u32 frame_sz:24; /* 12: 8 4 */
struct xdp_mem_info mem; /* 16 8 */
struct net_device * dev_rx; /* 24 8 */
u32 flags; /* 32 4 *//* size: 40, cachelines: 1, members: 8 */ /* padding: 4 */ /* last cacheline: 40 bytes */ };
Details for struct xdp_buff, it already contains 4 bytes padding.
$ pahole -C xdp_buff net/core/xdp.o
struct xdp_buff {
void * data; /* 0 8 */
void * data_end; /* 8 8 */
void * data_meta; /* 16 8 */
void * data_hard_start; /* 24 8 */
struct xdp_rxq_info * rxq; /* 32 8 */
struct xdp_txq_info * txq; /* 40 8 */
u32 frame_sz; /* 48 4 */
u16 flags; /* 52 2 *//* size: 56, cachelines: 1, members: 8 */ /* padding: 2 */ /* last cacheline: 56 bytes */ };
Re: [PATCH v13 bpf-next 02/18] xdp: introduce flags field in xdp_buff/xdp_frame
Quoted 37 lines
(Minor changes requested below)
Quoted 29 lines · Lorenzo Bianconi
Introduce flags field in
xdp_frameandxdp_bufferdata 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 theskb_shared_infostructure at the end of the first buffer to link together subsequent buffers belonging to the same frame.Acked-by John Fastabend <[email protected]>Signed-off-by Lorenzo Bianconi <[email protected]>--- include/net/xdp.h | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+)include/net/xdp.h +4
-0@@ -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;include/net/xdp.h struct xdp_buff { · line 81
Quoted 4 lines
include/net/xdp.h +1
-0@@ -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*/ +u16 flags;/* supported values defined in xdp_flags */ ^^^^^^^^^
Quoted 1 line
Variable/enum is named "
xdp_buff_flags", but comment says "xdp_flags".
ack, I will fix it in v14
Quoted 3 lines
I think we should change flags to use u32, because
xdp_buffalready contain 4 byte padding. (pahole output provided as help below)
ack, I will fix it in v14
Quoted 31 lines
Quoted 26 lines
include/net/xdp.h +16
-0}; +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 voidxdp_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 voidinclude/net/xdp.h struct xdp_frame { · line 146
Quoted 4 lines
include/net/xdp.h +1
-0@@ -122,8 +143,14 @@ struct xdp_frame {*/ struct xdp_mem_info mem;struct net_device *dev_rx;/* used by cpumap */ +u16 flags;/* supported values defined in xdp_flags */ ^^^^^^^^^
Quoted 5 lines
Variable/enum is named "
xdp_buff_flags", but comment says "xdp_flags".Here (for
xdp_frame) I also think we should change flags to u32, because adding this u16 cause extra padding anyhow. (pahole output provided as help below).
ack, I will fix it in v14
Quoted 95 lines
Quoted 19 lines
include/net/xdp.h +6
-0}; +static __always_inline bool xdp_frame_is_mb(struct xdp_frame *frame) +{ +return !!(frame->flags &XDP_FLAGS_MULTI_BUFF ); +} +#define XDP_BULK_QUEUE_SIZE 16struct 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 inlineinclude/net/xdp.h int xdp_update_frame_from_buff(struct xdp_buff *xdp, · line 240
Quoted 7 lines
include/net/xdp.h +1
-0@@ -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 ; }Details below... no need to read any further
Investigating struct
xdp_framewith pahole:$ pahole -C xdp_frame net/core/xdp.o struct xdp_frame { void * data; /* 0 8 */ u16 len; /* 8 2 */ u16 headroom; /* 10 2 */ u32 metasize:8; /* 12: 0 4 */ u32 frame_sz:24; /* 12: 8 4 */ struct xdp_mem_info mem; /* 16 8 */ struct net_device * dev_rx; /* 24 8 *//* size: 32, cachelines: 1, members: 7 */ /* last cacheline: 32 bytes */ };pahole -C
xdp_framenet/core/xdp.o
structxdp_frame{void * data; /* 0 8 */ u16 len; /* 8 2 */ u16 headroom; /* 10 2 */ u32 metasize:8; /* 12: 0 4 */ u32 frame_sz:24; /* 12: 8 4 */ struct xdp_mem_info mem; /* 16 8 */ struct net_device * dev_rx; /* 24 8 */ u16 flags; /* 32 2 *//* size: 40, cachelines: 1, members: 8 */ /* padding: 6 */ /* last cacheline: 40 bytes */ };$ pahole -C xdp_frame net/core/xdp.o struct xdp_frame { void * data; /* 0 8 */ u16 len; /* 8 2 */ u16 headroom; /* 10 2 */ u32 metasize:8; /* 12: 0 4 */ u32 frame_sz:24; /* 12: 8 4 */ struct xdp_mem_info mem; /* 16 8 */ struct net_device * dev_rx; /* 24 8 */ u32 flags; /* 32 4 *//* size: 40, cachelines: 1, members: 8 */ /* padding: 4 */ /* last cacheline: 40 bytes */ };Details for struct
xdp_buff, it already contains 4 bytes padding.$ pahole -C xdp_buff net/core/xdp.o struct xdp_buff { void * data; /* 0 8 */ void * data_end; /* 8 8 */ void * data_meta; /* 16 8 */ void * data_hard_start; /* 24 8 */ struct xdp_rxq_info * rxq; /* 32 8 */ struct xdp_txq_info * txq; /* 40 8 */ u32 frame_sz; /* 48 4 */ u16 flags; /* 52 2 */
Quoted 4 lines
/* size: 56, cachelines: 1, members: 8 */ /* padding: 2 */ /* last cacheline: 56 bytes */ };
ack, right.
Regards,
Lorenzo
Quoted 1 line
PATCH v13 3/18 net: mvneta: update mb bit before passing the xdp buffer to eBPF layer
In reply to Lorenzo BianconiUpdate 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.
--- drivers/net/ethernet/marvell/mvneta.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-)
drivers/net/ethernet/marvell/mvneta.c +18 -5
@@ -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; }
Signature · 1 line
2.31.1
PATCH v13 4/18 net: mvneta: simplify mvneta_swbm_add_rx_fragment management
In reply to Lorenzo BianconiRelying 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.
--- drivers/net/ethernet/marvell/mvneta.c | 42 ++++++++++----------------- 1 file changed, 15 insertions(+), 27 deletions(-)
drivers/net/ethernet/marvell/mvneta.c +15 -27
@@ -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 ();
Signature · 1 line
2.31.1
PATCH v13 5/18 net: xdp: add xdp_update_skb_shared_info utility routine
In reply to Lorenzo BianconiIntroduce 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.
--- include/net/xdp.h | 33 ++++++++++++++++++++++++++++++++- net/core/xdp.c | 17 +++++++++++++++++ 2 files changed, 49 insertions(+), 1 deletion(-)
include/net/xdp.h +32 -1
@@ -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 voidxdp_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 16struct 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__)
net/core/xdp.c +17 -0
@@ -531,8 +531,20 @@ struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf,struct sk_buff *skb, struct net_device *dev) { + unsigned int frag_size, frag_tsize;unsigned int headroom, frame_size;void *hard_start; +u8 nr_frags; + +/* xdp multi-buff frame */ +if (unlikely (xdp_frame_is_mb (xdpf))) { +struct skb_shared_info *sinfo; + + sinfo =xdp_get_shared_info_from_frame (xdpf); + frag_tsize = sinfo->xdp_frags_tsize; + frag_size = sinfo->xdp_frags_size; + nr_frags = sinfo->nr_frags; + }/* Part of headroom was reserved to xdpf */ headroom =sizeof (*xdpf) + xdpf->headroom;
@@ -552,6 +564,11 @@ 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, + frag_size, frag_tsize, +xdp_frame_is_frag_pfmemalloc (xdpf)); +/* Essential SKB info: protocol and skb->dev */ skb->protocol =eth_type_trans (skb, dev);
Signature · 1 line
2.31.1
Re: [PATCH v13 bpf-next 05/18] net: xdp: add xdp_update_skb_shared_info utility routine
Quoted 74 lines · Lorenzo Bianconi
Introduce
xdp_update_skb_shared_inforoutine to update frags array metadata inskb_shared_infodata structure converting to a skb from axdp_bufforxdp_frame.
According to the currentskb_shared_infoarchitecture in xdp_frame/xdp_buff and to the xdp multi-buff support, there is
no need to runskb_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.
IntroduceXDP_FLAGS_PF_MEMALLOCflag inxdp_buff_flagsin order to mark thexdp_bufforxdp_frameas under memory-pressure if pages of the frags array are under memory pressure. Doing so we can avoid looping over all fragments inxdp_update_skb_shared_inforoutine. The driver is expected to set the flag constructing thexdp_bufferusingxdp_buff_set_frag_pfmemallocutility routine.
Rely onxdp_update_skb_shared_infoin__xdp_build_skb_from_frameroutine converting the multi-buffxdp_frameto a skb after performing aXDP_REDIRECT.Acked-by John Fastabend <[email protected]>Signed-off-by Lorenzo Bianconi <[email protected]>--- include/net/xdp.h | 33 ++++++++++++++++++++++++++++++++- net/core/xdp.c | 17 +++++++++++++++++ 2 files changed, 49 insertions(+), 1 deletion(-)include/net/xdp.h +20
-1@@ -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 voidxdp_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 16struct 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
include/net/xdp.h static inline void xdp_scrub_frame(struct xdp_frame *frame) · line 217
Quoted 10 lines
include/net/xdp.h +10
-0+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;
Do we need to clear gso_type here as it is shared/union with xdp_frags_size ? (see below ... it is already cleared before call)
Quoted 31 lines
include/net/xdp.h +2
-0+} +/* 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__)net/core/xdp.c +12
-0@@ -531,8 +531,20 @@ struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf,struct sk_buff *skb, struct net_device *dev) { + unsigned int frag_size, frag_tsize;unsigned int headroom, frame_size;void *hard_start; +u8 nr_frags; + +/* xdp multi-buff frame */ +if (unlikely (xdp_frame_is_mb (xdpf))) { +struct skb_shared_info *sinfo; + + sinfo =xdp_get_shared_info_from_frame (xdpf); + frag_tsize = sinfo->xdp_frags_tsize; + frag_size = sinfo->xdp_frags_size; + nr_frags = sinfo->nr_frags; + }/* Part of headroom was reserved to xdpf */ headroom =sizeof (*xdpf) + xdpf->headroom;
net/core/xdp.c struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf, · line 571
Quoted 8 lines
net/core/xdp.c +5
-0@@ -552,6 +564,11 @@ 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, + frag_size, frag_tsize, +xdp_frame_is_frag_pfmemalloc (xdpf)); +
There is a build_skb_around() call before this call, which via __build_skb_around() will clear top part of skb_shared_info. (Thus, clearing gso_type not needed ... see above)
net/core/xdp.c struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf, · line 574
Quoted 3 lines
net/core/xdp.c +0
-0/* Essential SKB info: protocol and skb->dev */ skb->protocol =eth_type_trans (skb, dev);
Re: [PATCH v13 bpf-next 05/18] net: xdp: add xdp_update_skb_shared_info utility routine
[...]
Quoted 39 lines
Do we need to clear
gso_typehere as it is shared/union withxdp_frags_size?
(see below ... it is already cleared before call)Quoted 33 lines
include/net/xdp.h +2
-0+} +/* 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__)net/core/xdp.c +13
-0@@ -531,8 +531,20 @@ struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf,struct sk_buff *skb, struct net_device *dev) { + unsigned int frag_size, frag_tsize;unsigned int headroom, frame_size;void *hard_start; +u8 nr_frags; + +/* xdp multi-buff frame */ +if (unlikely (xdp_frame_is_mb (xdpf))) { +struct skb_shared_info *sinfo; + + sinfo =xdp_get_shared_info_from_frame (xdpf); + frag_tsize = sinfo->xdp_frags_tsize; + frag_size = sinfo->xdp_frags_size; + nr_frags = sinfo->nr_frags; + }/* Part of headroom was reserved to xdpf */ headroom =sizeof (*xdpf) + xdpf->headroom;@@ -552,6 +564,11 @@ 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)))
Quoted 8 lines
net/core/xdp.c struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf, · line 571
Quoted 4 lines
net/core/xdp.c +4
-0+xdp_update_skb_shared_info (skb, nr_frags, + frag_size, frag_tsize, +xdp_frame_is_frag_pfmemalloc (xdpf)); +There is a
build_skb_around()call before this call, which via__build_skb_around()will clear top part ofskb_shared_info. (Thus, clearinggso_typenot needed ... see above)
yes, this is why I need save sinfo->nr_frags, sinfo->xdp_frags_size, ...
Regards,
Lorenzo
Quoted 7 lines
net/core/xdp.c struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf, · line 573
Quoted 3 lines
net/core/xdp.c +0
-0/* Essential SKB info: protocol and skb->dev */ skb->protocol =eth_type_trans (skb, dev);
PATCH v13 6/18 net: marvell: rely on xdp_update_skb_shared_info utility routine
In reply to Lorenzo BianconiRely 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.
--- drivers/net/ethernet/marvell/mvneta.c | 35 +++++++++++++++------------ 1 file changed, 20 insertions(+), 15 deletions(-)
drivers/net/ethernet/marvell/mvneta.c +20 -15
@@ -2304,11 +2304,19 @@ 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); } + +/* last fragment */ +if (len == *size) + sinfo->xdp_frags_tsize = sinfo->nr_frags *PAGE_SIZE ; *size -= len; }
@@ -2316,13 +2324,18 @@ static struct sk_buff * 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); + unsigned int size, truesize;struct sk_buff *skb;u8 num_frags; -int i; -if (unlikely (xdp_buff_is_mb (xdp))) +if (unlikely (xdp_buff_is_mb (xdp))) { +struct skb_shared_info *sinfo; + + sinfo =xdp_get_shared_info_from_buff (xdp); + truesize = sinfo->xdp_frags_tsize; + size = sinfo->xdp_frags_size; num_frags = sinfo->nr_frags; + } skb =build_skb (xdp->data_hard_start,PAGE_SIZE );if (!skb)
@@ -2334,18 +2347,10 @@ 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, size, truesize, +xdp_buff_is_frag_pfmemalloc (xdp)); -out:return skb; }
Signature · 1 line
2.31.1
PATCH v13 7/18 xdp: add multi-buff support to xdp_return_{buff/frame}
In reply to Lorenzo BianconiTake 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.
--- include/net/xdp.h | 18 ++++++++++++++-- net/core/xdp.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 69 insertions(+), 3 deletions(-)
include/net/xdp.h +16 -2
@@ -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,
net/core/xdp.c +53 -1
84 lines not on this page · raw message
Signature · 1 line
2.31.1
PATCH v13 8/18 net: mvneta: add multi buffer support to XDP_TX
In reply to Lorenzo BianconiIntroduce the capability to map non-linear xdp buffer running mvneta_xdp_submit_frame() for XDP_TX and XDP_REDIRECT
--- drivers/net/ethernet/marvell/mvneta.c | 112 +++++++++++++++++--------- 1 file changed, 76 insertions(+), 36 deletions(-)
drivers/net/ethernet/marvell/mvneta.c +76 -36
@@ -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++; }
Signature · 1 line
2.31.1
PATCH v13 9/18 net: mvneta: enable jumbo frames for XDP
In reply to Lorenzo BianconiEnable the capability to receive jumbo frames even if the interface is running in XDP mode
--- drivers/net/ethernet/marvell/mvneta.c | 10 ---------- 1 file changed, 10 deletions(-)
drivers/net/ethernet/marvell/mvneta.c +0 -10
@@ -3767,11 +3767,6 @@ 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); -return -EINVAL ; - } - dev->mtu = mtu;if (!netif_running (dev)) {
@@ -4481,11 +4476,6 @@ 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" ); -return -EOPNOTSUPP ; - } -if (pp->bm_priv) {NL_SET_ERR_MSG_MOD (extack,"Hardware Buffer Management not supported on XDP" );
Signature · 1 line
2.31.1
PATCH v13 10/18 bpf: add multi-buff support to the bpf_xdp_adjust_tail() API
In reply to Lorenzo BianconiFrom: Eelco Chaudron <[email protected]>
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.
--- include/net/xdp.h | 9 +++++++ net/core/filter.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++ net/core/xdp.c | 5 ++-- 3 files changed, 72 insertions(+), 2 deletions(-)
include/net/xdp.h +9 -0
@@ -145,6 +145,13 @@ xdp_get_shared_info_from_buff(struct xdp_buff *xdp)return (struct skb_shared_info *)xdp_data_hard_end (xdp); } +static inline unsigned int xdp_get_frag_tailroom (const skb_frag_t *frag) +{ +struct page *page =skb_frag_page (frag); + +return page_size (page) -skb_frag_size (frag) -skb_frag_off (frag); +} +struct xdp_frame {void *data;u16 len;
@@ -290,6 +297,8 @@ 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);
net/core/filter.c +60 -0
71 lines not on this page · raw message
net/core/xdp.c +3 -2
@@ -339,8 +339,8 @@ 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;
@@ -373,6 +373,7 @@ 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) {
Signature · 1 line
2.31.1
PATCH v13 11/18 bpf: introduce bpf_xdp_get_buff_len helper
In reply to Lorenzo BianconiIntroduce bpf_xdp_get_buff_len helper in order to return the xdp buffer total size (linear and paged area)
--- include/uapi/linux/bpf.h | 7 +++++++ net/core/filter.c | 23 +++++++++++++++++++++++ tools/include/uapi/linux/bpf.h | 7 +++++++ 3 files changed, 37 insertions(+)
include/uapi/linux/bpf.h +7 -0
@@ -4877,6 +4877,12 @@ union bpf_attr {* Get the struct pt_regs associated with **task**. * Return * A pointer to struct pt_regs. +* +* 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), \
@@ -5055,6 +5061,7 @@ union bpf_attr {FN (get_func_ip), \FN (get_attach_cookie), \FN (task_pt_regs), \ +FN (xdp_get_buff_len), \/* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper
net/core/filter.c +23 -0
@@ -3784,6 +3784,27 @@ 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) +{ +u64 len = xdp->data_end - xdp->data; + +if (unlikely (xdp_buff_is_mb (xdp))) { +struct skb_shared_info *sinfo; + + sinfo =xdp_get_shared_info_from_buff (xdp); + len += sinfo->xdp_frags_size; + } +return len; +} + +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 :
@@ -7531,6 +7552,8 @@ 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:
tools/include/uapi/linux/bpf.h +7 -0
@@ -4877,6 +4877,12 @@ union bpf_attr {* Get the struct pt_regs associated with **task**. * Return * A pointer to struct pt_regs. +* +* 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), \
@@ -5055,6 +5061,7 @@ union bpf_attr {FN (get_func_ip), \FN (get_attach_cookie), \FN (task_pt_regs), \ +FN (xdp_get_buff_len), \/* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper
Signature · 1 line
2.31.1
PATCH v13 12/18 bpf: add multi-buffer support to xdp copy helpers
In reply to Lorenzo BianconiFrom: Eelco Chaudron <[email protected]>
This patch adds support for multi-buffer for the following helpers:
- bpf_xdp_output()
- bpf_perf_event_output()
--- kernel/trace/bpf_trace.c | 3 + net/core/filter.c | 68 +++++++- .../selftests/bpf/prog_tests/xdp_bpf2bpf.c | 151 +++++++++++++----- .../selftests/bpf/progs/test_xdp_bpf2bpf.c | 2 +- 4 files changed, 180 insertions(+), 44 deletions(-)
kernel/trace/bpf_trace.c +3 -0
@@ -1441,6 +1441,7 @@ 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)
@@ -1538,6 +1539,8 @@ 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 ?
net/core/filter.c +64 -4
90 lines not on this page · raw message
tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c +112 -39
188 lines not on this page · raw message
tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c +1 -1
@@ -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,
Signature · 1 line
2.31.1
PATCH v13 13/18 bpf: move user_size out of bpf_test_init
In reply to Lorenzo BianconiRely on data_size_in in bpf_test_init routine signature. This is a preliminary patch to introduce xdp multi-buff selftest
--- net/bpf/test_run.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-)
net/bpf/test_run.c +7 -6
@@ -246,11 +246,10 @@ bool bpf_prog_test_check_kfunc_call(u32 kfunc_id)return btf_id_set_contains (&test_sk_kfunc_ids, kfunc_id); } -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)
@@ -571,7 +570,8 @@ 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);
@@ -782,7 +782,8 @@ 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;
@@ -866,7 +867,7 @@ 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);
Signature · 1 line
2.31.1
PATCH v13 14/18 bpf: introduce multibuff support to bpf_prog_test_run_xdp()
In reply to Lorenzo BianconiIntroduce 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
--- net/bpf/test_run.c | 54 ++++++++++++++++++++++++++++++++++++---------- 1 file changed, 43 insertions(+), 11 deletions(-)
net/bpf/test_run.c +43 -11
@@ -750,16 +750,16 @@ 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 )
@@ -779,11 +779,10 @@ 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;
@@ -793,11 +792,45 @@ 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_tsize +=PAGE_SIZE ; + sinfo->xdp_frags_size += data_len; + size += data_len; + } +xdp_buff_set_mb (&xdp); + } +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
@@ -808,10 +841,7 @@ 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)
@@ -821,6 +851,8 @@ int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr, out: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);
Signature · 1 line
2.31.1
PATCH v13 15/18 bpf: test_run: add xdp_shared_info pointer in bpf_test_finish signature
In reply to Lorenzo Bianconiintroduce 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
--- net/bpf/test_run.c | 48 +++++++++++++++++++++++++++++++++++++--------- 1 file changed, 39 insertions(+), 9 deletions(-)
net/bpf/test_run.c +39 -9
@@ -129,7 +129,8 @@ 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 ;
@@ -144,8 +145,36 @@ static int bpf_test_finish(const union bpf_attr *kattr, err = -ENOSPC ; } -if (data_out &©_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)))
@@ -674,7 +703,8 @@ 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 ));
@@ -842,8 +872,8 @@ 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 ));
@@ -934,8 +964,8 @@ 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 ));
@@ -1039,7 +1069,7 @@ 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));
Signature · 1 line
2.31.1
PATCH v13 16/18 bpf: update xdp_adjust_tail selftest to include multi-buffer
In reply to Lorenzo BianconiFrom: Eelco Chaudron <[email protected]>
This change adds test cases for the multi-buffer scenarios when shrinking and growing.
--- .../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(-)
tools/testing/selftests/bpf/prog_tests/xdp_adjust_tail.c +118 -0
@@ -130,6 +130,120 @@ 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 (); }
tools/testing/selftests/bpf/progs/test_xdp_adjust_tail_grow.c +7 -3
@@ -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 */ }
tools/testing/selftests/bpf/progs/test_xdp_adjust_tail_shrink.c +28 -4
@@ -14,14 +14,38 @@ int _version SEC("version") = 1; SEC("xdp_adjust_tail_shrink")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 ;
Signature · 1 line
2.31.1
PATCH v13 17/18 net: xdp: introduce bpf_xdp_adjust_data helper
In reply to Lorenzo BianconiFor XDP frames split over multiple buffers, the xdp_md->data and xdp_md->data_end pointers will point to the start and end of the first fragment only. bpf_xdp_adjust_data can be used to access subsequent fragments by moving the data pointers. To use, an XDP program can call this helper with the byte offset of the packet payload that
it wants to access; the helper will move xdp_md->data and xdp_md ->data_end so they point to the requested payload offset and to the end of the fragment containing this byte offset, and return the byte offset of the start of the fragment.
To move back to the beginning of the packet, simply call the helper with an offset of '0'.
Note also that the helpers that modify the packet boundaries (bpf_xdp_adjust_head(), bpf_xdp_adjust_tail() and bpf_xdp_adjust_meta()) will fail if the pointers have been moved; it is the responsibility of the BPF program to move them back before using these helpers.
--- include/net/xdp.h | 8 +++++ include/uapi/linux/bpf.h | 32 +++++++++++++++++ net/bpf/test_run.c | 8 +++++ net/core/filter.c | 65 +++++++++++++++++++++++++++++++++- tools/include/uapi/linux/bpf.h | 32 +++++++++++++++++ 5 files changed, 144 insertions(+), 1 deletion(-)
include/net/xdp.h +8 -0
@@ -82,6 +82,11 @@ struct xdp_buff {struct xdp_txq_info *txq;u32 frame_sz;/* frame size to deduce data_hard_end/reserved tailroom*/ u16 flags;/* supported values defined in xdp_flags */ +/* xdp multi-buff metadata used for frags iteration */ +struct { +u16 headroom;/* frame headroom: data - data_hard_start */ +u16 headlen;/* first buffer length: data_end - data */ + } mb; }; static __always_inline bool xdp_buff_is_mb(struct xdp_buff *xdp)
@@ -127,6 +132,9 @@ xdp_prepare_buff(struct xdp_buff *xdp, unsigned char *hard_start, xdp->data = data; xdp->data_end = data + data_len; xdp->data_meta = meta_valid ? data : data +1 ; +/* mb metadata for frags iteration */ + xdp->mb.headroom = headroom; + xdp->mb.headlen = data_len; }/* Reserve memory area at end-of data area.
include/uapi/linux/bpf.h +32 -0
@@ -4883,6 +4883,37 @@ 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_adjust_data(struct xdp_buff *xdp_md, u32 offset) +* Description +* For XDP frames split over multiple buffers, the +* *xdp_md*\ **->data** and *xdp_md *\ **->data_end** pointers +* will point to the start and end of the first fragment only. +* This helper can be used to access subsequent fragments by +* moving the data pointers. To use, an XDP program can call +* this helper with the byte offset of the packet payload that +* it wants to access; the helper will move *xdp_md*\ **->data** +* and *xdp_md *\ **->data_end** so they point to the requested +* payload offset and to the end of the fragment containing this +* byte offset, and return the byte offset of the start of the +* fragment. +* To move back to the beginning of the packet, simply call the +* helper with an offset of '0'. +* Note also that the helpers that modify the packet boundaries +* (*bpf_xdp_adjust_head()*, *bpf_xdp_adjust_tail()* and +* *bpf_xdp_adjust_meta()*) will fail if the pointers have been +* moved; it is the responsibility of the BPF program to move them +* back before using these helpers. +* +* A call to this helper is susceptible to change the underlying +* packet buffer. Therefore, at load time, all checks on pointers +* previously done by the verifier are invalidated and must be +* performed again, if the helper is used in combination with +* direct packet access. +* Return +* offset between the beginning of the current fragment and +* original *xdp_md*\ **->data** on success, or a negative error +* in case of failure. */ #define __BPF_FUNC_MAPPER (FN ) \ FN(unspec), \
@@ -5062,6 +5093,7 @@ union bpf_attr {FN (get_attach_cookie), \FN (task_pt_regs), \FN (xdp_get_buff_len), \ +FN (xdp_adjust_data), \/* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper
net/bpf/test_run.c +8 -0
@@ -757,6 +757,8 @@ static int xdp_convert_md_to_buff(struct xdp_md *xdp_md, struct xdp_buff *xdp) } xdp->data = xdp->data_meta + xdp_md->data; + xdp->mb.headroom = xdp->data - xdp->data_hard_start; + xdp->mb.headlen = xdp->data_end - xdp->data;return 0 ; free_dev:
@@ -871,6 +873,12 @@ int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,if (ret) goto out; +/* data pointers need to be reset after frag iteration */ +if (unlikely (xdp.data_hard_start + xdp.mb.headroom != xdp.data)) { + ret = -EFAULT ; + goto out; + } + size = xdp.data_end - xdp.data_meta + sinfo->xdp_frags_size; ret =bpf_test_finish (kattr, uattr, xdp.data_meta, sinfo, size, retval, duration);
net/core/filter.c +64 -1
107 lines not on this page · raw message
tools/include/uapi/linux/bpf.h +32 -0
@@ -4883,6 +4883,37 @@ 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_adjust_data(struct xdp_buff *xdp_md, u32 offset) +* Description +* For XDP frames split over multiple buffers, the +* *xdp_md*\ **->data** and *xdp_md *\ **->data_end** pointers +* will point to the start and end of the first fragment only. +* This helper can be used to access subsequent fragments by +* moving the data pointers. To use, an XDP program can call +* this helper with the byte offset of the packet payload that +* it wants to access; the helper will move *xdp_md*\ **->data** +* and *xdp_md *\ **->data_end** so they point to the requested +* payload offset and to the end of the fragment containing this +* byte offset, and return the byte offset of the start of the +* fragment. +* To move back to the beginning of the packet, simply call the +* helper with an offset of '0'. +* Note also that the helpers that modify the packet boundaries +* (*bpf_xdp_adjust_head()*, *bpf_xdp_adjust_tail()* and +* *bpf_xdp_adjust_meta()*) will fail if the pointers have been +* moved; it is the responsibility of the BPF program to move them +* back before using these helpers. +* +* A call to this helper is susceptible to change the underlying +* packet buffer. Therefore, at load time, all checks on pointers +* previously done by the verifier are invalidated and must be +* performed again, if the helper is used in combination with +* direct packet access. +* Return +* offset between the beginning of the current fragment and +* original *xdp_md*\ **->data** on success, or a negative error +* in case of failure. */ #define __BPF_FUNC_MAPPER (FN ) \ FN(unspec), \
@@ -5062,6 +5093,7 @@ union bpf_attr {FN (get_attach_cookie), \FN (task_pt_regs), \FN (xdp_get_buff_len), \ +FN (xdp_adjust_data), \/* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper
Signature · 1 line
2.31.1
PATCH v13 18/18 bpf: add bpf_xdp_adjust_data selftest
In reply to Lorenzo BianconiIntroduce kernel selftest for new bpf_xdp_adjust_data helper.
--- .../bpf/prog_tests/xdp_adjust_data.c | 63 +++++++++++++++++++ .../bpf/progs/test_xdp_update_frags.c | 45 +++++++++++++ 2 files changed, 108 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/xdp_adjust_data.c create mode 100644 tools/testing/selftests/bpf/progs/test_xdp_update_frags.c
tools/testing/selftests/bpf/prog_tests/xdp_adjust_data.c new file +63 -0
@@ -0,0 +1,63 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <test_progs.h> +#include <network_helpers.h> + +void test_xdp_update_frag (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 */ + + err =bpf_prog_test_run (prog_fd,1 , buf,128 , + buf, &size, &retval, &duration); + +/* test_xdp_update_frags: buf[16]: 0xaa -> 0xbb */ +CHECK (err || retval !=XDP_PASS || buf[16 ] !=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) */ + + err =bpf_prog_test_run (prog_fd,1 , buf,9000 , + buf, &size, &retval, &duration); + +/* test_xdp_update_frags: buf[5000]: 0xaa -> 0xbb */ +CHECK (err || retval !=XDP_PASS || buf[5000 ] !=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_data (void ) +{ +if (test__start_subtest ("xdp_adjust_data" )) +test_xdp_update_frag (); +}
tools/testing/selftests/bpf/progs/test_xdp_update_frags.c new file +45 -0
45 lines not on this page · raw message
Signature · 1 line
2.31.1