add multi-buff support for xdp running in generic mode
Subsystems (5)
v9 cover add multi-buff support for xdp running in generic mode
Introduce multi-buffer support for xdp running in generic mode not always linearizing the skb in netif_receive_generic_xdp routine. Introduce generic percpu page_pools allocator.
Changes since v8:
- fix veth regression introduce in veth.sh selftest
Changes since v7:
- fix sparse warnings
Changes since v6:
- remove patch 4/5 'net: page_pool: make stats available just for global pools'
- rename netif_skb_segment_for_xdp() in skb_cow_data_for_xdp()/skb_pp_cow_data()
- rename net_page_pool_alloc() in net_page_pool_create()
- rename page_pool percpu pointer in system_page_pool
- set percpu page_pool memory size
Changes since v5:
- move percpu page_pool pointer out of softnet_data in a dedicated variable
- make page_pool stats available just for global pools
- rely on netif_skb_segment_for_xdp utility routine in veth driver Changes since v4:
- fix compilation error if page_pools are not enabled
Changes since v3:
- introduce page_pool in softnet_data structure
- rely on page_pools for xdp_generic code
Changes since v2:
- rely on napi_alloc_frag() and napi_build_skb() to build the new skb Changes since v1:
- explicitly keep the skb segmented in netif_skb_check_for_generic_xdp() and do not rely on pskb_expand_head()
Lorenzo Bianconi (4):
net: add generic percpu page_pool allocator
xdp: rely on skb pointer reference in do_xdp_generic and
netif_receive_generic_xdp
xdp: add multi-buff support for xdp running in generic mode
veth: rely on skb_pp_cow_data utility routine
drivers/net/tun.c | 4 +- drivers/net/veth.c | 74 +------------------ include/linux/netdevice.h | 2 +- include/linux/skbuff.h | 4 ++ include/net/page_pool/types.h | 3 + net/core/dev.c | 131 +++++++++++++++++++++++++++------- net/core/page_pool.c | 23 ++++-- net/core/skbuff.c | 97 ++++++++++++++++++++++++- 8 files changed, 231 insertions(+), 107 deletions(-)
Signature · 1 line
2.43.0
PATCH v9 1/4 net: add generic percpu page_pool allocator
Introduce generic percpu page_pools allocator.
Moreover add page_pool_create_percpu() and cpuid filed in page_pool struct in order to recycle the page in the page_pool "hot" cache if napi_pp_put_page() is running on the same cpu.
This is a preliminary patch to add xdp multi-buff support for xdp running in generic mode.
--- include/net/page_pool/types.h | 3 +++ net/core/dev.c | 45 +++++++++++++++++++++++++++++++++++ net/core/page_pool.c | 23 ++++++++++++++---- net/core/skbuff.c | 5 ++-- 4 files changed, 70 insertions(+), 6 deletions(-)
include/net/page_pool/types.h +3 -0
@@ -128,6 +128,7 @@ struct page_pool_stats {struct page_pool {struct page_pool_params_fast p; +int cpuid;bool has_init_callback;long frag_users;
@@ -203,6 +204,8 @@ struct page *page_pool_alloc_pages(struct page_pool *pool, gfp_t gfp);struct page *page_pool_alloc_frag (struct page_pool *pool,unsigned int *offset,unsigned int size,gfp_t gfp);struct page_pool *page_pool_create (const struct page_pool_params *params); +struct page_pool *page_pool_create_percpu (const struct page_pool_params *params, +int cpuid);struct xdp_mem_info ;
net/core/dev.c +45 -0
75 lines not on this page · raw message
net/core/page_pool.c +19 -4
@@ -171,13 +171,16 @@ static void page_pool_producer_unlock(struct page_pool *pool, }static int page_pool_init (struct page_pool *pool, -const struct page_pool_params *params) +const struct page_pool_params *params, +int cpuid) {unsigned int ring_qsize =1024 ;/* Default */ memcpy (&pool->p, ¶ms->fast,sizeof (pool->p));memcpy (&pool->slow, ¶ms->slow,sizeof (pool->slow)); + pool->cpuid = cpuid; +/* Validate only known flags were used */ if (pool->p.flags & ~(PP_FLAG_ALL ))return -EINVAL ;
@@ -253,10 +256,12 @@ static void page_pool_uninit(struct page_pool *pool) }/** -* page_pool_create() - create a page pool. +* page_pool_create_percpu() - create a page pool for a given cpu. * @params: parameters, see struct page_pool_params +* @cpuid: cpu identifier */ -struct page_pool *page_pool_create (const struct page_pool_params *params) +struct page_pool * +page_pool_create_percpu (const struct page_pool_params *params,int cpuid) {struct page_pool *pool;int err;
@@ -265,7 +270,7 @@ struct page_pool *page_pool_create(const struct page_pool_params *params)if (!pool)return ERR_PTR (-ENOMEM ); - err =page_pool_init (pool, params); + err =page_pool_init (pool, params, cpuid);if (err <0 ) goto err_free;
@@ -282,6 +287,16 @@ struct page_pool *page_pool_create(const struct page_pool_params *params)kfree (pool);return ERR_PTR (err); } +EXPORT_SYMBOL (page_pool_create_percpu); + +/** +* page_pool_create() - create a page pool +* @params: parameters, see struct page_pool_params +*/ +struct page_pool *page_pool_create (const struct page_pool_params *params) +{ +return page_pool_create_percpu (params,-1 ); +}EXPORT_SYMBOL (page_pool_create);static void page_pool_return_page (struct page_pool *pool,struct page *page);
net/core/skbuff.c +3 -2
@@ -923,9 +923,10 @@ bool napi_pp_put_page(struct page *page, bool napi_safe)*/ if (napi_safe ||in_softirq ()) {const struct napi_struct *napi =READ_ONCE (pp->p.napi); +unsigned int cpuid =smp_processor_id (); - allow_direct = napi && -READ_ONCE (napi->list_owner) ==smp_processor_id (); + allow_direct = napi &&READ_ONCE (napi->list_owner) == cpuid; + allow_direct |= (pp->cpuid == cpuid); }/* Driver set this to memory recycling info. Reset it on recycle.
Signature · 1 line
2.43.0
PATCH v9 2/4 xdp: rely on skb pointer reference in do_xdp_generic and netif_receive_generic_xdp
In reply to Lorenzo BianconiRely on skb pointer reference instead of the skb pointer in do_xdp_generic and netif_receive_generic_xdp routine signatures.
This is a preliminary patch to add multi-buff support for xdp running in generic mode where we will need to reallocate the skb to avoid linearization and we will need to make it visible to do_xdp_generic() caller.
--- drivers/net/tun.c | 4 ++-- include/linux/netdevice.h | 2 +- net/core/dev.c | 16 +++++++++------- 3 files changed, 12 insertions(+), 10 deletions(-)
drivers/net/tun.c +2 -2
@@ -1926,7 +1926,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,rcu_read_lock (); xdp_prog =rcu_dereference (tun->xdp_prog);if (xdp_prog) { - ret =do_xdp_generic (xdp_prog, skb); + ret =do_xdp_generic (xdp_prog, &skb);if (ret !=XDP_PASS ) {rcu_read_unlock ();local_bh_enable ();
@@ -2516,7 +2516,7 @@ static int tun_xdp_one(struct tun_struct *tun,skb_record_rx_queue (skb, tfile->queue_index);if (skb_xdp) { - ret =do_xdp_generic (xdp_prog, skb); + ret =do_xdp_generic (xdp_prog, &skb);if (ret !=XDP_PASS ) { ret =0 ; goto out;
include/linux/netdevice.h +1 -1
@@ -3958,7 +3958,7 @@ static inline void dev_consume_skb_any(struct sk_buff *skb)u32 bpf_prog_run_generic_xdp (struct sk_buff *skb,struct xdp_buff *xdp,struct bpf_prog *xdp_prog);void generic_xdp_tx (struct sk_buff *skb,struct bpf_prog *xdp_prog); -int do_xdp_generic (struct bpf_prog *xdp_prog,struct sk_buff *skb); +int do_xdp_generic (struct bpf_prog *xdp_prog,struct sk_buff **pskb);int netif_rx (struct sk_buff *skb);int __netif_rx (struct sk_buff *skb);
net/core/dev.c +9 -7
@@ -4936,10 +4936,11 @@ u32 bpf_prog_run_generic_xdp(struct sk_buff *skb, struct xdp_buff *xdp,return act; } -static u32 netif_receive_generic_xdp (struct sk_buff *skb, +static u32 netif_receive_generic_xdp (struct sk_buff **pskb,struct xdp_buff *xdp,struct bpf_prog *xdp_prog) { +struct sk_buff *skb = *pskb;u32 act =XDP_DROP ;/* Reinjected packets coming from act_mirred or similar should
@@ -5020,24 +5021,24 @@ void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog)static DEFINE_STATIC_KEY_FALSE (generic_xdp_needed_key); -int do_xdp_generic (struct bpf_prog *xdp_prog,struct sk_buff *skb) +int do_xdp_generic (struct bpf_prog *xdp_prog,struct sk_buff **pskb) {if (xdp_prog) {struct xdp_buff xdp;u32 act;int err; - act =netif_receive_generic_xdp (skb, &xdp, xdp_prog); + act =netif_receive_generic_xdp (pskb, &xdp, xdp_prog);if (act !=XDP_PASS ) {switch (act) {case XDP_REDIRECT : - err =xdp_do_generic_redirect (skb->dev, skb, + err =xdp_do_generic_redirect ((*pskb)->dev, *pskb, &xdp, xdp_prog);if (err) goto out_redir;break ;case XDP_TX : -generic_xdp_tx (skb, xdp_prog); +generic_xdp_tx (*pskb, xdp_prog);break ; }return XDP_DROP ;
@@ -5045,7 +5046,7 @@ int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff *skb) }return XDP_PASS ; out_redir: -kfree_skb_reason (skb,SKB_DROP_REASON_XDP ); +kfree_skb_reason (*pskb,SKB_DROP_REASON_XDP );return XDP_DROP ; }EXPORT_SYMBOL_GPL (do_xdp_generic);
@@ -5368,7 +5369,8 @@ static int __netif_receive_skb_core(struct sk_buff **pskb, bool pfmemalloc,int ret2;migrate_disable (); - ret2 =do_xdp_generic (rcu_dereference (skb->dev->xdp_prog), skb); + ret2 =do_xdp_generic (rcu_dereference (skb->dev->xdp_prog), + &skb);migrate_enable ();if (ret2 !=XDP_PASS ) {
Signature · 1 line
2.43.0
PATCH v9 3/4 xdp: add multi-buff support for xdp running in generic mode
In reply to Lorenzo BianconiSimilar to native xdp, do not always linearize the skb in netif_receive_generic_xdp routine but create a non-linear xdp_buff to be processed by the eBPF program. This allow to add multi-buffer support for xdp running in generic mode.
--- include/linux/skbuff.h | 2 + net/core/dev.c | 70 +++++++++++++++++++++++--------- net/core/skbuff.c | 91 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 144 insertions(+), 19 deletions(-)
include/linux/skbuff.h +2 -0
@@ -3446,6 +3446,8 @@ static inline void skb_frag_ref(struct sk_buff *skb, int f)__skb_frag_ref (&skb_shinfo (skb)->frags[f]); } +int skb_cow_data_for_xdp (struct page_pool *pool,struct sk_buff **pskb, +struct bpf_prog *prog);bool napi_pp_put_page (struct page *page,bool napi_safe); static inline void
net/core/dev.c +51 -19
116 lines not on this page · raw message
net/core/skbuff.c +91 -0
97 lines not on this page · raw message
Signature · 1 line
2.43.0
Re: [PATCH v9 net-next 3/4] xdp: add multi-buff support for xdp running in generic mode
Quoted 14 lines · Lorenzo Bianconi
Similar to native xdp, do not always linearize the skb in
netif_receive_generic_xdproutine but create a non-linearxdp_buffto be processed by the eBPF program. This allow to add multi-buffer support for xdp running in generic mode.Reviewed-by Toke Hoiland-Jorgensen <[email protected]>Signed-off-by Lorenzo Bianconi <[email protected]>--- include/linux/skbuff.h | 2 + net/core/dev.c | 70 +++++++++++++++++++++++--------- net/core/skbuff.c | 91 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 144 insertions(+), 19 deletions(-)
[...]
Quoted 58 lines
net/core/skbuff.c +50
-0@@ -895,6 +895,97 @@ static bool is_pp_page(struct page *page)return (page->pp_magic & ~0x3UL ) ==PP_SIGNATURE ; } +static int skb_pp_cow_data (struct page_pool *pool,struct sk_buff **pskb, +unsigned int headroom) +{ +#if IS_ENABLED (CONFIG_PAGE_POOL ) +u32 size, truesize, len, max_head_size, off; +struct sk_buff *skb = *pskb, *nskb; +int err, i, head_off; +void *data; + +/* XDP does not support fraglist so we need to linearize +* the skb. +*/ +if (skb_has_frag_list (skb)) +return -EOPNOTSUPP ; + + max_head_size =SKB_WITH_OVERHEAD (PAGE_SIZE - headroom); +if (skb->len > max_head_size +MAX_SKB_FRAGS *PAGE_SIZE ) +return -ENOMEM ; + + size =min_t (u32, skb->len, max_head_size); + truesize =SKB_HEAD_ALIGN (size) + headroom; + data =page_pool_dev_alloc_va (pool, &truesize); +if (!data) +return -ENOMEM ; + + nskb =napi_build_skb (data, truesize); +if (!nskb) { +page_pool_free_va (pool, data, true); +return -ENOMEM ; + } + +skb_reserve (nskb, headroom); +skb_copy_header (nskb, skb); +skb_mark_for_recycle (nskb); + + err =skb_copy_bits (skb,0 , nskb->data, size); +if (err) { +consume_skb (nskb); +return err; + } +skb_put (nskb, size); + + head_off =skb_headroom (nskb) -skb_headroom (skb); +skb_headers_offset_update (nskb, head_off); + + off = size; + len = skb->len - off; +for (i =0 ; i <MAX_SKB_FRAGS && off < skb->len; i++) { +struct page *page; +u32 page_off;
net/core/skbuff.c static bool is_pp_page(struct page *page) · line 957
Quoted 10 lines
net/core/skbuff.c +10
-0+ + size =min_t (u32, len,PAGE_SIZE ); + truesize = size; + + page =page_pool_dev_alloc (pool, &page_off, &truesize); +if (!data) { +consume_skb (nskb); +return -ENOMEM ; + } +
This should check for !page instead, no?
(picked up as CID 1583654 by the coverity scan for linux-next)
Re: [PATCH v9 net-next 3/4] xdp: add multi-buff support for xdp running in generic mode
[...]
Quoted 23 lines
Quoted 23 lines
net/core/skbuff.c +23
-0+ nskb =napi_build_skb (data, truesize); +if (!nskb) { +page_pool_free_va (pool, data, true); +return -ENOMEM ; + } + +skb_reserve (nskb, headroom); +skb_copy_header (nskb, skb); +skb_mark_for_recycle (nskb); + + err =skb_copy_bits (skb,0 , nskb->data, size); +if (err) { +consume_skb (nskb); +return err; + } +skb_put (nskb, size); + + head_off =skb_headroom (nskb) -skb_headroom (skb); +skb_headers_offset_update (nskb, head_off); + + off = size; + len = skb->len - off; +for (i =0 ; i <MAX_SKB_FRAGS && off < skb->len; i++) {
Quoted 8 lines
net/core/skbuff.c static bool is_pp_page(struct page *page) · line 953
Quoted 8 lines
net/core/skbuff.c +8
-0+struct page *page; +u32 page_off; + + size =min_t (u32, len,PAGE_SIZE ); + truesize = size; + + page =page_pool_dev_alloc (pool, &page_off, &truesize); +if (!data) {
ack, right. I will post a fix, thx for reporting the issue.
Regards,
Lorenzo
Quoted 9 lines
net/core/skbuff.c static bool is_pp_page(struct page *page) · line 957
Quoted 4 lines
net/core/skbuff.c +4
-0+consume_skb (nskb); +return -ENOMEM ; + } +This should check for !page instead, no?
(picked up as CID 1583654 by the coverity scan for linux-next)
PATCH v9 4/4 veth: rely on skb_pp_cow_data utility routine
In reply to Lorenzo BianconiRely on skb_pp_cow_data utility routine and remove duplicated code.
--- drivers/net/veth.c | 74 ++---------------------------------------- include/linux/skbuff.h | 2 ++ net/core/skbuff.c | 5 +-- 3 files changed, 7 insertions(+), 74 deletions(-)
drivers/net/veth.c +2 -72
@@ -729,80 +729,10 @@ static int veth_convert_skb_to_xdp_buff(struct veth_rq *rq,if (skb_shared (skb) ||skb_head_is_locked (skb) ||skb_shinfo (skb)->nr_frags ||skb_headroom (skb) <XDP_PACKET_HEADROOM ) { -u32 size, len, max_head_size, off, truesize, page_offset; -struct sk_buff *nskb; -struct page *page; -int i, head_off; -void *va; - -/* We need a private copy of the skb and data buffers since -* the ebpf program can modify it. We segment the original skb -* into order-0 pages without linearize it. -* -* Make sure we have enough space for linear and paged area -*/ - max_head_size =SKB_WITH_OVERHEAD (PAGE_SIZE - -VETH_XDP_HEADROOM ); -if (skb->len >PAGE_SIZE *MAX_SKB_FRAGS + max_head_size) - goto drop; - - size =min_t (u32, skb->len, max_head_size); - truesize =SKB_HEAD_ALIGN (size) +VETH_XDP_HEADROOM ; - -/* Allocate skb head */ - va =page_pool_dev_alloc_va (rq->page_pool, &truesize); -if (!va) - goto drop; - - nskb =napi_build_skb (va, truesize); -if (!nskb) { -page_pool_free_va (rq->page_pool, va, true); +if (skb_pp_cow_data (rq->page_pool, pskb,XDP_PACKET_HEADROOM )) goto drop; - } - -skb_reserve (nskb,VETH_XDP_HEADROOM ); -skb_copy_header (nskb, skb); -skb_mark_for_recycle (nskb); - -if (skb_copy_bits (skb,0 , nskb->data, size)) { -consume_skb (nskb); - goto drop; - } -skb_put (nskb, size); - head_off =skb_headroom (nskb) -skb_headroom (skb); -skb_headers_offset_update (nskb, head_off); - -/* Allocate paged area of new skb */ - off = size; - len = skb->len - off; - -for (i =0 ; i <MAX_SKB_FRAGS && off < skb->len; i++) { - size =min_t (u32, len,PAGE_SIZE ); - truesize = size; - - page =page_pool_dev_alloc (rq->page_pool, &page_offset, - &truesize); -if (!page) { -consume_skb (nskb); - goto drop; - } - -skb_add_rx_frag (nskb, i, page, page_offset, size, - truesize); -if (skb_copy_bits (skb, off, -page_address (page) + page_offset, - size)) { -consume_skb (nskb); - goto drop; - } - - len -= size; - off += size; - } - -consume_skb (skb); - skb = nskb; + skb = *pskb; }/* SKB "head" area always have tailroom for skb_shared_info */
include/linux/skbuff.h +2 -0
@@ -3446,6 +3446,8 @@ static inline void skb_frag_ref(struct sk_buff *skb, int f)__skb_frag_ref (&skb_shinfo (skb)->frags[f]); } +int skb_pp_cow_data (struct page_pool *pool,struct sk_buff **pskb, +unsigned int headroom);int skb_cow_data_for_xdp (struct page_pool *pool,struct sk_buff **pskb,struct bpf_prog *prog);bool napi_pp_put_page (struct page *page,bool napi_safe);
net/core/skbuff.c +3 -2
@@ -895,8 +895,8 @@ static bool is_pp_page(struct page *page)return (page->pp_magic & ~0x3UL ) ==PP_SIGNATURE ; } -static int skb_pp_cow_data (struct page_pool *pool,struct sk_buff **pskb, -unsigned int headroom) +int skb_pp_cow_data (struct page_pool *pool,struct sk_buff **pskb, +unsigned int headroom) {#if IS_ENABLED (CONFIG_PAGE_POOL )u32 size, truesize, len, max_head_size, off;
@@ -975,6 +975,7 @@ static int skb_pp_cow_data(struct page_pool *pool, struct sk_buff **pskb,return -EOPNOTSUPP ;#endif } +EXPORT_SYMBOL (skb_pp_cow_data);int skb_cow_data_for_xdp (struct page_pool *pool,struct sk_buff **pskb,struct bpf_prog *prog)
Signature · 1 line
2.43.0
This series was applied to netdev/net-next.git (main) by Jakub Kicinski <[email protected]>:
Hello:
This series was applied to netdev/net-next.git (main) by Jakub Kicinski <[email protected]>:
Quoted 30 lines · On Mon, 12 Feb 2024 10:50:53 +0100 you wrote:
Introduce multi-buffer support for xdp running in generic mode not always linearizing the skb in
netif_receive_generic_xdproutine. Introduce generic percpupage_poolsallocator.Changes since v8:
- fix veth regression introduce inveth.shselftest
Changes since v7:
- fix sparse warnings
Changes since v6:
- remove patch 4/5 'net:page_pool: make stats available just for global pools'
- renamenetif_skb_segment_for_xdp()in skb_cow_data_for_xdp()/skb_pp_cow_data()
- renamenet_page_pool_alloc()innet_page_pool_create()
- renamepage_poolpercpu pointer insystem_page_pool
- set percpupage_poolmemory size
Changes since v5:
- move percpupage_poolpointer out ofsoftnet_datain a dedicated variable
- makepage_poolstats available just for global pools
- rely onnetif_skb_segment_for_xdputility routine in veth driver Changes since v4:
- fix compilation error ifpage_poolsare not enabled
Changes since v3:
- introducepage_poolinsoftnet_datastructure
- rely onpage_poolsforxdp_genericcode
Changes since v2:
- rely onnapi_alloc_frag()andnapi_build_skb()to build the new skb Changes since v1:
- explicitly keep the skb segmented innetif_skb_check_for_generic_xdp()and do not rely onpskb_expand_head()
Quoted 1 line
[...]
Here is the summary with links:
- [v9,net-next,1/4] net: add generic percpu page_pool allocator
https://git.kernel.org/netdev/net-next/c/2b0cfa6e4956 - [v9,net-next,2/4] xdp: rely on skb pointer reference in do_xdp_generic and netif_receive_generic_xdp https://git.kernel.org/netdev/net-next/c/4d2bb0bfe874 - [v9,net-next,3/4] xdp: add multi-buff support for xdp running in generic mode https://git.kernel.org/netdev/net-next/c/e6d5dbdd20aa - [v9,net-next,4/4] veth: rely on skb_pp_cow_data utility routine https://git.kernel.org/netdev/net-next/c/27accb3cc08a
You are awesome, thank you!
Signature · 2 lines
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