From ca5c94949facce1f67a4a9a9528a27f635ff3e78 Mon Sep 17 00:00:00 2001 From: Alexander Lobakin Date: Tue, 3 Dec 2024 18:37:24 +0100 Subject: [PATCH 1/8] xsk: align &xdp_buff_xsk harder MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit After the series "XSk buff on a diet" by Maciej, the greatest pow-2 which &xdp_buff_xsk can be divided got reduced from 16 to 8 on x86_64. Also, sizeof(xdp_buff_xsk) now is 120 bytes, which, taking the previous sentence into account, leads to that it leaves 8 bytes at the end of cacheline, which means an array of buffs will have its elements messed between the cachelines chaotically. Use __aligned_largest for this struct. This alignment is usually 16 bytes, which makes it fill two full cachelines and align an array nicely. ___cacheline_aligned may be excessive here, especially on arches with 128-256 byte CLs, as well as 32-bit arches (76 -> 96 bytes on MIPS32R2), while not doing better than _largest. Signed-off-by: Alexander Lobakin Reviewed-by: Toke Høiland-Jørgensen Link: https://patch.msgid.link/20241203173733.3181246-2-aleksander.lobakin@intel.com Signed-off-by: Jakub Kicinski --- include/net/xsk_buff_pool.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/net/xsk_buff_pool.h b/include/net/xsk_buff_pool.h index bb03cee716b3..7637799b6c19 100644 --- a/include/net/xsk_buff_pool.h +++ b/include/net/xsk_buff_pool.h @@ -29,7 +29,7 @@ struct xdp_buff_xsk { dma_addr_t frame_dma; struct xsk_buff_pool *pool; struct list_head list_node; -}; +} __aligned_largest; #define XSK_CHECK_PRIV_TYPE(t) BUILD_BUG_ON(sizeof(t) > offsetofend(struct xdp_buff_xsk, cb)) #define XSK_TX_COMPL_FITS(t) BUILD_BUG_ON(sizeof(struct xsk_tx_metadata_compl) > sizeof(t)) From 7cd1107f48e2a246c6a628c2381e1b8aafa4675a Mon Sep 17 00:00:00 2001 From: Alexander Lobakin Date: Tue, 3 Dec 2024 18:37:25 +0100 Subject: [PATCH 2/8] bpf, xdp: constify some bpf_prog * function arguments MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In lots of places, bpf_prog pointer is used only for tracing or other stuff that doesn't modify the structure itself. Same for net_device. Address at least some of them and add `const` attributes there. The object code didn't change, but that may prevent unwanted data modifications and also allow more helpers to have const arguments. Reviewed-by: Toke Høiland-Jørgensen Signed-off-by: Alexander Lobakin Signed-off-by: Jakub Kicinski --- include/linux/bpf.h | 12 ++++++------ include/linux/filter.h | 9 +++++---- include/linux/netdevice.h | 6 +++--- include/linux/skbuff.h | 2 +- kernel/bpf/devmap.c | 8 ++++---- net/core/dev.c | 10 +++++----- net/core/filter.c | 29 ++++++++++++++++------------- net/core/skbuff.c | 2 +- 8 files changed, 41 insertions(+), 37 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index eaee2a819f4c..ec3acb16359e 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2591,10 +2591,10 @@ int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_frame *xdpf, int dev_map_enqueue_multi(struct xdp_frame *xdpf, struct net_device *dev_rx, struct bpf_map *map, bool exclude_ingress); int dev_map_generic_redirect(struct bpf_dtab_netdev *dst, struct sk_buff *skb, - struct bpf_prog *xdp_prog); + const struct bpf_prog *xdp_prog); int dev_map_redirect_multi(struct net_device *dev, struct sk_buff *skb, - struct bpf_prog *xdp_prog, struct bpf_map *map, - bool exclude_ingress); + const struct bpf_prog *xdp_prog, + struct bpf_map *map, bool exclude_ingress); void __cpu_map_flush(struct list_head *flush_list); int cpu_map_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_frame *xdpf, @@ -2864,15 +2864,15 @@ struct sk_buff; static inline int dev_map_generic_redirect(struct bpf_dtab_netdev *dst, struct sk_buff *skb, - struct bpf_prog *xdp_prog) + const struct bpf_prog *xdp_prog) { return 0; } static inline int dev_map_redirect_multi(struct net_device *dev, struct sk_buff *skb, - struct bpf_prog *xdp_prog, struct bpf_map *map, - bool exclude_ingress) + const struct bpf_prog *xdp_prog, + struct bpf_map *map, bool exclude_ingress) { return 0; } diff --git a/include/linux/filter.h b/include/linux/filter.h index 3a21947f2fd4..9a5d23ae3855 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -1179,17 +1179,18 @@ static inline int xdp_ok_fwd_dev(const struct net_device *fwd, * This does not appear to be a real limitation for existing software. */ int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb, - struct xdp_buff *xdp, struct bpf_prog *prog); + struct xdp_buff *xdp, const struct bpf_prog *prog); int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp, - struct bpf_prog *prog); + const struct bpf_prog *prog); int xdp_do_redirect_frame(struct net_device *dev, struct xdp_buff *xdp, struct xdp_frame *xdpf, - struct bpf_prog *prog); + const struct bpf_prog *prog); void xdp_do_flush(void); -void bpf_warn_invalid_xdp_action(struct net_device *dev, struct bpf_prog *prog, u32 act); +void bpf_warn_invalid_xdp_action(const struct net_device *dev, + const struct bpf_prog *prog, u32 act); #ifdef CONFIG_INET struct sock *bpf_run_sk_reuseport(struct sock_reuseport *reuse, struct sock *sk, diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index ecc686409161..ecca21387a68 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3958,9 +3958,9 @@ 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 **pskb); + const struct bpf_prog *xdp_prog); +void generic_xdp_tx(struct sk_buff *skb, const struct bpf_prog *xdp_prog); +int do_xdp_generic(const struct bpf_prog *xdp_prog, struct sk_buff **pskb); int netif_rx(struct sk_buff *skb); int __netif_rx(struct sk_buff *skb); diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 58009fa66102..95452d1a07fc 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -3627,7 +3627,7 @@ static inline netmem_ref skb_frag_netmem(const skb_frag_t *frag) 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); + const struct bpf_prog *prog); /** * skb_frag_address - gets the address of the data contained in a paged fragment diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c index 7878be18e9d2..effde52bc857 100644 --- a/kernel/bpf/devmap.c +++ b/kernel/bpf/devmap.c @@ -678,7 +678,7 @@ int dev_map_enqueue_multi(struct xdp_frame *xdpf, struct net_device *dev_rx, } int dev_map_generic_redirect(struct bpf_dtab_netdev *dst, struct sk_buff *skb, - struct bpf_prog *xdp_prog) + const struct bpf_prog *xdp_prog) { int err; @@ -701,7 +701,7 @@ int dev_map_generic_redirect(struct bpf_dtab_netdev *dst, struct sk_buff *skb, static int dev_map_redirect_clone(struct bpf_dtab_netdev *dst, struct sk_buff *skb, - struct bpf_prog *xdp_prog) + const struct bpf_prog *xdp_prog) { struct sk_buff *nskb; int err; @@ -720,8 +720,8 @@ static int dev_map_redirect_clone(struct bpf_dtab_netdev *dst, } int dev_map_redirect_multi(struct net_device *dev, struct sk_buff *skb, - struct bpf_prog *xdp_prog, struct bpf_map *map, - bool exclude_ingress) + const struct bpf_prog *xdp_prog, + struct bpf_map *map, bool exclude_ingress) { struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map); struct bpf_dtab_netdev *dst, *last_dst = NULL; diff --git a/net/core/dev.c b/net/core/dev.c index 45a8c3dd4a64..40a2332e3fa0 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4931,7 +4931,7 @@ static struct netdev_rx_queue *netif_get_rxqueue(struct sk_buff *skb) } u32 bpf_prog_run_generic_xdp(struct sk_buff *skb, struct xdp_buff *xdp, - struct bpf_prog *xdp_prog) + const struct bpf_prog *xdp_prog) { void *orig_data, *orig_data_end, *hard_start; struct netdev_rx_queue *rxqueue; @@ -5033,7 +5033,7 @@ u32 bpf_prog_run_generic_xdp(struct sk_buff *skb, struct xdp_buff *xdp, } static int -netif_skb_check_for_xdp(struct sk_buff **pskb, struct bpf_prog *prog) +netif_skb_check_for_xdp(struct sk_buff **pskb, const struct bpf_prog *prog) { struct sk_buff *skb = *pskb; int err, hroom, troom; @@ -5057,7 +5057,7 @@ netif_skb_check_for_xdp(struct sk_buff **pskb, struct bpf_prog *prog) static u32 netif_receive_generic_xdp(struct sk_buff **pskb, struct xdp_buff *xdp, - struct bpf_prog *xdp_prog) + const struct bpf_prog *xdp_prog) { struct sk_buff *skb = *pskb; u32 mac_len, act = XDP_DROP; @@ -5110,7 +5110,7 @@ static u32 netif_receive_generic_xdp(struct sk_buff **pskb, * and DDOS attacks will be more effective. In-driver-XDP use dedicated TX * queues, so they do not have this starvation issue. */ -void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog) +void generic_xdp_tx(struct sk_buff *skb, const struct bpf_prog *xdp_prog) { struct net_device *dev = skb->dev; struct netdev_queue *txq; @@ -5135,7 +5135,7 @@ 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 **pskb) +int do_xdp_generic(const struct bpf_prog *xdp_prog, struct sk_buff **pskb) { struct bpf_net_context __bpf_net_ctx, *bpf_net_ctx; diff --git a/net/core/filter.c b/net/core/filter.c index 6625b3f563a4..fac245065b0a 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4348,9 +4348,9 @@ u32 xdp_master_redirect(struct xdp_buff *xdp) EXPORT_SYMBOL_GPL(xdp_master_redirect); static inline int __xdp_do_redirect_xsk(struct bpf_redirect_info *ri, - struct net_device *dev, + const struct net_device *dev, struct xdp_buff *xdp, - struct bpf_prog *xdp_prog) + const struct bpf_prog *xdp_prog) { enum bpf_map_type map_type = ri->map_type; void *fwd = ri->tgt_value; @@ -4371,10 +4371,10 @@ static inline int __xdp_do_redirect_xsk(struct bpf_redirect_info *ri, return err; } -static __always_inline int __xdp_do_redirect_frame(struct bpf_redirect_info *ri, - struct net_device *dev, - struct xdp_frame *xdpf, - struct bpf_prog *xdp_prog) +static __always_inline int +__xdp_do_redirect_frame(struct bpf_redirect_info *ri, struct net_device *dev, + struct xdp_frame *xdpf, + const struct bpf_prog *xdp_prog) { enum bpf_map_type map_type = ri->map_type; void *fwd = ri->tgt_value; @@ -4443,7 +4443,7 @@ static __always_inline int __xdp_do_redirect_frame(struct bpf_redirect_info *ri, } int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp, - struct bpf_prog *xdp_prog) + const struct bpf_prog *xdp_prog) { struct bpf_redirect_info *ri = bpf_net_ctx_get_ri(); enum bpf_map_type map_type = ri->map_type; @@ -4457,7 +4457,8 @@ int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp, EXPORT_SYMBOL_GPL(xdp_do_redirect); int xdp_do_redirect_frame(struct net_device *dev, struct xdp_buff *xdp, - struct xdp_frame *xdpf, struct bpf_prog *xdp_prog) + struct xdp_frame *xdpf, + const struct bpf_prog *xdp_prog) { struct bpf_redirect_info *ri = bpf_net_ctx_get_ri(); enum bpf_map_type map_type = ri->map_type; @@ -4472,9 +4473,9 @@ EXPORT_SYMBOL_GPL(xdp_do_redirect_frame); static int xdp_do_generic_redirect_map(struct net_device *dev, struct sk_buff *skb, struct xdp_buff *xdp, - struct bpf_prog *xdp_prog, void *fwd, - enum bpf_map_type map_type, u32 map_id, - u32 flags) + const struct bpf_prog *xdp_prog, + void *fwd, enum bpf_map_type map_type, + u32 map_id, u32 flags) { struct bpf_redirect_info *ri = bpf_net_ctx_get_ri(); struct bpf_map *map; @@ -4528,7 +4529,8 @@ static int xdp_do_generic_redirect_map(struct net_device *dev, } int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb, - struct xdp_buff *xdp, struct bpf_prog *xdp_prog) + struct xdp_buff *xdp, + const struct bpf_prog *xdp_prog) { struct bpf_redirect_info *ri = bpf_net_ctx_get_ri(); enum bpf_map_type map_type = ri->map_type; @@ -9075,7 +9077,8 @@ static bool xdp_is_valid_access(int off, int size, return __is_valid_xdp_access(off, size); } -void bpf_warn_invalid_xdp_action(struct net_device *dev, struct bpf_prog *prog, u32 act) +void bpf_warn_invalid_xdp_action(const struct net_device *dev, + const struct bpf_prog *prog, u32 act) { const u32 act_max = XDP_REDIRECT; diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 6841e61a6bd0..a441613a1e6c 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -1009,7 +1009,7 @@ int skb_pp_cow_data(struct page_pool *pool, struct sk_buff **pskb, EXPORT_SYMBOL(skb_pp_cow_data); int skb_cow_data_for_xdp(struct page_pool *pool, struct sk_buff **pskb, - struct bpf_prog *prog) + const struct bpf_prog *prog) { if (!prog->aux->xdp_has_frags) return -EINVAL; From dcf3827cde8621d2317a7f98e069adbdc2112982 Mon Sep 17 00:00:00 2001 From: Alexander Lobakin Date: Tue, 3 Dec 2024 18:37:26 +0100 Subject: [PATCH 3/8] xdp, xsk: constify read-only arguments of some static inline helpers MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Lots of read-only helpers for &xdp_buff and &xdp_frame, such as getting the frame length, skb_shared_info etc., don't have their arguments marked with `const` for no reason. Add the missing annotations to leave less place for mistakes and more for optimization. Reviewed-by: Toke Høiland-Jørgensen Signed-off-by: Alexander Lobakin Link: https://patch.msgid.link/20241203173733.3181246-4-aleksander.lobakin@intel.com Signed-off-by: Jakub Kicinski --- include/net/xdp.h | 29 +++++++++++++++++------------ include/net/xdp_sock_drv.h | 11 ++++++----- include/net/xsk_buff_pool.h | 2 +- 3 files changed, 24 insertions(+), 18 deletions(-) diff --git a/include/net/xdp.h b/include/net/xdp.h index e6770dd40c91..197808df1ee1 100644 --- a/include/net/xdp.h +++ b/include/net/xdp.h @@ -88,7 +88,7 @@ struct xdp_buff { u32 flags; /* supported values defined in xdp_buff_flags */ }; -static __always_inline bool xdp_buff_has_frags(struct xdp_buff *xdp) +static __always_inline bool xdp_buff_has_frags(const struct xdp_buff *xdp) { return !!(xdp->flags & XDP_FLAGS_HAS_FRAGS); } @@ -103,7 +103,8 @@ static __always_inline void xdp_buff_clear_frags_flag(struct xdp_buff *xdp) xdp->flags &= ~XDP_FLAGS_HAS_FRAGS; } -static __always_inline bool xdp_buff_is_frag_pfmemalloc(struct xdp_buff *xdp) +static __always_inline bool +xdp_buff_is_frag_pfmemalloc(const struct xdp_buff *xdp) { return !!(xdp->flags & XDP_FLAGS_FRAGS_PF_MEMALLOC); } @@ -144,15 +145,16 @@ xdp_prepare_buff(struct xdp_buff *xdp, unsigned char *hard_start, SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) static inline struct skb_shared_info * -xdp_get_shared_info_from_buff(struct xdp_buff *xdp) +xdp_get_shared_info_from_buff(const struct xdp_buff *xdp) { return (struct skb_shared_info *)xdp_data_hard_end(xdp); } -static __always_inline unsigned int xdp_get_buff_len(struct xdp_buff *xdp) +static __always_inline unsigned int +xdp_get_buff_len(const struct xdp_buff *xdp) { unsigned int len = xdp->data_end - xdp->data; - struct skb_shared_info *sinfo; + const struct skb_shared_info *sinfo; if (likely(!xdp_buff_has_frags(xdp))) goto out; @@ -177,12 +179,13 @@ struct xdp_frame { u32 flags; /* supported values defined in xdp_buff_flags */ }; -static __always_inline bool xdp_frame_has_frags(struct xdp_frame *frame) +static __always_inline bool xdp_frame_has_frags(const struct xdp_frame *frame) { return !!(frame->flags & XDP_FLAGS_HAS_FRAGS); } -static __always_inline bool xdp_frame_is_frag_pfmemalloc(struct xdp_frame *frame) +static __always_inline bool +xdp_frame_is_frag_pfmemalloc(const struct xdp_frame *frame) { return !!(frame->flags & XDP_FLAGS_FRAGS_PF_MEMALLOC); } @@ -201,7 +204,7 @@ static __always_inline void xdp_frame_bulk_init(struct xdp_frame_bulk *bq) } static inline struct skb_shared_info * -xdp_get_shared_info_from_frame(struct xdp_frame *frame) +xdp_get_shared_info_from_frame(const struct xdp_frame *frame) { void *data_hard_start = frame->data - frame->headroom - sizeof(*frame); @@ -249,7 +252,8 @@ int xdp_alloc_skb_bulk(void **skbs, int n_skb, gfp_t gfp); struct xdp_frame *xdpf_clone(struct xdp_frame *xdpf); static inline -void xdp_convert_frame_to_buff(struct xdp_frame *frame, struct xdp_buff *xdp) +void xdp_convert_frame_to_buff(const struct xdp_frame *frame, + struct xdp_buff *xdp) { xdp->data_hard_start = frame->data - frame->headroom - sizeof(*frame); xdp->data = frame->data; @@ -260,7 +264,7 @@ void xdp_convert_frame_to_buff(struct xdp_frame *frame, struct xdp_buff *xdp) } static inline -int xdp_update_frame_from_buff(struct xdp_buff *xdp, +int xdp_update_frame_from_buff(const struct xdp_buff *xdp, struct xdp_frame *xdp_frame) { int metasize, headroom; @@ -317,9 +321,10 @@ void xdp_flush_frame_bulk(struct xdp_frame_bulk *bq); void xdp_return_frame_bulk(struct xdp_frame *xdpf, struct xdp_frame_bulk *bq); -static __always_inline unsigned int xdp_get_frame_len(struct xdp_frame *xdpf) +static __always_inline unsigned int +xdp_get_frame_len(const struct xdp_frame *xdpf) { - struct skb_shared_info *sinfo; + const struct skb_shared_info *sinfo; unsigned int len = xdpf->len; if (likely(!xdp_frame_has_frags(xdpf))) diff --git a/include/net/xdp_sock_drv.h b/include/net/xdp_sock_drv.h index 40085afd9160..f3175a5d28f7 100644 --- a/include/net/xdp_sock_drv.h +++ b/include/net/xdp_sock_drv.h @@ -101,7 +101,7 @@ static inline struct xdp_buff *xsk_buff_alloc(struct xsk_buff_pool *pool) return xp_alloc(pool); } -static inline bool xsk_is_eop_desc(struct xdp_desc *desc) +static inline bool xsk_is_eop_desc(const struct xdp_desc *desc) { return !xp_mb_desc(desc); } @@ -143,7 +143,7 @@ static inline void xsk_buff_add_frag(struct xdp_buff *xdp) list_add_tail(&frag->list_node, &frag->pool->xskb_list); } -static inline struct xdp_buff *xsk_buff_get_frag(struct xdp_buff *first) +static inline struct xdp_buff *xsk_buff_get_frag(const struct xdp_buff *first) { struct xdp_buff_xsk *xskb = container_of(first, struct xdp_buff_xsk, xdp); struct xdp_buff *ret = NULL; @@ -200,7 +200,8 @@ static inline void *xsk_buff_raw_get_data(struct xsk_buff_pool *pool, u64 addr) XDP_TXMD_FLAGS_CHECKSUM | \ 0) -static inline bool xsk_buff_valid_tx_metadata(struct xsk_tx_metadata *meta) +static inline bool +xsk_buff_valid_tx_metadata(const struct xsk_tx_metadata *meta) { return !(meta->flags & ~XDP_TXMD_FLAGS_VALID); } @@ -337,7 +338,7 @@ static inline struct xdp_buff *xsk_buff_alloc(struct xsk_buff_pool *pool) return NULL; } -static inline bool xsk_is_eop_desc(struct xdp_desc *desc) +static inline bool xsk_is_eop_desc(const struct xdp_desc *desc) { return false; } @@ -360,7 +361,7 @@ static inline void xsk_buff_add_frag(struct xdp_buff *xdp) { } -static inline struct xdp_buff *xsk_buff_get_frag(struct xdp_buff *first) +static inline struct xdp_buff *xsk_buff_get_frag(const struct xdp_buff *first) { return NULL; } diff --git a/include/net/xsk_buff_pool.h b/include/net/xsk_buff_pool.h index 7637799b6c19..50779406bc2d 100644 --- a/include/net/xsk_buff_pool.h +++ b/include/net/xsk_buff_pool.h @@ -183,7 +183,7 @@ static inline bool xp_desc_crosses_non_contig_pg(struct xsk_buff_pool *pool, !(pool->dma_pages[addr >> PAGE_SHIFT] & XSK_NEXT_PG_CONTIG_MASK); } -static inline bool xp_mb_desc(struct xdp_desc *desc) +static inline bool xp_mb_desc(const struct xdp_desc *desc) { return desc->options & XDP_PKT_CONTD; } From f65966fe0178c06065d354c22fb456fc4370b527 Mon Sep 17 00:00:00 2001 From: Alexander Lobakin Date: Tue, 3 Dec 2024 18:37:27 +0100 Subject: [PATCH 4/8] xdp: allow attaching already registered memory model to xdp_rxq_info MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit One may need to register memory model separately from xdp_rxq_info. One simple example may be XDP test run code, but in general, it might be useful when memory model registering is managed by one layer and then XDP RxQ info by a different one. Allow such scenarios by adding a simple helper which "attaches" already registered memory model to the desired xdp_rxq_info. As this is mostly needed for Page Pool, add a special function to do that for a &page_pool pointer. Reviewed-by: Toke Høiland-Jørgensen Signed-off-by: Alexander Lobakin Link: https://patch.msgid.link/20241203173733.3181246-5-aleksander.lobakin@intel.com Signed-off-by: Jakub Kicinski --- include/net/xdp.h | 32 +++++++++++++++++++++++++++ net/core/xdp.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 88 insertions(+) diff --git a/include/net/xdp.h b/include/net/xdp.h index 197808df1ee1..1253fe21ede7 100644 --- a/include/net/xdp.h +++ b/include/net/xdp.h @@ -356,6 +356,38 @@ void xdp_rxq_info_unreg_mem_model(struct xdp_rxq_info *xdp_rxq); int xdp_reg_mem_model(struct xdp_mem_info *mem, enum xdp_mem_type type, void *allocator); void xdp_unreg_mem_model(struct xdp_mem_info *mem); +int xdp_reg_page_pool(struct page_pool *pool); +void xdp_unreg_page_pool(const struct page_pool *pool); +void xdp_rxq_info_attach_page_pool(struct xdp_rxq_info *xdp_rxq, + const struct page_pool *pool); + +/** + * xdp_rxq_info_attach_mem_model - attach registered mem info to RxQ info + * @xdp_rxq: XDP RxQ info to attach the memory info to + * @mem: already registered memory info + * + * If the driver registers its memory providers manually, it must use this + * function instead of xdp_rxq_info_reg_mem_model(). + */ +static inline void +xdp_rxq_info_attach_mem_model(struct xdp_rxq_info *xdp_rxq, + const struct xdp_mem_info *mem) +{ + xdp_rxq->mem = *mem; +} + +/** + * xdp_rxq_info_detach_mem_model - detach registered mem info from RxQ info + * @xdp_rxq: XDP RxQ info to detach the memory info from + * + * If the driver registers its memory providers manually and then attaches it + * via xdp_rxq_info_attach_mem_model(), it must call this function before + * xdp_rxq_info_unreg(). + */ +static inline void xdp_rxq_info_detach_mem_model(struct xdp_rxq_info *xdp_rxq) +{ + xdp_rxq->mem = (struct xdp_mem_info){ }; +} /* Drivers not supporting XDP metadata can use this helper, which * rejects any room expansion for metadata as a result. diff --git a/net/core/xdp.c b/net/core/xdp.c index bcc5551c6424..885a2a664bce 100644 --- a/net/core/xdp.c +++ b/net/core/xdp.c @@ -365,6 +365,62 @@ int xdp_rxq_info_reg_mem_model(struct xdp_rxq_info *xdp_rxq, EXPORT_SYMBOL_GPL(xdp_rxq_info_reg_mem_model); +/** + * xdp_reg_page_pool - register &page_pool as a memory provider for XDP + * @pool: &page_pool to register + * + * Can be used to register pools manually without connecting to any XDP RxQ + * info, so that the XDP layer will be aware of them. Then, they can be + * attached to an RxQ info manually via xdp_rxq_info_attach_page_pool(). + * + * Return: %0 on success, -errno on error. + */ +int xdp_reg_page_pool(struct page_pool *pool) +{ + struct xdp_mem_info mem; + + return xdp_reg_mem_model(&mem, MEM_TYPE_PAGE_POOL, pool); +} +EXPORT_SYMBOL_GPL(xdp_reg_page_pool); + +/** + * xdp_unreg_page_pool - unregister &page_pool from the memory providers list + * @pool: &page_pool to unregister + * + * A shorthand for manual unregistering page pools. If the pool was previously + * attached to an RxQ info, it must be detached first. + */ +void xdp_unreg_page_pool(const struct page_pool *pool) +{ + struct xdp_mem_info mem = { + .type = MEM_TYPE_PAGE_POOL, + .id = pool->xdp_mem_id, + }; + + xdp_unreg_mem_model(&mem); +} +EXPORT_SYMBOL_GPL(xdp_unreg_page_pool); + +/** + * xdp_rxq_info_attach_page_pool - attach registered pool to RxQ info + * @xdp_rxq: XDP RxQ info to attach the pool to + * @pool: pool to attach + * + * If the pool was registered manually, this function must be called instead + * of xdp_rxq_info_reg_mem_model() to connect it to the RxQ info. + */ +void xdp_rxq_info_attach_page_pool(struct xdp_rxq_info *xdp_rxq, + const struct page_pool *pool) +{ + struct xdp_mem_info mem = { + .type = MEM_TYPE_PAGE_POOL, + .id = pool->xdp_mem_id, + }; + + xdp_rxq_info_attach_mem_model(xdp_rxq, &mem); +} +EXPORT_SYMBOL_GPL(xdp_rxq_info_attach_page_pool); + /* XDP RX runs under NAPI protection, and in different delivery error * scenarios (e.g. queue full), it is possible to return the xdp_frame * while still leveraging this protection. The @napi_direct boolean From 9e25dd9d65d27aa94220831fe6453d935988801c Mon Sep 17 00:00:00 2001 From: Alexander Lobakin Date: Tue, 3 Dec 2024 18:37:28 +0100 Subject: [PATCH 5/8] xsk: allow attaching XSk pool via xdp_rxq_info_reg_mem_model() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When you register an XSk pool as XDP Rxq info memory model, you then need to manually attach it after the registration. Let the user combine both actions into one by just passing a pointer to the pool directly to xdp_rxq_info_reg_mem_model(), which will take care of calling xsk_pool_set_rxq_info(). This looks similar to how a &page_pool gets registered and reduce repeating driver code. Acked-by: Maciej Fijalkowski Reviewed-by: Toke Høiland-Jørgensen Signed-off-by: Alexander Lobakin Link: https://patch.msgid.link/20241203173733.3181246-6-aleksander.lobakin@intel.com Signed-off-by: Jakub Kicinski --- net/core/xdp.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/core/xdp.c b/net/core/xdp.c index 885a2a664bce..de1e9cb78718 100644 --- a/net/core/xdp.c +++ b/net/core/xdp.c @@ -358,6 +358,9 @@ int xdp_rxq_info_reg_mem_model(struct xdp_rxq_info *xdp_rxq, if (IS_ERR(xdp_alloc)) return PTR_ERR(xdp_alloc); + if (type == MEM_TYPE_XSK_BUFF_POOL && allocator) + xsk_pool_set_rxq_info(allocator, xdp_rxq); + if (trace_mem_connect_enabled() && xdp_alloc) trace_mem_connect(xdp_alloc, xdp_rxq); return 0; From e77d9aee951341119be16a991fcfc76d1154d22a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= Date: Tue, 3 Dec 2024 18:37:29 +0100 Subject: [PATCH 6/8] xdp: register system page pool as an XDP memory model MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit To make the system page pool usable as a source for allocating XDP frames, we need to register it with xdp_reg_mem_model(), so that page return works correctly. This is done in preparation for using the system page_pool to convert XDP_PASS XSk frames to skbs; for the same reason, make the per-cpu variable non-static so we can access it from other source files as well (but w/o exporting). Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Alexander Lobakin Link: https://patch.msgid.link/20241203173733.3181246-7-aleksander.lobakin@intel.com Signed-off-by: Jakub Kicinski --- include/linux/netdevice.h | 1 + net/core/dev.c | 10 +++++++++- 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index ecca21387a68..d1a8d98b132c 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3322,6 +3322,7 @@ struct softnet_data { }; DECLARE_PER_CPU_ALIGNED(struct softnet_data, softnet_data); +DECLARE_PER_CPU(struct page_pool *, system_page_pool); #ifndef CONFIG_PREEMPT_RT static inline int dev_recursion_level(void) diff --git a/net/core/dev.c b/net/core/dev.c index 40a2332e3fa0..c7f3dea3e0eb 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -460,7 +460,7 @@ EXPORT_PER_CPU_SYMBOL(softnet_data); * PP consumers must pay attention to run APIs in the appropriate context * (e.g. NAPI context). */ -static DEFINE_PER_CPU(struct page_pool *, system_page_pool); +DEFINE_PER_CPU(struct page_pool *, system_page_pool); #ifdef CONFIG_LOCKDEP /* @@ -12152,11 +12152,18 @@ static int net_page_pool_create(int cpuid) .nid = cpu_to_mem(cpuid), }; struct page_pool *pp_ptr; + int err; pp_ptr = page_pool_create_percpu(&page_pool_params, cpuid); if (IS_ERR(pp_ptr)) return -ENOMEM; + err = xdp_reg_page_pool(pp_ptr); + if (err) { + page_pool_destroy(pp_ptr); + return err; + } + per_cpu(system_page_pool, cpuid) = pp_ptr; #endif return 0; @@ -12290,6 +12297,7 @@ static int __init net_dev_init(void) if (!pp_ptr) continue; + xdp_unreg_page_pool(pp_ptr); page_pool_destroy(pp_ptr); per_cpu(system_page_pool, i) = NULL; } From 9bd9f72a74344b54cfb6fcabf1173e6c6e5c6952 Mon Sep 17 00:00:00 2001 From: Alexander Lobakin Date: Tue, 3 Dec 2024 18:37:30 +0100 Subject: [PATCH 7/8] netmem: add a couple of page helper wrappers MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add the following netmem counterparts: * virt_to_netmem() -- simple page_to_netmem(virt_to_page()) wrapper; * netmem_is_pfmemalloc() -- page_is_pfmemalloc() for page-backed netmems, false otherwise; and the following "unsafe" versions: * __netmem_to_page() * __netmem_get_pp() * __netmem_address() They do the same as their non-underscored buddies, but assume the netmem is always page-backed. When working with header &page_pools, you don't need to check whether netmem belongs to the host memory and you can never get NULL instead of &page. Checks for the LSB, clearing the LSB, branches take cycles and increase object code size, sometimes significantly. When you're sure your PP is always host, you can avoid this by using the underscored counterparts. Signed-off-by: Alexander Lobakin Reviewed-by: Toke Høiland-Jørgensen Link: https://patch.msgid.link/20241203173733.3181246-8-aleksander.lobakin@intel.com Signed-off-by: Jakub Kicinski --- include/net/netmem.h | 78 ++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 76 insertions(+), 2 deletions(-) diff --git a/include/net/netmem.h b/include/net/netmem.h index 8a6e20be4b9d..1b58faa4f20f 100644 --- a/include/net/netmem.h +++ b/include/net/netmem.h @@ -72,6 +72,22 @@ static inline bool netmem_is_net_iov(const netmem_ref netmem) return (__force unsigned long)netmem & NET_IOV; } +/** + * __netmem_to_page - unsafely get pointer to the &page backing @netmem + * @netmem: netmem reference to convert + * + * Unsafe version of netmem_to_page(). When @netmem is always page-backed, + * e.g. when it's a header buffer, performs faster and generates smaller + * object code (no check for the LSB, no WARN). When @netmem points to IOV, + * provokes undefined behaviour. + * + * Return: pointer to the &page (garbage if @netmem is not page-backed). + */ +static inline struct page *__netmem_to_page(netmem_ref netmem) +{ + return (__force struct page *)netmem; +} + /* This conversion fails (returns NULL) if the netmem_ref is not struct page * backed. */ @@ -80,7 +96,7 @@ static inline struct page *netmem_to_page(netmem_ref netmem) if (WARN_ON_ONCE(netmem_is_net_iov(netmem))) return NULL; - return (__force struct page *)netmem; + return __netmem_to_page(netmem); } static inline struct net_iov *netmem_to_net_iov(netmem_ref netmem) @@ -103,6 +119,17 @@ static inline netmem_ref page_to_netmem(struct page *page) return (__force netmem_ref)page; } +/** + * virt_to_netmem - convert virtual memory pointer to a netmem reference + * @data: host memory pointer to convert + * + * Return: netmem reference to the &page backing this virtual address. + */ +static inline netmem_ref virt_to_netmem(const void *data) +{ + return page_to_netmem(virt_to_page(data)); +} + static inline int netmem_ref_count(netmem_ref netmem) { /* The non-pp refcount of net_iov is always 1. On net_iov, we only @@ -127,6 +154,22 @@ static inline struct net_iov *__netmem_clear_lsb(netmem_ref netmem) return (struct net_iov *)((__force unsigned long)netmem & ~NET_IOV); } +/** + * __netmem_get_pp - unsafely get pointer to the &page_pool backing @netmem + * @netmem: netmem reference to get the pointer from + * + * Unsafe version of netmem_get_pp(). When @netmem is always page-backed, + * e.g. when it's a header buffer, performs faster and generates smaller + * object code (avoids clearing the LSB). When @netmem points to IOV, + * provokes invalid memory access. + * + * Return: pointer to the &page_pool (garbage if @netmem is not page-backed). + */ +static inline struct page_pool *__netmem_get_pp(netmem_ref netmem) +{ + return __netmem_to_page(netmem)->pp; +} + static inline struct page_pool *netmem_get_pp(netmem_ref netmem) { return __netmem_clear_lsb(netmem)->pp; @@ -158,12 +201,43 @@ static inline netmem_ref netmem_compound_head(netmem_ref netmem) return page_to_netmem(compound_head(netmem_to_page(netmem))); } +/** + * __netmem_address - unsafely get pointer to the memory backing @netmem + * @netmem: netmem reference to get the pointer for + * + * Unsafe version of netmem_address(). When @netmem is always page-backed, + * e.g. when it's a header buffer, performs faster and generates smaller + * object code (no check for the LSB). When @netmem points to IOV, provokes + * undefined behaviour. + * + * Return: pointer to the memory (garbage if @netmem is not page-backed). + */ +static inline void *__netmem_address(netmem_ref netmem) +{ + return page_address(__netmem_to_page(netmem)); +} + static inline void *netmem_address(netmem_ref netmem) { if (netmem_is_net_iov(netmem)) return NULL; - return page_address(netmem_to_page(netmem)); + return __netmem_address(netmem); +} + +/** + * netmem_is_pfmemalloc - check if @netmem was allocated under memory pressure + * @netmem: netmem reference to check + * + * Return: true if @netmem is page-backed and the page was allocated under + * memory pressure, false otherwise. + */ +static inline bool netmem_is_pfmemalloc(netmem_ref netmem) +{ + if (netmem_is_net_iov(netmem)) + return false; + + return page_is_pfmemalloc(netmem_to_page(netmem)); } static inline unsigned long netmem_get_dma_addr(netmem_ref netmem) From 024bfd2e9d80d7131f1178eb2235030b96f7ef0e Mon Sep 17 00:00:00 2001 From: Alexander Lobakin Date: Tue, 3 Dec 2024 18:37:31 +0100 Subject: [PATCH 8/8] page_pool: make page_pool_put_page_bulk() handle array of netmems MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently, page_pool_put_page_bulk() indeed takes an array of pointers to the data, not pages, despite the name. As one side effect, when you're freeing frags from &skb_shared_info, xdp_return_frame_bulk() converts page pointers to virtual addresses and then page_pool_put_page_bulk() converts them back. Moreover, data pointers assume every frag is placed in the host memory, making this function non-universal. Make page_pool_put_page_bulk() handle array of netmems. Pass frag netmems directly and use virt_to_netmem() when freeing xdpf->data, so that the PP core will then get the compound netmem and take care of the rest. Signed-off-by: Alexander Lobakin Reviewed-by: Toke Høiland-Jørgensen Link: https://patch.msgid.link/20241203173733.3181246-9-aleksander.lobakin@intel.com Signed-off-by: Jakub Kicinski --- include/net/page_pool/types.h | 8 ++++---- include/net/xdp.h | 2 +- net/core/page_pool.c | 30 +++++++++++++++--------------- net/core/xdp.c | 6 +++--- 4 files changed, 23 insertions(+), 23 deletions(-) diff --git a/include/net/page_pool/types.h b/include/net/page_pool/types.h index c022c410abe3..1ea16b0e9c79 100644 --- a/include/net/page_pool/types.h +++ b/include/net/page_pool/types.h @@ -259,8 +259,8 @@ void page_pool_disable_direct_recycling(struct page_pool *pool); void page_pool_destroy(struct page_pool *pool); void page_pool_use_xdp_mem(struct page_pool *pool, void (*disconnect)(void *), const struct xdp_mem_info *mem); -void page_pool_put_page_bulk(struct page_pool *pool, void **data, - int count); +void page_pool_put_netmem_bulk(struct page_pool *pool, netmem_ref *data, + u32 count); #else static inline void page_pool_destroy(struct page_pool *pool) { @@ -272,8 +272,8 @@ static inline void page_pool_use_xdp_mem(struct page_pool *pool, { } -static inline void page_pool_put_page_bulk(struct page_pool *pool, void **data, - int count) +static inline void page_pool_put_netmem_bulk(struct page_pool *pool, + netmem_ref *data, u32 count) { } #endif diff --git a/include/net/xdp.h b/include/net/xdp.h index 1253fe21ede7..f4020b29122f 100644 --- a/include/net/xdp.h +++ b/include/net/xdp.h @@ -194,7 +194,7 @@ xdp_frame_is_frag_pfmemalloc(const struct xdp_frame *frame) struct xdp_frame_bulk { int count; void *xa; - void *q[XDP_BULK_QUEUE_SIZE]; + netmem_ref q[XDP_BULK_QUEUE_SIZE]; }; static __always_inline void xdp_frame_bulk_init(struct xdp_frame_bulk *bq) diff --git a/net/core/page_pool.c b/net/core/page_pool.c index f89cf93f6eb4..4c85b77cfdac 100644 --- a/net/core/page_pool.c +++ b/net/core/page_pool.c @@ -840,22 +840,22 @@ void page_pool_put_unrefed_page(struct page_pool *pool, struct page *page, EXPORT_SYMBOL(page_pool_put_unrefed_page); /** - * page_pool_put_page_bulk() - release references on multiple pages + * page_pool_put_netmem_bulk() - release references on multiple netmems * @pool: pool from which pages were allocated - * @data: array holding page pointers - * @count: number of pages in @data + * @data: array holding netmem references + * @count: number of entries in @data * - * Tries to refill a number of pages into the ptr_ring cache holding ptr_ring - * producer lock. If the ptr_ring is full, page_pool_put_page_bulk() - * will release leftover pages to the page allocator. - * page_pool_put_page_bulk() is suitable to be run inside the driver NAPI tx + * Tries to refill a number of netmems into the ptr_ring cache holding ptr_ring + * producer lock. If the ptr_ring is full, page_pool_put_netmem_bulk() + * will release leftover netmems to the memory provider. + * page_pool_put_netmem_bulk() is suitable to be run inside the driver NAPI tx * completion loop for the XDP_REDIRECT use case. * * Please note the caller must not use data area after running - * page_pool_put_page_bulk(), as this function overwrites it. + * page_pool_put_netmem_bulk(), as this function overwrites it. */ -void page_pool_put_page_bulk(struct page_pool *pool, void **data, - int count) +void page_pool_put_netmem_bulk(struct page_pool *pool, netmem_ref *data, + u32 count) { int i, bulk_len = 0; bool allow_direct; @@ -864,7 +864,7 @@ void page_pool_put_page_bulk(struct page_pool *pool, void **data, allow_direct = page_pool_napi_local(pool); for (i = 0; i < count; i++) { - netmem_ref netmem = page_to_netmem(virt_to_head_page(data[i])); + netmem_ref netmem = netmem_compound_head(data[i]); /* It is not the last user for the page frag case */ if (!page_pool_is_last_ref(netmem)) @@ -873,7 +873,7 @@ void page_pool_put_page_bulk(struct page_pool *pool, void **data, netmem = __page_pool_put_page(pool, netmem, -1, allow_direct); /* Approved for bulk recycling in ptr_ring cache */ if (netmem) - data[bulk_len++] = (__force void *)netmem; + data[bulk_len++] = netmem; } if (!bulk_len) @@ -882,7 +882,7 @@ void page_pool_put_page_bulk(struct page_pool *pool, void **data, /* Bulk producer into ptr_ring page_pool cache */ in_softirq = page_pool_producer_lock(pool); for (i = 0; i < bulk_len; i++) { - if (__ptr_ring_produce(&pool->ring, data[i])) { + if (__ptr_ring_produce(&pool->ring, (__force void *)data[i])) { /* ring full */ recycle_stat_inc(pool, ring_full); break; @@ -899,9 +899,9 @@ void page_pool_put_page_bulk(struct page_pool *pool, void **data, * since put_page() with refcnt == 1 can be an expensive operation */ for (; i < bulk_len; i++) - page_pool_return_page(pool, (__force netmem_ref)data[i]); + page_pool_return_page(pool, data[i]); } -EXPORT_SYMBOL(page_pool_put_page_bulk); +EXPORT_SYMBOL(page_pool_put_netmem_bulk); static netmem_ref page_pool_drain_frag(struct page_pool *pool, netmem_ref netmem) diff --git a/net/core/xdp.c b/net/core/xdp.c index de1e9cb78718..938ad15c9857 100644 --- a/net/core/xdp.c +++ b/net/core/xdp.c @@ -518,7 +518,7 @@ void xdp_flush_frame_bulk(struct xdp_frame_bulk *bq) if (unlikely(!xa || !bq->count)) return; - page_pool_put_page_bulk(xa->page_pool, bq->q, bq->count); + page_pool_put_netmem_bulk(xa->page_pool, bq->q, bq->count); /* bq->xa is not cleared to save lookup, if mem.id same in next bulk */ bq->count = 0; } @@ -559,12 +559,12 @@ void xdp_return_frame_bulk(struct xdp_frame *xdpf, for (i = 0; i < sinfo->nr_frags; i++) { skb_frag_t *frag = &sinfo->frags[i]; - bq->q[bq->count++] = skb_frag_address(frag); + bq->q[bq->count++] = skb_frag_netmem(frag); if (bq->count == XDP_BULK_QUEUE_SIZE) xdp_flush_frame_bulk(bq); } } - bq->q[bq->count++] = xdpf->data; + bq->q[bq->count++] = virt_to_netmem(xdpf->data); } EXPORT_SYMBOL_GPL(xdp_return_frame_bulk);