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* xsk: Avoid starving the xsk further down the listAlbert Huang2023-10-241-0/+7
| | | | | | | | | | | | | | | | | | In the previous implementation, when multiple xsk sockets were associated with a single xsk_buff_pool, a situation could arise where the xsk_tx_list maintained data at the front for one xsk socket while starving the xsk sockets at the back of the list. This could result in issues such as the inability to transmit packets, increased latency, and jitter. To address this problem, we introduce a new variable called tx_budget_spent, which limits each xsk to transmit a maximum of MAX_PER_SOCKET_BUDGET tx descriptors. This allocation ensures equitable opportunities for subsequent xsk sockets to send tx descriptors. The value of MAX_PER_SOCKET_BUDGET is set to 32. Signed-off-by: Albert Huang <huangjie.albert@bytedance.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/20231023125732.82261-1-huangjie.albert@bytedance.com
* net, bpf: Add a warning if NAPI cb missed xdp_do_flush().Sebastian Andrzej Siewior2023-10-171-0/+9
| | | | | | | | | | | | | | | | | | | | | A few drivers were missing a xdp_do_flush() invocation after XDP_REDIRECT. Add three helper functions each for one of the per-CPU lists. Return true if the per-CPU list is non-empty and flush the list. Add xdp_do_check_flushed() which invokes each helper functions and creates a warning if one of the functions had a non-empty list. Hide everything behind CONFIG_DEBUG_NET. Suggested-by: Jesper Dangaard Brouer <hawk@kernel.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20231016125738.Yt79p1uF@linutronix.de
* xsk: add multi-buffer support for sockets sharing umemTirthendu Sarkar2023-09-151-0/+2
| | | | | | | | | | | | | | | | | | Userspace applications indicate their multi-buffer capability to xsk using XSK_USE_SG socket bind flag. For sockets using shared umem the bind flag may contain XSK_USE_SG only for the first socket. For any subsequent socket the only option supported is XDP_SHARED_UMEM. Add option XDP_UMEM_SG_FLAG in umem config flags to store the multi-buffer handling capability when indicated by XSK_USE_SG option in bing flag by the first socket. Use this to derive multi-buffer capability for subsequent sockets in xsk core. Signed-off-by: Tirthendu Sarkar <tirthendu.sarkar@intel.com> Fixes: 81470b5c3c66 ("xsk: introduce XSK_USE_SG bind flag for xsk socket") Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Link: https://lore.kernel.org/r/20230907035032.2627879-1-tirthendu.sarkar@intel.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* xsk: introduce wrappers and helpers for supporting multi-buffer in Tx pathTirthendu Sarkar2023-07-191-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | In Tx path, xsk core reserves space for each desc to be transmitted in the completion queue and it's address contained in it is stored in the skb destructor arg. After successful transmission the skb destructor submits the addr marking completion. To handle multiple descriptors per packet, now along with reserving space for each descriptor, the corresponding address is also stored in completion queue. The number of pending descriptors are stored in skb destructor arg and is used by the skb destructor to update completions. Introduce 'skb' in xdp_sock to store a partially built packet when __xsk_generic_xmit() must return before it sees the EOP descriptor for the current packet so that packet building can resume in next call of __xsk_generic_xmit(). Helper functions are introduced to set and get the pending descriptors in the skb destructor arg. Also, wrappers are introduced for storing descriptor addresses, submitting and cancelling (for unsuccessful transmissions) the number of completions. Signed-off-by: Tirthendu Sarkar <tirthendu.sarkar@intel.com> Link: https://lore.kernel.org/r/20230719132421.584801-7-maciej.fijalkowski@intel.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* xsk: introduce XSK_USE_SG bind flag for xsk socketTirthendu Sarkar2023-07-191-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | As of now xsk core drops any xdp_buff with data size greater than the xsk frame_size as set by the af_xdp application. With multi-buffer support introduced in the next patch xsk core can now split those buffers into multiple descriptors provided the af_xdp application can handle them. Such capability of the application needs to be independent of the xdp_prog's frag support capability since there are cases where even a single xdp_buffer may need to be split into multiple descriptors owing to a smaller xsk frame size. For e.g., with NIC rx_buffer size set to 4kB, a 3kB packet will constitute of a single buffer and so will be sent as such to AF_XDP layer irrespective of 'xdp.frags' capability of the XDP program. Now if the xsk frame size is set to 2kB by the AF_XDP application, then the packet will need to be split into 2 descriptors if AF_XDP application can handle multi-buffer, else it needs to be dropped. Applications can now advertise their frag handling capability to xsk core so that xsk core can decide if it should drop or split xdp_buffs that exceed xsk frame size. This is done using a new 'XSK_USE_SG' bind flag for the xdp socket. Signed-off-by: Tirthendu Sarkar <tirthendu.sarkar@intel.com> Link: https://lore.kernel.org/r/20230719132421.584801-3-maciej.fijalkowski@intel.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf, net: xskmap memory usageYafang Shao2023-03-071-0/+1
| | | | | | | | | | | | | | | | | | | | | A new helper is introduced to calculate xskmap memory usage. The xfsmap memory usage can be dynamically changed when we add or remove a xsk_map_node. Hence we need to track the count of xsk_map_node to get its memory usage. The result as follows, - before 10: xskmap name count_map flags 0x0 key 4B value 4B max_entries 65536 memlock 524288B - after 10: xskmap name count_map flags 0x0 <<< no elements case key 4B value 4B max_entries 65536 memlock 524608B Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Link: https://lore.kernel.org/r/20230305124615.12358-17-laoar.shao@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* net: Don't include filter.h from net/sock.hJakub Kicinski2021-12-291-0/+1
| | | | | | | | | | | | | | | | | | | sock.h is pretty heavily used (5k objects rebuilt on x86 after it's touched). We can drop the include of filter.h from it and add a forward declaration of struct sk_filter instead. This decreases the number of rebuilt objects when bpf.h is touched from ~5k to ~1k. There's a lot of missing includes this was masking. Primarily in networking tho, this time. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com> Acked-by: Stefano Garzarella <sgarzare@redhat.com> Link: https://lore.kernel.org/bpf/20211229004913.513372-1-kuba@kernel.org
* xdp: Add proper __rcu annotations to redirect map entriesToke Høiland-Jørgensen2021-06-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | XDP_REDIRECT works by a three-step process: the bpf_redirect() and bpf_redirect_map() helpers will lookup the target of the redirect and store it (along with some other metadata) in a per-CPU struct bpf_redirect_info. Next, when the program returns the XDP_REDIRECT return code, the driver will call xdp_do_redirect() which will use the information thus stored to actually enqueue the frame into a bulk queue structure (that differs slightly by map type, but shares the same principle). Finally, before exiting its NAPI poll loop, the driver will call xdp_do_flush(), which will flush all the different bulk queues, thus completing the redirect. Pointers to the map entries will be kept around for this whole sequence of steps, protected by RCU. However, there is no top-level rcu_read_lock() in the core code; instead drivers add their own rcu_read_lock() around the XDP portions of the code, but somewhat inconsistently as Martin discovered[0]. However, things still work because everything happens inside a single NAPI poll sequence, which means it's between a pair of calls to local_bh_disable()/local_bh_enable(). So Paul suggested[1] that we could document this intention by using rcu_dereference_check() with rcu_read_lock_bh_held() as a second parameter, thus allowing sparse and lockdep to verify that everything is done correctly. This patch does just that: we add an __rcu annotation to the map entry pointers and remove the various comments explaining the NAPI poll assurance strewn through devmap.c in favour of a longer explanation in filter.c. The goal is to have one coherent documentation of the entire flow, and rely on the RCU annotations as a "standard" way of communicating the flow in the map code (which can additionally be understood by sparse and lockdep). The RCU annotation replacements result in a fairly straight-forward replacement where READ_ONCE() becomes rcu_dereference_check(), WRITE_ONCE() becomes rcu_assign_pointer() and xchg() and cmpxchg() gets wrapped in the proper constructs to cast the pointer back and forth between __rcu and __kernel address space (for the benefit of sparse). The one complication is that xskmap has a few constructions where double-pointers are passed back and forth; these simply all gain __rcu annotations, and only the final reference/dereference to the inner-most pointer gets changed. With this, everything can be run through sparse without eliciting complaints, and lockdep can verify correctness even without the use of rcu_read_lock() in the drivers. Subsequent patches will clean these up from the drivers. [0] https://lore.kernel.org/bpf/20210415173551.7ma4slcbqeyiba2r@kafai-mbp.dhcp.thefacebook.com/ [1] https://lore.kernel.org/bpf/20210419165837.GA975577@paulmck-ThinkPad-P17-Gen-1/ Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210624160609.292325-6-toke@redhat.com
* bpf, xdp: Make bpf_redirect_map() a map operationBjörn Töpel2021-03-101-19/+0
| | | | | | | | | | | | | | | | | | Currently the bpf_redirect_map() implementation dispatches to the correct map-lookup function via a switch-statement. To avoid the dispatching, this change adds bpf_redirect_map() as a map operation. Each map provides its bpf_redirect_map() version, and correct function is automatically selected by the BPF verifier. A nice side-effect of the code movement is that the map lookup functions are now local to the map implementation files, which removes one additional function call. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/bpf/20210308112907.559576-2-bjorn.topel@gmail.com
* xsk: Fix race in SKB mode transmit with shared cqMagnus Karlsson2020-12-181-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | Fix a race when multiple sockets are simultaneously calling sendto() when the completion ring is shared in the SKB case. This is the case when you share the same netdev and queue id through the XDP_SHARED_UMEM bind flag. The problem is that multiple processes can be in xsk_generic_xmit() and call the backpressure mechanism in xskq_prod_reserve(xs->pool->cq). As this is a shared resource in this specific scenario, a race might occur since the rings are single-producer single-consumer. Fix this by moving the tx_completion_lock from the socket to the pool as the pool is shared between the sockets that share the completion ring. (The pool is not shared when this is not the case.) And then protect the accesses to xskq_prod_reserve() with this lock. The tx_completion_lock is renamed cq_lock to better reflect that it protects accesses to the potentially shared completion ring. Fixes: 35fcde7f8deb ("xsk: support for Tx") Reported-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Björn Töpel <bjorn.topel@intel.com> Link: https://lore.kernel.org/bpf/20201218134525.13119-2-magnus.karlsson@gmail.com
* xsk: Fix umem cleanup bug at socket destructMagnus Karlsson2020-11-201-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix a bug that is triggered when a partially setup socket is destroyed. For a fully setup socket, a socket that has been bound to a device, the cleanup of the umem is performed at the end of the buffer pool's cleanup work queue item. This has to be performed in a work queue, and not in RCU cleanup, as it is doing a vunmap that cannot execute in interrupt context. However, when a socket has only been partially set up so that a umem has been created but the buffer pool has not, the code erroneously directly calls the umem cleanup function instead of using a work queue, and this leads to a BUG_ON() in vunmap(). As there in this case is no buffer pool, we cannot use its work queue, so we need to introduce a work queue for the umem and schedule this for the cleanup. So in the case there is no pool, we are going to use the umem's own work queue to schedule the cleanup. But if there is a pool, the cleanup of the umem is still being performed by the pool's work queue, as it is important that the umem is cleaned up after the pool. Fixes: e5e1a4bc916d ("xsk: Fix possible memory leak at socket close") Reported-by: Marek Majtyka <marekx.majtyka@intel.com> Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Marek Majtyka <marekx.majtyka@intel.com> Link: https://lore.kernel.org/bpf/1605873219-21629-1-git-send-email-magnus.karlsson@gmail.com
* xsk: Rearrange internal structs for better performanceMagnus Karlsson2020-08-311-6/+7
| | | | | | | | | | | | | | Rearrange the xdp_sock, xdp_umem and xsk_buff_pool structures so that they get smaller and align better to the cache lines. In the previous commits of this patch set, these structs have been reordered with the focus on functionality and simplicity, not performance. This patch improves throughput performance by around 3%. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Björn Töpel <bjorn.topel@intel.com> Link: https://lore.kernel.org/bpf/1598603189-32145-10-git-send-email-magnus.karlsson@intel.com
* xsk: Enable sharing of dma mappingsMagnus Karlsson2020-08-311-0/+1
| | | | | | | | | | | | Enable the sharing of dma mappings by moving them out from the buffer pool. Instead we put each dma mapped umem region in a list in the umem structure. If dma has already been mapped for this umem and device, it is not mapped again and the existing dma mappings are reused. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Björn Töpel <bjorn.topel@intel.com> Link: https://lore.kernel.org/bpf/1598603189-32145-9-git-send-email-magnus.karlsson@intel.com
* xsk: Move addrs from buffer pool to umemMagnus Karlsson2020-08-311-0/+1
| | | | | | | | | | | Replicate the addrs pointer in the buffer pool to the umem. This mapping will be the same for all buffer pools sharing the same umem. In the buffer pool we leave the addrs pointer for performance reasons. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Björn Töpel <bjorn.topel@intel.com> Link: https://lore.kernel.org/bpf/1598603189-32145-8-git-send-email-magnus.karlsson@intel.com
* xsk: Move xsk_tx_list and its lock to buffer poolMagnus Karlsson2020-08-311-3/+1
| | | | | | | | | | | | Move the xsk_tx_list and the xsk_tx_list_lock from the umem to the buffer pool. This so that we in a later commit can share the umem between multiple HW queues. There is one xsk_tx_list per device and queue id, so it should be located in the buffer pool. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Björn Töpel <bjorn.topel@intel.com> Link: https://lore.kernel.org/bpf/1598603189-32145-7-git-send-email-magnus.karlsson@intel.com
* xsk: Move queue_id, dev and need_wakeup to buffer poolMagnus Karlsson2020-08-311-3/+0
| | | | | | | | | | | | | | | Move queue_id, dev, and need_wakeup from the umem to the buffer pool. This so that we in a later commit can share the umem between multiple HW queues. There is one buffer pool per dev and queue id, so these variables should belong to the buffer pool, not the umem. Need_wakeup is also something that is set on a per napi level, so there is usually one per device and queue id. So move this to the buffer pool too. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Björn Töpel <bjorn.topel@intel.com> Link: https://lore.kernel.org/bpf/1598603189-32145-6-git-send-email-magnus.karlsson@intel.com
* xsk: Move fill and completion rings to buffer poolMagnus Karlsson2020-08-311-2/+2
| | | | | | | | | | | | | | Move the fill and completion rings from the umem to the buffer pool. This so that we in a later commit can share the umem between multiple HW queue ids. In this case, we need one fill and completion ring per queue id. As the buffer pool is per queue id and napi id this is a natural place for it and one umem struture can be shared between these buffer pools. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Björn Töpel <bjorn.topel@intel.com> Link: https://lore.kernel.org/bpf/1598603189-32145-5-git-send-email-magnus.karlsson@intel.com
* xsk: Create and free buffer pool independently from umemMagnus Karlsson2020-08-311-2/+1
| | | | | | | | | | | | | | | | | Create and free the buffer pool independently from the umem. Move these operations that are performed on the buffer pool from the umem create and destroy functions to new create and destroy functions just for the buffer pool. This so that in later commits we can instantiate multiple buffer pools per umem when sharing a umem between HW queues and/or devices. We also erradicate the back pointer from the umem to the buffer pool as this will not work when we introduce the possibility to have multiple buffer pools per umem. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Björn Töpel <bjorn.topel@intel.com> Link: https://lore.kernel.org/bpf/1598603189-32145-4-git-send-email-magnus.karlsson@intel.com
* xsk: i40e: ice: ixgbe: mlx5: Rename xsk zero-copy driver interfacesMagnus Karlsson2020-08-311-0/+1
| | | | | | | | | | | | | | | | | Rename the AF_XDP zero-copy driver interface functions to better reflect what they do after the replacement of umems with buffer pools in the previous commit. Mostly it is about replacing the umem name from the function names with xsk_buff and also have them take the a buffer pool pointer instead of a umem. The various ring functions have also been renamed in the process so that they have the same naming convention as the internal functions in xsk_queue.h. This so that it will be clearer what they do and also for consistency. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Björn Töpel <bjorn.topel@intel.com> Link: https://lore.kernel.org/bpf/1598603189-32145-3-git-send-email-magnus.karlsson@intel.com
* xsk: Add new statisticsCiara Loftus2020-07-131-0/+4
| | | | | | | | | | | | | | It can be useful for the user to know the reason behind a dropped packet. Introduce new counters which track drops on the receive path caused by: 1. rx ring being full 2. fill ring being empty Also, on the tx path introduce a counter which tracks the number of times we attempt pull from the tx ring when it is empty. Signed-off-by: Ciara Loftus <ciara.loftus@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200708072835.4427-2-ciara.loftus@intel.com
* xsk: Remove MEM_TYPE_ZERO_COPY and corresponding codeBjörn Töpel2020-05-211-45/+0
| | | | | | | | | | | There are no users of MEM_TYPE_ZERO_COPY. Remove all corresponding code, including the "handle" member of struct xdp_buff. rfc->v1: Fixed spelling in commit message. (Björn) Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200520192103.355233-13-bjorn.topel@gmail.com
* xsk: Introduce AF_XDP buffer allocation APIBjörn Töpel2020-05-211-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to simplify AF_XDP zero-copy enablement for NIC driver developers, a new AF_XDP buffer allocation API is added. The implementation is based on a single core (single producer/consumer) buffer pool for the AF_XDP UMEM. A buffer is allocated using the xsk_buff_alloc() function, and returned using xsk_buff_free(). If a buffer is disassociated with the pool, e.g. when a buffer is passed to an AF_XDP socket, a buffer is said to be released. Currently, the release function is only used by the AF_XDP internals and not visible to the driver. Drivers using this API should register the XDP memory model with the new MEM_TYPE_XSK_BUFF_POOL type. The API is defined in net/xdp_sock_drv.h. The buffer type is struct xdp_buff, and follows the lifetime of regular xdp_buffs, i.e. the lifetime of an xdp_buff is restricted to a NAPI context. In other words, the API is not replacing xdp_frames. In addition to introducing the API and implementations, the AF_XDP core is migrated to use the new APIs. rfc->v1: Fixed build errors/warnings for m68k and riscv. (kbuild test robot) Added headroom/chunk size getter. (Maxim/Björn) v1->v2: Swapped SoBs. (Maxim) v2->v3: Initialize struct xdp_buff member frame_sz. (Björn) Add API to query the DMA address of a frame. (Maxim) Do DMA sync for CPU till the end of the frame to handle possible growth (frame_sz). (Maxim) Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200520192103.355233-6-bjorn.topel@gmail.com
* xsk: Move defines only used by AF_XDP internals to xsk.hBjörn Töpel2020-05-211-14/+0
| | | | | | | | | | | Move the XSK_NEXT_PG_CONTIG_{MASK,SHIFT}, and XDP_UMEM_USES_NEED_WAKEUP defines from xdp_sock.h to the AF_XDP internal xsk.h file. Also, start using the BIT{,_ULL} macro instead of explicit shifts. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200520192103.355233-5-bjorn.topel@gmail.com
* xsk: Move driver interface to xdp_sock_drv.hMagnus Karlsson2020-05-211-206/+8
| | | | | | | | | | | | | Move the AF_XDP zero-copy driver interface to its own include file called xdp_sock_drv.h. This, hopefully, will make it more clear for NIC driver implementors to know what functions to use for zero-copy support. v4->v5: Fix -Wmissing-prototypes by include header file. (Jakub) Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200520192103.355233-4-bjorn.topel@gmail.com
* xsk: Move xskmap.c to net/xdp/Björn Töpel2020-05-211-20/+0
| | | | | | | | | | | The XSKMAP is partly implemented by net/xdp/xsk.c. Move xskmap.c from kernel/bpf/ to net/xdp/, which is the logical place for AF_XDP related code. Also, move AF_XDP struct definitions, and function declarations only used by AF_XDP internals into net/xdp/xsk.h. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200520192103.355233-3-bjorn.topel@gmail.com
* xsk: Fix xsk_umem_xdp_frame_sz()Björn Töpel2020-05-211-1/+1
| | | | | | | | | | | | | | | | Calculating the "data_hard_end" for an XDP buffer coming from AF_XDP zero-copy mode, the return value of xsk_umem_xdp_frame_sz() is added to "data_hard_start". Currently, the chunk size of the UMEM is returned by xsk_umem_xdp_frame_sz(). This is not correct, if the fixed UMEM headroom is non-zero. Fix this by returning the chunk_size without the UMEM headroom. Fixes: 2a637c5b1aaf ("xdp: For Intel AF_XDP drivers add XDP frame_sz") Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200520192103.355233-2-bjorn.topel@gmail.com
* xdp: For Intel AF_XDP drivers add XDP frame_szJesper Dangaard Brouer2020-05-141-0/+11
| | | | | | | | | | | | | | | | | Intel drivers implement native AF_XDP zerocopy in separate C-files, that have its own invocation of bpf_prog_run_xdp(). The setup of xdp_buff is also handled in separately from normal code path. This patch update XDP frame_sz for AF_XDP zerocopy drivers i40e, ice and ixgbe, as the code changes needed are very similar. Introduce a helper function xsk_umem_xdp_frame_sz() for calculating frame size. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Björn Töpel <bjorn.topel@intel.com> Cc: intel-wired-lan@lists.osuosl.org Cc: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/158945347511.97035.8536753731329475655.stgit@firesoul
* xsk: Remove unnecessary member in xdp_umemMagnus Karlsson2020-05-041-1/+0
| | | | | | | | | | | Remove the unnecessary member of address in struct xdp_umem as it is only used during the umem registration. No need to carry this around as it is not used during run-time nor when unregistering the umem. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com> Link: https://lore.kernel.org/bpf/1588599232-24897-3-git-send-email-magnus.karlsson@intel.com
* xsk: Change two variable names for increased clarityMagnus Karlsson2020-05-041-2/+2
| | | | | | | | | | | | | | | | Change two variables names so that it is clearer what they represent. The first one is xsk_list that in fact only contains the list of AF_XDP sockets with a Tx component. Change this to xsk_tx_list for improved clarity. The second variable is size in the ring structure. One might think that this is the size of the ring, but it is in fact the size of the umem, copied into the ring structure to improve performance. Rename this variable umem_size to avoid any confusion. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com> Link: https://lore.kernel.org/bpf/1588599232-24897-2-git-send-email-magnus.karlsson@intel.com
* xsk: ixgbe: i40e: ice: mlx5: Xsk_umem_discard_addr to xsk_umem_release_addrMagnus Karlsson2019-12-201-5/+5
| | | | | | | | | | | | | Change the name of xsk_umem_discard_addr to xsk_umem_release_addr to better reflect the new naming of the AF_XDP queue manipulation functions. As this functions is used by drivers implementing support for AF_XDP zero-copy, it requires a name change to these drivers. The function xsk_umem_release_addr_rq has also changed name in the same fashion. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/1576759171-28550-10-git-send-email-magnus.karlsson@intel.com
* xsk: Change names of validation functionsMagnus Karlsson2019-12-201-2/+2
| | | | | | | | | | | | | | | | Change the names of the validation functions to better reflect what they are doing. The uppermost ones are reading entries from the rings and only the bottom ones validate entries. So xskq_cons_read_ is a better prefix name. Also change the xskq_cons_read_ functions to return a bool as the the descriptor or address is already returned by reference in the parameters. Everyone is using the return value as a bool anyway. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/1576759171-28550-9-git-send-email-magnus.karlsson@intel.com
* xsk: Make xskmap flush_list common for all map instancesBjörn Töpel2019-12-191-7/+4
| | | | | | | | | | | | | The xskmap flush list is used to track entries that need to flushed from via the xdp_do_flush_map() function. This list used to be per-map, but there is really no reason for that. Instead make the flush list global for all xskmaps, which simplifies __xsk_map_flush() and xsk_map_alloc(). Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/bpf/20191219061006.21980-5-bjorn.topel@gmail.com
* xsk: Restructure/inline XSKMAP lookup/redirect/flushBjörn Töpel2019-11-021-12/+39
| | | | | | | | | | | | | | | | | | | | | In this commit the XSKMAP entry lookup function used by the XDP redirect code is moved from the xskmap.c file to the xdp_sock.h header, so the lookup can be inlined from, e.g., the bpf_xdp_redirect_map() function. Further the __xsk_map_redirect() and __xsk_map_flush() is moved to the xsk.c, which lets the compiler inline the xsk_rcv() and xsk_flush() functions. Finally, all the XDP socket functions were moved from linux/bpf.h to net/xdp_sock.h, where most of the XDP sockets functions are anyway. This yields a ~2% performance boost for the xdpsock "rx_drop" scenario. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191101110346.15004-4-bjorn.topel@gmail.com
* xsk: add support to allow unaligned chunk placementKevin Laatz2019-08-311-4/+71
| | | | | | | | | | | | | | | | | | | | Currently, addresses are chunk size aligned. This means, we are very restricted in terms of where we can place chunk within the umem. For example, if we have a chunk size of 2k, then our chunks can only be placed at 0,2k,4k,6k,8k... and so on (ie. every 2k starting from 0). This patch introduces the ability to use unaligned chunks. With these changes, we are no longer bound to having to place chunks at a 2k (or whatever your chunk size is) interval. Since we are no longer dealing with aligned chunks, they can now cross page boundaries. Checks for page contiguity have been added in order to keep track of which pages are followed by a physically contiguous page. Signed-off-by: Kevin Laatz <kevin.laatz@intel.com> Signed-off-by: Ciara Loftus <ciara.loftus@intel.com> Signed-off-by: Bruce Richardson <bruce.richardson@intel.com> Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* xsk: remove AF_XDP socket from map when the socket is releasedBjörn Töpel2019-08-171-0/+18
| | | | | | | | | | | | | | | | | | When an AF_XDP socket is released/closed the XSKMAP still holds a reference to the socket in a "released" state. The socket will still use the netdev queue resource, and block newly created sockets from attaching to that queue, but no user application can access the fill/complete/rx/tx queues. This results in that all applications need to explicitly clear the map entry from the old "zombie state" socket. This should be done automatically. In this patch, the sockets tracks, and have a reference to, which maps it resides in. When the socket is released, it will remove itself from all maps. Suggested-by: Bruce Richardson <bruce.richardson@intel.com> Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* xsk: add support for need_wakeup flag in AF_XDP ringsMagnus Karlsson2019-08-171-1/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit adds support for a new flag called need_wakeup in the AF_XDP Tx and fill rings. When this flag is set, it means that the application has to explicitly wake up the kernel Rx (for the bit in the fill ring) or kernel Tx (for bit in the Tx ring) processing by issuing a syscall. Poll() can wake up both depending on the flags submitted and sendto() will wake up tx processing only. The main reason for introducing this new flag is to be able to efficiently support the case when application and driver is executing on the same core. Previously, the driver was just busy-spinning on the fill ring if it ran out of buffers in the HW and there were none on the fill ring. This approach works when the application is running on another core as it can replenish the fill ring while the driver is busy-spinning. Though, this is a lousy approach if both of them are running on the same core as the probability of the fill ring getting more entries when the driver is busy-spinning is zero. With this new feature the driver now sets the need_wakeup flag and returns to the application. The application can then replenish the fill queue and then explicitly wake up the Rx processing in the kernel using the syscall poll(). For Tx, the flag is only set to one if the driver has no outstanding Tx completion interrupts. If it has some, the flag is zero as it will be woken up by a completion interrupt anyway. As a nice side effect, this new flag also improves the performance of the case where application and driver are running on two different cores as it reduces the number of syscalls to the kernel. The kernel tells user space if it needs to be woken up by a syscall, and this eliminates many of the syscalls. This flag needs some simple driver support. If the driver does not support this, the Rx flag is always zero and the Tx flag is always one. This makes any application relying on this feature default to the old behaviour of not requiring any syscalls in the Rx path and always having to call sendto() in the Tx path. For backwards compatibility reasons, this feature has to be explicitly turned on using a new bind flag (XDP_USE_NEED_WAKEUP). I recommend that you always turn it on as it so far always have had a positive performance impact. The name and inspiration of the flag has been taken from io_uring by Jens Axboe. Details about this feature in io_uring can be found in http://kernel.dk/io_uring.pdf, section 8.3. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2019-07-081-0/+5
|\ | | | | | | | | | | Two cases of overlapping changes, nothing fancy. Signed-off-by: David S. Miller <davem@davemloft.net>
| * xdp: fix hang while unregistering device bound to xdp socketIlya Maximets2019-07-031-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Device that bound to XDP socket will not have zero refcount until the userspace application will not close it. This leads to hang inside 'netdev_wait_allrefs()' if device unregistering requested: # ip link del p1 < hang on recvmsg on netlink socket > # ps -x | grep ip 5126 pts/0 D+ 0:00 ip link del p1 # journalctl -b Jun 05 07:19:16 kernel: unregister_netdevice: waiting for p1 to become free. Usage count = 1 Jun 05 07:19:27 kernel: unregister_netdevice: waiting for p1 to become free. Usage count = 1 ... Fix that by implementing NETDEV_UNREGISTER event notification handler to properly clean up all the resources and unref device. This should also allow socket killing via ss(8) utility. Fixes: 965a99098443 ("xsk: add support for bind for Rx") Signed-off-by: Ilya Maximets <i.maximets@samsung.com> Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | xdp: fix race on generic receive pathIlya Maximets2019-07-091-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Unlike driver mode, generic xdp receive could be triggered by different threads on different CPU cores at the same time leading to the fill and rx queue breakage. For example, this could happen while sending packets from two processes to the first interface of veth pair while the second part of it is open with AF_XDP socket. Need to take a lock for each generic receive to avoid race. Fixes: c497176cb2e4 ("xsk: add Rx receive functions and poll support") Signed-off-by: Ilya Maximets <i.maximets@samsung.com> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Tested-by: William Tu <u9012063@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | xsk: Return the whole xdp_desc from xsk_umem_consume_txMaxim Mikityanskiy2019-06-271-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some drivers want to access the data transmitted in order to implement acceleration features of the NICs. It is also useful in AF_XDP TX flow. Change the xsk_umem_consume_tx API to return the whole xdp_desc, that contains the data pointer, length and DMA address, instead of only the latter two. Adapt the implementation of i40e and ixgbe to this change. Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com> Signed-off-by: Tariq Toukan <tariqt@mellanox.com> Acked-by: Saeed Mahameed <saeedm@mellanox.com> Cc: Björn Töpel <bjorn.topel@intel.com> Cc: Magnus Karlsson <magnus.karlsson@intel.com> Acked-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | xsk: Add API to check for available entries in FQMaxim Mikityanskiy2019-06-271-0/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | Add a function that checks whether the Fill Ring has the specified amount of descriptors available. It will be useful for mlx5e that wants to check in advance, whether it can allocate a bulk of RX descriptors, to get the best performance. Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com> Signed-off-by: Tariq Toukan <tariqt@mellanox.com> Acked-by: Saeed Mahameed <saeedm@mellanox.com> Acked-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf: Allow bpf_map_lookup_elem() on an xskmapJonathan Lemon2019-06-101-2/+2
|/ | | | | | | | | | | | | | Currently, the AF_XDP code uses a separate map in order to determine if an xsk is bound to a queue. Instead of doing this, have bpf_map_lookup_elem() return a xdp_sock. Rearrange some xdp_sock members to eliminate structure holes. Remove selftest - will be added back in later patch. Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* xsk: fix umem memory leak on cleanupBjörn Töpel2019-03-161-1/+0
| | | | | | | | | | | | | | | | | | | | When the umem is cleaned up, the task that created it might already be gone. If the task was gone, the xdp_umem_release function did not free the pages member of struct xdp_umem. It turned out that the task lookup was not needed at all; The code was a left-over when we moved from task accounting to user accounting [1]. This patch fixes the memory leak by removing the task lookup logic completely. [1] https://lore.kernel.org/netdev/20180131135356.19134-3-bjorn.topel@gmail.com/ Link: https://lore.kernel.org/netdev/c1cb2ca8-6a14-3980-8672-f3de0bb38dfd@suse.cz/ Fixes: c0c77d8fb787 ("xsk: add user memory registration support sockopt") Reported-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* xsk: add id to umemBjörn Töpel2019-01-251-0/+1
| | | | | | | | | This commit adds an id to the umem structure. The id uniquely identifies a umem instance, and will be exposed to user-space via the socket monitoring interface. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* ethtool: don't allow disabling queues with umem installedJakub Kicinski2018-10-051-0/+7
| | | | | | | | | | | We already check the RSS indirection table does not use queues which would be disabled by channel reconfiguration. Make sure user does not try to disable queues which have a UMEM and zero-copy AF_XDP socket installed. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* net: xsk: add a simple buffer reuse queueJakub Kicinski2018-09-251-0/+69
| | | | | | | | | | | | XSK UMEM is strongly single producer single consumer so reuse of frames is challenging. Add a simple "stash" of FILL packets to reuse for drivers to optionally make use of. This is useful when driver has to free (ndo_stop) or resize a ring with an active AF_XDP ZC socket. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Tested-by: Andrew Bowers <andrewx.bowers@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
* xsk: i40e: get rid of useless struct xdp_umem_propsMagnus Karlsson2018-09-011-6/+2
| | | | | | | | | | | | | This commit gets rid of the structure xdp_umem_props. It was there to be able to break a dependency at one point, but this is no longer needed. The values in the struct are instead stored directly in the xdp_umem structure. This simplifies the xsk code as well as af_xdp zero-copy drivers and as a bonus gets rid of one internal header file. The i40e driver is also adapted to the new interface in this commit. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* xsk: expose xdp_umem_get_{data,dma} to driversBjörn Töpel2018-08-291-0/+43
| | | | | | | | | | | | Move the xdp_umem_get_{data,dma} functions to include/net/xdp_sock.h, so that the upcoming zero-copy implementation in the Ethernet drivers can utilize them. Also, supply some dummy function implementations for CONFIG_XDP_SOCKETS=n configs. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* xsk: fix potential race in SKB TX completion codeMagnus Karlsson2018-07-021-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a potential race in the TX completion code for the SKB case. One process enters the sendmsg code of an AF_XDP socket in order to send a frame. The execution eventually trickles down to the driver that is told to send the packet. However, it decides to drop the packet due to some error condition (e.g., rings full) and frees the SKB. This will trigger the SKB destructor and a completion will be sent to the AF_XDP user space through its single-producer/single-consumer queues. At the same time a TX interrupt has fired on another core and it dispatches the TX completion code in the driver. It does its HW specific things and ends up freeing the SKB associated with the transmitted packet. This will trigger the SKB destructor and a completion will be sent to the AF_XDP user space through its single-producer/single-consumer queues. With a pseudo call stack, it would look like this: Core 1: sendmsg() being called in the application netdev_start_xmit() Driver entered through ndo_start_xmit Driver decides to free the SKB for some reason (e.g., rings full) Destructor of SKB called xskq_produce_addr() is called to signal completion to user space Core 2: TX completion irq NAPI loop Driver irq handler for TX completions Frees the SKB Destructor of SKB called xskq_produce_addr() is called to signal completion to user space We now have a violation of the single-producer/single-consumer principle for our queues as there are two threads trying to produce at the same time on the same queue. Fixed by introducing a spin_lock in the destructor. In regards to the performance, I get around 1.74 Mpps for txonly before and after the introduction of the spinlock. There is of course some impact due to the spin lock but it is in the less significant digits that are too noisy for me to measure. But let us say that the version without the spin lock got 1.745 Mpps in the best case and the version with 1.735 Mpps in the worst case, then that would mean a maximum drop in performance of 0.5%. Fixes: 35fcde7f8deb ("xsk: support for Tx") Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* xsk: wire upp Tx zero-copy functionsMagnus Karlsson2018-06-051-0/+9
| | | | | | | | Here we add the functionality required to support zero-copy Tx, and also exposes various zero-copy related functions for the netdevs. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>