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2020-05-21xsk: Move driver interface to xdp_sock_drv.hMagnus Karlsson
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
2020-05-21xsk: Move xskmap.c to net/xdp/Björn Töpel
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
2020-05-04xsk: Remove unnecessary member in xdp_umemMagnus Karlsson
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
2020-05-04xsk: Change two variable names for increased clarityMagnus Karlsson
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
2020-04-26xsk: Fix typo in xsk_umem_consume_tx and xsk_generic_xmit commentsTobias Klauser
s/backpreassure/backpressure/ Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/20200421232927.21082-1-tklauser@distanz.ch
2020-04-15xsk: Add missing check on user supplied headroom sizeMagnus Karlsson
Add a check that the headroom cannot be larger than the available space in the chunk. In the current code, a malicious user can set the headroom to a value larger than the chunk size minus the fixed XDP headroom. That way packets with a length larger than the supported size in the umem could get accepted and result in an out-of-bounds write. Fixes: c0c77d8fb787 ("xsk: add user memory registration support sockopt") Reported-by: Bui Quang Minh <minhquangbui99@gmail.com> Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://bugzilla.kernel.org/show_bug.cgi?id=207225 Link: https://lore.kernel.org/bpf/1586849715-23490-1-git-send-email-magnus.karlsson@intel.com
2020-04-06xsk: Fix out of boundary write in __xsk_rcv_memcpyLi RongQing
first_len is the remainder of the first page we're copying. If this size is larger, then out of page boundary write will otherwise happen. Fixes: c05cd3645814 ("xsk: add support to allow unaligned chunk placement") Signed-off-by: Li RongQing <lirongqing@baidu.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com> Acked-by: Björn Töpel <bjorn.topel@intel.com> Link: https://lore.kernel.org/bpf/1585813930-19712-1-git-send-email-lirongqing@baidu.com
2020-02-28xdp: Replace zero-length array with flexible-array memberGustavo A. R. Silva
The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com> Acked-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-11xsk: Publish global consumer pointers when NAPI is finishedMagnus Karlsson
The commit 4b638f13bab4 ("xsk: Eliminate the RX batch size") introduced a much more lazy way of updating the global consumer pointers from the kernel side, by only doing so when running out of entries in the fill or Tx rings (the rings consumed by the kernel). This can result in a deadlock with the user application if the kernel requires more than one entry to proceed and the application cannot put these entries in the fill ring because the kernel has not updated the global consumer pointer since the ring is not empty. Fix this by publishing the local kernel side consumer pointer whenever we have completed Rx or Tx processing in the kernel. This way, user space will have an up-to-date view of the consumer pointers whenever it gets to execute in the one core case (application and driver on the same core), or after a certain number of packets have been processed in the two core case (application and driver on different cores). A side effect of this patch is that the one core case gets better performance, but the two core case gets worse. The reason that the one core case improves is that updating the global consumer pointer is relatively cheap since the application by definition is not running when the kernel is (they are on the same core) and it is beneficial for the application, once it gets to run, to have pointers that are as up to date as possible since it then can operate on more packets and buffers. In the two core case, the most important performance aspect is to minimize the number of accesses to the global pointers since they are shared between two cores and bounces between the caches of those cores. This patch results in more updates to global state, which means lower performance in the two core case. Fixes: 4b638f13bab4 ("xsk: Eliminate the RX batch size") Reported-by: Ryan Goodfellow <rgoodfel@isi.edu> Reported-by: Maxim Mikityanskiy <maximmi@mellanox.com> 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> Acked-by: Maxim Mikityanskiy <maximmi@mellanox.com> Link: https://lore.kernel.org/bpf/1581348432-6747-1-git-send-email-magnus.karlsson@intel.com
2020-01-31mm, tree-wide: rename put_user_page*() to unpin_user_page*()John Hubbard
In order to provide a clearer, more symmetric API for pinning and unpinning DMA pages. This way, pin_user_pages*() calls match up with unpin_user_pages*() calls, and the API is a lot closer to being self-explanatory. Link: http://lkml.kernel.org/r/20200107224558.2362728-23-jhubbard@nvidia.com Signed-off-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Björn Töpel <bjorn.topel@intel.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Leon Romanovsky <leonro@mellanox.com> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-01-31net/xdp: set FOLL_PIN via pin_user_pages()John Hubbard
Convert net/xdp to use the new pin_longterm_pages() call, which sets FOLL_PIN. Setting FOLL_PIN is now required for code that requires tracking of pinned pages. In partial anticipation of this work, the net/xdp code was already calling put_user_page() instead of put_page(). Therefore, in order to convert from the get_user_pages()/put_page() model, to the pin_user_pages()/put_user_page() model, the only change required here is to change get_user_pages() to pin_user_pages(). Link: http://lkml.kernel.org/r/20200107224558.2362728-18-jhubbard@nvidia.com Signed-off-by: John Hubbard <jhubbard@nvidia.com> Acked-by: Björn Töpel <bjorn.topel@intel.com> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Leon Romanovsky <leonro@mellanox.com> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-01-22xsk, net: Make sock_def_readable() have external linkageBjörn Töpel
XDP sockets use the default implementation of struct sock's sk_data_ready callback, which is sock_def_readable(). This function is called in the XDP socket fast-path, and involves a retpoline. By letting sock_def_readable() have external linkage, and being called directly, the retpoline can be avoided. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200120092917.13949-1-bjorn.topel@gmail.com
2020-01-15xsk: Support allocations of large umemsMagnus Karlsson
When registering a umem area that is sufficiently large (>1G on an x86), kmalloc cannot be used to allocate one of the internal data structures, as the size requested gets too large. Use kvmalloc instead that falls back on vmalloc if the allocation is too large for kmalloc. Also add accounting for this structure as it is triggered by a user space action (the XDP_UMEM_REG setsockopt) and it is by far the largest structure of kernel allocated memory in xsk. Reported-by: Ryan Goodfellow <rgoodfel@isi.edu> Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com> Link: https://lore.kernel.org/bpf/1578995365-7050-1-git-send-email-magnus.karlsson@intel.com
2019-12-27Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller
Daniel Borkmann says: ==================== pull-request: bpf-next 2019-12-27 The following pull-request contains BPF updates for your *net-next* tree. We've added 127 non-merge commits during the last 17 day(s) which contain a total of 110 files changed, 6901 insertions(+), 2721 deletions(-). There are three merge conflicts. Conflicts and resolution looks as follows: 1) Merge conflict in net/bpf/test_run.c: There was a tree-wide cleanup c593642c8be0 ("treewide: Use sizeof_field() macro") which gets in the way with b590cb5f802d ("bpf: Switch to offsetofend in BPF_PROG_TEST_RUN"): <<<<<<< HEAD if (!range_is_zero(__skb, offsetof(struct __sk_buff, priority) + sizeof_field(struct __sk_buff, priority), ======= if (!range_is_zero(__skb, offsetofend(struct __sk_buff, priority), >>>>>>> 7c8dce4b166113743adad131b5a24c4acc12f92c There are a few occasions that look similar to this. Always take the chunk with offsetofend(). Note that there is one where the fields differ in here: <<<<<<< HEAD if (!range_is_zero(__skb, offsetof(struct __sk_buff, tstamp) + sizeof_field(struct __sk_buff, tstamp), ======= if (!range_is_zero(__skb, offsetofend(struct __sk_buff, gso_segs), >>>>>>> 7c8dce4b166113743adad131b5a24c4acc12f92c Just take the one with offsetofend() /and/ gso_segs. Latter is correct due to 850a88cc4096 ("bpf: Expose __sk_buff wire_len/gso_segs to BPF_PROG_TEST_RUN"). 2) Merge conflict in arch/riscv/net/bpf_jit_comp.c: (I'm keeping Bjorn in Cc here for a double-check in case I got it wrong.) <<<<<<< HEAD if (is_13b_check(off, insn)) return -1; emit(rv_blt(tcc, RV_REG_ZERO, off >> 1), ctx); ======= emit_branch(BPF_JSLT, RV_REG_T1, RV_REG_ZERO, off, ctx); >>>>>>> 7c8dce4b166113743adad131b5a24c4acc12f92c Result should look like: emit_branch(BPF_JSLT, tcc, RV_REG_ZERO, off, ctx); 3) Merge conflict in arch/riscv/include/asm/pgtable.h: <<<<<<< HEAD ======= #define VMALLOC_SIZE (KERN_VIRT_SIZE >> 1) #define VMALLOC_END (PAGE_OFFSET - 1) #define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE) #define BPF_JIT_REGION_SIZE (SZ_128M) #define BPF_JIT_REGION_START (PAGE_OFFSET - BPF_JIT_REGION_SIZE) #define BPF_JIT_REGION_END (VMALLOC_END) /* * Roughly size the vmemmap space to be large enough to fit enough * struct pages to map half the virtual address space. Then * position vmemmap directly below the VMALLOC region. */ #define VMEMMAP_SHIFT \ (CONFIG_VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT) #define VMEMMAP_SIZE BIT(VMEMMAP_SHIFT) #define VMEMMAP_END (VMALLOC_START - 1) #define VMEMMAP_START (VMALLOC_START - VMEMMAP_SIZE) #define vmemmap ((struct page *)VMEMMAP_START) >>>>>>> 7c8dce4b166113743adad131b5a24c4acc12f92c Only take the BPF_* defines from there and move them higher up in the same file. Remove the rest from the chunk. The VMALLOC_* etc defines got moved via 01f52e16b868 ("riscv: define vmemmap before pfn_to_page calls"). Result: [...] #define __S101 PAGE_READ_EXEC #define __S110 PAGE_SHARED_EXEC #define __S111 PAGE_SHARED_EXEC #define VMALLOC_SIZE (KERN_VIRT_SIZE >> 1) #define VMALLOC_END (PAGE_OFFSET - 1) #define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE) #define BPF_JIT_REGION_SIZE (SZ_128M) #define BPF_JIT_REGION_START (PAGE_OFFSET - BPF_JIT_REGION_SIZE) #define BPF_JIT_REGION_END (VMALLOC_END) /* * Roughly size the vmemmap space to be large enough to fit enough * struct pages to map half the virtual address space. Then * position vmemmap directly below the VMALLOC region. */ #define VMEMMAP_SHIFT \ (CONFIG_VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT) #define VMEMMAP_SIZE BIT(VMEMMAP_SHIFT) #define VMEMMAP_END (VMALLOC_START - 1) #define VMEMMAP_START (VMALLOC_START - VMEMMAP_SIZE) [...] Let me know if there are any other issues. Anyway, the main changes are: 1) Extend bpftool to produce a struct (aka "skeleton") tailored and specific to a provided BPF object file. This provides an alternative, simplified API compared to standard libbpf interaction. Also, add libbpf extern variable resolution for .kconfig section to import Kconfig data, from Andrii Nakryiko. 2) Add BPF dispatcher for XDP which is a mechanism to avoid indirect calls by generating a branch funnel as discussed back in bpfconf'19 at LSF/MM. Also, add various BPF riscv JIT improvements, from Björn Töpel. 3) Extend bpftool to allow matching BPF programs and maps by name, from Paul Chaignon. 4) Support for replacing cgroup BPF programs attached with BPF_F_ALLOW_MULTI flag for allowing updates without service interruption, from Andrey Ignatov. 5) Cleanup and simplification of ring access functions for AF_XDP with a bonus of 0-5% performance improvement, from Magnus Karlsson. 6) Enable BPF JITs for x86-64 and arm64 by default. Also, final version of audit support for BPF, from Daniel Borkmann and latter with Jiri Olsa. 7) Move and extend test_select_reuseport into BPF program tests under BPF selftests, from Jakub Sitnicki. 8) Various BPF sample improvements for xdpsock for customizing parameters to set up and benchmark AF_XDP, from Jay Jayatheerthan. 9) Improve libbpf to provide a ulimit hint on permission denied errors. Also change XDP sample programs to attach in driver mode by default, from Toke Høiland-Jørgensen. 10) Extend BPF test infrastructure to allow changing skb mark from tc BPF programs, from Nikita V. Shirokov. 11) Optimize prologue code sequence in BPF arm32 JIT, from Russell King. 12) Fix xdp_redirect_cpu BPF sample to manually attach to tracepoints after libbpf conversion, from Jesper Dangaard Brouer. 13) Minor misc improvements from various others. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-20xsk: Use struct_size() helperMagnus Karlsson
Improve readability and maintainability by using the struct_size() helper when allocating the AF_XDP rings. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/1576759171-28550-13-git-send-email-magnus.karlsson@intel.com
2019-12-20xsk: Add function naming comments and reorder functionsMagnus Karlsson
Add comments on how the ring access functions are named and how they are supposed to be used for producers and consumers. The functions are also reordered so that the consumer functions are in the beginning and the producer functions in the end, for easier reference. Put this in a separate patch as the diff might look a little odd, but no functionality has changed in this patch. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/1576759171-28550-12-git-send-email-magnus.karlsson@intel.com
2019-12-20xsk: Remove unnecessary READ_ONCE of dataMagnus Karlsson
There are two unnecessary READ_ONCE of descriptor data. These are not needed since the data is written by the producer before it signals that the data is available by incrementing the producer pointer. As the access to this producer pointer is serialized and the consumer always reads the descriptor after it has read and synchronized with the producer counter, the write of the descriptor will have fully completed and it does not matter if the consumer has any read tearing. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/1576759171-28550-11-git-send-email-magnus.karlsson@intel.com
2019-12-20xsk: ixgbe: i40e: ice: mlx5: Xsk_umem_discard_addr to xsk_umem_release_addrMagnus Karlsson
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
2019-12-20xsk: Change names of validation functionsMagnus Karlsson
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
2019-12-20xsk: Simplify the consumer ring access functionsMagnus Karlsson
Simplify and refactor consumer ring functions. The consumer first "peeks" to find descriptors or addresses that are available to read from the ring, then reads them and finally "releases" these descriptors once it is done. The two local variables cons_tail and cons_head are turned into one single variable called cached_cons. cached_tail referred to the cached value of the global consumer pointer and will be stored in cached_cons. For cached_head, we just use cached_prod instead as it was not used for a consumer queue before. It also better reflects what it really is now: a cached copy of the producer pointer. The names of the functions are also renamed in the same manner as the producer functions. The new functions are called xskq_cons_ followed by what it does. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/1576759171-28550-8-git-send-email-magnus.karlsson@intel.com
2019-12-20xsk: Simplify xskq_nb_avail and xskq_nb_freeMagnus Karlsson
At this point, there are no users of the functions xskq_nb_avail and xskq_nb_free that take any other number of entries argument than 1, so let us get rid of the second argument that takes the number of entries. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/1576759171-28550-7-git-send-email-magnus.karlsson@intel.com
2019-12-20xsk: Eliminate the RX batch sizeMagnus Karlsson
In the xsk consumer ring code there is a variable called RX_BATCH_SIZE that dictates the minimum number of entries that we try to grab from the fill and Tx rings. In fact, the code always try to grab the maximum amount of entries from these rings. The only thing this variable does is to throw an error if there is less than 16 (as it is defined) entries on the ring. There is no reason to do this and it will just lead to weird behavior from user space's point of view. So eliminate this variable. With this change, we will be able to simplify the xskq_nb_free and xskq_nb_avail code in the next commit. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/1576759171-28550-6-git-send-email-magnus.karlsson@intel.com
2019-12-20xsk: Standardize naming of producer ring access functionsMagnus Karlsson
Adopt the naming of the producer ring access functions to have a similar naming convention as the functions in libbpf, but adapted to the kernel. You first reserve a number of entries that you later submit to the global state of the ring. This is much clearer, IMO, than the one that was in the kernel part. Once renamed, we also discover that two functions are actually the same, so remove one of them. Some of the primitive ring submission operations are also the same so break these out into __xskq_prod_submit that the upper level ring access functions can use. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/1576759171-28550-5-git-send-email-magnus.karlsson@intel.com
2019-12-20xsk: Consolidate to one single cached producer pointerMagnus Karlsson
Currently, the xsk ring code has two cached producer pointers: prod_head and prod_tail. This patch consolidates these two into a single one called cached_prod to make the code simpler and easier to maintain. This will be in line with the user space part of the the code found in libbpf, that only uses a single cached pointer. The Rx path only uses the two top level functions xskq_produce_batch_desc and xskq_produce_flush_desc and they both use prod_head and never prod_tail. So just move them over to cached_prod. The Tx XDP_DRV path uses xskq_produce_addr_lazy and xskq_produce_flush_addr_n and unnecessarily operates on both prod_tail and prod_head, so move them over to just use cached_prod by skipping the intermediate step of updating prod_tail. The Tx path in XDP_SKB mode uses xskq_reserve_addr and xskq_produce_addr. They currently use both cached pointers, but we can operate on the global producer pointer in xskq_produce_addr since it has to be updated anyway, thus eliminating the use of both cached pointers. We can also remove the xskq_nb_free in xskq_produce_addr since it is already called in xskq_reserve_addr. No need to do it twice. When there is only one cached producer pointer, we can also simplify xskq_nb_free by removing one argument. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/1576759171-28550-4-git-send-email-magnus.karlsson@intel.com
2019-12-20xsk: Simplify detection of empty and full ringsMagnus Karlsson
In order to set the correct return flags for poll, the xsk code has to check if the Rx queue is empty and if the Tx queue is full. This code was unnecessarily large and complex as it used the functions that are used to update the local state from the global state (xskq_nb_free and xskq_nb_avail). Since we are not doing this nor updating any data dependent on this state, we can simplify the functions. Another benefit from this is that we can also simplify the xskq_nb_free and xskq_nb_avail functions in a later commit. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/1576759171-28550-3-git-send-email-magnus.karlsson@intel.com
2019-12-20xsk: Eliminate the lazy update thresholdMagnus Karlsson
The lazy update threshold was introduced to keep the producer and consumer some distance apart in the completion ring. This was important in the beginning of the development of AF_XDP as the ring format as that point in time was very sensitive to the producer and consumer being on the same cache line. This is not the case anymore as the current ring format does not degrade in any noticeable way when this happens. Moreover, this threshold makes it impossible to run the system with rings that have less than 128 entries. So let us remove this threshold and just get one entry from the ring as in all other functions. This will enable us to remove this function in a later commit. Note that xskq_produce_addr_lazy followed by xskq_produce_flush_addr_n are still not the same function as xskq_produce_addr() as it operates on another cached pointer. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/1576759171-28550-2-git-send-email-magnus.karlsson@intel.com
2019-12-19xsk: Make xskmap flush_list common for all map instancesBjörn Töpel
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
2019-12-19xsk: Add rcu_read_lock around the XSK wakeupMaxim Mikityanskiy
The XSK wakeup callback in drivers makes some sanity checks before triggering NAPI. However, some configuration changes may occur during this function that affect the result of those checks. For example, the interface can go down, and all the resources will be destroyed after the checks in the wakeup function, but before it attempts to use these resources. Wrap this callback in rcu_read_lock to allow driver to synchronize_rcu before actually destroying the resources. xsk_wakeup is a new function that encapsulates calling ndo_xsk_wakeup wrapped into the RCU lock. After this commit, xsk_poll starts using xsk_wakeup and checks xs->zc instead of ndo_xsk_wakeup != NULL to decide ndo_xsk_wakeup should be called. It also fixes a bug introduced with the need_wakeup feature: a non-zero-copy socket may be used with a driver supporting zero-copy, and in this case ndo_xsk_wakeup should not be called, so the xs->zc check is the correct one. Fixes: 77cd0d7b3f25 ("xsk: add support for need_wakeup flag in AF_XDP rings") Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com> Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191217162023.16011-2-maximmi@mellanox.com
2019-11-24xsk: Fix xsk_poll()'s return typeLuc Van Oostenryck
xsk_poll() is defined as returning 'unsigned int' but the .poll method is declared as returning '__poll_t', a bitwise type. Fix this by using the proper return type and using the EPOLL constants instead of the POLL ones, as required for __poll_t. Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Björn Töpel <bjorn.topel@intel.com> Link: https://lore.kernel.org/bpf/20191120001042.30830-1-luc.vanoostenryck@gmail.com
2019-11-02Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller
Alexei Starovoitov says: ==================== pull-request: bpf-next 2019-11-02 The following pull-request contains BPF updates for your *net-next* tree. We've added 30 non-merge commits during the last 7 day(s) which contain a total of 41 files changed, 1864 insertions(+), 474 deletions(-). The main changes are: 1) Fix long standing user vs kernel access issue by introducing bpf_probe_read_user() and bpf_probe_read_kernel() helpers, from Daniel. 2) Accelerated xskmap lookup, from Björn and Maciej. 3) Support for automatic map pinning in libbpf, from Toke. 4) Cleanup of BTF-enabled raw tracepoints, from Alexei. 5) Various fixes to libbpf and selftests. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-02xsk: Restructure/inline XSKMAP lookup/redirect/flushBjörn Töpel
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
2019-10-23xsk: Fix registration of Rx-only socketsMagnus Karlsson
Having Rx-only AF_XDP sockets can potentially lead to a crash in the system by a NULL pointer dereference in xsk_umem_consume_tx(). This function iterates through a list of all sockets tied to a umem and checks if there are any packets to send on the Tx ring. Rx-only sockets do not have a Tx ring, so this will cause a NULL pointer dereference. This will happen if you have registered one or more Rx-only sockets to a umem and the driver is checking the Tx ring even on Rx, or if the XDP_SHARED_UMEM mode is used and there is a mix of Rx-only and other sockets tied to the same umem. Fixed by only putting sockets with a Tx component on the list that xsk_umem_consume_tx() iterates over. Fixes: ac98d8aab61b ("xsk: wire upp Tx zero-copy functions") Reported-by: Kal Cutter Conley <kal.conley@dectris.com> Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com> Link: https://lore.kernel.org/bpf/1571645818-16244-1-git-send-email-magnus.karlsson@intel.com
2019-10-03xsk: Fix crash in poll when device does not support ndo_xsk_wakeupMagnus Karlsson
Fixes a crash in poll() when an AF_XDP socket is opened in copy mode and the bound device does not have ndo_xsk_wakeup defined. Avoid trying to call the non-existing ndo and instead call the internal xsk sendmsg function to send packets in the same way (from the application's point of view) as calling sendmsg() in any mode or poll() in zero-copy mode would have done. The application should behave in the same way independent on if zero-copy mode or copy mode is used. Fixes: 77cd0d7b3f25 ("xsk: add support for need_wakeup flag in AF_XDP rings") Reported-by: syzbot+a5765ed8cdb1cca4d249@syzkaller.appspotmail.com Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/1569997919-11541-1-git-send-email-magnus.karlsson@intel.com
2019-09-28Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netLinus Torvalds
Pull networking fixes from David Miller: 1) Sanity check URB networking device parameters to avoid divide by zero, from Oliver Neukum. 2) Disable global multicast filter in NCSI, otherwise LLDP and IPV6 don't work properly. Longer term this needs a better fix tho. From Vijay Khemka. 3) Small fixes to selftests (use ping when ping6 is not present, etc.) from David Ahern. 4) Bring back rt_uses_gateway member of struct rtable, it's semantics were not well understood and trying to remove it broke things. From David Ahern. 5) Move usbnet snaity checking, ignore endpoints with invalid wMaxPacketSize. From Bjørn Mork. 6) Missing Kconfig deps for sja1105 driver, from Mao Wenan. 7) Various small fixes to the mlx5 DR steering code, from Alaa Hleihel, Alex Vesker, and Yevgeny Kliteynik 8) Missing CAP_NET_RAW checks in various places, from Ori Nimron. 9) Fix crash when removing sch_cbs entry while offloading is enabled, from Vinicius Costa Gomes. 10) Signedness bug fixes, generally in looking at the result given by of_get_phy_mode() and friends. From Dan Crapenter. 11) Disable preemption around BPF_PROG_RUN() calls, from Eric Dumazet. 12) Don't create VRF ipv6 rules if ipv6 is disabled, from David Ahern. 13) Fix quantization code in tcp_bbr, from Kevin Yang. * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (127 commits) net: tap: clean up an indentation issue nfp: abm: fix memory leak in nfp_abm_u32_knode_replace tcp: better handle TCP_USER_TIMEOUT in SYN_SENT state sk_buff: drop all skb extensions on free and skb scrubbing tcp_bbr: fix quantization code to not raise cwnd if not probing bandwidth mlxsw: spectrum_flower: Fail in case user specifies multiple mirror actions Documentation: Clarify trap's description mlxsw: spectrum: Clear VLAN filters during port initialization net: ena: clean up indentation issue NFC: st95hf: clean up indentation issue net: phy: micrel: add Asym Pause workaround for KSZ9021 net: socionext: ave: Avoid using netdev_err() before calling register_netdev() ptp: correctly disable flags on old ioctls lib: dimlib: fix help text typos net: dsa: microchip: Always set regmap stride to 1 nfp: flower: fix memory leak in nfp_flower_spawn_vnic_reprs nfp: flower: prevent memory leak in nfp_flower_spawn_phy_reprs net/sched: Set default of CONFIG_NET_TC_SKB_EXT to N vrf: Do not attempt to create IPv6 mcast rule if IPv6 is disabled net: sched: sch_sfb: don't call qdisc_put() while holding tree lock ...
2019-09-24net/xdp: convert put_page() to put_user_page*()John Hubbard
For pages that were retained via get_user_pages*(), release those pages via the new put_user_page*() routines, instead of via put_page() or release_pages(). This is part a tree-wide conversion, as described in fc1d8e7cca2d ("mm: introduce put_user_page*(), placeholder versions"). Link: http://lkml.kernel.org/r/20190724044537.10458-4-jhubbard@nvidia.com Signed-off-by: John Hubbard <jhubbard@nvidia.com> Acked-by: Björn Töpel <bjorn.topel@intel.com> Cc: Björn Töpel <bjorn.topel@intel.com> Cc: Magnus Karlsson <magnus.karlsson@intel.com> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm: introduce page_size()Matthew Wilcox (Oracle)
Patch series "Make working with compound pages easier", v2. These three patches add three helpers and convert the appropriate places to use them. This patch (of 3): It's unnecessarily hard to find out the size of a potentially huge page. Replace 'PAGE_SIZE << compound_order(page)' with page_size(page). Link: http://lkml.kernel.org/r/20190721104612.19120-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-19xsk: relax UMEM headroom alignmentBjörn Töpel
This patch removes the 64B alignment of the UMEM headroom. There is really no reason for it, and having a headroom less than 64B should be valid. Fixes: c0c77d8fb787 ("xsk: add user memory registration support sockopt") Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-09-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller
Daniel Borkmann says: ==================== The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) Add the ability to use unaligned chunks in the AF_XDP umem. By relaxing where the chunks can be placed, it allows to use an arbitrary buffer size and place whenever there is a free address in the umem. Helps more seamless DPDK AF_XDP driver integration. Support for i40e, ixgbe and mlx5e, from Kevin and Maxim. 2) Addition of a wakeup flag for AF_XDP tx and fill rings so the application can wake up the kernel for rx/tx processing which avoids busy-spinning of the latter, useful when app and driver is located on the same core. Support for i40e, ixgbe and mlx5e, from Magnus and Maxim. 3) bpftool fixes for printf()-like functions so compiler can actually enforce checks, bpftool build system improvements for custom output directories, and addition of 'bpftool map freeze' command, from Quentin. 4) Support attaching/detaching XDP programs from 'bpftool net' command, from Daniel. 5) Automatic xskmap cleanup when AF_XDP socket is released, and several barrier/{read,write}_once fixes in AF_XDP code, from Björn. 6) Relicense of bpf_helpers.h/bpf_endian.h for future libbpf inclusion as well as libbpf versioning improvements, from Andrii. 7) Several new BPF kselftests for verifier precision tracking, from Alexei. 8) Several BPF kselftest fixes wrt endianess to run on s390x, from Ilya. 9) And more BPF kselftest improvements all over the place, from Stanislav. 10) Add simple BPF map op cache for nfp driver to batch dumps, from Jakub. 11) AF_XDP socket umem mapping improvements for 32bit archs, from Ivan. 12) Add BPF-to-BPF call and BTF line info support for s390x JIT, from Yauheni. 13) Small optimization in arm64 JIT to spare 1 insns for BPF_MOD, from Jerin. 14) Fix an error check in bpf_tcp_gen_syncookie() helper, from Petar. 15) Various minor fixes and cleanups, from Nathan, Masahiro, Masanari, Peter, Wei, Yue. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-05xsk: lock the control mutex in sock_diag interfaceBjörn Töpel
When accessing the members of an XDP socket, the control mutex should be held. This commit fixes that. Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com> Fixes: a36b38aa2af6 ("xsk: add sock_diag interface for AF_XDP") Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-09-05xsk: use state member for socket synchronizationBjörn Töpel
Prior the state variable was introduced by Ilya, the dev member was used to determine whether the socket was bound or not. However, when dev was read, proper SMP barriers and READ_ONCE were missing. In order to address the missing barriers and READ_ONCE, we start using the state variable as a point of synchronization. The state member read/write is paired with proper SMP barriers, and from this follows that the members described above does not need READ_ONCE if used in conjunction with state check. In all syscalls and the xsk_rcv path we check if state is XSK_BOUND. If that is the case we do a SMP read barrier, and this implies that the dev, umem and all rings are correctly setup. Note that no READ_ONCE are needed for these variable if used when state is XSK_BOUND (plus the read barrier). To summarize: The members struct xdp_sock members dev, queue_id, umem, fq, cq, tx, rx, and state were read lock-less, with incorrect barriers and missing {READ, WRITE}_ONCE. Now, umem, fq, cq, tx, rx, and state are read lock-less. When these members are updated, WRITE_ONCE is used. When read, READ_ONCE are only used when read outside the control mutex (e.g. mmap) or, not synchronized with the state member (XSK_BOUND plus smp_rmb()) Note that dev and queue_id do not need a WRITE_ONCE or READ_ONCE, due to the introduce state synchronization (XSK_BOUND plus smp_rmb()). Introducing the state check also fixes a race, found by syzcaller, in xsk_poll() where umem could be accessed when stale. Suggested-by: Hillf Danton <hdanton@sina.com> Reported-by: syzbot+c82697e3043781e08802@syzkaller.appspotmail.com Fixes: 77cd0d7b3f25 ("xsk: add support for need_wakeup flag in AF_XDP rings") Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-09-05xsk: avoid store-tearing when assigning umemBjörn Töpel
The umem member of struct xdp_sock is read outside of the control mutex, in the mmap implementation, and needs a WRITE_ONCE to avoid potential store-tearing. Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com> Fixes: 423f38329d26 ("xsk: add umem fill queue support and mmap") Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-09-05xsk: avoid store-tearing when assigning queuesBjörn Töpel
Use WRITE_ONCE when doing the store of tx, rx, fq, and cq, to avoid potential store-tearing. These members are read outside of the control mutex in the mmap implementation. Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com> Fixes: 37b076933a8e ("xsk: add missing write- and data-dependency barrier") Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-08-31xsk: add support to allow unaligned chunk placementKevin Laatz
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>
2019-08-27Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
Minor conflict in r8169, bug fix had two versions in net and net-next, take the net-next hunks. Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-21xdp: xdp_umem: replace kmap on vmap for umem mapIvan Khoronzhuk
For 64-bit there is no reason to use vmap/vunmap, so use page_address as it was initially. For 32 bits, in some apps, like in samples xdpsock_user.c when number of pgs in use is quite big, the kmap memory can be not enough, despite on this, kmap looks like is deprecated in such cases as it can block and should be used rather for dynamic mm. Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org> Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-08-20xdp: unpin xdp umem pages in error pathIvan Khoronzhuk
Fix mem leak caused by missed unpin routine for umem pages. Fixes: 8aef7340ae9695 ("xsk: introduce xdp_umem_page") Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org> Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-08-17xsk: remove AF_XDP socket from map when the socket is releasedBjörn Töpel
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>
2019-08-17xsk: add support for need_wakeup flag in AF_XDP ringsMagnus Karlsson
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>
2019-08-17xsk: replace ndo_xsk_async_xmit with ndo_xsk_wakeupMagnus Karlsson
This commit replaces ndo_xsk_async_xmit with ndo_xsk_wakeup. This new ndo provides the same functionality as before but with the addition of a new flags field that is used to specifiy if Rx, Tx or both should be woken up. The previous ndo only woke up Tx, as implied by the name. The i40e and ixgbe drivers (which are all the supported ones) are updated with this new interface. This new ndo will be used by the new need_wakeup functionality of XDP sockets that need to be able to wake up both Rx and Tx driver processing. 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>
2019-08-09xdp: xdp_umem: fix umem pages mapping for 32bits systemsIvan Khoronzhuk
Use kmap instead of page_address as it's not always in low memory. Acked-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>