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linux/net/core/devmem.h

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netdev: support binding dma-buf to netdevice Add a netdev_dmabuf_binding struct which represents the dma-buf-to-netdevice binding. The netlink API will bind the dma-buf to rx queues on the netdevice. On the binding, the dma_buf_attach & dma_buf_map_attachment will occur. The entries in the sg_table from mapping will be inserted into a genpool to make it ready for allocation. The chunks in the genpool are owned by a dmabuf_chunk_owner struct which holds the dma-buf offset of the base of the chunk and the dma_addr of the chunk. Both are needed to use allocations that come from this chunk. We create a new type that represents an allocation from the genpool: net_iov. We setup the net_iov allocation size in the genpool to PAGE_SIZE for simplicity: to match the PAGE_SIZE normally allocated by the page pool and given to the drivers. The user can unbind the dmabuf from the netdevice by closing the netlink socket that established the binding. We do this so that the binding is automatically unbound even if the userspace process crashes. The binding and unbinding leaves an indicator in struct netdev_rx_queue that the given queue is bound, and the binding is actuated by resetting the rx queue using the queue API. The netdev_dmabuf_binding struct is refcounted, and releases its resources only when all the refs are released. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> # excluding netlink Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-4-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:47 +00:00
net: generalise net_iov chunk owners Currently net_iov stores a pointer to struct dmabuf_genpool_chunk_owner, which serves as a useful abstraction to share data and provide a context. However, it's too devmem specific, and we want to reuse it for other memory providers, and for that we need to decouple net_iov from devmem. Make net_iov to point to a new base structure called net_iov_area, which dmabuf_genpool_chunk_owner extends. Reviewed-by: Mina Almasry <almasrymina@google.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: David Wei <dw@davidwei.uk> Link: https://patch.msgid.link/20250204215622.695511-4-dw@davidwei.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-04 13:56:14 -08:00
net: devmem: move list_add to net_devmem_bind_dmabuf. It's annoying for the list_add to be outside net_devmem_bind_dmabuf, but the list_del is in net_devmem_unbind_dmabuf. Make it consistent by having both the list_add/del be inside the net_devmem_[un]bind_dmabuf. Cc: ap420073@gmail.com Signed-off-by: Mina Almasry <almasrymina@google.com> Tested-by: Taehee Yoo <ap420073@gmail.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250523230524.1107879-2-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-23 23:05:17 +00:00
net: generalise net_iov chunk owners Currently net_iov stores a pointer to struct dmabuf_genpool_chunk_owner, which serves as a useful abstraction to share data and provide a context. However, it's too devmem specific, and we want to reuse it for other memory providers, and for that we need to decouple net_iov from devmem. Make net_iov to point to a new base structure called net_iov_area, which dmabuf_genpool_chunk_owner extends. Reviewed-by: Mina Almasry <almasrymina@google.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: David Wei <dw@davidwei.uk> Link: https://patch.msgid.link/20250204215622.695511-4-dw@davidwei.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-04 13:56:14 -08:00
netdev: support binding dma-buf to netdevice Add a netdev_dmabuf_binding struct which represents the dma-buf-to-netdevice binding. The netlink API will bind the dma-buf to rx queues on the netdevice. On the binding, the dma_buf_attach & dma_buf_map_attachment will occur. The entries in the sg_table from mapping will be inserted into a genpool to make it ready for allocation. The chunks in the genpool are owned by a dmabuf_chunk_owner struct which holds the dma-buf offset of the base of the chunk and the dma_addr of the chunk. Both are needed to use allocations that come from this chunk. We create a new type that represents an allocation from the genpool: net_iov. We setup the net_iov allocation size in the genpool to PAGE_SIZE for simplicity: to match the PAGE_SIZE normally allocated by the page pool and given to the drivers. The user can unbind the dmabuf from the netdevice by closing the netlink socket that established the binding. We do this so that the binding is automatically unbound even if the userspace process crashes. The binding and unbinding leaves an indicator in struct netdev_rx_queue that the given queue is bound, and the binding is actuated by resetting the rx queue using the queue API. The netdev_dmabuf_binding struct is refcounted, and releases its resources only when all the refs are released. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> # excluding netlink Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-4-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:47 +00:00
net: devmem: fix kernel panic when netlink socket close after module unload Kernel panic occurs when a devmem TCP socket is closed after NIC module is unloaded. This is Devmem TCP unregistration scenarios. number is an order. (a)netlink socket close (b)pp destroy (c)uninstall result 1 2 3 OK 1 3 2 (d)Impossible 2 1 3 OK 3 1 2 (e)Kernel panic 2 3 1 (d)Impossible 3 2 1 (d)Impossible (a) netdev_nl_sock_priv_destroy() is called when devmem TCP socket is closed. (b) page_pool_destroy() is called when the interface is down. (c) mp_ops->uninstall() is called when an interface is unregistered. (d) There is no scenario in mp_ops->uninstall() is called before page_pool_destroy(). Because unregister_netdevice_many_notify() closes interfaces first and then calls mp_ops->uninstall(). (e) netdev_nl_sock_priv_destroy() accesses struct net_device to acquire netdev_lock(). But if the interface module has already been removed, net_device pointer is invalid, so it causes kernel panic. In summary, there are only 3 possible scenarios. A. sk close -> pp destroy -> uninstall. B. pp destroy -> sk close -> uninstall. C. pp destroy -> uninstall -> sk close. Case C is a kernel panic scenario. In order to fix this problem, It makes mp_dmabuf_devmem_uninstall() set binding->dev to NULL. It indicates an bound net_device was unregistered. It makes netdev_nl_sock_priv_destroy() do not acquire netdev_lock() if binding->dev is NULL. A new binding->lock is added to protect a dev of a binding. So, lock ordering is like below. priv->lock netdev_lock(dev) binding->lock Tests: Scenario A: ./ncdevmem -s 192.168.1.4 -c 192.168.1.2 -f $interface -l -p 8000 \ -v 7 -t 1 -q 1 & pid=$! sleep 10 kill $pid ip link set $interface down modprobe -rv $module Scenario B: ./ncdevmem -s 192.168.1.4 -c 192.168.1.2 -f $interface -l -p 8000 \ -v 7 -t 1 -q 1 & pid=$! sleep 10 ip link set $interface down kill $pid modprobe -rv $module Scenario C: ./ncdevmem -s 192.168.1.4 -c 192.168.1.2 -f $interface -l -p 8000 \ -v 7 -t 1 -q 1 & pid=$! sleep 10 modprobe -rv $module sleep 5 kill $pid Splat looks like: Oops: general protection fault, probably for non-canonical address 0xdffffc001fffa9f7: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI KASAN: probably user-memory-access in range [0x00000000fffd4fb8-0x00000000fffd4fbf] CPU: 0 UID: 0 PID: 2041 Comm: ncdevmem Tainted: G B W 6.15.0-rc1+ #2 PREEMPT(undef) 0947ec89efa0fd68838b78e36aa1617e97ff5d7f Tainted: [B]=BAD_PAGE, [W]=WARN RIP: 0010:__mutex_lock (./include/linux/sched.h:2244 kernel/locking/mutex.c:400 kernel/locking/mutex.c:443 kernel/locking/mutex.c:605 kernel/locking/mutex.c:746) Code: ea 03 80 3c 02 00 0f 85 4f 13 00 00 49 8b 1e 48 83 e3 f8 74 6a 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 34 48 89 fa 48 c1 ea 03 <0f> b6 f RSP: 0018:ffff88826f7ef730 EFLAGS: 00010203 RAX: dffffc0000000000 RBX: 00000000fffd4f88 RCX: ffffffffaa9bc811 RDX: 000000001fffa9f7 RSI: 0000000000000008 RDI: 00000000fffd4fbc RBP: ffff88826f7ef8b0 R08: 0000000000000000 R09: ffffed103e6aa1a4 R10: 0000000000000007 R11: ffff88826f7ef442 R12: fffffbfff669f65e R13: ffff88812a830040 R14: ffff8881f3550d20 R15: 00000000fffd4f88 FS: 0000000000000000(0000) GS:ffff888866c05000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000563bed0cb288 CR3: 00000001a7c98000 CR4: 00000000007506f0 PKRU: 55555554 Call Trace: <TASK> ... netdev_nl_sock_priv_destroy (net/core/netdev-genl.c:953 (discriminator 3)) genl_release (net/netlink/genetlink.c:653 net/netlink/genetlink.c:694 net/netlink/genetlink.c:705) ... netlink_release (net/netlink/af_netlink.c:737) ... __sock_release (net/socket.c:647) sock_close (net/socket.c:1393) Fixes: 1d22d3060b9b ("net: drop rtnl_lock for queue_mgmt operations") Signed-off-by: Taehee Yoo <ap420073@gmail.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250514154028.1062909-1-ap420073@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-14 15:40:28 +00:00
netdev: support binding dma-buf to netdevice Add a netdev_dmabuf_binding struct which represents the dma-buf-to-netdevice binding. The netlink API will bind the dma-buf to rx queues on the netdevice. On the binding, the dma_buf_attach & dma_buf_map_attachment will occur. The entries in the sg_table from mapping will be inserted into a genpool to make it ready for allocation. The chunks in the genpool are owned by a dmabuf_chunk_owner struct which holds the dma-buf offset of the base of the chunk and the dma_addr of the chunk. Both are needed to use allocations that come from this chunk. We create a new type that represents an allocation from the genpool: net_iov. We setup the net_iov allocation size in the genpool to PAGE_SIZE for simplicity: to match the PAGE_SIZE normally allocated by the page pool and given to the drivers. The user can unbind the dmabuf from the netdevice by closing the netlink socket that established the binding. We do this so that the binding is automatically unbound even if the userspace process crashes. The binding and unbinding leaves an indicator in struct netdev_rx_queue that the given queue is bound, and the binding is actuated by resetting the rx queue using the queue API. The netdev_dmabuf_binding struct is refcounted, and releases its resources only when all the refs are released. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> # excluding netlink Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-4-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:47 +00:00
net: devmem: Implement TX path Augment dmabuf binding to be able to handle TX. Additional to all the RX binding, we also create tx_vec needed for the TX path. Provide API for sendmsg to be able to send dmabufs bound to this device: - Provide a new dmabuf_tx_cmsg which includes the dmabuf to send from. - MSG_ZEROCOPY with SCM_DEVMEM_DMABUF cmsg indicates send from dma-buf. Devmem is uncopyable, so piggyback off the existing MSG_ZEROCOPY implementation, while disabling instances where MSG_ZEROCOPY falls back to copying. We additionally pipe the binding down to the new zerocopy_fill_skb_from_devmem which fills a TX skb with net_iov netmems instead of the traditional page netmems. We also special case skb_frag_dma_map to return the dma-address of these dmabuf net_iovs instead of attempting to map pages. The TX path may release the dmabuf in a context where we cannot wait. This happens when the user unbinds a TX dmabuf while there are still references to its netmems in the TX path. In that case, the netmems will be put_netmem'd from a context where we can't unmap the dmabuf, Resolve this by making __net_devmem_dmabuf_binding_free schedule_work'd. Based on work by Stanislav Fomichev <sdf@fomichev.me>. A lot of the meat of the implementation came from devmem TCP RFC v1[1], which included the TX path, but Stan did all the rebasing on top of netmem/net_iov. Cc: Stanislav Fomichev <sdf@fomichev.me> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250508004830.4100853-5-almasrymina@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-08 00:48:24 +00:00
netdev: support binding dma-buf to netdevice Add a netdev_dmabuf_binding struct which represents the dma-buf-to-netdevice binding. The netlink API will bind the dma-buf to rx queues on the netdevice. On the binding, the dma_buf_attach & dma_buf_map_attachment will occur. The entries in the sg_table from mapping will be inserted into a genpool to make it ready for allocation. The chunks in the genpool are owned by a dmabuf_chunk_owner struct which holds the dma-buf offset of the base of the chunk and the dma_addr of the chunk. Both are needed to use allocations that come from this chunk. We create a new type that represents an allocation from the genpool: net_iov. We setup the net_iov allocation size in the genpool to PAGE_SIZE for simplicity: to match the PAGE_SIZE normally allocated by the page pool and given to the drivers. The user can unbind the dmabuf from the netdevice by closing the netlink socket that established the binding. We do this so that the binding is automatically unbound even if the userspace process crashes. The binding and unbinding leaves an indicator in struct netdev_rx_queue that the given queue is bound, and the binding is actuated by resetting the rx queue using the queue API. The netdev_dmabuf_binding struct is refcounted, and releases its resources only when all the refs are released. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> # excluding netlink Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-4-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:47 +00:00
net: add get_netmem/put_netmem support Currently net_iovs support only pp ref counts, and do not support a page ref equivalent. This is fine for the RX path as net_iovs are used exclusively with the pp and only pp refcounting is needed there. The TX path however does not use pp ref counts, thus, support for get_page/put_page equivalent is needed for netmem. Support get_netmem/put_netmem. Check the type of the netmem before passing it to page or net_iov specific code to obtain a page ref equivalent. For dmabuf net_iovs, we obtain a ref on the underlying binding. This ensures the entire binding doesn't disappear until all the net_iovs have been put_netmem'ed. We do not need to track the refcount of individual dmabuf net_iovs as we don't allocate/free them from a pool similar to what the buddy allocator does for pages. This code is written to be extensible by other net_iov implementers. get_netmem/put_netmem will check the type of the netmem and route it to the correct helper: pages -> [get|put]_page() dmabuf net_iovs -> net_devmem_[get|put]_net_iov() new net_iovs -> new helpers Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250508004830.4100853-3-almasrymina@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-08 00:48:22 +00:00
net: devmem: Implement TX path Augment dmabuf binding to be able to handle TX. Additional to all the RX binding, we also create tx_vec needed for the TX path. Provide API for sendmsg to be able to send dmabufs bound to this device: - Provide a new dmabuf_tx_cmsg which includes the dmabuf to send from. - MSG_ZEROCOPY with SCM_DEVMEM_DMABUF cmsg indicates send from dma-buf. Devmem is uncopyable, so piggyback off the existing MSG_ZEROCOPY implementation, while disabling instances where MSG_ZEROCOPY falls back to copying. We additionally pipe the binding down to the new zerocopy_fill_skb_from_devmem which fills a TX skb with net_iov netmems instead of the traditional page netmems. We also special case skb_frag_dma_map to return the dma-address of these dmabuf net_iovs instead of attempting to map pages. The TX path may release the dmabuf in a context where we cannot wait. This happens when the user unbinds a TX dmabuf while there are still references to its netmems in the TX path. In that case, the netmems will be put_netmem'd from a context where we can't unmap the dmabuf, Resolve this by making __net_devmem_dmabuf_binding_free schedule_work'd. Based on work by Stanislav Fomichev <sdf@fomichev.me>. A lot of the meat of the implementation came from devmem TCP RFC v1[1], which included the TX path, but Stan did all the rebasing on top of netmem/net_iov. Cc: Stanislav Fomichev <sdf@fomichev.me> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250508004830.4100853-5-almasrymina@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-08 00:48:24 +00:00
netdev: support binding dma-buf to netdevice Add a netdev_dmabuf_binding struct which represents the dma-buf-to-netdevice binding. The netlink API will bind the dma-buf to rx queues on the netdevice. On the binding, the dma_buf_attach & dma_buf_map_attachment will occur. The entries in the sg_table from mapping will be inserted into a genpool to make it ready for allocation. The chunks in the genpool are owned by a dmabuf_chunk_owner struct which holds the dma-buf offset of the base of the chunk and the dma_addr of the chunk. Both are needed to use allocations that come from this chunk. We create a new type that represents an allocation from the genpool: net_iov. We setup the net_iov allocation size in the genpool to PAGE_SIZE for simplicity: to match the PAGE_SIZE normally allocated by the page pool and given to the drivers. The user can unbind the dmabuf from the netdevice by closing the netlink socket that established the binding. We do this so that the binding is automatically unbound even if the userspace process crashes. The binding and unbinding leaves an indicator in struct netdev_rx_queue that the given queue is bound, and the binding is actuated by resetting the rx queue using the queue API. The netdev_dmabuf_binding struct is refcounted, and releases its resources only when all the refs are released. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> # excluding netlink Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-4-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:47 +00:00
net: devmem: Implement TX path Augment dmabuf binding to be able to handle TX. Additional to all the RX binding, we also create tx_vec needed for the TX path. Provide API for sendmsg to be able to send dmabufs bound to this device: - Provide a new dmabuf_tx_cmsg which includes the dmabuf to send from. - MSG_ZEROCOPY with SCM_DEVMEM_DMABUF cmsg indicates send from dma-buf. Devmem is uncopyable, so piggyback off the existing MSG_ZEROCOPY implementation, while disabling instances where MSG_ZEROCOPY falls back to copying. We additionally pipe the binding down to the new zerocopy_fill_skb_from_devmem which fills a TX skb with net_iov netmems instead of the traditional page netmems. We also special case skb_frag_dma_map to return the dma-address of these dmabuf net_iovs instead of attempting to map pages. The TX path may release the dmabuf in a context where we cannot wait. This happens when the user unbinds a TX dmabuf while there are still references to its netmems in the TX path. In that case, the netmems will be put_netmem'd from a context where we can't unmap the dmabuf, Resolve this by making __net_devmem_dmabuf_binding_free schedule_work'd. Based on work by Stanislav Fomichev <sdf@fomichev.me>. A lot of the meat of the implementation came from devmem TCP RFC v1[1], which included the TX path, but Stan did all the rebasing on top of netmem/net_iov. Cc: Stanislav Fomichev <sdf@fomichev.me> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250508004830.4100853-5-almasrymina@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-08 00:48:24 +00:00
net: devmem: fix DMA direction on unmapping Looks like we always unmap the DMA_BUF with DMA_FROM_DEVICE direction. While at it unexport __net_devmem_dmabuf_binding_free(), it's internal. Found by code inspection. Fixes: bd61848900bf ("net: devmem: Implement TX path") Acked-by: Stanislav Fomichev <sdf@fomichev.me> Reviewed-by: Mina Almasry <almasrymina@google.com> Link: https://patch.msgid.link/20250801011335.2267515-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-31 18:13:35 -07:00
net: devmem: Implement TX path Augment dmabuf binding to be able to handle TX. Additional to all the RX binding, we also create tx_vec needed for the TX path. Provide API for sendmsg to be able to send dmabufs bound to this device: - Provide a new dmabuf_tx_cmsg which includes the dmabuf to send from. - MSG_ZEROCOPY with SCM_DEVMEM_DMABUF cmsg indicates send from dma-buf. Devmem is uncopyable, so piggyback off the existing MSG_ZEROCOPY implementation, while disabling instances where MSG_ZEROCOPY falls back to copying. We additionally pipe the binding down to the new zerocopy_fill_skb_from_devmem which fills a TX skb with net_iov netmems instead of the traditional page netmems. We also special case skb_frag_dma_map to return the dma-address of these dmabuf net_iovs instead of attempting to map pages. The TX path may release the dmabuf in a context where we cannot wait. This happens when the user unbinds a TX dmabuf while there are still references to its netmems in the TX path. In that case, the netmems will be put_netmem'd from a context where we can't unmap the dmabuf, Resolve this by making __net_devmem_dmabuf_binding_free schedule_work'd. Based on work by Stanislav Fomichev <sdf@fomichev.me>. A lot of the meat of the implementation came from devmem TCP RFC v1[1], which included the TX path, but Stan did all the rebasing on top of netmem/net_iov. Cc: Stanislav Fomichev <sdf@fomichev.me> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250508004830.4100853-5-almasrymina@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-08 00:48:24 +00:00
netdev: support binding dma-buf to netdevice Add a netdev_dmabuf_binding struct which represents the dma-buf-to-netdevice binding. The netlink API will bind the dma-buf to rx queues on the netdevice. On the binding, the dma_buf_attach & dma_buf_map_attachment will occur. The entries in the sg_table from mapping will be inserted into a genpool to make it ready for allocation. The chunks in the genpool are owned by a dmabuf_chunk_owner struct which holds the dma-buf offset of the base of the chunk and the dma_addr of the chunk. Both are needed to use allocations that come from this chunk. We create a new type that represents an allocation from the genpool: net_iov. We setup the net_iov allocation size in the genpool to PAGE_SIZE for simplicity: to match the PAGE_SIZE normally allocated by the page pool and given to the drivers. The user can unbind the dmabuf from the netdevice by closing the netlink socket that established the binding. We do this so that the binding is automatically unbound even if the userspace process crashes. The binding and unbinding leaves an indicator in struct netdev_rx_queue that the given queue is bound, and the binding is actuated by resetting the rx queue using the queue API. The netdev_dmabuf_binding struct is refcounted, and releases its resources only when all the refs are released. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> # excluding netlink Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-4-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:47 +00:00
net: generalise net_iov chunk owners Currently net_iov stores a pointer to struct dmabuf_genpool_chunk_owner, which serves as a useful abstraction to share data and provide a context. However, it's too devmem specific, and we want to reuse it for other memory providers, and for that we need to decouple net_iov from devmem. Make net_iov to point to a new base structure called net_iov_area, which dmabuf_genpool_chunk_owner extends. Reviewed-by: Mina Almasry <almasrymina@google.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: David Wei <dw@davidwei.uk> Link: https://patch.msgid.link/20250204215622.695511-4-dw@davidwei.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-04 13:56:14 -08:00
netdev: support binding dma-buf to netdevice Add a netdev_dmabuf_binding struct which represents the dma-buf-to-netdevice binding. The netlink API will bind the dma-buf to rx queues on the netdevice. On the binding, the dma_buf_attach & dma_buf_map_attachment will occur. The entries in the sg_table from mapping will be inserted into a genpool to make it ready for allocation. The chunks in the genpool are owned by a dmabuf_chunk_owner struct which holds the dma-buf offset of the base of the chunk and the dma_addr of the chunk. Both are needed to use allocations that come from this chunk. We create a new type that represents an allocation from the genpool: net_iov. We setup the net_iov allocation size in the genpool to PAGE_SIZE for simplicity: to match the PAGE_SIZE normally allocated by the page pool and given to the drivers. The user can unbind the dmabuf from the netdevice by closing the netlink socket that established the binding. We do this so that the binding is automatically unbound even if the userspace process crashes. The binding and unbinding leaves an indicator in struct netdev_rx_queue that the given queue is bound, and the binding is actuated by resetting the rx queue using the queue API. The netdev_dmabuf_binding struct is refcounted, and releases its resources only when all the refs are released. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> # excluding netlink Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-4-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:47 +00:00
net: devmem: Implement TX path Augment dmabuf binding to be able to handle TX. Additional to all the RX binding, we also create tx_vec needed for the TX path. Provide API for sendmsg to be able to send dmabufs bound to this device: - Provide a new dmabuf_tx_cmsg which includes the dmabuf to send from. - MSG_ZEROCOPY with SCM_DEVMEM_DMABUF cmsg indicates send from dma-buf. Devmem is uncopyable, so piggyback off the existing MSG_ZEROCOPY implementation, while disabling instances where MSG_ZEROCOPY falls back to copying. We additionally pipe the binding down to the new zerocopy_fill_skb_from_devmem which fills a TX skb with net_iov netmems instead of the traditional page netmems. We also special case skb_frag_dma_map to return the dma-address of these dmabuf net_iovs instead of attempting to map pages. The TX path may release the dmabuf in a context where we cannot wait. This happens when the user unbinds a TX dmabuf while there are still references to its netmems in the TX path. In that case, the netmems will be put_netmem'd from a context where we can't unmap the dmabuf, Resolve this by making __net_devmem_dmabuf_binding_free schedule_work'd. Based on work by Stanislav Fomichev <sdf@fomichev.me>. A lot of the meat of the implementation came from devmem TCP RFC v1[1], which included the TX path, but Stan did all the rebasing on top of netmem/net_iov. Cc: Stanislav Fomichev <sdf@fomichev.me> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250508004830.4100853-5-almasrymina@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-08 00:48:24 +00:00
netdev: support binding dma-buf to netdevice Add a netdev_dmabuf_binding struct which represents the dma-buf-to-netdevice binding. The netlink API will bind the dma-buf to rx queues on the netdevice. On the binding, the dma_buf_attach & dma_buf_map_attachment will occur. The entries in the sg_table from mapping will be inserted into a genpool to make it ready for allocation. The chunks in the genpool are owned by a dmabuf_chunk_owner struct which holds the dma-buf offset of the base of the chunk and the dma_addr of the chunk. Both are needed to use allocations that come from this chunk. We create a new type that represents an allocation from the genpool: net_iov. We setup the net_iov allocation size in the genpool to PAGE_SIZE for simplicity: to match the PAGE_SIZE normally allocated by the page pool and given to the drivers. The user can unbind the dmabuf from the netdevice by closing the netlink socket that established the binding. We do this so that the binding is automatically unbound even if the userspace process crashes. The binding and unbinding leaves an indicator in struct netdev_rx_queue that the given queue is bound, and the binding is actuated by resetting the rx queue using the queue API. The netdev_dmabuf_binding struct is refcounted, and releases its resources only when all the refs are released. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> # excluding netlink Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-4-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:47 +00:00
net: devmem: Implement TX path Augment dmabuf binding to be able to handle TX. Additional to all the RX binding, we also create tx_vec needed for the TX path. Provide API for sendmsg to be able to send dmabufs bound to this device: - Provide a new dmabuf_tx_cmsg which includes the dmabuf to send from. - MSG_ZEROCOPY with SCM_DEVMEM_DMABUF cmsg indicates send from dma-buf. Devmem is uncopyable, so piggyback off the existing MSG_ZEROCOPY implementation, while disabling instances where MSG_ZEROCOPY falls back to copying. We additionally pipe the binding down to the new zerocopy_fill_skb_from_devmem which fills a TX skb with net_iov netmems instead of the traditional page netmems. We also special case skb_frag_dma_map to return the dma-address of these dmabuf net_iovs instead of attempting to map pages. The TX path may release the dmabuf in a context where we cannot wait. This happens when the user unbinds a TX dmabuf while there are still references to its netmems in the TX path. In that case, the netmems will be put_netmem'd from a context where we can't unmap the dmabuf, Resolve this by making __net_devmem_dmabuf_binding_free schedule_work'd. Based on work by Stanislav Fomichev <sdf@fomichev.me>. A lot of the meat of the implementation came from devmem TCP RFC v1[1], which included the TX path, but Stan did all the rebasing on top of netmem/net_iov. Cc: Stanislav Fomichev <sdf@fomichev.me> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250508004830.4100853-5-almasrymina@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-08 00:48:24 +00:00
net: devmem: pull out dma_dev out of net_devmem_bind_dmabuf Fetch the DMA device before calling net_devmem_bind_dmabuf() and pass it on as a parameter. This is needed for an upcoming change which will read the DMA device per queue. This patch has no functional changes. Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com> Reviewed-by: Mina Almasry <almasrymina@google.com> Link: https://patch.msgid.link/20250827144017.1529208-7-dtatulea@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-27 17:39:59 +03:00
net: devmem: Implement TX path Augment dmabuf binding to be able to handle TX. Additional to all the RX binding, we also create tx_vec needed for the TX path. Provide API for sendmsg to be able to send dmabufs bound to this device: - Provide a new dmabuf_tx_cmsg which includes the dmabuf to send from. - MSG_ZEROCOPY with SCM_DEVMEM_DMABUF cmsg indicates send from dma-buf. Devmem is uncopyable, so piggyback off the existing MSG_ZEROCOPY implementation, while disabling instances where MSG_ZEROCOPY falls back to copying. We additionally pipe the binding down to the new zerocopy_fill_skb_from_devmem which fills a TX skb with net_iov netmems instead of the traditional page netmems. We also special case skb_frag_dma_map to return the dma-address of these dmabuf net_iovs instead of attempting to map pages. The TX path may release the dmabuf in a context where we cannot wait. This happens when the user unbinds a TX dmabuf while there are still references to its netmems in the TX path. In that case, the netmems will be put_netmem'd from a context where we can't unmap the dmabuf, Resolve this by making __net_devmem_dmabuf_binding_free schedule_work'd. Based on work by Stanislav Fomichev <sdf@fomichev.me>. A lot of the meat of the implementation came from devmem TCP RFC v1[1], which included the TX path, but Stan did all the rebasing on top of netmem/net_iov. Cc: Stanislav Fomichev <sdf@fomichev.me> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250508004830.4100853-5-almasrymina@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-08 00:48:24 +00:00
net: devmem: move list_add to net_devmem_bind_dmabuf. It's annoying for the list_add to be outside net_devmem_bind_dmabuf, but the list_del is in net_devmem_unbind_dmabuf. Make it consistent by having both the list_add/del be inside the net_devmem_[un]bind_dmabuf. Cc: ap420073@gmail.com Signed-off-by: Mina Almasry <almasrymina@google.com> Tested-by: Taehee Yoo <ap420073@gmail.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250523230524.1107879-2-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-23 23:05:17 +00:00
net: devmem: Implement TX path Augment dmabuf binding to be able to handle TX. Additional to all the RX binding, we also create tx_vec needed for the TX path. Provide API for sendmsg to be able to send dmabufs bound to this device: - Provide a new dmabuf_tx_cmsg which includes the dmabuf to send from. - MSG_ZEROCOPY with SCM_DEVMEM_DMABUF cmsg indicates send from dma-buf. Devmem is uncopyable, so piggyback off the existing MSG_ZEROCOPY implementation, while disabling instances where MSG_ZEROCOPY falls back to copying. We additionally pipe the binding down to the new zerocopy_fill_skb_from_devmem which fills a TX skb with net_iov netmems instead of the traditional page netmems. We also special case skb_frag_dma_map to return the dma-address of these dmabuf net_iovs instead of attempting to map pages. The TX path may release the dmabuf in a context where we cannot wait. This happens when the user unbinds a TX dmabuf while there are still references to its netmems in the TX path. In that case, the netmems will be put_netmem'd from a context where we can't unmap the dmabuf, Resolve this by making __net_devmem_dmabuf_binding_free schedule_work'd. Based on work by Stanislav Fomichev <sdf@fomichev.me>. A lot of the meat of the implementation came from devmem TCP RFC v1[1], which included the TX path, but Stan did all the rebasing on top of netmem/net_iov. Cc: Stanislav Fomichev <sdf@fomichev.me> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250508004830.4100853-5-almasrymina@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-08 00:48:24 +00:00
netdev: support binding dma-buf to netdevice Add a netdev_dmabuf_binding struct which represents the dma-buf-to-netdevice binding. The netlink API will bind the dma-buf to rx queues on the netdevice. On the binding, the dma_buf_attach & dma_buf_map_attachment will occur. The entries in the sg_table from mapping will be inserted into a genpool to make it ready for allocation. The chunks in the genpool are owned by a dmabuf_chunk_owner struct which holds the dma-buf offset of the base of the chunk and the dma_addr of the chunk. Both are needed to use allocations that come from this chunk. We create a new type that represents an allocation from the genpool: net_iov. We setup the net_iov allocation size in the genpool to PAGE_SIZE for simplicity: to match the PAGE_SIZE normally allocated by the page pool and given to the drivers. The user can unbind the dmabuf from the netdevice by closing the netlink socket that established the binding. We do this so that the binding is automatically unbound even if the userspace process crashes. The binding and unbinding leaves an indicator in struct netdev_rx_queue that the given queue is bound, and the binding is actuated by resetting the rx queue using the queue API. The netdev_dmabuf_binding struct is refcounted, and releases its resources only when all the refs are released. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> # excluding netlink Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-4-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:47 +00:00
netdev: netdevice devmem allocator Implement netdev devmem allocator. The allocator takes a given struct netdev_dmabuf_binding as input and allocates net_iov from that binding. The allocation simply delegates to the binding's genpool for the allocation logic and wraps the returned memory region in a net_iov struct. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-5-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:48 +00:00
net: generalise net_iov chunk owners Currently net_iov stores a pointer to struct dmabuf_genpool_chunk_owner, which serves as a useful abstraction to share data and provide a context. However, it's too devmem specific, and we want to reuse it for other memory providers, and for that we need to decouple net_iov from devmem. Make net_iov to point to a new base structure called net_iov_area, which dmabuf_genpool_chunk_owner extends. Reviewed-by: Mina Almasry <almasrymina@google.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: David Wei <dw@davidwei.uk> Link: https://patch.msgid.link/20250204215622.695511-4-dw@davidwei.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-04 13:56:14 -08:00
netdev: netdevice devmem allocator Implement netdev devmem allocator. The allocator takes a given struct netdev_dmabuf_binding as input and allocates net_iov from that binding. The allocation simply delegates to the binding's genpool for the allocation logic and wraps the returned memory region in a net_iov struct. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-5-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:48 +00:00
net: generalise net_iov chunk owners Currently net_iov stores a pointer to struct dmabuf_genpool_chunk_owner, which serves as a useful abstraction to share data and provide a context. However, it's too devmem specific, and we want to reuse it for other memory providers, and for that we need to decouple net_iov from devmem. Make net_iov to point to a new base structure called net_iov_area, which dmabuf_genpool_chunk_owner extends. Reviewed-by: Mina Almasry <almasrymina@google.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: David Wei <dw@davidwei.uk> Link: https://patch.msgid.link/20250204215622.695511-4-dw@davidwei.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-04 13:56:14 -08:00
netdev: netdevice devmem allocator Implement netdev devmem allocator. The allocator takes a given struct netdev_dmabuf_binding as input and allocates net_iov from that binding. The allocation simply delegates to the binding's genpool for the allocation logic and wraps the returned memory region in a net_iov struct. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-5-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:48 +00:00
net: generalise net_iov chunk owners Currently net_iov stores a pointer to struct dmabuf_genpool_chunk_owner, which serves as a useful abstraction to share data and provide a context. However, it's too devmem specific, and we want to reuse it for other memory providers, and for that we need to decouple net_iov from devmem. Make net_iov to point to a new base structure called net_iov_area, which dmabuf_genpool_chunk_owner extends. Reviewed-by: Mina Almasry <almasrymina@google.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: David Wei <dw@davidwei.uk> Link: https://patch.msgid.link/20250204215622.695511-4-dw@davidwei.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-04 13:56:14 -08:00
netdev: netdevice devmem allocator Implement netdev devmem allocator. The allocator takes a given struct netdev_dmabuf_binding as input and allocates net_iov from that binding. The allocation simply delegates to the binding's genpool for the allocation logic and wraps the returned memory region in a net_iov struct. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-5-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:48 +00:00
net: prefix devmem specific helpers Add prefixes to all helpers that are specific to devmem TCP, i.e. net_iov_binding[_id]. Reviewed-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Mina Almasry <almasrymina@google.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: David Wei <dw@davidwei.uk> Link: https://patch.msgid.link/20250204215622.695511-3-dw@davidwei.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-04 13:56:13 -08:00
netdev: netdevice devmem allocator Implement netdev devmem allocator. The allocator takes a given struct netdev_dmabuf_binding as input and allocates net_iov from that binding. The allocation simply delegates to the binding's genpool for the allocation logic and wraps the returned memory region in a net_iov struct. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-5-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:48 +00:00
net: generalise net_iov chunk owners Currently net_iov stores a pointer to struct dmabuf_genpool_chunk_owner, which serves as a useful abstraction to share data and provide a context. However, it's too devmem specific, and we want to reuse it for other memory providers, and for that we need to decouple net_iov from devmem. Make net_iov to point to a new base structure called net_iov_area, which dmabuf_genpool_chunk_owner extends. Reviewed-by: Mina Almasry <almasrymina@google.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: David Wei <dw@davidwei.uk> Link: https://patch.msgid.link/20250204215622.695511-4-dw@davidwei.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-04 13:56:14 -08:00
netdev: netdevice devmem allocator Implement netdev devmem allocator. The allocator takes a given struct netdev_dmabuf_binding as input and allocates net_iov from that binding. The allocation simply delegates to the binding's genpool for the allocation logic and wraps the returned memory region in a net_iov struct. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-5-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:48 +00:00
net: prefix devmem specific helpers Add prefixes to all helpers that are specific to devmem TCP, i.e. net_iov_binding[_id]. Reviewed-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Mina Almasry <almasrymina@google.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: David Wei <dw@davidwei.uk> Link: https://patch.msgid.link/20250204215622.695511-3-dw@davidwei.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-04 13:56:13 -08:00
tcp: RX path for devmem TCP In tcp_recvmsg_locked(), detect if the skb being received by the user is a devmem skb. In this case - if the user provided the MSG_SOCK_DEVMEM flag - pass it to tcp_recvmsg_devmem() for custom handling. tcp_recvmsg_devmem() copies any data in the skb header to the linear buffer, and returns a cmsg to the user indicating the number of bytes returned in the linear buffer. tcp_recvmsg_devmem() then loops over the unaccessible devmem skb frags, and returns to the user a cmsg_devmem indicating the location of the data in the dmabuf device memory. cmsg_devmem contains this information: 1. the offset into the dmabuf where the payload starts. 'frag_offset'. 2. the size of the frag. 'frag_size'. 3. an opaque token 'frag_token' to return to the kernel when the buffer is to be released. The pages awaiting freeing are stored in the newly added sk->sk_user_frags, and each page passed to userspace is get_page()'d. This reference is dropped once the userspace indicates that it is done reading this page. All pages are released when the socket is destroyed. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20240910171458.219195-10-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:53 +00:00
net: generalise net_iov chunk owners Currently net_iov stores a pointer to struct dmabuf_genpool_chunk_owner, which serves as a useful abstraction to share data and provide a context. However, it's too devmem specific, and we want to reuse it for other memory providers, and for that we need to decouple net_iov from devmem. Make net_iov to point to a new base structure called net_iov_area, which dmabuf_genpool_chunk_owner extends. Reviewed-by: Mina Almasry <almasrymina@google.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: David Wei <dw@davidwei.uk> Link: https://patch.msgid.link/20250204215622.695511-4-dw@davidwei.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-04 13:56:14 -08:00
tcp: RX path for devmem TCP In tcp_recvmsg_locked(), detect if the skb being received by the user is a devmem skb. In this case - if the user provided the MSG_SOCK_DEVMEM flag - pass it to tcp_recvmsg_devmem() for custom handling. tcp_recvmsg_devmem() copies any data in the skb header to the linear buffer, and returns a cmsg to the user indicating the number of bytes returned in the linear buffer. tcp_recvmsg_devmem() then loops over the unaccessible devmem skb frags, and returns to the user a cmsg_devmem indicating the location of the data in the dmabuf device memory. cmsg_devmem contains this information: 1. the offset into the dmabuf where the payload starts. 'frag_offset'. 2. the size of the frag. 'frag_size'. 3. an opaque token 'frag_token' to return to the kernel when the buffer is to be released. The pages awaiting freeing are stored in the newly added sk->sk_user_frags, and each page passed to userspace is get_page()'d. This reference is dropped once the userspace indicates that it is done reading this page. All pages are released when the socket is destroyed. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20240910171458.219195-10-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:53 +00:00
net: devmem: Implement TX path Augment dmabuf binding to be able to handle TX. Additional to all the RX binding, we also create tx_vec needed for the TX path. Provide API for sendmsg to be able to send dmabufs bound to this device: - Provide a new dmabuf_tx_cmsg which includes the dmabuf to send from. - MSG_ZEROCOPY with SCM_DEVMEM_DMABUF cmsg indicates send from dma-buf. Devmem is uncopyable, so piggyback off the existing MSG_ZEROCOPY implementation, while disabling instances where MSG_ZEROCOPY falls back to copying. We additionally pipe the binding down to the new zerocopy_fill_skb_from_devmem which fills a TX skb with net_iov netmems instead of the traditional page netmems. We also special case skb_frag_dma_map to return the dma-address of these dmabuf net_iovs instead of attempting to map pages. The TX path may release the dmabuf in a context where we cannot wait. This happens when the user unbinds a TX dmabuf while there are still references to its netmems in the TX path. In that case, the netmems will be put_netmem'd from a context where we can't unmap the dmabuf, Resolve this by making __net_devmem_dmabuf_binding_free schedule_work'd. Based on work by Stanislav Fomichev <sdf@fomichev.me>. A lot of the meat of the implementation came from devmem TCP RFC v1[1], which included the TX path, but Stan did all the rebasing on top of netmem/net_iov. Cc: Stanislav Fomichev <sdf@fomichev.me> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250508004830.4100853-5-almasrymina@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-08 00:48:24 +00:00
netdev: support binding dma-buf to netdevice Add a netdev_dmabuf_binding struct which represents the dma-buf-to-netdevice binding. The netlink API will bind the dma-buf to rx queues on the netdevice. On the binding, the dma_buf_attach & dma_buf_map_attachment will occur. The entries in the sg_table from mapping will be inserted into a genpool to make it ready for allocation. The chunks in the genpool are owned by a dmabuf_chunk_owner struct which holds the dma-buf offset of the base of the chunk and the dma_addr of the chunk. Both are needed to use allocations that come from this chunk. We create a new type that represents an allocation from the genpool: net_iov. We setup the net_iov allocation size in the genpool to PAGE_SIZE for simplicity: to match the PAGE_SIZE normally allocated by the page pool and given to the drivers. The user can unbind the dmabuf from the netdevice by closing the netlink socket that established the binding. We do this so that the binding is automatically unbound even if the userspace process crashes. The binding and unbinding leaves an indicator in struct netdev_rx_queue that the given queue is bound, and the binding is actuated by resetting the rx queue using the queue API. The netdev_dmabuf_binding struct is refcounted, and releases its resources only when all the refs are released. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> # excluding netlink Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-4-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:47 +00:00
net: devmem: Implement TX path Augment dmabuf binding to be able to handle TX. Additional to all the RX binding, we also create tx_vec needed for the TX path. Provide API for sendmsg to be able to send dmabufs bound to this device: - Provide a new dmabuf_tx_cmsg which includes the dmabuf to send from. - MSG_ZEROCOPY with SCM_DEVMEM_DMABUF cmsg indicates send from dma-buf. Devmem is uncopyable, so piggyback off the existing MSG_ZEROCOPY implementation, while disabling instances where MSG_ZEROCOPY falls back to copying. We additionally pipe the binding down to the new zerocopy_fill_skb_from_devmem which fills a TX skb with net_iov netmems instead of the traditional page netmems. We also special case skb_frag_dma_map to return the dma-address of these dmabuf net_iovs instead of attempting to map pages. The TX path may release the dmabuf in a context where we cannot wait. This happens when the user unbinds a TX dmabuf while there are still references to its netmems in the TX path. In that case, the netmems will be put_netmem'd from a context where we can't unmap the dmabuf, Resolve this by making __net_devmem_dmabuf_binding_free schedule_work'd. Based on work by Stanislav Fomichev <sdf@fomichev.me>. A lot of the meat of the implementation came from devmem TCP RFC v1[1], which included the TX path, but Stan did all the rebasing on top of netmem/net_iov. Cc: Stanislav Fomichev <sdf@fomichev.me> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250508004830.4100853-5-almasrymina@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-08 00:48:24 +00:00
netdev: support binding dma-buf to netdevice Add a netdev_dmabuf_binding struct which represents the dma-buf-to-netdevice binding. The netlink API will bind the dma-buf to rx queues on the netdevice. On the binding, the dma_buf_attach & dma_buf_map_attachment will occur. The entries in the sg_table from mapping will be inserted into a genpool to make it ready for allocation. The chunks in the genpool are owned by a dmabuf_chunk_owner struct which holds the dma-buf offset of the base of the chunk and the dma_addr of the chunk. Both are needed to use allocations that come from this chunk. We create a new type that represents an allocation from the genpool: net_iov. We setup the net_iov allocation size in the genpool to PAGE_SIZE for simplicity: to match the PAGE_SIZE normally allocated by the page pool and given to the drivers. The user can unbind the dmabuf from the netdevice by closing the netlink socket that established the binding. We do this so that the binding is automatically unbound even if the userspace process crashes. The binding and unbinding leaves an indicator in struct netdev_rx_queue that the given queue is bound, and the binding is actuated by resetting the rx queue using the queue API. The netdev_dmabuf_binding struct is refcounted, and releases its resources only when all the refs are released. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> # excluding netlink Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-4-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:47 +00:00
net: devmem: Implement TX path Augment dmabuf binding to be able to handle TX. Additional to all the RX binding, we also create tx_vec needed for the TX path. Provide API for sendmsg to be able to send dmabufs bound to this device: - Provide a new dmabuf_tx_cmsg which includes the dmabuf to send from. - MSG_ZEROCOPY with SCM_DEVMEM_DMABUF cmsg indicates send from dma-buf. Devmem is uncopyable, so piggyback off the existing MSG_ZEROCOPY implementation, while disabling instances where MSG_ZEROCOPY falls back to copying. We additionally pipe the binding down to the new zerocopy_fill_skb_from_devmem which fills a TX skb with net_iov netmems instead of the traditional page netmems. We also special case skb_frag_dma_map to return the dma-address of these dmabuf net_iovs instead of attempting to map pages. The TX path may release the dmabuf in a context where we cannot wait. This happens when the user unbinds a TX dmabuf while there are still references to its netmems in the TX path. In that case, the netmems will be put_netmem'd from a context where we can't unmap the dmabuf, Resolve this by making __net_devmem_dmabuf_binding_free schedule_work'd. Based on work by Stanislav Fomichev <sdf@fomichev.me>. A lot of the meat of the implementation came from devmem TCP RFC v1[1], which included the TX path, but Stan did all the rebasing on top of netmem/net_iov. Cc: Stanislav Fomichev <sdf@fomichev.me> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250508004830.4100853-5-almasrymina@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-08 00:48:24 +00:00
netdev: support binding dma-buf to netdevice Add a netdev_dmabuf_binding struct which represents the dma-buf-to-netdevice binding. The netlink API will bind the dma-buf to rx queues on the netdevice. On the binding, the dma_buf_attach & dma_buf_map_attachment will occur. The entries in the sg_table from mapping will be inserted into a genpool to make it ready for allocation. The chunks in the genpool are owned by a dmabuf_chunk_owner struct which holds the dma-buf offset of the base of the chunk and the dma_addr of the chunk. Both are needed to use allocations that come from this chunk. We create a new type that represents an allocation from the genpool: net_iov. We setup the net_iov allocation size in the genpool to PAGE_SIZE for simplicity: to match the PAGE_SIZE normally allocated by the page pool and given to the drivers. The user can unbind the dmabuf from the netdevice by closing the netlink socket that established the binding. We do this so that the binding is automatically unbound even if the userspace process crashes. The binding and unbinding leaves an indicator in struct netdev_rx_queue that the given queue is bound, and the binding is actuated by resetting the rx queue using the queue API. The netdev_dmabuf_binding struct is refcounted, and releases its resources only when all the refs are released. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> # excluding netlink Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-4-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:47 +00:00
net: add get_netmem/put_netmem support Currently net_iovs support only pp ref counts, and do not support a page ref equivalent. This is fine for the RX path as net_iovs are used exclusively with the pp and only pp refcounting is needed there. The TX path however does not use pp ref counts, thus, support for get_page/put_page equivalent is needed for netmem. Support get_netmem/put_netmem. Check the type of the netmem before passing it to page or net_iov specific code to obtain a page ref equivalent. For dmabuf net_iovs, we obtain a ref on the underlying binding. This ensures the entire binding doesn't disappear until all the net_iovs have been put_netmem'ed. We do not need to track the refcount of individual dmabuf net_iovs as we don't allocate/free them from a pool similar to what the buddy allocator does for pages. This code is written to be extensible by other net_iov implementers. get_netmem/put_netmem will check the type of the netmem and route it to the correct helper: pages -> [get|put]_page() dmabuf net_iovs -> net_devmem_[get|put]_net_iov() new net_iovs -> new helpers Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250508004830.4100853-3-almasrymina@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-08 00:48:22 +00:00
netdev: netdevice devmem allocator Implement netdev devmem allocator. The allocator takes a given struct netdev_dmabuf_binding as input and allocates net_iov from that binding. The allocation simply delegates to the binding's genpool for the allocation logic and wraps the returned memory region in a net_iov struct. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-5-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:48 +00:00
net: prepare for non devmem TCP memory providers There is a good bunch of places in generic paths assuming that the only page pool memory provider is devmem TCP. As we want to reuse the net_iov and provider infrastructure, we need to patch it up and explicitly check the provider type when we branch into devmem TCP code. Reviewed-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: David Wei <dw@davidwei.uk> Link: https://patch.msgid.link/20250204215622.695511-9-dw@davidwei.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-04 13:56:19 -08:00
net: devmem: Implement TX path Augment dmabuf binding to be able to handle TX. Additional to all the RX binding, we also create tx_vec needed for the TX path. Provide API for sendmsg to be able to send dmabufs bound to this device: - Provide a new dmabuf_tx_cmsg which includes the dmabuf to send from. - MSG_ZEROCOPY with SCM_DEVMEM_DMABUF cmsg indicates send from dma-buf. Devmem is uncopyable, so piggyback off the existing MSG_ZEROCOPY implementation, while disabling instances where MSG_ZEROCOPY falls back to copying. We additionally pipe the binding down to the new zerocopy_fill_skb_from_devmem which fills a TX skb with net_iov netmems instead of the traditional page netmems. We also special case skb_frag_dma_map to return the dma-address of these dmabuf net_iovs instead of attempting to map pages. The TX path may release the dmabuf in a context where we cannot wait. This happens when the user unbinds a TX dmabuf while there are still references to its netmems in the TX path. In that case, the netmems will be put_netmem'd from a context where we can't unmap the dmabuf, Resolve this by making __net_devmem_dmabuf_binding_free schedule_work'd. Based on work by Stanislav Fomichev <sdf@fomichev.me>. A lot of the meat of the implementation came from devmem TCP RFC v1[1], which included the TX path, but Stan did all the rebasing on top of netmem/net_iov. Cc: Stanislav Fomichev <sdf@fomichev.me> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250508004830.4100853-5-almasrymina@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-08 00:48:24 +00:00
net: prepare for non devmem TCP memory providers There is a good bunch of places in generic paths assuming that the only page pool memory provider is devmem TCP. As we want to reuse the net_iov and provider infrastructure, we need to patch it up and explicitly check the provider type when we branch into devmem TCP code. Reviewed-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: David Wei <dw@davidwei.uk> Link: https://patch.msgid.link/20250204215622.695511-9-dw@davidwei.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-04 13:56:19 -08:00
netdev: support binding dma-buf to netdevice Add a netdev_dmabuf_binding struct which represents the dma-buf-to-netdevice binding. The netlink API will bind the dma-buf to rx queues on the netdevice. On the binding, the dma_buf_attach & dma_buf_map_attachment will occur. The entries in the sg_table from mapping will be inserted into a genpool to make it ready for allocation. The chunks in the genpool are owned by a dmabuf_chunk_owner struct which holds the dma-buf offset of the base of the chunk and the dma_addr of the chunk. Both are needed to use allocations that come from this chunk. We create a new type that represents an allocation from the genpool: net_iov. We setup the net_iov allocation size in the genpool to PAGE_SIZE for simplicity: to match the PAGE_SIZE normally allocated by the page pool and given to the drivers. The user can unbind the dmabuf from the netdevice by closing the netlink socket that established the binding. We do this so that the binding is automatically unbound even if the userspace process crashes. The binding and unbinding leaves an indicator in struct netdev_rx_queue that the given queue is bound, and the binding is actuated by resetting the rx queue using the queue API. The netdev_dmabuf_binding struct is refcounted, and releases its resources only when all the refs are released. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> # excluding netlink Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-4-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:47 +00:00
netdev: netdevice devmem allocator Implement netdev devmem allocator. The allocator takes a given struct netdev_dmabuf_binding as input and allocates net_iov from that binding. The allocation simply delegates to the binding's genpool for the allocation logic and wraps the returned memory region in a net_iov struct. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-5-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:48 +00:00
net: add get_netmem/put_netmem support Currently net_iovs support only pp ref counts, and do not support a page ref equivalent. This is fine for the RX path as net_iovs are used exclusively with the pp and only pp refcounting is needed there. The TX path however does not use pp ref counts, thus, support for get_page/put_page equivalent is needed for netmem. Support get_netmem/put_netmem. Check the type of the netmem before passing it to page or net_iov specific code to obtain a page ref equivalent. For dmabuf net_iovs, we obtain a ref on the underlying binding. This ensures the entire binding doesn't disappear until all the net_iovs have been put_netmem'ed. We do not need to track the refcount of individual dmabuf net_iovs as we don't allocate/free them from a pool similar to what the buddy allocator does for pages. This code is written to be extensible by other net_iov implementers. get_netmem/put_netmem will check the type of the netmem and route it to the correct helper: pages -> [get|put]_page() dmabuf net_iovs -> net_devmem_[get|put]_net_iov() new net_iovs -> new helpers Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250508004830.4100853-3-almasrymina@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-08 00:48:22 +00:00
netdev: support binding dma-buf to netdevice Add a netdev_dmabuf_binding struct which represents the dma-buf-to-netdevice binding. The netlink API will bind the dma-buf to rx queues on the netdevice. On the binding, the dma_buf_attach & dma_buf_map_attachment will occur. The entries in the sg_table from mapping will be inserted into a genpool to make it ready for allocation. The chunks in the genpool are owned by a dmabuf_chunk_owner struct which holds the dma-buf offset of the base of the chunk and the dma_addr of the chunk. Both are needed to use allocations that come from this chunk. We create a new type that represents an allocation from the genpool: net_iov. We setup the net_iov allocation size in the genpool to PAGE_SIZE for simplicity: to match the PAGE_SIZE normally allocated by the page pool and given to the drivers. The user can unbind the dmabuf from the netdevice by closing the netlink socket that established the binding. We do this so that the binding is automatically unbound even if the userspace process crashes. The binding and unbinding leaves an indicator in struct netdev_rx_queue that the given queue is bound, and the binding is actuated by resetting the rx queue using the queue API. The netdev_dmabuf_binding struct is refcounted, and releases its resources only when all the refs are released. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> # excluding netlink Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-4-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:47 +00:00
net: Fix net_devmem_bind_dmabuf for non-devmem configs Fix the signature of the net_devmem_bind_dmabuf API for CONFIG_NET_DEVMEM=n. Fixes: bd61848900bf ("net: devmem: Implement TX path") Signed-off-by: Pranjal Shrivastava <praan@google.com> Link: https://patch.msgid.link/20250528211058.1826608-1-praan@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-28 21:10:58 +00:00
net: devmem: pull out dma_dev out of net_devmem_bind_dmabuf Fetch the DMA device before calling net_devmem_bind_dmabuf() and pass it on as a parameter. This is needed for an upcoming change which will read the DMA device per queue. This patch has no functional changes. Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com> Reviewed-by: Mina Almasry <almasrymina@google.com> Link: https://patch.msgid.link/20250827144017.1529208-7-dtatulea@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-27 17:39:59 +03:00
net: devmem: Implement TX path Augment dmabuf binding to be able to handle TX. Additional to all the RX binding, we also create tx_vec needed for the TX path. Provide API for sendmsg to be able to send dmabufs bound to this device: - Provide a new dmabuf_tx_cmsg which includes the dmabuf to send from. - MSG_ZEROCOPY with SCM_DEVMEM_DMABUF cmsg indicates send from dma-buf. Devmem is uncopyable, so piggyback off the existing MSG_ZEROCOPY implementation, while disabling instances where MSG_ZEROCOPY falls back to copying. We additionally pipe the binding down to the new zerocopy_fill_skb_from_devmem which fills a TX skb with net_iov netmems instead of the traditional page netmems. We also special case skb_frag_dma_map to return the dma-address of these dmabuf net_iovs instead of attempting to map pages. The TX path may release the dmabuf in a context where we cannot wait. This happens when the user unbinds a TX dmabuf while there are still references to its netmems in the TX path. In that case, the netmems will be put_netmem'd from a context where we can't unmap the dmabuf, Resolve this by making __net_devmem_dmabuf_binding_free schedule_work'd. Based on work by Stanislav Fomichev <sdf@fomichev.me>. A lot of the meat of the implementation came from devmem TCP RFC v1[1], which included the TX path, but Stan did all the rebasing on top of netmem/net_iov. Cc: Stanislav Fomichev <sdf@fomichev.me> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250508004830.4100853-5-almasrymina@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-08 00:48:24 +00:00
net: Fix net_devmem_bind_dmabuf for non-devmem configs Fix the signature of the net_devmem_bind_dmabuf API for CONFIG_NET_DEVMEM=n. Fixes: bd61848900bf ("net: devmem: Implement TX path") Signed-off-by: Pranjal Shrivastava <praan@google.com> Link: https://patch.msgid.link/20250528211058.1826608-1-praan@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-28 21:10:58 +00:00
net: devmem: move list_add to net_devmem_bind_dmabuf. It's annoying for the list_add to be outside net_devmem_bind_dmabuf, but the list_del is in net_devmem_unbind_dmabuf. Make it consistent by having both the list_add/del be inside the net_devmem_[un]bind_dmabuf. Cc: ap420073@gmail.com Signed-off-by: Mina Almasry <almasrymina@google.com> Tested-by: Taehee Yoo <ap420073@gmail.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250523230524.1107879-2-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-23 23:05:17 +00:00
netdev: support binding dma-buf to netdevice Add a netdev_dmabuf_binding struct which represents the dma-buf-to-netdevice binding. The netlink API will bind the dma-buf to rx queues on the netdevice. On the binding, the dma_buf_attach & dma_buf_map_attachment will occur. The entries in the sg_table from mapping will be inserted into a genpool to make it ready for allocation. The chunks in the genpool are owned by a dmabuf_chunk_owner struct which holds the dma-buf offset of the base of the chunk and the dma_addr of the chunk. Both are needed to use allocations that come from this chunk. We create a new type that represents an allocation from the genpool: net_iov. We setup the net_iov allocation size in the genpool to PAGE_SIZE for simplicity: to match the PAGE_SIZE normally allocated by the page pool and given to the drivers. The user can unbind the dmabuf from the netdevice by closing the netlink socket that established the binding. We do this so that the binding is automatically unbound even if the userspace process crashes. The binding and unbinding leaves an indicator in struct netdev_rx_queue that the given queue is bound, and the binding is actuated by resetting the rx queue using the queue API. The netdev_dmabuf_binding struct is refcounted, and releases its resources only when all the refs are released. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> # excluding netlink Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-4-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:47 +00:00
net: devmem: Implement TX path Augment dmabuf binding to be able to handle TX. Additional to all the RX binding, we also create tx_vec needed for the TX path. Provide API for sendmsg to be able to send dmabufs bound to this device: - Provide a new dmabuf_tx_cmsg which includes the dmabuf to send from. - MSG_ZEROCOPY with SCM_DEVMEM_DMABUF cmsg indicates send from dma-buf. Devmem is uncopyable, so piggyback off the existing MSG_ZEROCOPY implementation, while disabling instances where MSG_ZEROCOPY falls back to copying. We additionally pipe the binding down to the new zerocopy_fill_skb_from_devmem which fills a TX skb with net_iov netmems instead of the traditional page netmems. We also special case skb_frag_dma_map to return the dma-address of these dmabuf net_iovs instead of attempting to map pages. The TX path may release the dmabuf in a context where we cannot wait. This happens when the user unbinds a TX dmabuf while there are still references to its netmems in the TX path. In that case, the netmems will be put_netmem'd from a context where we can't unmap the dmabuf, Resolve this by making __net_devmem_dmabuf_binding_free schedule_work'd. Based on work by Stanislav Fomichev <sdf@fomichev.me>. A lot of the meat of the implementation came from devmem TCP RFC v1[1], which included the TX path, but Stan did all the rebasing on top of netmem/net_iov. Cc: Stanislav Fomichev <sdf@fomichev.me> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250508004830.4100853-5-almasrymina@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-08 00:48:24 +00:00
netdev: support binding dma-buf to netdevice Add a netdev_dmabuf_binding struct which represents the dma-buf-to-netdevice binding. The netlink API will bind the dma-buf to rx queues on the netdevice. On the binding, the dma_buf_attach & dma_buf_map_attachment will occur. The entries in the sg_table from mapping will be inserted into a genpool to make it ready for allocation. The chunks in the genpool are owned by a dmabuf_chunk_owner struct which holds the dma-buf offset of the base of the chunk and the dma_addr of the chunk. Both are needed to use allocations that come from this chunk. We create a new type that represents an allocation from the genpool: net_iov. We setup the net_iov allocation size in the genpool to PAGE_SIZE for simplicity: to match the PAGE_SIZE normally allocated by the page pool and given to the drivers. The user can unbind the dmabuf from the netdevice by closing the netlink socket that established the binding. We do this so that the binding is automatically unbound even if the userspace process crashes. The binding and unbinding leaves an indicator in struct netdev_rx_queue that the given queue is bound, and the binding is actuated by resetting the rx queue using the queue API. The netdev_dmabuf_binding struct is refcounted, and releases its resources only when all the refs are released. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> # excluding netlink Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-4-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:47 +00:00
netdev: netdevice devmem allocator Implement netdev devmem allocator. The allocator takes a given struct netdev_dmabuf_binding as input and allocates net_iov from that binding. The allocation simply delegates to the binding's genpool for the allocation logic and wraps the returned memory region in a net_iov struct. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-5-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:48 +00:00
tcp: RX path for devmem TCP In tcp_recvmsg_locked(), detect if the skb being received by the user is a devmem skb. In this case - if the user provided the MSG_SOCK_DEVMEM flag - pass it to tcp_recvmsg_devmem() for custom handling. tcp_recvmsg_devmem() copies any data in the skb header to the linear buffer, and returns a cmsg to the user indicating the number of bytes returned in the linear buffer. tcp_recvmsg_devmem() then loops over the unaccessible devmem skb frags, and returns to the user a cmsg_devmem indicating the location of the data in the dmabuf device memory. cmsg_devmem contains this information: 1. the offset into the dmabuf where the payload starts. 'frag_offset'. 2. the size of the frag. 'frag_size'. 3. an opaque token 'frag_token' to return to the kernel when the buffer is to be released. The pages awaiting freeing are stored in the newly added sk->sk_user_frags, and each page passed to userspace is get_page()'d. This reference is dropped once the userspace indicates that it is done reading this page. All pages are released when the socket is destroyed. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20240910171458.219195-10-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:53 +00:00
net: prefix devmem specific helpers Add prefixes to all helpers that are specific to devmem TCP, i.e. net_iov_binding[_id]. Reviewed-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Mina Almasry <almasrymina@google.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: David Wei <dw@davidwei.uk> Link: https://patch.msgid.link/20250204215622.695511-3-dw@davidwei.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-04 13:56:13 -08:00
tcp: RX path for devmem TCP In tcp_recvmsg_locked(), detect if the skb being received by the user is a devmem skb. In this case - if the user provided the MSG_SOCK_DEVMEM flag - pass it to tcp_recvmsg_devmem() for custom handling. tcp_recvmsg_devmem() copies any data in the skb header to the linear buffer, and returns a cmsg to the user indicating the number of bytes returned in the linear buffer. tcp_recvmsg_devmem() then loops over the unaccessible devmem skb frags, and returns to the user a cmsg_devmem indicating the location of the data in the dmabuf device memory. cmsg_devmem contains this information: 1. the offset into the dmabuf where the payload starts. 'frag_offset'. 2. the size of the frag. 'frag_size'. 3. an opaque token 'frag_token' to return to the kernel when the buffer is to be released. The pages awaiting freeing are stored in the newly added sk->sk_user_frags, and each page passed to userspace is get_page()'d. This reference is dropped once the userspace indicates that it is done reading this page. All pages are released when the socket is destroyed. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20240910171458.219195-10-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:53 +00:00
net: prepare for non devmem TCP memory providers There is a good bunch of places in generic paths assuming that the only page pool memory provider is devmem TCP. As we want to reuse the net_iov and provider infrastructure, we need to patch it up and explicitly check the provider type when we branch into devmem TCP code. Reviewed-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: David Wei <dw@davidwei.uk> Link: https://patch.msgid.link/20250204215622.695511-9-dw@davidwei.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-04 13:56:19 -08:00
net: devmem: Implement TX path Augment dmabuf binding to be able to handle TX. Additional to all the RX binding, we also create tx_vec needed for the TX path. Provide API for sendmsg to be able to send dmabufs bound to this device: - Provide a new dmabuf_tx_cmsg which includes the dmabuf to send from. - MSG_ZEROCOPY with SCM_DEVMEM_DMABUF cmsg indicates send from dma-buf. Devmem is uncopyable, so piggyback off the existing MSG_ZEROCOPY implementation, while disabling instances where MSG_ZEROCOPY falls back to copying. We additionally pipe the binding down to the new zerocopy_fill_skb_from_devmem which fills a TX skb with net_iov netmems instead of the traditional page netmems. We also special case skb_frag_dma_map to return the dma-address of these dmabuf net_iovs instead of attempting to map pages. The TX path may release the dmabuf in a context where we cannot wait. This happens when the user unbinds a TX dmabuf while there are still references to its netmems in the TX path. In that case, the netmems will be put_netmem'd from a context where we can't unmap the dmabuf, Resolve this by making __net_devmem_dmabuf_binding_free schedule_work'd. Based on work by Stanislav Fomichev <sdf@fomichev.me>. A lot of the meat of the implementation came from devmem TCP RFC v1[1], which included the TX path, but Stan did all the rebasing on top of netmem/net_iov. Cc: Stanislav Fomichev <sdf@fomichev.me> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250508004830.4100853-5-almasrymina@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-08 00:48:24 +00:00
net: check for driver support in netmem TX We should not enable netmem TX for drivers that don't declare support. Check for driver netmem TX support during devmem TX binding and fail if the driver does not have the functionality. Check for driver support in validate_xmit_skb as well. Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250508004830.4100853-9-almasrymina@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-08 00:48:28 +00:00
netdev: support binding dma-buf to netdevice Add a netdev_dmabuf_binding struct which represents the dma-buf-to-netdevice binding. The netlink API will bind the dma-buf to rx queues on the netdevice. On the binding, the dma_buf_attach & dma_buf_map_attachment will occur. The entries in the sg_table from mapping will be inserted into a genpool to make it ready for allocation. The chunks in the genpool are owned by a dmabuf_chunk_owner struct which holds the dma-buf offset of the base of the chunk and the dma_addr of the chunk. Both are needed to use allocations that come from this chunk. We create a new type that represents an allocation from the genpool: net_iov. We setup the net_iov allocation size in the genpool to PAGE_SIZE for simplicity: to match the PAGE_SIZE normally allocated by the page pool and given to the drivers. The user can unbind the dmabuf from the netdevice by closing the netlink socket that established the binding. We do this so that the binding is automatically unbound even if the userspace process crashes. The binding and unbinding leaves an indicator in struct netdev_rx_queue that the given queue is bound, and the binding is actuated by resetting the rx queue using the queue API. The netdev_dmabuf_binding struct is refcounted, and releases its resources only when all the refs are released. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> # excluding netlink Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-4-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-10 17:14:47 +00:00