kernel/linux.git/net/core/Makefile, branch v6.18.21

queue_api: add support for fetching per queue DMA dev

2025-08-28T23:05:31+00:00

For zerocopy (io_uring, devmem), there is an assumption that the parent device can do DMA. However that is not always the case: - Scalable Function netdevs [1] have the DMA device in the grandparent. - For Multi-PF netdevs [2] queues can be associated to different DMA devices. This patch introduces the a queue based interface for allowing drivers to expose a different DMA device for zerocopy. [1] Documentation/networking/device_drivers/ethernet/mellanox/mlx5/switchdev.rst [2] Documentation/networking/multi-pf-netdev.rst Signed-off-by: Dragos Tatulea Reviewed-by: Pavel Begunkov Reviewed-by: Mina Almasry Link: https://patch.msgid.link/20250827144017.1529208-3-dtatulea@nvidia.com Signed-off-by: Jakub Kicinski

net: rename rtnl_net_debug to lock_debug

2025-04-03T22:32:08+00:00

And make it selected by CONFIG_DEBUG_NET. Don't rename any of the structs/functions. Next patch will use rtnl_net_debug_event in netdevsim. Reviewed-by: Jakub Kicinski Signed-off-by: Stanislav Fomichev Link: https://patch.msgid.link/20250401163452.622454-5-sdf@fomichev.me Signed-off-by: Jakub Kicinski

net: hold netdev instance lock during rtnetlink operations

2025-03-06T20:59:44+00:00

To preserve the atomicity, hold the lock while applying multiple attributes. The major issue with a full conversion to the instance lock are software nesting devices (bonding/team/vrf/etc). Those devices call into the core stack for their lower (potentially real hw) devices. To avoid explicitly wrapping all those places into instance lock/unlock, introduce new API boundaries: - (some) existing dev_xxx calls are now considered "external" (to drivers) APIs and they transparently grab the instance lock if needed (dev_api.c) - new netif_xxx calls are internal core stack API (naming is sketchy, I've tried netdev_xxx_locked per Jakub's suggestion, but it feels a bit verbose; but happy to get back to this naming scheme if this is the preference) This avoids touching most of the existing ioctl/sysfs/drivers paths. Note the special handling of ndo_xxx_slave operations: I exploit the fact that none of the drivers that call these functions need/use instance lock. At the same time, they use dev_xxx APIs, so the lower device has to be unlocked. Changes in unregister_netdevice_many_notify (to protect dev->state with instance lock) trigger lockdep - the loop over close_list (mostly from cleanup_net) introduces spurious ordering issues. netdev_lock_cmp_fn has a justification on why it's ok to suppress for now. Cc: Saeed Mahameed Signed-off-by: Stanislav Fomichev Link: https://patch.msgid.link/20250305163732.2766420-7-sdf@fomichev.me Signed-off-by: Jakub Kicinski

net: Implement fault injection forcing skb reallocation

2024-11-12T11:05:33+00:00

Introduce a fault injection mechanism to force skb reallocation. The primary goal is to catch bugs related to pointer invalidation after potential skb reallocation. The fault injection mechanism aims to identify scenarios where callers retain pointers to various headers in the skb but fail to reload these pointers after calling a function that may reallocate the data. This type of bug can lead to memory corruption or crashes if the old, now-invalid pointers are used. By forcing reallocation through fault injection, we can stress-test code paths and ensure proper pointer management after potential skb reallocations. Add a hook for fault injection in the following functions: * pskb_trim_rcsum() * pskb_may_pull_reason() * pskb_trim() As the other fault injection mechanism, protect it under a debug Kconfig called CONFIG_FAIL_SKB_REALLOC. This patch was *heavily* inspired by Jakub's proposal from: https://lore.kernel.org/all/20240719174140.47a868e6@kernel.org/ CC: Akinobu Mita Suggested-by: Jakub Kicinski Signed-off-by: Breno Leitao Reviewed-by: Akinobu Mita Acked-by: Paolo Abeni Acked-by: Guillaume Nault Link: https://patch.msgid.link/20241107-fault_v6-v6-1-1b82cb6ecacd@debian.org Signed-off-by: Paolo Abeni

rtnetlink: Add ASSERT_RTNL_NET() placeholder for netdev notifier.

2024-10-08T13:16:59+00:00

The global and per-netns netdev notifier depend on RTNL, and its dependency is not so clear due to nested calls. Let's add a placeholder to place ASSERT_RTNL_NET() for each event. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Signed-off-by: Paolo Abeni

netdev: support binding dma-buf to netdevice

2024-09-12T03:44:31+00:00

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 Signed-off-by: Kaiyuan Zhang Signed-off-by: Mina Almasry Reviewed-by: Pavel Begunkov # excluding netlink Acked-by: Daniel Vetter Reviewed-by: Jakub Kicinski Link: https://patch.msgid.link/20240910171458.219195-4-almasrymina@google.com Signed-off-by: Jakub Kicinski

netdev: add netdev_rx_queue_restart()

2024-09-12T03:44:30+00:00

Add netdev_rx_queue_restart(), which resets an rx queue using the queue API recently merged[1]. The queue API was merged to enable the core net stack to reset individual rx queues to actuate changes in the rx queue's configuration. In later patches in this series, we will use netdev_rx_queue_restart() to reset rx queues after binding or unbinding dmabuf configuration, which will cause reallocation of the page_pool to repopulate its memory using the new configuration. [1] https://lore.kernel.org/netdev/20240430231420.699177-1-shailend@google.com/T/ Signed-off-by: David Wei Signed-off-by: Mina Almasry Reviewed-by: Pavel Begunkov Reviewed-by: Jakub Kicinski Link: https://patch.msgid.link/20240910171458.219195-2-almasrymina@google.com Signed-off-by: Jakub Kicinski

net: add IEEE 802.1q specific helpers

2024-05-08T09:35:09+00:00

IEEE 802.1q specification provides recommendation and examples which can be used as good default values for different drivers. This patch implements mapping examples documented in IEEE 802.1Q-2022 in Annex I "I.3 Traffic type to traffic class mapping" and IETF DSCP naming and mapping DSCP to Traffic Type inspired by RFC8325. This helpers will be used in followup patches for dsa/microchip DCB implementation. Signed-off-by: Oleksij Rempel Signed-off-by: David S. Miller

net: net_test: add tests for IP tunnel flags conversion helpers

2024-04-01T09:49:28+00:00

Now that there are helpers for converting IP tunnel flags between the old __be16 format and the bitmap format, make sure they work as expected by adding a couple of tests to the networking testing suite. The helpers are all inline, so no dependencies on the related CONFIG_* (or a standalone module) are needed. Cover three possible cases: 1. No bits past BIT(15) are set, VTI/SIT bits are not set. This conversion is almost a direct assignment. 2. No bits past BIT(15) are set, but VTI/SIT bit is set. During the conversion, it must be transformed into BIT(16) in the bitmap, but still compatible with the __be16 format. 3. The bitmap has bits past BIT(15) set (not the VTI/SIT one). The result will be truncated. Note that currently __IP_TUNNEL_FLAG_NUM is 17 (incl. special), which means that the result of this case is currently semi-false-positive. When BIT(17) is finally here, it will be adjusted accordingly. Signed-off-by: Alexander Lobakin Signed-off-by: David S. Miller

net: introduce struct net_hotdata

2024-03-08T05:12:41+00:00

Instead of spreading networking critical fields all over the places, add a custom net_hotdata structure so that we can precisely control its layout. In this first patch, move : - gro_normal_batch used in rx (GRO stack) - offload_base used in rx and tx (GRO and TSO stacks) Signed-off-by: Eric Dumazet Acked-by: Soheil Hassas Yeganeh Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20240306160031.874438-2-edumazet@google.com Signed-off-by: Jakub Kicinski