948d4f214f
This is the basic implementation of veth driver XDP. Incoming packets are sent from the peer veth device in the form of skb, so this is generally doing the same thing as generic XDP. This itself is not so useful, but a starting point to implement other useful veth XDP features like TX and REDIRECT. This introduces NAPI when XDP is enabled, because XDP is now heavily relies on NAPI context. Use ptr_ring to emulate NIC ring. Tx function enqueues packets to the ring and peer NAPI handler drains the ring. Currently only one ring is allocated for each veth device, so it does not scale on multiqueue env. This can be resolved by allocating rings on the per-queue basis later. Note that NAPI is not used but netif_rx is used when XDP is not loaded, so this does not change the default behaviour. v6: - Check skb->len only when allocation is needed. - Add __GFP_NOWARN to alloc_page() as it can be triggered by external events. v3: - Fix race on closing the device. - Add extack messages in ndo_bpf. v2: - Squashed with the patch adding NAPI. - Implement adjust_tail. - Don't acquire consumer lock because it is guarded by NAPI. - Make poll_controller noop since it is unnecessary. - Register rxq_info on enabling XDP rather than on opening the device. Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.