Add documentation for the XDP_SHARED_UMEM feature when a UMEM is
shared between different queues and/or netdevs.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Link: https://lore.kernel.org/bpf/1598603189-32145-16-git-send-email-magnus.karlsson@intel.com
Add more documentation about the new Rx-only and Tx-only sockets in
libbpf and also how libbpf can now support shared umems. Also found
two pieces that could be improved in the text, that got fixed in this
commit.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: William Tu <u9012063@gmail.com>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Link: https://lore.kernel.org/bpf/1573148860-30254-6-git-send-email-magnus.karlsson@intel.com
Added sections on all the bind flags, libbpf, all the setsockopts and
all the getsockopts. Also updated the document to reflect the latest
features and to correct some spelling errors.
v1 -> v2:
* Updated XDP program with latest BTF map format
* Added one more FAQ entry
* Some minor edits and corrections
v2 -> v3:
* Simplified XDP_SHARED_UMEM example XDP program
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/1571648224-16889-1-git-send-email-magnus.karlsson@intel.com
The addition of unaligned chunks mode, the documentation needs to be
updated to indicate that the incoming addr to the fill ring will only be
masked if the user application is run in the aligned chunk mode. This patch
also adds a line to explicitly indicate that the incoming addr will not be
masked if running the user application in the unaligned chunk mode.
Signed-off-by: Kevin Laatz <kevin.laatz@intel.com>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Fix documentation that mention xdpsock_kern.c which has been
replaced by code embedded in libbpf.
Signed-off-by: Eric Leblond <eric@regit.org>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Fix Sphinx warnings in Documentation/networking/af_xdp.rst by
adding indentation:
Documentation/networking/af_xdp.rst:319: WARNING: Literal block expected; none found.
Documentation/networking/af_xdp.rst:326: WARNING: Literal block expected; none found.
Fixes: 0f4a9b7d4e ("xsk: add FAQ to facilitate for first time users")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Magnus Karlsson <magnus.karlsson@intel.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Added an FAQ section in Documentation/networking/af_xdp.rst to help
first time users with common problems. As problems are getting
identified, entries will be added to the FAQ.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Fix a simple typo: Completetion -> Completion
Signed-off-by: Konrad Djimeli <kdjimeli@igalia.com>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Currently, AF_XDP only supports a fixed frame-size memory scheme where
each frame is referenced via an index (idx). A user passes the frame
index to the kernel, and the kernel acts upon the data. Some NICs,
however, do not have a fixed frame-size model, instead they have a
model where a memory window is passed to the hardware and multiple
frames are filled into that window (referred to as the "type-writer"
model).
By changing the descriptor format from the current frame index
addressing scheme, AF_XDP can in the future be extended to support
these kinds of NICs.
In the index-based model, an idx refers to a frame of size
frame_size. Addressing a frame in the UMEM is done by offseting the
UMEM starting address by a global offset, idx * frame_size + offset.
Communicating via the fill- and completion-rings are done by means of
idx.
In this commit, the idx is removed in favor of an address (addr),
which is a relative address ranging over the UMEM. To convert an
idx-based address to the new addr is simply: addr = idx * frame_size +
offset.
We also stop referring to the UMEM "frame" as a frame. Instead it is
simply called a chunk.
To transfer ownership of a chunk to the kernel, the addr of the chunk
is passed in the fill-ring. Note, that the kernel will mask addr to
make it chunk aligned, so there is no need for userspace to do
that. E.g., for a chunk size of 2k, passing an addr of 2048, 2050 or
3000 to the fill-ring will refer to the same chunk.
On the completion-ring, the addr will match that of the Tx descriptor,
passed to the kernel.
Changing the descriptor format to use chunks/addr will allow for
future changes to move to a type-writer based model, where multiple
frames can reside in one chunk. In this model passing one single chunk
into the fill-ring, would potentially result in multiple Rx
descriptors.
This commit changes the uapi of AF_XDP sockets, and updates the
documentation.
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This is a sample application for AF_XDP sockets. The application
supports three different modes of operation: rxdrop, txonly and l2fwd.
To show-case a simple round-robin load-balancing between a set of
sockets in an xskmap, set the RR_LB compile time define option to 1 in
"xdpsock.h".
v2: The entries variable was calculated twice in {umem,xq}_nb_avail.
Co-authored-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Magnus Karlsson
Kevin Laatz
Eric Leblond
Randy Dunlap
Konrad Djimeli
Björn Töpel