This change actually defines the (initial) metadata layout
that should be used by AF_XDP userspace (xsk_tx_metadata).
The first field is flags which requests appropriate offloads,
followed by the offload-specific fields. The supported per-device
offloads are exported via netlink (new xsk-flags).
The offloads themselves are still implemented in a bit of a
framework-y fashion that's left from my initial kfunc attempt.
I'm introducing new xsk_tx_metadata_ops which drivers are
supposed to implement. The drivers are also supposed
to call xsk_tx_metadata_request/xsk_tx_metadata_complete in
the right places. Since xsk_tx_metadata_{request,_complete}
are static inline, we don't incur any extra overhead doing
indirect calls.
The benefit of this scheme is as follows:
- keeps all metadata layout parsing away from driver code
- makes it easy to grep and see which drivers implement what
- don't need any extra flags to maintain to keep track of what
offloads are implemented; if the callback is implemented - the offload
is supported (used by netlink reporting code)
Two offloads are defined right now:
1. XDP_TXMD_FLAGS_CHECKSUM: skb-style csum_start+csum_offset
2. XDP_TXMD_FLAGS_TIMESTAMP: writes TX timestamp back into metadata
area upon completion (tx_timestamp field)
XDP_TXMD_FLAGS_TIMESTAMP is also implemented for XDP_COPY mode: it writes
SW timestamp from the skb destructor (note I'm reusing hwtstamps to pass
metadata pointer).
The struct is forward-compatible and can be extended in the future
by appending more fields.
Reviewed-by: Song Yoong Siang <yoong.siang.song@intel.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20231127190319.1190813-3-sdf@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add new xdp-rx-metadata-features member to netdev netlink
which exports a bitmask of supported kfuncs. Most of the patch
is autogenerated (headers), the only relevant part is netdev.yaml
and the changes in netdev-genl.c to marshal into netlink.
Example output on veth:
$ ip link add veth0 type veth peer name veth1 # ifndex == 12
$ ./tools/net/ynl/samples/netdev 12
Select ifc ($ifindex; or 0 = dump; or -2 ntf check): 12
veth1[12] xdp-features (23): basic redirect rx-sg xdp-rx-metadata-features (3): timestamp hash xdp-zc-max-segs=0
Cc: netdev@vger.kernel.org
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20230913171350.369987-3-sdf@google.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Also add support to pass topdir to ynl-regen.sh (Jakub) and call
it from the makefile to update the UAPI headers.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Co-developed-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20230727163001.3952878-4-sdf@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Introduce new netlink attribute NETDEV_A_DEV_XDP_ZC_MAX_SEGS that will
carry maximum fragments that underlying ZC driver is able to handle on
TX side. It is going to be included in netlink response only when driver
supports ZC. Any value higher than 1 implies multi-buffer ZC support on
underlying device.
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20230719132421.584801-11-maciej.fijalkowski@intel.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
I relicensed Netlink spec code to GPL-2.0 OR BSD-3-Clause but
we still put a slightly different license on the uAPI header
than the rest of the code. Use the Linux-syscall-note on all
the specs and all generated code. It's moot for kernel code,
but should not hurt. This way the licenses match everywhere.
Cc: Chuck Lever <chuck.lever@oracle.com>
Fixes: 37d9df224d ("ynl: re-license uniformly under GPL-2.0 OR BSD-3-Clause")
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Introduce xdp_set_features_flag utility routine in order to update
dynamically xdp_features according to the dynamic hw configuration via
ethtool (e.g. changing number of hw rx/tx queues).
Add xdp_clear_features_flag() in order to clear all xdp_feature flag.
Reviewed-by: Shay Agroskin <shayagr@amazon.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
I was intending to make all the Netlink Spec code BSD-3-Clause
to ease the adoption but it appears that:
- I fumbled the uAPI and used "GPL WITH uAPI note" there
- it gives people pause as they expect GPL in the kernel
As suggested by Chuck re-license under dual. This gives us benefit
of full BSD freedom while fulfilling the broad "kernel is under GPL"
expectations.
Link: https://lore.kernel.org/all/20230304120108.05dd44c5@kernel.org/
Link: https://lore.kernel.org/r/20230306200457.3903854-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Fix a repeated copy/paste typo.
Fixes: d3d854fd6a ("netdev-genl: create a simple family for netdev stuff")
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a Netlink spec-compatible family for netdevs.
This is a very simple implementation without much
thought going into it.
It allows us to reap all the benefits of Netlink specs,
one can use the generic client to issue the commands:
$ ./cli.py --spec netdev.yaml --dump dev_get
[{'ifindex': 1, 'xdp-features': set()},
{'ifindex': 2, 'xdp-features': {'basic', 'ndo-xmit', 'redirect'}},
{'ifindex': 3, 'xdp-features': {'rx-sg'}}]
the generic python library does not have flags-by-name
support, yet, but we also don't have to carry strings
in the messages, as user space can get the names from
the spec.
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Co-developed-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Co-developed-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Co-developed-by: Marek Majtyka <alardam@gmail.com>
Signed-off-by: Marek Majtyka <alardam@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/327ad9c9868becbe1e601b580c962549c8cd81f2.1675245258.git.lorenzo@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Stanislav Fomichev