Cristian
Thanks for updating the patch set. As I mentioned in my previous email, we are
working on adding support for this as a new P4C CPU target. We plan to open
source the compiler backend in the near future.
Cheers,
Han
On 9/10/20, 8:27 AM, "dev on behalf of Cristian Dumitrescu"
wrote:
This patch set introduces a new pipeline type that combines the DPDK
performance with the flexibility of the P4-16 language[1]. The new API
can be used either by itself to code a complete software switch (SWX)
or data plane app, or in combination with the open-source P4 compiler
P4C [2], potentially acting as a P4C back-end, thus allowing the P4
programs to be translated to the DPDK API and run on multi-core CPUs.
Main new features:
* Nothing is hard-wired, everything is dynamically defined: The packet
headers (i.e. protocols), the packet meta-data, the actions, the
tables and the pipeline itself are dynamically defined instead of
having to be selected from a pre-defined set.
* Instructions: The actions and the life of the packet through the
pipeline are defined with instructions that manipulate the pipeline
objects mentioned above. The pipeline is the main function of the
packet program, with actions as subroutines triggered by the tables.
* Call external plugins: Extern objects and functions can be defined
to call functionality that cannot be efficiently implemented with
the existing pipeline-oriented instruction set, such as: special
error detecting/correcting codes, crypto, meters, stats arrays,
heuristics, etc.
* Better control plane interaction: Transaction-oriented table update
mechanism that supports multi-table atomic updates. Multiple tables
can be updated in a single step with only the before and after table
sets visible to the packets. Alignment with P4Runtime [3].
* Performance: Multiple packets are in-flight within the pipeline at
any moment. Each packet is owned by a different time-sharing thread
in run-to-completion, with the thread pausing before memory access
operations such as packet I/O and table lookup to allow the memory
prefetch to complete. The instructions are verified and translated
at initialization time with no run-time impact. The instructions are
also optimized to detect and "fuse" frequently used patterns into
vector-like instructions transparently to the user.
API deprecation and maturing roadmap:
* The existing pipeline stable API (rte_pipeline.h) to be deprecated
prior to and removed as part of the DPDK 21.11 LTS release.
* The new SWX pipeline experimental API (rte_swx_pipeline.h) to mature
and become stable as part of the same DPDK 21.11 LTS release.
V4 changes:
* Spell check fixes.
V3 changes:
* Removed the library Makefile support to align with the latest DPDK.
V2 changes:
* Updated the title and commit messages to reflect the introduction of
the new SWX pipeline type.
* Added the API deprecation and maturing roadmap to the cover letter.
* Added support for building the SWX pipeline based on specification
file with syntax aligned to the P4 language. The spec file may be
generated by the P4C compiler in the future (see patch 32). Reworked
the examples accordingly (see patches 39, 40 and 41).
* Added support for the SWX sink port (used for packet drop or log)
when PCAP library is disabled from the build.
* Added checks to the application CLI commands to prevent execution
when dependencies of the current command have previously failed (see
patch 38).
* Fixed build warning for 32-bit targets due to the printing of 64-bit
statistics counters (see patch 38).
[1] P4-16 specification: https://p4.org/p4-spec/docs/P4-16-v1.2.1.pdf
[2] P4-16 compiler: https://github.com/p4lang/p4c
[3] P4Runtime specification:
https://p4.org/p4runtime/spec/v1.2.0/P4Runtime-Spec.pdf
Cristian Dumitrescu (41):
pipeline: add new SWX pipeline type
pipeline: add SWX pipeline input port
pipeline: add SWX pipeline output port
pipeline: add SWX headers and meta-data
pipeline: add SWX extern objects and funcs
pipeline: add SWX pipeline action
pipeline: add SWX pipeline tables
pipeline: add SWX pipeline instructions
pipeline: add SWX rx and extract instructions
pipeline: add SWX tx and emit instructions
pipeline: add header validate and invalidate SWX instructions
pipeline: add SWX mov instruction
pipeline: add SWX dma instruction
pipeline: introduce SWX add instruction
pipeline: introduce SWX sub instruction
pipeline: introduce SWX ckadd instruction
pipeline: introduce SWX cksub instruction
pipeline: introduce SWX and instruction
pipeline: introduce SWX or instruction
pipeline: in
