On 6 Jan 2026, at 8:59, Eli Britstein via dev wrote:
> Acked-by: Eli Britstein <elibr.nvidia.com>
Thanks Eli for taking the time to review this massive series, much appreciated!
//Eelco
>> -----Original Message-----
>> From: Eli Britstein
>> Sent: Tuesday, 6 January 2026 7:43
>> To: [email protected]
>> Subject: Re: [ovs-dev] [PATCH v4 00/40] Architectural refactoring of hardware
>> offload infrastructure.
>>
>> LGTM.
>>
>> On 05/01/2026 17:13, Eelco Chaudron wrote:
>>> This RFC patch series introduces a major architectural refactoring of
>>> Open vSwitch's hardware offload infrastructure. It replaces the
>>> tightly coupled `netdev-offload` implementation with a new, modular
>>> `dpif-offload-provider` framework.
>>>
>>> MOTIVATION
>>> -------------------------------------------------------------
>>> The existing `netdev-offload` API tightly couples datapath
>>> implementations (like `dpif-netdev`) with specific offload
>>> technologies (DPDK's rte_flow). This design has several
>>> limitations:
>>>
>>> - Rigid Architecture: It creates complex dependencies,
>>> making the code difficult to maintain and extend.
>>>
>>> - Limited Flexibility: Supporting multiple offload backends
>>> simultaneously or adding new ones is cumbersome.
>>>
>>> - Inconsistent APIs: The logic for handling different
>>> offload types is scattered, leading to an inconsistent
>>> and hard-to-follow API surface.
>>>
>>> This refactoring aims to resolve these issues by creating a clean
>>> separation of concerns, improving modularity, and establishing a clear
>>> path for future hardware offload integrations.
>>>
>>> PROPOSED SOLUTION: THE `DPIF-OFFLOAD-PROVIDER` FRAMEWORK
>>> -------------------------------------------------------------
>>> This series introduces the `dpif-offload-provider` framework, which
>>> functions similarly to the existing `dpif-provider` pattern. It treats
>>> hardware offload as a distinct layer with multiple, dynamically
>>> selectable backends.
>>>
>>> Key features of the new framework include:
>>>
>>> 1. Modular Architecture: A clean separation between the
>>> generic datapath interface and specific offload
>>> provider implementations (e.g., `dpif-offload-tc`,
>>> `dpif-offload-dpdk`). `dpif` layers are now generic
>>> clients of the offload API.
>>>
>>> 2. Provider-based System: Allows multiple offload backends
>>> to coexist.
>>>
>>> 3. Unified and Asynchronous API: Establishes a consistent
>>> API across all offload providers. For userspace
>>> datapaths, the API is extended to support asynchronous
>>> flow operations with callbacks, making `dpif-netdev` a
>>> more efficient client.
>>>
>>> 4. Enhanced Configuration: Provides granular control over
>>> offload provider selection through a global and per-port
>>> priority system (`hw-offload-priority`), allowing
>>> fine-tuned policies for different hardware.
>>>
>>> 5. Improved Testing: Includes a new test framework
>>> specifically for validating DPDKs rte_flow offloads,
>>> enhancing long-term maintainability.
>>>
>>> PATCH SERIES ORGANIZATION
>>> -------------------------------------------------------------
>>> This large series is organized logically to facilitate
>>> review:
>>>
>>> 1. Framework Foundation: The initial patches establish the
>>> core `dpif-offload-provider` framework, including the
>>> necessary APIs for port management, flow mark
>>> allocation, configuration, and a dummy provider for
>>> testing.
>>>
>>> 2. Provider Implementation: These patches introduce the new
>>> `dpif-offload-tc` and `dpif-offload-dpdk` providers,
>>> building out their specific implementations on top of
>>> the new framework.
>>>
>>> 3. API Migration and Decoupling: The bulk of the series
>>> systematically migrates functionality from the legacy
>>> `netdev-offload` layer to the new providers. Key
>>> commits here decouple `dpif-netdev` and, crucially,
>>> `dpif-netlink` from their hardware offload
>>> entanglements.
>>>
>>> 4. Cleanup: The final patches remove the now-redundant
>>> global APIs and structures from `netdev-offload`,
>>> completing the transition.
>>>
>>> BACKWARD COMPATIBILITY
>>> -------------------------------------------------------------
>>> This refactoring maintains full API compatibility from a user's
>>> perspective. All existing `ovs-vsctl` and `ovs-appctl` commands
>>> continue to function as before. The changes are primarily internal
>>> architectural improvements designed to make OVS more robust and
>>> extensible.
>>>
>>> REQUEST FOR COMMENTS
>>> -------------------------------------------------------------
>>> This is a significant architectural change that affects core OVS
>>> infrastructure. We welcome feedback on:
>>>
>>> - The overall architectural approach and the
>>> `dpif-offload-provider` concept.
>>> - The API design, particularly the new asynchronous model
>>> for `dpif-netdev`.
>>> - The migration strategy and any potential backward
>>> compatibility concerns.
>>> - Performance implications of the new framework.
>>>
>>> -------------------------------------------------------------
>>> Changes from v1:
>>> - Fixed issues reported by Aaron and my AI experiments.
>>> - See individual patches for specific changes.
>>>
>>> Changes from v2:
>>> - See individual patches for specific changes.
>>>
>>> Changes from v3:
>>> - In patch 7, removed leftover netdev_close(port->netdev)
>>> causing netdev reference count issues.
>>> - Changed naming for dpif_offload_impl_type enum entries.
>>> - Merged previous patch 36, 'dpif-netdev: Add full name
>>> to the dp_netdev structure', with the next patch.
>>>
>>> Eelco Chaudron (40):
>>> dpif-offload-provider: Add dpif-offload-provider implementation.
>>> dpif-offload: Add provider for tc offload.
>>> dpif-offload: Add provider for dpdk (rte_flow).
>>> dpif-offload: Allow configuration of offload provider priority.
>>> dpif-offload: Move hw-offload configuration to dpif-offload.
>>> dpif-offload: Add offload provider set_config API.
>>> dpif-offload: Add port registration and management APIs.
>>> dpif-offload-tc: Add port management framework.
>>> dpif-offload-dpdk: Add port management framework.
>>> dpif-offload: Validate mandatory port class callbacks on registration.
>>> dpif-offload: Allow per-port offload provider priority config.
>>> dpif-offload: Introduce provider debug information API.
>>> dpif-offload: Call flow-flush netdev-offload APIs via dpif-offload.
>>> dpif-offload: Call meter netdev-offload APIs via dpif-offload.
>>> dpif-offload: Move the flow_get_n_flows() netdev-offload API to dpif.
>>> dpif-offload: Move hw_post_process netdev API to dpif.
>>> dpif-offload: Add flow dump APIs to dpif-offload.
>>> dpif-offload: Move the tc flow dump netdev APIs to dpif-offload.
>>> dpif-netlink: Remove netlink-offload integration.
>>> dpif-netlink: Add API to get offloaded netdev from port_id.
>>> dpif-offload: Add API to find offload implementation type.
>>> dpif-offload: Add operate implementation to dpif-offload.
>>> netdev-offload: Temporarily move thread-related APIs to dpif-netdev.
>>> dpif-offload: Add port dump APIs to dpif-offload.
>>> dpif-netdev: Remove indirect DPDK netdev offload API calls.
>>> dpif: Add dpif_get_features() API.
>>> dpif-offload: Add flow operations to dpif-offload-tc.
>>> dpif-netlink: Remove entangled hardware offload.
>>> dpif-offload-tc: Remove netdev-offload dependency.
>>> netdev_dummy: Remove hardware offload override.
>>> dpif-offload: Move the netdev_any_oor() API to dpif-offload.
>>> netdev-offload: Remove the global netdev-offload API.
>>> dpif-offload: Add inline flow APIs for userspace datapaths.
>>> dpif_netdev: Fix nullable memcpy in queue_netdev_flow_put().
>>> dpif-offload: Move offload_stats_get() API to dpif-offload.
>>> dpif-offload-dpdk: Abstract rte_flow implementation from dpif-netdev.
>>> dpif-offload-dummy: Add flow add/del/get APIs.
>>> netdev-offload: Fold netdev-offload APIs and files into dpif-offload.
>>> tests: Fix NSH decap header test for real Ethernet devices.
>>> tests: Add a simple DPDK rte_flow test framework.
>>>
>>> Documentation/topics/testing.rst | 19 +
>>> include/openvswitch/json.h | 1 +
>>> include/openvswitch/netdev.h | 1 +
>>> lib/automake.mk | 17 +-
>>> lib/dp-packet.h | 1 +
>>> lib/dpctl.c | 50 +-
>>> lib/dpdk.c | 2 -
>>> lib/dpif-netdev-avx512.c | 4 +-
>>> lib/dpif-netdev-private-flow.h | 9 +-
>>> lib/dpif-netdev.c | 1244 +++---------
>>> lib/dpif-netlink.c | 557 +----
>>> ...load-dpdk.c => dpif-offload-dpdk-netdev.c} | 592 ++++--
>>> lib/dpif-offload-dpdk-private.h | 73 +
>>> lib/dpif-offload-dpdk.c | 1186 +++++++++++
>>> lib/dpif-offload-dummy.c | 920 +++++++++
>>> lib/dpif-offload-provider.h | 421 ++++
>>> ...-offload-tc.c => dpif-offload-tc-netdev.c} | 238 ++-
>>> lib/dpif-offload-tc-private.h | 76 +
>>> lib/dpif-offload-tc.c | 877 ++++++++
>>> lib/dpif-offload.c | 1790 +++++++++++++++++
>>> lib/dpif-offload.h | 221 ++
>>> lib/dpif-provider.h | 65 +-
>>> lib/dpif.c | 166 +-
>>> lib/dpif.h | 14 +-
>>> lib/dummy.h | 9 +
>>> lib/json.c | 7 +
>>> lib/netdev-dpdk.c | 9 +-
>>> lib/netdev-dpdk.h | 2 +-
>>> lib/netdev-dummy.c | 199 +-
>>> lib/netdev-linux.c | 3 +-
>>> lib/netdev-offload-provider.h | 148 --
>>> lib/netdev-offload.c | 910 ---------
>>> lib/netdev-offload.h | 169 --
>>> lib/netdev-provider.h | 10 +-
>>> lib/netdev.c | 71 +-
>>> lib/netdev.h | 22 +
>>> lib/tc.c | 2 +-
>>> ofproto/ofproto-dpif-upcall.c | 50 +-
>>> ofproto/ofproto-dpif.c | 90 +-
>>> tests/.gitignore | 3 +
>>> tests/automake.mk | 24 +
>>> tests/dpif-netdev.at | 40 +-
>>> tests/ofproto-dpif.at | 170 ++
>>> tests/ofproto-macros.at | 17 +-
>>> tests/sendpkt.py | 12 +-
>>> tests/system-dpdk-offloads-macros.at | 236 +++
>>> tests/system-dpdk-offloads-testsuite.at | 28 +
>>> tests/system-dpdk-offloads.at | 223 ++
>>> tests/system-dpdk.at | 35 +
>>> tests/system-kmod-macros.at | 5 +
>>> tests/system-offloads-testsuite-macros.at | 5 +
>>> tests/system-offloads-traffic.at | 48 +
>>> tests/system-traffic.at | 9 +-
>>> tests/system-userspace-macros.at | 5 +
>>> vswitchd/bridge.c | 7 +-
>>> vswitchd/vswitch.xml | 43 +
>>> 56 files changed, 7808 insertions(+), 3347 deletions(-)
>>> rename lib/{netdev-offload-dpdk.c => dpif-offload-dpdk-netdev.c} (83%)
>>> create mode 100644 lib/dpif-offload-dpdk-private.h
>>> create mode 100644 lib/dpif-offload-dpdk.c
>>> create mode 100644 lib/dpif-offload-dummy.c
>>> create mode 100644 lib/dpif-offload-provider.h
>>> rename lib/{netdev-offload-tc.c => dpif-offload-tc-netdev.c} (95%)
>>> create mode 100644 lib/dpif-offload-tc-private.h
>>> create mode 100644 lib/dpif-offload-tc.c
>>> create mode 100644 lib/dpif-offload.c
>>> create mode 100644 lib/dpif-offload.h
>>> delete mode 100644 lib/netdev-offload-provider.h
>>> delete mode 100644 lib/netdev-offload.c
>>> delete mode 100644 lib/netdev-offload.h
>>> create mode 100644 tests/system-dpdk-offloads-macros.at
>>> create mode 100644 tests/system-dpdk-offloads-testsuite.at
>>> create mode 100644 tests/system-dpdk-offloads.at
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