Re: [dpdk-dev] [PATCH v4 00/12] introduce fail-safe PMD

[Stephen Hemminger <stephen@networkplumber.org>]

On Mon, 29 May 2017 15:42:12 +0200
Gaetan Rivet <gaetan.rivet@6wind.com> wrote:

> This PMD intercepts and manages Ethernet device removal events issued by
> slave PMDs and re-initializes them transparently when brought back so that
> existing applications do not need to be modified to benefit from true
> hot-plugging support.
> 
> The stacked PMD approach shares many similarities with the bonding PMD but
> with a different purpose. While bonding provides the ability to group
> several links into a single logical device for enhanced throughput and
> supports fail-over at link level, this one manages the sudden disappearance
> of the underlying device; it guarantees applications face a valid device in
> working order at all times.
> 
> Each fail-safe instance is configured to run atop one or several
> devices, with one defined as the preferred device. Hot-plug events are
> handled on all of them, and Tx is always directed to the preferred device
> if present or to the next available failover device (Rx is always performed
> on all devices for simplicity).
> 
> Moreover, the configured slaves (preferred or failover) do not need to be
> present at initialization time and may appear later.
> 
> Slaves configuration is continuously synchronized with that of the virtual
> device, which exposes their common set of capabilities to the application.
> Failure to apply the current configuration state to a slave for any reason
> simply reschedules its initialization.
> 
> This patchset depends on:
> 
> eal: complete attach / detach support
> http://dpdk.org/ml/archives/dev/2017-May/066366.html
> http://dpdk.org/dev/patchwork/patch/24522/
> 
> ethdev: add flow API rule copy function
> http://dpdk.org/ml/archives/dev/2017-May/066145.html
> http://dpdk.org/dev/patchwork/patch/24406/
> 
> ethdev: add isolated mode to flow API
> http://dpdk.org/ml/archives/dev/2017-April/064327.html
> http://dpdk.org/dev/patchwork/patch/23741/
> 
> v1 --> v2:
> 
>   - Wrote documentation
>   - Fixed commit logs, signed-off-by
>   - Added LSC event support
>   - A few minor fixes
> 
> v2 --> v3:
> 
>   - Numerous bug fixes.
>   - Complete sub-EAL rework to follow new bus API.
>   - burst protection on sub removal.
>   - more flexible sub definition.
>   - flow isolated mode support.
> 
> v3 --> v4:
> 
>   - Split back commits
>        net/failsafe: add fast burst functions
>        net/failsafe: support device removal
>     That were squashed by error during a rebase
>   - Fix segfault on port plugin
>   - Fix isolate mode support for MLX4 ports plugin
> 
> Gaetan Rivet (12):
>   ethdev: save VLAN filter setting
>   ethdev: add deferred intermediate device state
>   ethdev: count devices consistently
>   net/failsafe: add fail-safe PMD
>   net/failsafe: add plug-in support
>   net/failsafe: add flexible device definition
>   net/failsafe: support flow API
>   net/failsafe: support offload capabilities
>   net/failsafe: add fast burst functions
>   net/failsafe: support device removal
>   net/failsafe: support link status change event
>   net/failsafe: support flow API isolation mode
> 
>  MAINTAINERS                             |   5 +
>  config/common_base                      |   6 +
>  doc/guides/nics/fail_safe.rst           | 186 +++++++
>  doc/guides/nics/features/failsafe.ini   |  32 ++
>  doc/guides/nics/index.rst               |   1 +
>  drivers/net/Makefile                    |   2 +
>  drivers/net/failsafe/Makefile           |  74 +++
>  drivers/net/failsafe/failsafe.c         | 305 +++++++++++
>  drivers/net/failsafe/failsafe_args.c    | 475 +++++++++++++++++
>  drivers/net/failsafe/failsafe_eal.c     | 140 +++++
>  drivers/net/failsafe/failsafe_ether.c   | 431 ++++++++++++++++
>  drivers/net/failsafe/failsafe_flow.c    | 245 +++++++++
>  drivers/net/failsafe/failsafe_ops.c     | 869 ++++++++++++++++++++++++++++++++
>  drivers/net/failsafe/failsafe_private.h | 377 ++++++++++++++
>  drivers/net/failsafe/failsafe_rxtx.c    | 204 ++++++++
>  lib/librte_ether/rte_ethdev.c           |  38 +-
>  lib/librte_ether/rte_ethdev.h           |  24 +-
>  mk/rte.app.mk                           |   1 +
>  18 files changed, 3399 insertions(+), 16 deletions(-)
>  create mode 100644 doc/guides/nics/fail_safe.rst
>  create mode 100644 doc/guides/nics/features/failsafe.ini
>  create mode 100644 drivers/net/failsafe/Makefile
>  create mode 100644 drivers/net/failsafe/failsafe.c
>  create mode 100644 drivers/net/failsafe/failsafe_args.c
>  create mode 100644 drivers/net/failsafe/failsafe_eal.c
>  create mode 100644 drivers/net/failsafe/failsafe_ether.c
>  create mode 100644 drivers/net/failsafe/failsafe_flow.c
>  create mode 100644 drivers/net/failsafe/failsafe_ops.c
>  create mode 100644 drivers/net/failsafe/failsafe_private.h
>  create mode 100644 drivers/net/failsafe/failsafe_rxtx.c
> 

Discussed in tech-board meeting and accepted for inclusion in 17.08 release.
Longer term this driver would benefit from better hot plug support

Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>