> -----Original Message-----
> From: Dmitry Kozlyuk <dkozl...@nvidia.com>
> Sent: Tuesday, October 19, 2021 3:37 PM
> To: dev@dpdk.org
> Cc: Ori Kam <or...@nvidia.com>; NBU-Contact-Thomas Monjalon
> <tho...@monjalon.net>; Ferruh
> Yigit <ferruh.yi...@intel.com>; Andrew Rybchenko
> <andrew.rybche...@oktetlabs.ru>
> Subject: [PATCH v3 2/6] ethdev: add capability to keep shared objects on
> restart
>
> rte_flow_action_handle_create() did not mention what happens with an indirect
> action when a device
> is stopped and started again.
> It is natural for some indirect actions, like counter, to be persistent.
> Keeping others at least saves application time and complexity.
> However, not all PMDs can support it, or the support may be limited by
> particular action kinds, that is,
> combinations of action type and the value of the transfer bit in its
> configuration.
>
> Add a device capability to indicate if at least some indirect actions are
> kept across the above sequence.
> Without this capability the behavior is still unspecified, and application is
> required to destroy the
> indirect actions before stopping the device.
> In the future, indirect actions may not be the only type of objects shared
> between flow rules. The
> capability bit intends to cover all possible types of such objects, hence its
> name.
>
> Declare that the application can test for the persistence of a particular
> indirect action kind by
> attempting to create an indirect action of that kind when the device is
> stopped and checking for the
> specific error type.
> This is logical because if the PMD can to create an indirect action when the
> device is not started and
> use it after the start happens, it is natural that it can move its internal
> flow shared object to the same
> state when the device is stopped and restore the state when the device is
> started.
>
> Indirect action persistence across a reconfigurations is not required.
> In case a PMD cannot keep the indirect actions across reconfiguration, it is
> allowed just to report an
> error.
> Application must then flush the indirect actions before attempting it.
>
> Signed-off-by: Dmitry Kozlyuk <dkozl...@nvidia.com>
> ---
> doc/guides/prog_guide/rte_flow.rst | 24 ++++++++++++++++++++++++
> lib/ethdev/rte_ethdev.h | 3 +++
> 2 files changed, 27 insertions(+)
>
> diff --git a/doc/guides/prog_guide/rte_flow.rst
> b/doc/guides/prog_guide/rte_flow.rst
> index ff67b211e3..19e17f453d 100644
> --- a/doc/guides/prog_guide/rte_flow.rst
> +++ b/doc/guides/prog_guide/rte_flow.rst
> @@ -2810,6 +2810,30 @@ updated depend on the type of the ``action`` and
> different for every type.
> The indirect action specified data (e.g. counter) can be queried by
> ``rte_flow_action_handle_query()``.
>
> +If ``RTE_ETH_DEV_CAPA_FLOW_SHARED_OBJECT_KEEP`` is not advertised,
> +indirect actions cannot be created until the device is started for the
> +first time and cannot be kept when the device is stopped.
> +However, PMD also does not flush them automatically on stop, so the
> +application must call ``rte_flow_action_handle_destroy()``
> +before stopping the device to ensure no indirect actions remain.
> +
> +If ``RTE_ETH_DEV_CAPA_FLOW_SHARED_OBJECT_KEEP`` is advertised, this
> +means that the PMD can keep at least some indirect actions across
> +device stop and start.
> +However, ``rte_eth_dev_configure()`` may fail if any indirect actions
> +remain, so the application must destroy them before attempting a
> reconfiguration.
> +Keeping may be only supported for certain kinds of indirect actions.
> +A kind is a combination of an action type and a value of its transfer bit.
> +To test if a particular kind of indirect actions is kept, the
> +application must try to create a valid indirect action of that kind
> +when the device is stopped (after it has been configured or started
> previously).
> +If it fails with an error of type ``RTE_FLOW_ERROR_TYPE_STATE``,
> +indirect actions of this kind are flushed when the device is stopped.
> +If it succeeds, all indirect actions of the same kind are kept when the
> +device is stopped.
> +Indirect actions of a kept kind that are created when the device is
> +stopped, including the ones created for the test, will be kept after the
> device start.
> +
> .. _table_rte_flow_action_handle:
>
> .. table:: INDIRECT
> diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h index
> a0b388bb25..12fc7262eb 100644
> --- a/lib/ethdev/rte_ethdev.h
> +++ b/lib/ethdev/rte_ethdev.h
> @@ -94,6 +94,7 @@
> * depending on the device capabilities:
> *
> * - flow rules
> + * - flow-related shared objects, e.g. indirect actions
> *
> * Any other configuration will not be stored and will need to be re-entered
> * before a call to rte_eth_dev_start().
> @@ -1452,6 +1453,8 @@ struct rte_eth_conf { #define
> RTE_ETH_DEV_CAPA_RUNTIME_TX_QUEUE_SETUP 0x00000002
> /** Device supports keeping flow rules across restart. */ #define
> RTE_ETH_DEV_CAPA_FLOW_RULE_KEEP 0x00000004
> +/** Device supports keeping shared flow objects across restart. */
> +#define RTE_ETH_DEV_CAPA_FLOW_SHARED_OBJECT_KEEP 0x00000008
> /**@}*/
>
> /*
> --
> 2.25.1
Acked-by: Ori Kam <or...@nvidia.com>
Best,
Ori
