Re: [dpdk-dev] [PATCH v4 2/6] ethdev: add capability to keep shared objects on restart

[Ajit Khaparde <ajit.khaparde@broadcom.com>]

On Wed, Oct 20, 2021 at 11:35 PM Dmitry Kozlyuk <dkozlyuk@oss.nvidia.com> wrote:
>
> 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 <dkozlyuk@nvidia.com>
Acked-by: Ajit Khaparde <ajit.khaparde@broadcom.com>

>