Re: [dpdk-dev] [PATCH v6 1/3] ethdev: support device reset and recovery events

[Thomas Monjalon <thomas@monjalon.net>]

09/10/2020 05:48, Kalesh A P:
> From: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
> 
> Adding support for device reset and recovery events in the
> rte_eth_event framework. FW error and FW reset conditions would be
> managed internally by PMD without needing application intervention.
> In such cases, PMD would need reset/recovery events to notify application
> that PMD is undergoing a reset.
> 
> Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com>
> Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
> Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
> Reviewed-by: Asaf Penso <asafp@nvidia.com>

The ethdev maintainers are not Cc'ed.
Please use the option --cc-cmd devtools/get-maintainer.sh


> +Error recovery support
> +~~~~~~~~~~~~~~~~~~~~~~
> +
> +When the PMD detects a FW reset or error condition, it will try to recover
> +from the error without needing the application intervention. In such cases,
> +PMD would need events to notify the application that it is undergoing
> +an error recovery.
> +
> +The PMD will trigger RTE_ETH_EVENT_ERR_RECOVERING event to notify the
> +application that PMD detected a FW reset or FW error condition. PMD will
> +try to recover from the error by itself. Data path will be halted and
> +control path operations would fail during the recovery period.
> +
> +The PMD will trigger RTE_ETH_EVENT_RECOVERED event to notify the application
> +that the it has recovered from the error condition. Control path and data path
> +are up now. Since the device undergone a reset, flow rules offloaded prior to
> +the reset will be lost and the application has to recreate the rules again.
> diff --git a/lib/librte_ethdev/rte_ethdev.h b/lib/librte_ethdev/rte_ethdev.h
> index 9759f13..9b4b015 100644
> --- a/lib/librte_ethdev/rte_ethdev.h
> +++ b/lib/librte_ethdev/rte_ethdev.h
> @@ -3207,6 +3207,23 @@ enum rte_eth_event_type {
>  	RTE_ETH_EVENT_DESTROY,  /**< port is released */
>  	RTE_ETH_EVENT_IPSEC,    /**< IPsec offload related event */
>  	RTE_ETH_EVENT_FLOW_AGED,/**< New aged-out flows is detected */
> +	RTE_ETH_EVENT_ERR_RECOVERING,
> +			/**< port recovering from an error
> +			 *
> +			 * PMD detected a FW reset or error condition.
> +			 * PMD will try to recover from the error.
> +			 * Data path will be halted and Control path operations
> +			 * would fail at this time.
> +			 */

Does it mean the application has nothing to do when receiving this event?
I think the app should stop polling at least.

> +	RTE_ETH_EVENT_RECOVERED,
> +			/**< port recovered from an error
> +			 *
> +			 * PMD has recovered from the error condition.
> +			 * Control path and Data path are up now.
> +			 * Since the device undergone a reset, flow rules
> +			 * offloaded prior to the reset will be lost and
> +			 * the application has to recreate the rules again.
> +			 */

Please be more precise.
Should the app re-configure the port, setup the queues, start the port?