> In the proactive error handling mode, the PMD will set the data path > pointers to dummy functions and then try recovery, in this period the > application may still invoking data path API. This will introduce a > race-condition with data path which may lead to crash [1]. > > Although the PMD added delay after setting data path pointers to cover > the above race-condition, it reduces the probability, but it doesn't > solve the problem. > > To solve the race-condition problem fundamentally, the following > requirements are added: > 1. The PMD should set the data path pointers to dummy functions after > report RTE_ETH_EVENT_ERR_RECOVERING event. > 2. The application should stop data path API invocation when process > the RTE_ETH_EVENT_ERR_RECOVERING event. > 3. The PMD should set the data path pointers to valid functions before > report RTE_ETH_EVENT_RECOVERY_SUCCESS event. > 4. The application should enable data path API invocation when process > the RTE_ETH_EVENT_RECOVERY_SUCCESS event. > > Also, this patch introduce a driver internal function > rte_eth_fp_ops_setup which used as an help function for PMD. > > [1] > http://patchwork.dpdk.org/project/dpdk/patch/20230220060839.1267349-2-ashok.k.kal...@intel.com/ > > Fixes: eb0d471a8941 ("ethdev: add proactive error handling mode") > Cc: sta...@dpdk.org > > Signed-off-by: Chengwen Feng <fengcheng...@huawei.com> > --- > doc/guides/prog_guide/poll_mode_drv.rst | 20 +++++++--------- > lib/ethdev/ethdev_driver.c | 8 +++++++ > lib/ethdev/ethdev_driver.h | 10 ++++++++ > lib/ethdev/rte_ethdev.h | 32 +++++++++++++++---------- > lib/ethdev/version.map | 1 + > 5 files changed, 46 insertions(+), 25 deletions(-) > > diff --git a/doc/guides/prog_guide/poll_mode_drv.rst > b/doc/guides/prog_guide/poll_mode_drv.rst > index c145a9066c..e380ff135a 100644 > --- a/doc/guides/prog_guide/poll_mode_drv.rst > +++ b/doc/guides/prog_guide/poll_mode_drv.rst > @@ -638,14 +638,9 @@ different from the application invokes recovery in > PASSIVE mode, > the PMD automatically recovers from error in PROACTIVE mode, > and only a small amount of work is required for the application. > > -During error detection and automatic recovery, > -the PMD sets the data path pointers to dummy functions > -(which will prevent the crash), > -and also make sure the control path operations fail with a return code > ``-EBUSY``. > - > -Because the PMD recovers automatically, > -the application can only sense that the data flow is disconnected for a while > -and the control API returns an error in this period. > +During error detection and automatic recovery, the PMD sets the data path > +pointers to dummy functions and also make sure the control path operations > +failed with a return code ``-EBUSY``. > > In order to sense the error happening/recovering, > as well as to restore some additional configuration, > @@ -653,9 +648,9 @@ three events are available: > > ``RTE_ETH_EVENT_ERR_RECOVERING`` > Notify the application that an error is detected > - and the recovery is being started. > + and the recovery is about to start. > Upon receiving the event, the application should not invoke > - any control path function until receiving > + any control and data path API until receiving > ``RTE_ETH_EVENT_RECOVERY_SUCCESS`` or ``RTE_ETH_EVENT_RECOVERY_FAILED`` > event. > > .. note:: > @@ -666,8 +661,9 @@ three events are available: > > ``RTE_ETH_EVENT_RECOVERY_SUCCESS`` > Notify the application that the recovery from error is successful, > - the PMD already re-configures the port, > - and the effect is the same as a restart operation. > + the PMD already re-configures the port. > + The application should restore some additional configuration, and then > + enable data path API invocation. > > ``RTE_ETH_EVENT_RECOVERY_FAILED`` > Notify the application that the recovery from error failed, > diff --git a/lib/ethdev/ethdev_driver.c b/lib/ethdev/ethdev_driver.c > index 0be1e8ca04..f994653fe9 100644 > --- a/lib/ethdev/ethdev_driver.c > +++ b/lib/ethdev/ethdev_driver.c > @@ -515,6 +515,14 @@ rte_eth_dma_zone_free(const struct rte_eth_dev *dev, > const char *ring_name, > return rc; > } > > +void > +rte_eth_fp_ops_setup(struct rte_eth_dev *dev) > +{ > + if (dev == NULL) > + return; > + eth_dev_fp_ops_setup(rte_eth_fp_ops + dev->data->port_id, dev); > +} > + > const struct rte_memzone * > rte_eth_dma_zone_reserve(const struct rte_eth_dev *dev, const char > *ring_name, > uint16_t queue_id, size_t size, unsigned int align, > diff --git a/lib/ethdev/ethdev_driver.h b/lib/ethdev/ethdev_driver.h > index 2c9d615fb5..0d964d1f67 100644 > --- a/lib/ethdev/ethdev_driver.h > +++ b/lib/ethdev/ethdev_driver.h > @@ -1621,6 +1621,16 @@ int > rte_eth_dma_zone_free(const struct rte_eth_dev *eth_dev, const char *name, > uint16_t queue_id); > > +/** > + * @internal > + * Setup eth fast-path API to ethdev values. > + * > + * @param dev > + * Pointer to struct rte_eth_dev. > + */ > +__rte_internal > +void rte_eth_fp_ops_setup(struct rte_eth_dev *dev); > + > /** > * @internal > * Atomically set the link status for the specific device. > diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h > index 049641d57c..44ee7229c1 100644 > --- a/lib/ethdev/rte_ethdev.h > +++ b/lib/ethdev/rte_ethdev.h > @@ -3944,25 +3944,28 @@ enum rte_eth_event_type { > */ > RTE_ETH_EVENT_RX_AVAIL_THRESH, > /** Port recovering from a hardware or firmware error. > - * If PMD supports proactive error recovery, > - * it should trigger this event to notify application > - * that it detected an error and the recovery is being started. > - * Upon receiving the event, the application should not invoke any > control path API > - * (such as rte_eth_dev_configure/rte_eth_dev_stop...) until receiving > - * RTE_ETH_EVENT_RECOVERY_SUCCESS or RTE_ETH_EVENT_RECOVERY_FAILED > event. > - * The PMD will set the data path pointers to dummy functions, > - * and re-set the data path pointers to non-dummy functions > - * before reporting RTE_ETH_EVENT_RECOVERY_SUCCESS event. > - * It means that the application cannot send or receive any packets > - * during this period. > + * > + * If PMD supports proactive error recovery, it should trigger this > + * event to notify application that it detected an error and the > + * recovery is about to start. > + * > + * Upon receiving the event, the application should not invoke any > + * control and data path API until receiving > + * RTE_ETH_EVENT_RECOVERY_SUCCESS or RTE_ETH_EVENT_RECOVERY_FAILED > + * event. > + * > + * Once this event is reported, the PMD will set the data path pointers > + * to dummy functions, and re-set the data path pointers to valid > + * functions before reporting RTE_ETH_EVENT_RECOVERY_SUCCESS event. > + * > * @note Before the PMD reports the recovery result, > * the PMD may report the RTE_ETH_EVENT_ERR_RECOVERING event again, > * because a larger error may occur during the recovery. > */ > RTE_ETH_EVENT_ERR_RECOVERING, > /** Port recovers successfully from the error. > - * The PMD already re-configured the port, > - * and the effect is the same as a restart operation. > + * > + * The PMD already re-configured the port: > * a) The following operation will be retained: (alphabetically) > * - DCB configuration > * - FEC configuration > @@ -3989,6 +3992,9 @@ enum rte_eth_event_type { > * (@see RTE_ETH_DEV_CAPA_FLOW_SHARED_OBJECT_KEEP) > * c) Any other configuration will not be stored > * and will need to be re-configured. > + * > + * The application should restore some additional configuration > + * (see above case b/c), and then enable data path API invocation. > */ > RTE_ETH_EVENT_RECOVERY_SUCCESS, > /** Port recovery failed. > diff --git a/lib/ethdev/version.map b/lib/ethdev/version.map > index 357d1a88c0..c273e0bdae 100644 > --- a/lib/ethdev/version.map > +++ b/lib/ethdev/version.map > @@ -320,6 +320,7 @@ INTERNAL { > rte_eth_devices; > rte_eth_dma_zone_free; > rte_eth_dma_zone_reserve; > + rte_eth_fp_ops_setup; > rte_eth_hairpin_queue_peer_bind; > rte_eth_hairpin_queue_peer_unbind; > rte_eth_hairpin_queue_peer_update; > -- Acked-by: Konstantin Ananyev <konstantin.anan...@huawei.com>
> 2.17.1
