[ovs-dev] [PATCH] netdev-dpdk: add support for the RTE_ETH_EVENT_INTR_RESET event

Ilya Maximets i.maximets at samsung.com
Thu Sep 5 12:40:41 UTC 2019


Hi Eelco,
Thanks for the patch! Looks reasonable.

One comment is that it's better to explicitly initialize the
flag in common_construct.  I see that we doesn't initialize
'started' flag, but this might be fixed too.

More comments inline.

Best regards, Ilya Maximets.

On 05.09.2019 14:48, Eelco Chaudron wrote:
> Currently, OVS does not register and therefore not handle the
> interface reset event from the DPDK framework. This would cause a
> problem in cases where a VF is used as an interface, and its
> configuration changes.
> 
> As an example in the following scenario the MAC change is not
> detected/acted upon until OVS is restarted without the patch applied:
> 
> $ echo 1 > /sys/bus/pci/devices/0000:05:00.1/sriov_numvfs
> $ ovs-vsctl add-port ovs_pvp_br0 dpdk0 -- \
>           set Interface dpdk0 type=dpdk -- \
>           set Interface dpdk0 options:dpdk-devargs=0000:05:0a.0
> 
> $ ip link set p5p2 vf 0 mac 52:54:00:92:d3:33
> 
> Signed-off-by: Eelco Chaudron <echaudro at redhat.com>
> ---
>  lib/netdev-dpdk.c | 49 +++++++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 47 insertions(+), 2 deletions(-)
> 
> diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
> index bc20d6843..a23150387 100644
> --- a/lib/netdev-dpdk.c
> +++ b/lib/netdev-dpdk.c
> @@ -362,6 +362,7 @@ struct netdev_dpdk {
>          bool attached;
>          /* If true, rte_eth_dev_start() was successfully called */
>          bool started;
> +        bool reset_needed;

This will produce a hole in the structure as members will no longer
fit into a single cacheline.  And cacheline markers will be misaligned.

See details for similar issue here:
https://mail.openvswitch.org/pipermail/ovs-dev/2019-September/362349.html

Possible solution is to turn existing flags into bit fields or stop
avoiding the problem and drop most of padding in the structure.


>          struct eth_addr hwaddr;
>          int mtu;
>          int socket_id;
> @@ -1735,6 +1736,34 @@ netdev_dpdk_process_devargs(struct netdev_dpdk *dev,
>      return new_port_id;
>  }
>  
> +static int
> +dpdk_eth_event_callback(uint16_t port_id, enum rte_eth_event_type type,

s/uint16_t/dpdk_port_t/

> +                        void *param OVS_UNUSED, void *ret_param OVS_UNUSED)
> +{
> +    struct netdev_dpdk *dev;
> +
> +    switch ((int)type) {

Do we need this cast?

> +

Empty line not needed.

> +    case RTE_ETH_EVENT_INTR_RESET:
> +

Empty line not needed.

> +        ovs_mutex_lock(&dpdk_mutex);
> +        dev = netdev_dpdk_lookup_by_port_id(port_id);
> +        if (dev) {
> +            ovs_mutex_lock(&dev->mutex);
> +            dev->reset_needed = true;
> +            netdev_request_reconfigure(&dev->up);> +            ovs_mutex_unlock(&dev->mutex);

Maybe it'll be good to add at leas debug logs here?

> +        }
> +        ovs_mutex_unlock(&dpdk_mutex);
> +        break;
> +
> +    default:
> +        /* Ignore all other types */
> +        break;
> +   }
> +   return 0;
> +}
> +
>  static void
>  dpdk_set_rxq_config(struct netdev_dpdk *dev, const struct smap *args)
>      OVS_REQUIRES(dev->mutex)
> @@ -3777,6 +3806,8 @@ netdev_dpdk_class_init(void)
>      /* This function can be called for different classes.  The initialization
>       * needs to be done only once */
>      if (ovsthread_once_start(&once)) {
> +        int ret;
> +
>          ovs_thread_create("dpdk_watchdog", dpdk_watchdog, NULL);
>          unixctl_command_register("netdev-dpdk/set-admin-state",
>                                   "[netdev] up|down", 1, 2,
> @@ -3790,6 +3821,14 @@ netdev_dpdk_class_init(void)
>                                   "[netdev]", 0, 1,
>                                   netdev_dpdk_get_mempool_info, NULL);
>  
> +        ret = rte_eth_dev_callback_register(RTE_ETH_ALL,
> +                                            RTE_ETH_EVENT_INTR_RESET,
> +                                            dpdk_eth_event_callback, NULL);
> +
> +        if (ret != 0) {
> +            VLOG_ERR("Ethernet device callback register error %d", ret);

It's better to print rte_strerror(-ret).

> +        }
> +
>          ovsthread_once_done(&once);
>      }
>  
> @@ -4150,13 +4189,19 @@ netdev_dpdk_reconfigure(struct netdev *netdev)
>          && dev->rxq_size == dev->requested_rxq_size
>          && dev->txq_size == dev->requested_txq_size
>          && dev->socket_id == dev->requested_socket_id
> -        && dev->started) {
> +        && dev->started && !dev->reset_needed) {
>          /* Reconfiguration is unnecessary */
>  
>          goto out;
>      }
>  
> -    rte_eth_dev_stop(dev->port_id);
> +    if (dev->reset_needed) {
> +        rte_eth_dev_reset(dev->port_id);
> +        dev->reset_needed = false;
> +    } else {
> +        rte_eth_dev_stop(dev->port_id);
> +    }
> +
>      dev->started = false;
>  
>      err = netdev_dpdk_mempool_configure(dev);
> 


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