Re: [dpdk-dev] [PATCH 1/3] app/testpmd: add port reset command into testpmd

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 3/3/2017 4:56 AM, Wei Zhao wrote:
> Add vf port reset command into testpmd project, it is the interface for
> user to reset vf port.

I think it is better to change the order of this patch, first implement
new API in ethdev, later this patch implement new API in testpmd.

> 
> Signed-off-by: Wei Zhao <wei.zhao1@intel.com>
> Signed-off-by: Wenzhuo Lu <wenzhuo.lu@intel.com>
> ---
>  app/test-pmd/cmdline.c | 17 ++++++++++---
>  app/test-pmd/testpmd.c | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  app/test-pmd/testpmd.h |  1 +
>  3 files changed, 81 insertions(+), 4 deletions(-)
> 
> diff --git a/app/test-pmd/cmdline.c b/app/test-pmd/cmdline.c
> index 43fc636..59db672 100644
> --- a/app/test-pmd/cmdline.c
> +++ b/app/test-pmd/cmdline.c
> @@ -596,6 +596,9 @@ static void cmd_help_long_parsed(void *parsed_result,
>  			"port close (port_id|all)\n"
>  			"    Close all ports or port_id.\n\n"
>  
> +			"port reset (port_id|all)\n"
> +			"    Reset all ports or port_id.\n\n"

It is not clear what reset does to the port. This is only for VF right?
Adding reset here hides that it is for VF.

<...>

> @@ -601,6 +602,7 @@ init_config(void)
>  	if (init_fwd_streams() < 0)
>  		rte_exit(EXIT_FAILURE, "FAIL from init_fwd_streams()\n");
>  
> +

This may be unintentional.

<...>

> @@ -1350,6 +1363,10 @@ start_port(portid_t pid)
>  				return -1;
>  			}
>  		}
> +
> +		/* register reset interrupt callback */
> +		rte_eth_dev_callback_register(pi, RTE_ETH_EVENT_INTR_RESET,
> +			reset_event_callback, NULL);

So each port started will register a callback to handle reset events,

1- isn't this overkill for the usecases that does not need this reset?
2- should there be an unregister event?
3- This issue can be fixed in testpmd, but for user application, is this
the suggested way?

>  		if (port->need_reconfig_queues > 0) {
>  			port->need_reconfig_queues = 0;
>  			/* setup tx queues */
> @@ -1559,6 +1576,56 @@ close_port(portid_t pid)
>  }
>  
>  void
> +reset_port(portid_t pid)
> +{
> +	portid_t pi;
> +	struct rte_port *port;
> +
> +	if (port_id_is_invalid(pid, ENABLED_WARN))
> +		return;
> +
> +	printf("Closing ports...\n");
> +
> +	FOREACH_PORT(pi, ports) {

Since we already know the port_id (pid), why iterating through all ports?

> +		if (pid != pi && pid != (portid_t)RTE_PORT_ALL)
> +			continue;
> +
> +		if (port_is_forwarding(pi) != 0 && test_done == 0) {
> +			printf("Please remove port %d from forwarding "
> +					"configuration.\n", pi);
> +			continue;
> +		}
> +
> +		if (port_is_bonding_slave(pi)) {
> +			printf("Please remove port %d from "
> +					"bonded device.\n", pi);
> +			continue;
> +		}
> +
> +		if (!reset_ports[pi]) {
> +			printf("vf must get reset port %d info from "
> +					"pf before reset.\n", pi);
> +			continue;
> +		}

Can there be a timing issue here? Is it possible that reset occurred
already and we are in the middle of the callback function when this
check done?

<...>