Re: [dpdk-dev] [PATCH] app/testpmd: fix hotplug

[Matan Azrad <matan@mellanox.com>]

Hi

From: Ferruh Yigit
> The 'port_id_is_invalid()' check in the 'detach_port_device()' is breaking the
> hotplug support, since at that stage port will be closed and validity check
> always fail [1] and removing the device is not really completed.
> 
> But this cause the vfio request interrupt keep triggered continuously and
> makes the application unusable, since port is closed but device is not
> removed, the remove path keep generating error log:
> 
> EAL: can not get port by device 0000:00:05.0!
> EAL: can not get port by device 0000:00:05.0!
> EAL: can not get port by device 0000:00:05.0!
> EAL: can not get port by device 0000:00:05.0!
> EAL: can not get port by device 0000:00:05.0!
> EAL: can not get port by device 0000:00:05.0!
> 
> Fixed by removing 'port_id_is_invalid()' check from 'detach_port_device()',
> anyway it shouldn't be required. Without this check device remove works as
> expected.
> 
> Only "Invalid port_id=0" logs seen a few times, which is because the actual
> removal not done synchronously but an alarm set for it, until the alarm fired
> application may receive many interrupts, expect the first ones cause the
> error.
> So this patch also removes the logging from checking the invalid port in
> 'rmv_port_callback()' to reduce the noise.
> 
> [1]
> rmv_port_callback()
>   stop_port(port_id);
>   close_port(port_id);
>   detach_port_device(port_id);
> 
> Fixes: 43d0e304980a ("app/testpmd: fix invalid port detaching")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
> ---
>  app/test-pmd/testpmd.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c index
> f9f4cd1d3..3323013bb 100644
> --- a/app/test-pmd/testpmd.c
> +++ b/app/test-pmd/testpmd.c
> @@ -2641,9 +2641,6 @@ detach_port_device(portid_t port_id)
> 
>  	printf("Removing a device...\n");
> 
> -	if (port_id_is_invalid(port_id, ENABLED_WARN))
> -		return;
> -

I don't think this is the correct fix.

See the line below - you use the port structure, it makes sense to check its validity before.

>  	dev = rte_eth_devices[port_id].device;
>  	if (dev == NULL) {
>  		printf("Device already removed\n");
> @@ -2875,7 +2872,8 @@ rmv_port_callback(void *arg)
>  	int org_no_link_check = no_link_check;
>  	portid_t port_id = (intptr_t)arg;
> 
> -	RTE_ETH_VALID_PORTID_OR_RET(port_id);
> +	if (!rte_eth_dev_is_valid_port(port_id))
> +		return;
> 
>  	if (!test_done && port_is_forwarding(port_id)) {
>  		need_to_start = 1;

IMO the correct fix is to change this function to get pointer to rte_device instead of port ID and change the Testpmd command line to get the device instead of port ID.

Matan