Re: [dpdk-dev] [dpdk-stable] [PATCH v3 1/7] ethdev: fix port data reset timing

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

On 3/30/2018 11:39 AM, Ferruh Yigit wrote:
> On 3/28/2018 1:07 PM, Matan Azrad wrote:
>> Hi Ferruh
>>
>>> From: Ferruh Yigit, Wednesday, March 28, 2018 1:38 AM
>>> On 3/5/2018 3:12 PM, Matan Azrad wrote:
>>>> Hi Ferruh
>>>>
>>>> From: Ferruh Yigit, Sent: Monday, March 5, 2018 5:07 PM
>>>>> On 3/5/2018 2:52 PM, Matan Azrad wrote:
>>>>>> HI
>>>>>>
>>>>>> From: Ferruh Yigit, Sent: Monday, March 5, 2018 1:24 PM
>>>>>>> On 1/18/2018 4:35 PM, Matan Azrad wrote:
>>>>>>>> rte_eth_dev_data structure is allocated per ethdev port and can be
>>>>>>>> used to get a data of the port internally.
>>>>>>>>
>>>>>>>> rte_eth_dev_attach_secondary tries to find the port identifier
>>>>>>>> using rte_eth_dev_data name field comparison and may get an
>>>>>>>> identifier of invalid port in case of this port was released by
>>>>>>>> the primary process because the port release API doesn't reset the
>>> port data.
>>>>>>>>
>>>>>>>> So, it will be better to reset the port data in release time
>>>>>>>> instead of allocation time.
>>>>>>>>
>>>>>>>> Move the port data reset to the port release API.
>>>>>>>>
>>>>>>>> Fixes: d948f596fee2 ("ethdev: fix port data mismatched in multiple
>>>>>>>> process model")
>>>>>>>> Cc: stable@dpdk.org
>>>>>>>>
>>>>>>>> Signed-off-by: Matan Azrad <matan@mellanox.com>
>>>>>>>> ---
>>>>>>>>  lib/librte_ether/rte_ethdev.c | 2 +-
>>>>>>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>>>>>>
>>>>>>>> diff --git a/lib/librte_ether/rte_ethdev.c
>>>>>>>> b/lib/librte_ether/rte_ethdev.c index 7044159..156231c 100644
>>>>>>>> --- a/lib/librte_ether/rte_ethdev.c
>>>>>>>> +++ b/lib/librte_ether/rte_ethdev.c
>>>>>>>> @@ -204,7 +204,6 @@ struct rte_eth_dev *
>>>>>>>>  		return NULL;
>>>>>>>>  	}
>>>>>>>>
>>>>>>>> -	memset(&rte_eth_dev_data[port_id], 0, sizeof(struct
>>>>>>> rte_eth_dev_data));
>>>>>>>>  	eth_dev = eth_dev_get(port_id);
>>>>>>>>  	snprintf(eth_dev->data->name, sizeof(eth_dev->data->name),
>>>>>>> "%s", name);
>>>>>>>>  	eth_dev->data->port_id = port_id; @@ -252,6 +251,7 @@ struct
>>>>>>>> rte_eth_dev *
>>>>>>>>  	if (eth_dev == NULL)
>>>>>>>>  		return -EINVAL;
>>>>>>>>
>>>>>>>> +	memset(eth_dev->data, 0, sizeof(struct
>>> rte_eth_dev_data));
>>>>>>>
>>>>>>> Hi Matan,
>>>>>>>
>>>>>>> What most of the vdev release path does is:
>>>>>>>
>>>>>>> eth_dev = rte_eth_dev_allocated(...)
>>>>>>> rte_free(eth_dev->data->dev_private);
>>>>>>> rte_free(eth_dev->data);
>>>>>>> rte_eth_dev_release_port(eth_dev);
>>>>>>>
>>>>>>> Since eth_dev->data freed, memset() it in
>>>>>>> rte_eth_dev_release_port() will be problem.
>>>>>>>
>>>>>>> We don't run remove path that is why we didn't hit the issue but
>>>>>>> this seems problem for all virtual PMDs.
>>>>>>
>>>>>> Yes, it is a problem and should be fixed:
>>>>>> For vdevs which use private rte_eth_dev_data the remove order can
>>> be:
>>>>>> 	private_data = eth_dev->data;
>>>>>> 	rte_free(eth_dev->data->dev_private);
>>>>>> 	rte_eth_dev_release_port(eth_dev); /* The last operation working
>>>>> on ethdev structure. */
>>>>>> 	rte_free(private_data);
>>>>>
>>>>> Do we need to save "private_data"?
>>>>
>>>> Just to emphasis that eth_dev structure should not more be available after
>>> rte_eth_dev_release_port().
>>>> Maybe in the future rte_eth_dev_release_port() will zero eth_dev
>>>> structure too :)
>>>
>>> Hi Matan,
>>>
>>> Reminder of this issue, it would be nice to fix in this release.
>>>
>>
>> Regarding the private rte_eth_dev_data, it should be fixed in the next thread:
>> https://dpdk.org/dev/patchwork/patch/35632/
>>
>> Regarding the rte_eth_dev_pci_release() function: I'm going to send a fix.
> 
> Thanks Matan for the patch,
> 
> But rte_eth_dev_release_port() is still broken because of this change, please
> check _rte_eth_dev_callback_process() which uses dev->data->port_id.

Hi Matan,

Any update on this?
As mentioned above rte_eth_dev_release_port() is still broken.

Thanks,
ferruh

> 
>>
>>>>
>>>>>>
>>>>>>
>>>>>>> Also rte_eth_dev_pci_release() looks problematic now.
>>>>>>
>>>>>> Yes, again, the last operation working on ethdev structure should be
>>>>> rte_eth_dev_release_port().
>>>>>>
>>>>>> So need to fix all vdevs and the rte_eth_dev_pci_release() function.
>>>>>>
>>>>>> Any comments?
>>>>>>
>>>>
>>
>