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

[Ferruh Yigit]

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 at dpdk.org
>>>>>>>
>>>>>>> Signed-off-by: Matan Azrad <matan at 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.

> 
>>>
>>>>>
>>>>>
>>>>>> 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?
>>>>>
>>>
>