Re: [dpdk-dev] [PATCH] cryptodev: fix invalid dev_id after a pmd close

["Meunier, Julien (Nokia - FR/Paris-Saclay)" <julien.meunier@nokia.com>]

Hi

On 15/10/2019 15:44, Akhil Goyal wrote:
> 
>>
>> Hi Julien
>>
>>>
>>> Each cryptodev are indexed with its dev_id in the global
>>> rte_crypto_devices variable. nb_devs is incremented / decremented each
>>> time a cryptodev is created / deleted. The goal of nb_devs is to prevent
>>> the user to get an invalid dev_id.
>>>
>>> Let's imagine DPDK has configured N cryptodevs. If the cryptodev=1 is
>>> removed at runtime, the latest cryptodev N cannot be accessible, because
>>> nb_devs=N-1.
>>>
>>> In order to prevent this kind of behavior, let's remove the check with
>>> nb_devs and iterate in all the rte_crypto_devices elements: if data is
>>> not NULL, that means a valid cryptodev is available.
>>>
>>> Fixes: d11b0f30df88 ("cryptodev: introduce API and framework for crypto
>>> devices")
>>> Cc: stable@dpdk.org
>>>
>>> Signed-off-by: Julien Meunier <julien.meunier@nokia.com>
>>> ---
> // snip//
> 
>>> @@ -560,7 +570,13 @@ rte_cryptodev_get_dev_id(const char *name)
>>>   uint8_t
>>>   rte_cryptodev_count(void)
>>>   {
>>> -	return cryptodev_globals.nb_devs;
>>> +	uint8_t i, dev_count = 0;
>>> +
>>> +	for (i = 0; i < RTE_CRYPTO_MAX_DEVS; i++)
>>> +		if (cryptodev_globals.devs[i].data != NULL)
>>> +			dev_count++;
>>> +
>>> +	return dev_count;
>>>   }
>>
>> Why do you want to remove the nb_devs? We can have it updated
>> (incremented/decremented)
>> While allocate/release of the device.
>> The point is, whenever somebody call rte_cryptodev_count() it will do a lookup
>> of valid data
>> pointer.
> 
> Could you please do the requested change. This patch need to be integrated by this week.
> 
> Thanks.
> 
Sorry, I was busy on other tasks. I will propose a new patch today by 
keeping the nb_devs field.

Regards.

-- 
Julien Meunier