On 1/18/2022 11:21 AM, kumaraparameshwaran rathinavel wrote:
Comment moved down.
Please don't top post, it makes very hard to follow the discussion and bad
for archives to visit discussion later.
On Tue, Jan 18, 2022 at 3:17 PM Ferruh Yigit <[email protected]
<mailto:[email protected]>> wrote:
On 1/17/2022 6:33 PM, Thomas Monjalon wrote:
> 17/01/2022 19:28, Ferruh Yigit:
>>> + ret = rte_eth_dev_get_port_by_name(request_param->port_name,
&port_id);
>>> + if (ret) {
>>> + TAP_LOG(ERR, "Failed to get port id for %s",
>>> + request_param->port_name);
>>> + return -1;
>>> + }
>>> + dev = &rte_eth_devices[port_id];
>>
>> Since this is not really related with your patch, I want to have a
separate thread for it.
>>
>> It is not good to access the 'rte_eth_devices' global variable directly
from a driver, that
>> is error prone.
>>
>> Btw, what 'peer' supposed to contain?
>>
>> It can be solved by adding an internal API, only for drivers to get
eth_dev from the name,
>> like: 'rte_eth_dev_get_by_name()'.
>> This way a few other usage can be converted to this API.
>>
>> @Thomas and @Andrew what do you think about the new API proposal?
>
> It looks similar to rte_eth_dev_get_port_by_name() which returns a
port_id.
Exactly, but get eth_dev directly for drivers. For drivers no need to work
with port_id
handler, they can use eth_dev directly.
Another solution can be an getter function for drivers, which gets port_id
and returns
the eth_dev.
> It is a bit strange for an ethdev driver to not have access to its own
ethdev struct.
> Isn't there something broken in the logic?
>
This is callback function between primary and secondary applications sync.
So port name
will be same for both, but eth_dev will be different and port_id may be
different.
Driver finds its own eth_dev from the shared port name.
Just wanted to bring it to your attention,
In Mellanox driver there is a requirement to exchange fds between primary and
secondary and similar usage is seen, the primary sends the port_id and the
secondary refers to the rte_eth_devices in the driver,
The functions are
- mlx5_mp_secondary_handle in secondary
- mlx5_mp_req_start_rxtx in primary which is invoked from
mlx5_dev_start.
In my implementation I have used the name and invoked get_port_by_name, I can
also pass the port_id from the primary to make it uniform. So with similar
usage in Mellanox is there a problem there as well on referring to the
rte_eth_devices from the PMD ?
It would be same, still will be accessing to the 'rte_eth_devices'.
That is why a new API for drivers may help.
