Re: [dpdk-dev] [PATCH V2] ethdev: add dev configured flag

[Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>]

On 7/7/21 10:39 AM, David Marchand wrote:
> On Tue, Jul 6, 2021 at 10:36 AM Andrew Rybchenko
> <andrew.rybchenko@oktetlabs.ru> wrote:
>>
>> @David, could you take a look at the ABI breakage warnings for
>> the patch. May we ignore it since ABI looks backward
>> compatible? Or should be marked as a minor change ABI
>> which is backward compatible with DPDK_21?
> 
> The whole eth_dev_shared_data area has always been reset to 0 at the
> first port allocation in a dpdk application life.
> Subsequent calls to rte_eth_dev_release_port() reset every port
> eth_dev->data to 0.
> 
> This bit flag is added in a hole of the structure, and it is
> set/manipulated internally of ethdev.
> 
> So unless the application was doing something nasty like highjacking
> this empty hole in the structure, I see no problem with the change wrt
> ABI.
> 
> 
> I wonder if libabigail is too strict on this report.
> Or maybe there is some extreme consideration on what a compiler could
> do about this hole...

I was wondering if it could be any specifics related to big-
little endian vs bit fields placement, but throw the idea
away...

> Dodji?
> 
> 
> For now, we can waive the warning.
> I'll look into the exception rule to add.

Thanks a lot. I'll hold on the patch for now.