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To: David Marchand <david.marchand@redhat.com>,
 Dodji Seketeli <dodji@redhat.com>
Cc: Huisong Li <lihuisong@huawei.com>, dev <dev@dpdk.org>,
 Thomas Monjalon <thomas@monjalon.net>, "Yigit, Ferruh"
 <ferruh.yigit@intel.com>, "Ananyev, Konstantin"
 <konstantin.ananyev@intel.com>, Ray Kinsella <mdr@ashroe.eu>
References: <1620460836-38506-1-git-send-email-lihuisong@huawei.com>
 <1625544608-30590-1-git-send-email-lihuisong@huawei.com>
 <966ec9cd-9142-b40d-b059-b63c8ece66bf@oktetlabs.ru>
 <CAJFAV8xVC=WcjFtj-h9kVWM4zU4fmXjeqRm-76oodh9cBiXt1A@mail.gmail.com>
From: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
Organization: OKTET Labs
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Subject: Re: [dpdk-dev] [PATCH V2] ethdev: add dev configured flag
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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.