From: "Burakov, Anatoly" <anatoly.burakov@intel.com>
To: Thomas Monjalon <thomas@monjalon.net>,
"Xia, Chenbo" <chenbo.xia@intel.com>,
David Marchand <david.marchand@redhat.com>,
"Ferruh Yigit" <ferruh.yigit@intel.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH v1 1/2] vfio: make API return values consistent
Date: Thu, 28 Oct 2021 16:40:28 +0100 [thread overview]
Message-ID: <3db19e94-dd25-e9ca-80ee-e4fea233f1cd@intel.com> (raw)
In-Reply-To: <9347411.UhhQB40C69@thomas>
On 28-Oct-21 3:53 PM, Thomas Monjalon wrote:
> 28/10/2021 13:32, Ferruh Yigit:
>> On 10/28/2021 12:11 PM, Xia, Chenbo wrote:
>>>> -----Original Message-----
>>>> From: Burakov, Anatoly <anatoly.burakov@intel.com>
>>>> Sent: Thursday, October 28, 2021 6:30 PM
>>>> To: Xia, Chenbo <chenbo.xia@intel.com>; dev@dpdk.org
>>>> Subject: Re: [dpdk-dev] [PATCH v1 1/2] vfio: make API return values consistent
>>>>
>>>> Hi Chenbo,
>>>>
>>>>> And do we need backport? As 'return -1' does not align with the API doxygen.
>>>>>
>>>>> Thanks,
>>>>> Chenbo
>>>>>
>>>> Maybe it's the FreeBSD implementation that needs to be adjusted then,
>>>> because none of those functions are valid on FreeBSD, and the
>>>> documentation for VFIO functions explicitly mentions that on FreeBSD,
>>>> they should return an error. I went with adjusting Linux implementation
>>>> to minimize the amount of changes we have to make (and only change code
>>>> path that no one uses in the first place), but maybe that was a wrong
>>>> decision.
>>>>
>>>> I'm not sure if changing the API return value to match what was
>>>> documented counts as an API change, so maybe backport to stable is not
>>>> advised here.
>>>
>>> It's not a API change. My point is whether VFIO is present, users just use
>>> the API to check if vfio support is there. In a kernel version that does not
>>> support VFIO, he uses 'if(rte_vfio_is_enabled(XXX))' to check as the doxygen
>>> says its return value should be 1 as true or 0 as false. He will get true (-1)
>>> but VFIO is not there. That's why I think it's a bug and should be backported.
>>>
>>> But I think we can first discuss if we should drop the dummy implementation
>>> as DPDK requires Linux kernel version >= 4.4 now so VFIO is always present.
>>> I think it depends on by saying 'DPDK requires kernel version >= 4.4'. It's
>>> a real _requirement_ or only a recommendation?
>>>
>>> Ferruh, David & Thomas, What do you think?
>>>
>>
>> My understanding is, it is a requirement. DPDK does not guarantee support for
>> kernels < 4.4.
>
> Do we have a kernel version check at runtime?
> I think we should add a warning if running too old kernel.
>
Perhaps we should (there's a `uname()` call, should be fairly
straightforward to implement), but obviously this would be outside the
scope for this patchset.
--
Thanks,
Anatoly
next prev parent reply other threads:[~2021-10-28 15:40 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-16 10:36 Anatoly Burakov
2021-09-16 10:36 ` [dpdk-dev] [PATCH v1 2/2] vfio: add errno on unsupported platforms Anatoly Burakov
2021-09-16 10:39 ` Bruce Richardson
2021-09-22 3:31 ` Xia, Chenbo
2021-09-22 3:30 ` [dpdk-dev] [PATCH v1 1/2] vfio: make API return values consistent Xia, Chenbo
2021-09-22 9:26 ` Ferruh Yigit
2021-09-22 11:30 ` Xia, Chenbo
2021-10-28 8:21 ` David Marchand
2021-10-28 10:29 ` Burakov, Anatoly
2021-10-28 11:11 ` Xia, Chenbo
2021-10-28 11:32 ` Ferruh Yigit
2021-10-28 13:00 ` Burakov, Anatoly
2021-10-28 14:53 ` Thomas Monjalon
2021-10-28 15:40 ` Burakov, Anatoly [this message]
2021-10-28 16:38 ` Stephen Hemminger
2021-10-28 13:49 ` [dpdk-dev] [PATCH v2 1/4] vfio: drop fallback Linux implementation Anatoly Burakov
2021-10-28 13:49 ` [dpdk-dev] [PATCH v2 2/4] vfio: fix wrong return value for FreeBSD Anatoly Burakov
2021-10-28 13:49 ` [dpdk-dev] [PATCH v2 3/4] vfio: fix documentation to match intended behavior Anatoly Burakov
2021-10-28 13:49 ` [dpdk-dev] [PATCH v2 4/4] vfio: add errno on unsupported platforms Anatoly Burakov
2021-10-28 14:13 ` Burakov, Anatoly
2021-10-28 14:15 ` [dpdk-dev] [PATCH v3 1/4] vfio: drop fallback Linux implementation Anatoly Burakov
2021-10-28 14:15 ` [dpdk-dev] [PATCH v3 2/4] vfio: fix wrong return value for FreeBSD Anatoly Burakov
2021-11-05 2:50 ` Xia, Chenbo
2021-10-28 14:15 ` [dpdk-dev] [PATCH v3 3/4] vfio: fix documentation to match intended behavior Anatoly Burakov
2021-11-05 2:57 ` [dpdk-dev] [dpdk-stable] " Xia, Chenbo
2021-10-28 14:15 ` [dpdk-dev] [PATCH v3 4/4] vfio: add errno on unsupported platforms Anatoly Burakov
2021-11-08 15:55 ` [dpdk-dev] [dpdk-stable] " David Marchand
2021-11-01 6:27 ` [dpdk-dev] [PATCH v3 1/4] vfio: drop fallback Linux implementation Xia, Chenbo
2021-11-01 13:57 ` Burakov, Anatoly
2021-11-05 2:48 ` Xia, Chenbo
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