[dpdk-dev] [PATCH v6 4/9] ethdev: support sub function representor

[Xueming(Steven) Li]

>-----Original Message-----
>From: Andrew Rybchenko <andrew.rybchenko at oktetlabs.ru>
>Sent: Monday, February 15, 2021 4:26 PM
>To: Xueming(Steven) Li <xuemingl at nvidia.com>
>Cc: dev at dpdk.org; Slava Ovsiienko <viacheslavo at nvidia.com>; Asaf Penso <asafp at nvidia.com>; NBU-Contact-Thomas Monjalon
><thomas at monjalon.net>; Ferruh Yigit <ferruh.yigit at intel.com>
>Subject: Re: [PATCH v6 4/9] ethdev: support sub function representor
>
>Hi,
>
>On 2/14/21 6:21 AM, Xueming Li wrote:
>> SubFunction is a portion of the PCI device, created on demand, a SF
>> netdev has its own dedicated queues(txq, rxq). A SF netdev supports
>> eswitch representation offload similar to existing PF and VF
>> representors.
>>
>> To support SF representor, this patch introduces new devargs syntax,
>> examples:
>>  representor=sf0               - single SubFunction representor
>>  representor=sf[1,3,5]         - single list
>>  representor=sf[0-3],          - single range
>>  representor=sf[0,2-6,8,10-12] - list with singles and ranges
>>
>> Signed-off-by: Xueming Li <xuemingl at nvidia.com>
>> Acked-by: Viacheslav Ovsiienko <viacheslavo at nvidia.com>
>> Acked-by: Thomas Monjalon <thomas at monjalon.net>
>> Acked-by: Andrew Rybchenko <andrew.rybchenko at oktetlabs.ru>
>
>What happens if I try to mix different types of representors:
>A: -a DBDF,representor=sf0,representor=vf1

Currently, the next representor will overwrite type of first, but append to representor ports.

>B: -a DBDF,representor=sf0 -a DBDF,representor=vf1 (DBDF is the same in args B in both cases).

This is a behavior of EAL, if DBDF are same, only the first get probed, even if the second is "sf1"

>
>I'm not trying to say that it must work, since most likely hotplug will be used to add representors. But behaviour must be consistent
>(error?).

Good catch, agree with error, will add check.

>
>The question is raised here, since it is the first patch where the second type of representor appears.
>
>Andrew.