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Subject: Re: VDPA Debug/Statistics
To:     Eli Cohen <elic@nvidia.com>, "Michael S. Tsirkin" <mst@redhat.com>
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        Majd Dibbiny <majd@nvidia.com>,
        Maor Dickman <maord@nvidia.com>,
        Shahaf Shuler <shahafs@mellanox.com>,
        Parav Pandit <parav@mellanox.com>
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From:   Jason Wang <jasowang@redhat.com>
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Date:   Wed, 12 Aug 2020 10:09:22 +0800
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On 2020/8/11 下午7:58, Eli Cohen wrote:
> On Tue, Aug 11, 2020 at 11:26:20AM +0000, Eli Cohen wrote:
>> Hi All
>>
>> Currently, the only statistics we get for a VDPA instance comes from the virtio_net device instance. Since VDPA involves hardware acceleration, there can be quite a lot of information that can be fetched from the underlying device. Currently there is no generic method to fetch this information.
>>
>> One way of doing this can be to create a the host, a net device for
>> each VDPA instance, and use it to get this information or do some
>> configuration. Ethtool can be used in such a case


The problems are:

- vDPA is not net specific
- vDPA should be transparent to host networking stack


>>
>> I would like to hear what you think about this or maybe you have some other ideas to address this topic.
>>
>> Thanks,
>> Eli
> Something I'm not sure I understand is how are vdpa instances created on mellanox cards? There's a devlink command for that, is that right?
> Can that be extended for stats?
>
> Currently any VF will be probed as VDPA device. We're adding devlink support but I am not sure if devlink is suitable for displaying statistics. We will discuss internally but I wanted to know why you guys think.


I agree with Michael, if it's possible, integrating stats with devlink 
should be the best. Having another interface with is just for stats 
looks not good.

Thanks


>
> --
> MST
>