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Subject: Re: [PATCH v1] vdpa/mlx5: Restore the hardware used index after
 change map
To:     Jason Wang <jasowang@redhat.com>, Eli Cohen <elic@nvidia.com>
Cc:     mst@redhat.com, virtualization@lists.linux-foundation.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
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From:   Si-Wei Liu <si-wei.liu@oracle.com>
Organization: Oracle Corporation
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On 2/19/2021 6:38 PM, Jason Wang wrote:
>>>
>>>
>>> Right now the value is exposed to userspace via GET_VRING_BASE, so 
>>> only last_avail_idx is synced. If we need sync last_used_idx, we 
>>> should also sync pending indices which requires more thoughts.
>> Technically it doesn't sound right - crossing the boundary a bit even 
>> with simplified form of assumption. But depending on how userspace 
>> could make use of this API, it doesn't seem it breaks existing 
>> functionality for the moment.
>
>
> I don't get here, maybe you can explain a little bit more? 
Please refer to the email I just sent.

https://lore.kernel.org/lkml/033b0806-4037-5755-a1fa-91dbb58bab2e@oracle.com/

-Siwei