Linux Virtualization - Jul 2020 - [PATCH vhost next 06/10] vdpa: Add means to communicate vq status on get_vq_state

On 2020/7/16 ??6:25, Eli Cohen wrote:
> On Thu, Jul 16, 2020 at 05:35:18PM +0800, Jason Wang wrote:
>> On 2020/7/16 ??4:21, Eli Cohen wrote:
>>> On Thu, Jul 16, 2020 at 04:11:00PM +0800, Jason Wang wrote:
>>>> On 2020/7/16 ??3:23, Eli Cohen wrote:
>>>>> Currently, get_vq_state() is used only to pass the
available index value
>>>>> of a vq. Extend the struct to return status on the VQ to
the caller.
>>>>> For now, define VQ_STATE_NOT_READY. In the future it will
be extended to
>>>>> include other infomration.
>>>>>
>>>>> Modify current vdpa driver to update this field.
>>>>>
>>>>> Reviewed-by: Parav Pandit<parav at mellanox.com>
>>>>> Signed-off-by: Eli Cohen<eli at mellanox.com>
>>>> What's the difference between this and get_vq_ready()?
>>>>
>>>> Thanks
>>>>
>>> There is no difference. It is just a way to communicate a problem
to
>>> with the state of the VQ back to the caller. This is not available
now.
>>> I think an asynchronous is preferred but that is not available
>>> currently.
>>
>> I still don't see the reason, maybe you can give me an example?
>>
>>
> My intention was to provide a mechainsm to return meaningful information
> on the state of the vq. For example, when you fail to get the state of
> the VQ.
>
> Maybe I could just change the prototype of the function to return int
> and the driver could put an error if it has trouble returning the vq
> state.

That's fine.

Thanks