Virtualization - Aug 2021 - [PATCH v10 10/17] virtio: Handle device reset failure in register_virtio_device()

? 2021/8/4 ??5:07, Yongji Xie ??:
> On Wed, Aug 4, 2021 at 4:54 PM Jason Wang <jasowang at redhat.com>
wrote:
>>
>> ? 2021/8/4 ??4:50, Yongji Xie ??:
>>> On Wed, Aug 4, 2021 at 4:32 PM Jason Wang <jasowang at
redhat.com> wrote:
>>>> ? 2021/8/3 ??5:38, Yongji Xie ??:
>>>>> On Tue, Aug 3, 2021 at 4:09 PM Jason Wang <jasowang at
redhat.com> wrote:
>>>>>> ? 2021/7/29 ??3:34, Xie Yongji ??:
>>>>>>> The device reset may fail in virtio-vdpa case now,
so add checks to
>>>>>>> its return value and fail the
register_virtio_device().
>>>>>> So the reset() would be called by the driver during
remove as well, or
>>>>>> is it sufficient to deal only with the reset during
probe?
>>>>>>
>>>>> Actually there is no way to handle failure during removal.
And it
>>>>> should be safe with the protection of software IOTLB even
if the
>>>>> reset() fails.
>>>>>
>>>>> Thanks,
>>>>> Yongji
>>>> If this is true, does it mean we don't even need to care
about reset
>>>> failure?
>>>>
>>> But we need to handle the failure in the vhost-vdpa case, isn't
it?
>>
>> Yes, but:
>>
>> - This patch is for virtio not for vhost, if we don't care virtio,
we
>> can avoid the changes
>> - For vhost, there could be two ways probably:
>>
>> 1) let the set_status to report error
>> 2) require userspace to re-read for status
>>
>> It looks to me you want to go with 1) and I'm not sure whether or
not
>> it's too late to go with 2).
>>
> Looks like 2) can't work if reset failure happens in
> vhost_vdpa_release() and vhost_vdpa_open().

Yes, you're right.

Thanks

>
> Thanks,
> Yongji
>