Re: [PATCH v10 10/17] virtio: Handle device reset failure in register_virtio_device()

[Jason Wang <jasowang@redhat.com>]

在 2021/8/4 下午5:07, Yongji Xie 写道:
> On Wed, Aug 4, 2021 at 4:54 PM Jason Wang <jasowang@redhat.com> wrote:
>>
>> 在 2021/8/4 下午4:50, Yongji Xie 写道:
>>> On Wed, Aug 4, 2021 at 4:32 PM Jason Wang <jasowang@redhat.com> wrote:
>>>> 在 2021/8/3 下午5:38, Yongji Xie 写道:
>>>>> On Tue, Aug 3, 2021 at 4:09 PM Jason Wang <jasowang@redhat.com> wrote:
>>>>>> 在 2021/7/29 下午3:34, Xie Yongji 写道:
>>>>>>> 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
>