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

[Jason Wang]

在 2021/8/4 下午4:50, Yongji Xie 写道:
> On Wed, Aug 4, 2021 at 4:32 PM Jason Wang <jasowang@xxxxxxxxxx> 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@xxxxxxxxxx> 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).

Thanks


> Thanks,
> Yongji