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

[Jason Wang]

在 2021/8/4 下午5:07, Yongji Xie 写道:
> On Wed, Aug 4, 2021 at 4:54 PM Jason Wang <jasowang@xxxxxxxxxx> 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@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).
> 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