Re: [PATCH v8 09/10] vduse: Introduce VDUSE - vDPA Device in Userspace

[Jason Wang <jasowang@xxxxxxxxxx>]

在 2021/6/24 下午12:46, Yongji Xie 写道:
> > So we need to deal with both FEATURES_OK and reset, but probably not
> > DRIVER_OK.
> OK, I see. Thanks for the explanation. One more question is how about
> clearing the corresponding status bit in get_status() rather than
> making set_status() fail. Since the spec recommends this way for
> validation which is done in virtio_dev_remove() and
> virtio_finalize_features().
>
> Thanks,
> Yongji

I think you can. Or it would be even better that we just don't set the 
bit during set_status().

I just realize that in vdpa_reset() we had:

static inline void vdpa_reset(struct vdpa_device *vdev)
{
        const struct vdpa_config_ops *ops = vdev->config;

        vdev->features_valid = false;
        ops->set_status(vdev, 0);
}

We probably need to add the synchronization here. E.g re-read with a 
timeout.

Thanks