Re: [PATCH v10 04/17] vdpa: Fail the vdpa_reset() if fail to set device status to zero

[Yongji Xie]

On Tue, Aug 3, 2021 at 3:58 PM Jason Wang <jasowang@xxxxxxxxxx> wrote:
>
>
> 在 2021/7/29 下午3:34, Xie Yongji 写道:
> > Re-read the device status to ensure it's set to zero during
> > resetting. Otherwise, fail the vdpa_reset() after timeout.
> >
> > Signed-off-by: Xie Yongji <xieyongji@xxxxxxxxxxxxx>
> > ---
> >   include/linux/vdpa.h | 15 ++++++++++++++-
> >   1 file changed, 14 insertions(+), 1 deletion(-)
> >
> > diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
> > index 406d53a606ac..d1a80ef05089 100644
> > --- a/include/linux/vdpa.h
> > +++ b/include/linux/vdpa.h
> > @@ -6,6 +6,7 @@
> >   #include <linux/device.h>
> >   #include <linux/interrupt.h>
> >   #include <linux/vhost_iotlb.h>
> > +#include <linux/delay.h>
> >
> >   /**
> >    * struct vdpa_calllback - vDPA callback definition.
> > @@ -340,12 +341,24 @@ static inline struct device *vdpa_get_dma_dev(struct vdpa_device *vdev)
> >       return vdev->dma_dev;
> >   }
> >
> > -static inline void vdpa_reset(struct vdpa_device *vdev)
> > +#define VDPA_RESET_TIMEOUT_MS 1000
> > +
> > +static inline int vdpa_reset(struct vdpa_device *vdev)
> >   {
> >       const struct vdpa_config_ops *ops = vdev->config;
> > +     int timeout = 0;
> >
> >       vdev->features_valid = false;
> >       ops->set_status(vdev, 0);
> > +     while (ops->get_status(vdev)) {
> > +             timeout += 20;
> > +             if (timeout > VDPA_RESET_TIMEOUT_MS)
> > +                     return -EIO;
> > +
> > +             msleep(20);
> > +     }
>
>
> I wonder if it's better to do this in the vDPA parent?
>
> Thanks
>

Sorry, I didn't get you here. Do you mean vDPA parent driver (e.g.
VDUSE)? Actually I didn't find any other place where I can do
set_status() and get_status().

Thanks,
Yongji