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From:   Eugenio Perez Martin <eperezma@redhat.com>
Date:   Fri, 8 Jul 2022 13:30:19 +0200
Message-ID: <CAJaqyWcsesMV5DSs7sCrsJmZX=QED7p7UXa_7H=1UHfQTnKS6w@mail.gmail.com>
Subject: Re: [PATCH v6 1/4] vdpa: Add suspend operation
To:     Jason Wang <jasowang@redhat.com>
Cc:     netdev <netdev@vger.kernel.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        virtualization <virtualization@lists.linux-foundation.org>,
        kvm <kvm@vger.kernel.org>, "Michael S. Tsirkin" <mst@redhat.com>,
        Parav Pandit <parav@nvidia.com>,
        Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
        Cindy Lu <lulu@redhat.com>,
        "Kamde, Tanuj" <tanuj.kamde@amd.com>,
        Si-Wei Liu <si-wei.liu@oracle.com>,
        "Uminski, Piotr" <Piotr.Uminski@intel.com>,
        habetsm.xilinx@gmail.com, "Dawar, Gautam" <gautam.dawar@amd.com>,
        Pablo Cascon Katchadourian <pabloc@xilinx.com>,
        Zhu Lingshan <lingshan.zhu@intel.com>,
        Laurent Vivier <lvivier@redhat.com>,
        Longpeng <longpeng2@huawei.com>,
        Dinan Gunawardena <dinang@xilinx.com>,
        Martin Petrus Hubertus Habets <martinh@xilinx.com>,
        Martin Porter <martinpo@xilinx.com>,
        Eli Cohen <elic@nvidia.com>, ecree.xilinx@gmail.com,
        Wu Zongyong <wuzongyong@linux.alibaba.com>,
        Stefano Garzarella <sgarzare@redhat.com>,
        Dan Carpenter <dan.carpenter@oracle.com>,
        Harpreet Singh Anand <hanand@xilinx.com>,
        Xie Yongji <xieyongji@bytedance.com>,
        Zhang Min <zhang.min9@zte.com.cn>
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On Wed, Jun 29, 2022 at 6:10 AM Jason Wang <jasowang@redhat.com> wrote:
>
> On Fri, Jun 24, 2022 at 12:07 AM Eugenio P=C3=A9rez <eperezma@redhat.com>=
 wrote:
> >
> > This operation is optional: It it's not implemented, backend feature bi=
t
> > will not be exposed.
>
> A question, do we allow suspending a device without DRIVER_OK?
>

That should be invalid. In particular, vdpa_sim will resume in that
case, but I guess it would depend on the device.

Do you think it should be controlled in the vdpa frontend code?

Thanks!

> Thanks
>
> >
> > Signed-off-by: Eugenio P=C3=A9rez <eperezma@redhat.com>
> > ---
> >  include/linux/vdpa.h | 4 ++++
> >  1 file changed, 4 insertions(+)
> >
> > diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
> > index 7b4a13d3bd91..d282f464d2f1 100644
> > --- a/include/linux/vdpa.h
> > +++ b/include/linux/vdpa.h
> > @@ -218,6 +218,9 @@ struct vdpa_map_file {
> >   * @reset:                     Reset device
> >   *                             @vdev: vdpa device
> >   *                             Returns integer: success (0) or error (=
< 0)
> > + * @suspend:                   Suspend or resume the device (optional)
> > + *                             @vdev: vdpa device
> > + *                             Returns integer: success (0) or error (=
< 0)
> >   * @get_config_size:           Get the size of the configuration space=
 includes
> >   *                             fields that are conditional on feature =
bits.
> >   *                             @vdev: vdpa device
> > @@ -319,6 +322,7 @@ struct vdpa_config_ops {
> >         u8 (*get_status)(struct vdpa_device *vdev);
> >         void (*set_status)(struct vdpa_device *vdev, u8 status);
> >         int (*reset)(struct vdpa_device *vdev);
> > +       int (*suspend)(struct vdpa_device *vdev);
> >         size_t (*get_config_size)(struct vdpa_device *vdev);
> >         void (*get_config)(struct vdpa_device *vdev, unsigned int offse=
t,
> >                            void *buf, unsigned int len);
> > --
> > 2.31.1
> >
>