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From:   Jason Wang <jasowang@redhat.com>
Date:   Tue, 12 Jul 2022 16:04:23 +0800
Message-ID: <CACGkMEsr=2LjU1-UDV1SF9vJPty2003YKORHZMSr1W-p9eNr+A@mail.gmail.com>
Subject: Re: [PATCH v6 1/4] vdpa: Add suspend operation
To:     Eugenio Perez Martin <eperezma@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 Fri, Jul 8, 2022 at 7:31 PM Eugenio Perez Martin <eperezma@redhat.com> w=
rote:
>
> 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.co=
m> wrote:
> > >
> > > This operation is optional: It it's not implemented, backend feature =
bit
> > > 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.

Yes, and that will match our virtio spec patch (STOP bit).

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

The vdpa bus should validate this at least.

Thanks

>
> 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 (optiona=
l)
> > > + *                             @vdev: vdpa device
> > > + *                             Returns integer: success (0) or error=
 (< 0)
> > >   * @get_config_size:           Get the size of the configuration spa=
ce includes
> > >   *                             fields that are conditional on featur=
e 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 off=
set,
> > >                            void *buf, unsigned int len);
> > > --
> > > 2.31.1
> > >
> >
>