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From:   Jason Wang <jasowang@redhat.com>
Date:   Fri, 11 Aug 2023 10:10:28 +0800
Message-ID: <CACGkMEvWE4bSzULPcMRx_UZ96Y+RzG8cL_P3zURwuaRCZRrx0A@mail.gmail.com>
Subject: Re: [PATCH] virtio_mmio: add suspend and resume calls for virtio_mmio devices
To:     "Michael S. Tsirkin" <mst@redhat.com>
Cc:     Anvesh Jain P <quic_ajainp@quicinc.com>,
        Xuan Zhuo <xuanzhuo@linux.alibaba.com>,
        Venkata Rao Kakani <quic_vkakani@quicinc.com>,
        virtualization@lists.linux-foundation.org,
        linux-kernel@vger.kernel.org
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On Fri, Aug 11, 2023 at 3:45=E2=80=AFAM Michael S. Tsirkin <mst@redhat.com>=
 wrote:
>
> On Fri, Jul 28, 2023 at 12:31:27PM +0530, Anvesh Jain P wrote:
> > Handle suspend and resume calls for virtio mmio devices from
> > PM core. Expose these notifications to virtio drivers that can quiesce =
and
> > resume vq operations. Update virtio pm ops to handle freeze& restore an=
d
> > suspend & resume callbacks separately.
> >
> > Signed-off-by: Anvesh Jain P <quic_ajainp@quicinc.com>
> > Signed-off-by: Venkata Rao Kakani <quic_vkakani@quicinc.com>
>
> okey but what is the motivation? does this addition of 200 LOC
> achieve something new? what is the issue fixed here?

+1

And I think we need an example that can use the new ops.

Thanks

>
>
> > ---
> >  drivers/virtio/virtio.c      | 112 +++++++++++++++++++++++++++++++++++
> >  drivers/virtio/virtio_mmio.c |  50 +++++++++++++++-
> >  include/linux/virtio.h       |  12 ++++
> >  3 files changed, 173 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
> > index 3893dc29eb26..c6f25a267600 100644
> > --- a/drivers/virtio/virtio.c
> > +++ b/drivers/virtio/virtio.c
> > @@ -551,6 +551,118 @@ int virtio_device_restore(struct virtio_device *d=
ev)
> >       return ret;
> >  }
> >  EXPORT_SYMBOL_GPL(virtio_device_restore);
> > +
> > +int virtio_device_suspend(struct virtio_device *dev)
> > +{
> > +     struct virtio_driver *drv =3D drv_to_virtio(dev->dev.driver);
> > +
> > +     virtio_config_disable(dev);
> > +
> > +     dev->failed =3D dev->config->get_status(dev) & VIRTIO_CONFIG_S_FA=
ILED;
> > +
> > +     if (drv && drv->suspend)
> > +             return drv->suspend(dev);
> > +
> > +     return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(virtio_device_suspend);
> > +
> > +int virtio_device_resume(struct virtio_device *dev)
> > +{
> > +     struct virtio_driver *drv =3D drv_to_virtio(dev->dev.driver);
> > +     int ret;
> > +
> > +     if (drv && drv->resume) {
> > +             ret =3D drv->resume(dev);
> > +             if (ret)
> > +                     goto err;
> > +
> > +             if (!(dev->config->get_status(dev) & VIRTIO_CONFIG_S_DRIV=
ER_OK))
> > +                     virtio_device_ready(dev);
> > +
> > +             virtio_config_enable(dev);
> > +     }
> > +
> > +     return 0;
> > +err:
> > +     virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
> > +     return ret;
> > +}
> > +EXPORT_SYMBOL_GPL(virtio_device_resume);
> > +
> > +int virtio_device_suspend_late(struct virtio_device *dev)
> > +{
> > +     struct virtio_driver *drv =3D drv_to_virtio(dev->dev.driver);
> > +
> > +     virtio_config_disable(dev);
> > +
> > +     dev->failed =3D dev->config->get_status(dev) & VIRTIO_CONFIG_S_FA=
ILED;
> > +
> > +     if (drv && drv->suspend_late)
> > +             return drv->suspend_late(dev);
> > +
> > +     return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(virtio_device_suspend_late);
> > +
> > +int virtio_device_resume_early(struct virtio_device *dev)
> > +{
> > +     struct virtio_driver *drv =3D drv_to_virtio(dev->dev.driver);
> > +     int ret;
> > +
> > +     if (drv && drv->resume_early) {
> > +             ret =3D drv->resume_early(dev);
> > +             if (ret)
> > +                     goto err;
> > +             if (!(dev->config->get_status(dev) & VIRTIO_CONFIG_S_DRIV=
ER_OK))
> > +                     virtio_device_ready(dev);
> > +
> > +             virtio_config_enable(dev);
> > +     }
> > +
> > +     return 0;
> > +err:
> > +     virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
> > +     return ret;
> > +}
> > +EXPORT_SYMBOL_GPL(virtio_device_resume_early);
> > +
> > +int virtio_device_suspend_noirq(struct virtio_device *dev)
> > +{
> > +     struct virtio_driver *drv =3D drv_to_virtio(dev->dev.driver);
> > +
> > +     virtio_config_disable(dev);
> > +
> > +     dev->failed =3D dev->config->get_status(dev) & VIRTIO_CONFIG_S_FA=
ILED;
> > +
> > +     if (drv && drv->suspend_noirq)
> > +             return drv->suspend_noirq(dev);
> > +
> > +     return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(virtio_device_suspend_noirq);
> > +
> > +int virtio_device_resume_noirq(struct virtio_device *dev)
> > +{
> > +     struct virtio_driver *drv =3D drv_to_virtio(dev->dev.driver);
> > +     int ret;
> > +
> > +     if (drv && drv->resume_noirq) {
> > +             ret =3D drv->resume_noirq(dev);
> > +             if (ret)
> > +                     goto err;
> > +             if (!(dev->config->get_status(dev) & VIRTIO_CONFIG_S_DRIV=
ER_OK))
> > +                     virtio_device_ready(dev);
> > +
> > +             virtio_config_enable(dev);
> > +     }
> > +
> > +     return 0;
> > +err:
> > +     virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
> > +     return ret;
> > +}
> > +EXPORT_SYMBOL_GPL(virtio_device_resume_noirq);
> >  #endif
> >
> >  static int virtio_init(void)
> > diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.=
c
> > index a46a4a29e929..9385c7e65da9 100644
> > --- a/drivers/virtio/virtio_mmio.c
> > +++ b/drivers/virtio/virtio_mmio.c
> > @@ -596,9 +596,57 @@ static int virtio_mmio_restore(struct device *dev)
> >
> >       return virtio_device_restore(&vm_dev->vdev);
> >  }
> > +static int virtio_mmio_suspend(struct device *dev)
> > +{
> > +       struct virtio_mmio_device *vm_dev =3D dev_get_drvdata(dev);
> > +
> > +       return virtio_device_suspend(&vm_dev->vdev);
> > +}
> > +
> > +static int virtio_mmio_resume(struct device *dev)
> > +{
> > +       struct virtio_mmio_device *vm_dev =3D dev_get_drvdata(dev);
> > +
> > +       return virtio_device_resume(&vm_dev->vdev);
> > +}
> > +
> > +static int virtio_mmio_suspend_late(struct device *dev)
> > +{
> > +       struct virtio_mmio_device *vm_dev =3D dev_get_drvdata(dev);
> > +
> > +       return virtio_device_suspend_late(&vm_dev->vdev);
> > +}
> > +
> > +static int virtio_mmio_resume_early(struct device *dev)
> > +{
> > +       struct virtio_mmio_device *vm_dev =3D dev_get_drvdata(dev);
> > +
> > +       return virtio_device_resume_early(&vm_dev->vdev);
> > +}
> > +
> > +static int virtio_mmio_suspend_noirq(struct device *dev)
> > +{
> > +       struct virtio_mmio_device *vm_dev =3D dev_get_drvdata(dev);
> > +
> > +       return virtio_device_suspend_noirq(&vm_dev->vdev);
> > +}
> > +
> > +static int virtio_mmio_resume_noirq(struct device *dev)
> > +{
> > +       struct virtio_mmio_device *vm_dev =3D dev_get_drvdata(dev);
> > +
> > +       return virtio_device_resume_noirq(&vm_dev->vdev);
> > +}
> >
> >  static const struct dev_pm_ops virtio_mmio_pm_ops =3D {
> > -     SET_SYSTEM_SLEEP_PM_OPS(virtio_mmio_freeze, virtio_mmio_restore)
> > +       .freeze         =3D virtio_mmio_freeze,
> > +       .restore        =3D virtio_mmio_restore,
> > +       .suspend        =3D virtio_mmio_suspend,
> > +       .resume         =3D virtio_mmio_resume,
> > +       .suspend_late   =3D virtio_mmio_suspend_late,
> > +       .resume_early   =3D virtio_mmio_resume_early,
> > +       .suspend_noirq  =3D virtio_mmio_suspend_noirq,
> > +       .resume_noirq   =3D virtio_mmio_resume_noirq,
> >  };
> >  #endif
> >
> > diff --git a/include/linux/virtio.h b/include/linux/virtio.h
> > index de6041deee37..e88b321408e9 100644
> > --- a/include/linux/virtio.h
> > +++ b/include/linux/virtio.h
> > @@ -145,6 +145,12 @@ void virtio_config_changed(struct virtio_device *d=
ev);
> >  #ifdef CONFIG_PM_SLEEP
> >  int virtio_device_freeze(struct virtio_device *dev);
> >  int virtio_device_restore(struct virtio_device *dev);
> > +int virtio_device_suspend(struct virtio_device *dev);
> > +int virtio_device_resume(struct virtio_device *dev);
> > +int virtio_device_suspend_late(struct virtio_device *dev);
> > +int virtio_device_resume_early(struct virtio_device *dev);
> > +int virtio_device_suspend_noirq(struct virtio_device *dev);
> > +int virtio_device_resume_noirq(struct virtio_device *dev);
> >  #endif
> >  void virtio_reset_device(struct virtio_device *dev);
> >
> > @@ -187,6 +193,12 @@ struct virtio_driver {
> >  #ifdef CONFIG_PM
> >       int (*freeze)(struct virtio_device *dev);
> >       int (*restore)(struct virtio_device *dev);
> > +     int (*suspend)(struct virtio_device *dev);
> > +     int (*resume)(struct virtio_device *dev);
> > +     int (*suspend_late)(struct virtio_device *dev);
> > +     int (*resume_early)(struct virtio_device *dev);
> > +     int (*suspend_noirq)(struct virtio_device *dev);
> > +     int (*resume_noirq)(struct virtio_device *dev);
> >  #endif
> >  };
> >
> >
> > base-commit: 3f01e9fed8454dcd89727016c3e5b2fbb8f8e50c
> > --
> > 2.17.1
>