Re: [PATCH V3 2/3] vduse: suspend

[Jason Wang <jasowang@xxxxxxxxxx>]

On Mon, May 20, 2024 at 11:21 PM Steve Sistare
<steven.sistare@xxxxxxxxxx> wrote:
>
> Support the suspend operation.  There is little to do, except flush to
> guarantee no workers are running when suspend returns.
>
> Signed-off-by: Steve Sistare <steven.sistare@xxxxxxxxxx>
> ---
>  drivers/vdpa/vdpa_user/vduse_dev.c | 24 ++++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
>
> diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
> index 73c89701fc9d..7dc46f771f12 100644
> --- a/drivers/vdpa/vdpa_user/vduse_dev.c
> +++ b/drivers/vdpa/vdpa_user/vduse_dev.c
> @@ -472,6 +472,18 @@ static void vduse_dev_reset(struct vduse_dev *dev)
>         up_write(&dev->rwsem);
>  }
>
> +static void vduse_flush_work(struct vduse_dev *dev)
> +{
> +       flush_work(&dev->inject);
> +
> +       for (int i = 0; i < dev->vq_num; i++) {
> +               struct vduse_virtqueue *vq = dev->vqs[i];
> +
> +               flush_work(&vq->inject);
> +               flush_work(&vq->kick);
> +       }
> +}
> +
>  static int vduse_vdpa_set_vq_address(struct vdpa_device *vdpa, u16 idx,
>                                 u64 desc_area, u64 driver_area,
>                                 u64 device_area)
> @@ -724,6 +736,17 @@ static int vduse_vdpa_reset(struct vdpa_device *vdpa)
>         return ret;
>  }
>
> +static int vduse_vdpa_suspend(struct vdpa_device *vdpa)
> +{
> +       struct vduse_dev *dev = vdpa_to_vduse(vdpa);
> +
> +       down_write(&dev->rwsem);
> +       vduse_flush_work(dev);
> +       up_write(&dev->rwsem);

Can this forbid the new work to be scheduled?

static int vduse_dev_queue_irq_work(struct vduse_dev *dev,
                                    struct work_struct *irq_work,
                                    int irq_effective_cpu)
{
        int ret = -EINVAL;

        down_read(&dev->rwsem);
        if (!(dev->status & VIRTIO_CONFIG_S_DRIVER_OK))
                goto unlock;

        ret = 0;
        if (irq_effective_cpu == IRQ_UNBOUND)
                queue_work(vduse_irq_wq, irq_work);
        else
                queue_work_on(irq_effective_cpu,
                      vduse_irq_bound_wq, irq_work);
unlock:
        up_read(&dev->rwsem);

        return ret;
}

Thanks

> +
> +       return 0;
> +}
> +
>  static u32 vduse_vdpa_get_generation(struct vdpa_device *vdpa)
>  {
>         struct vduse_dev *dev = vdpa_to_vduse(vdpa);
> @@ -806,6 +829,7 @@ static const struct vdpa_config_ops vduse_vdpa_config_ops = {
>         .set_vq_affinity        = vduse_vdpa_set_vq_affinity,
>         .get_vq_affinity        = vduse_vdpa_get_vq_affinity,
>         .reset                  = vduse_vdpa_reset,
> +       .suspend                = vduse_vdpa_suspend,
>         .set_map                = vduse_vdpa_set_map,
>         .free                   = vduse_vdpa_free,
>  };
> --
> 2.39.3
>