[RFC PATCH v2 2/3] drm/i915/gvt: Introduce enable_direct_flip attribute

[Zhenyu Wang]

On 2019.05.10 12:15:27 +0800, Tina Zhang wrote:
> This attribute is introduced to work as a switch of the gvt-g vGPU direct
> flip function. Userspace can simply switch on/off the direct flip
> function by echoing 1/0 to this attributte.
> 
> Signed-off-by: Tina Zhang <tina.zhang at intel.com>
> ---

I do not think this is appropriate interface which doesn't align with
vGPU lifecycle and also doesn't work together with control state of vfio
gfx ioctl. Why this?

>  drivers/gpu/drm/i915/gvt/kvmgt.c | 38 ++++++++++++++++++++++++++++++++++++++
>  1 file changed, 38 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
> index a68addf..2911818 100644
> --- a/drivers/gpu/drm/i915/gvt/kvmgt.c
> +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
> @@ -1581,12 +1581,50 @@ hw_id_show(struct device *dev, struct device_attribute *attr,
>  	return sprintf(buf, "\n");
>  }
>  
> +static ssize_t
> +enable_direct_flip_show(struct device *dev, struct device_attribute *attr,
> +	 char *buf)
> +{
> +	struct mdev_device *mdev = mdev_from_dev(dev);
> +
> +	if (mdev) {
> +		struct intel_vgpu *vgpu = (struct intel_vgpu *)
> +			mdev_get_drvdata(mdev);
> +		return sprintf(buf, "%u\n",
> +			       vgpu->display.shadow_fbs.enable_direct_flip);
> +	}
> +	return sprintf(buf, "\n");
> +}
> +
> +static ssize_t
> +enable_direct_flip_store(struct device *dev, struct device_attribute *attr,
> +			     const char *buf, size_t n)
> +{
> +	struct mdev_device *mdev = mdev_from_dev(dev);
> +	ssize_t ret;
> +	u32 val;
> +
> +	ret = kstrtou32(buf, 0, &val);
> +	if (ret)
> +		return ret;
> +
> +	if (mdev) {
> +		struct intel_vgpu *vgpu = (struct intel_vgpu *)
> +			mdev_get_drvdata(mdev);
> +		vgpu->display.shadow_fbs.enable_direct_flip = !!val;
> +	}
> +
> +	return n;
> +}
> +
>  static DEVICE_ATTR_RO(vgpu_id);
>  static DEVICE_ATTR_RO(hw_id);
> +static DEVICE_ATTR_RW(enable_direct_flip);
>  
>  static struct attribute *intel_vgpu_attrs[] = {
>  	&dev_attr_vgpu_id.attr,
>  	&dev_attr_hw_id.attr,
> +	&dev_attr_enable_direct_flip.attr,
>  	NULL
>  };
>  
> -- 
> 2.7.4
> 
> _______________________________________________
> intel-gvt-dev mailing list
> intel-gvt-dev at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gvt-dev

-- 
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