[PATCH] drm/virtgpu: Add PM support for suspend/resume

[PATCH] drm/virtgpu: Add PM support for suspend/resume

[Morris Pan]

Add freeze/restore callbacks to handle system suspend/resume.
During freeze, delete virtqueues and reset device.
During restore, reinitialize virtqueues and mark device ready.

Signed-off-by: Morris Pan <morris.pan@mediatek.com>
---
 drivers/gpu/drm/virtio/virtgpu_drv.c | 40 +++++++++++++++++++++++++++-
 1 file changed, 39 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.c b/drivers/gpu/drm/virtio/virtgpu_drv.c
index a5ce96fb8a1d..fbca0a82958c 100644
--- a/drivers/gpu/drm/virtio/virtgpu_drv.c
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.c
@@ -145,6 +145,40 @@ static void virtio_gpu_config_changed(struct virtio_device *vdev)
 	schedule_work(&vgdev->config_changed_work);
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int virtgpu_freeze(struct virtio_device *vdev)
+{
+	vdev->config->del_vqs(vdev);
+	virtio_reset_device(vdev);
+
+	return 0;
+}
+
+static int virtgpu_restore(struct virtio_device *vdev)
+{
+	int ret;
+	struct virtqueue *vqs[2];
+	struct drm_device *dev = vdev->priv;
+	struct virtio_gpu_device *vgdev = dev->dev_private;
+	struct virtqueue_info vqs_info[] = {
+		{ "control", virtio_gpu_ctrl_ack },
+		{ "cursor", virtio_gpu_cursor_ack },
+	};
+
+	ret = virtio_find_vqs(vdev, 2, vqs, vqs_info, NULL);
+	if (ret) {
+		DRM_ERROR("failed to find virtio queues\n");
+		return ret;
+	}
+
+	vgdev->ctrlq.vq = vqs[0];
+	vgdev->cursorq.vq = vqs[1];
+	virtio_device_ready(vdev);
+
+	return 0;
+}
+#endif
+
 static struct virtio_device_id id_table[] = {
 	{ VIRTIO_ID_GPU, VIRTIO_DEV_ANY_ID },
 	{ 0 },
@@ -172,7 +206,11 @@ static struct virtio_driver virtio_gpu_driver = {
 	.probe = virtio_gpu_probe,
 	.remove = virtio_gpu_remove,
 	.shutdown = virtio_gpu_shutdown,
-	.config_changed = virtio_gpu_config_changed
+	.config_changed = virtio_gpu_config_changed,
+#ifdef CONFIG_PM_SLEEP
+	.freeze = virtgpu_freeze,
+	.restore = virtgpu_restore
+#endif
 };
 
 static int __init virtio_gpu_driver_init(void)
-- 
2.45.2

Re: [PATCH] drm/virtgpu: Add PM support for suspend/resume

[Thomas Zimmermann]

Hi

Am 01.04.26 um 08:10 schrieb Morris Pan:
> Add freeze/restore callbacks to handle system suspend/resume.
> During freeze, delete virtqueues and reset device.
> During restore, reinitialize virtqueues and mark device ready.
>
> Signed-off-by: Morris Pan <morris.pan@mediatek.com>
> ---
>   drivers/gpu/drm/virtio/virtgpu_drv.c | 40 +++++++++++++++++++++++++++-
>   1 file changed, 39 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.c b/drivers/gpu/drm/virtio/virtgpu_drv.c
> index a5ce96fb8a1d..fbca0a82958c 100644
> --- a/drivers/gpu/drm/virtio/virtgpu_drv.c
> +++ b/drivers/gpu/drm/virtio/virtgpu_drv.c
> @@ -145,6 +145,40 @@ static void virtio_gpu_config_changed(struct virtio_device *vdev)
>   	schedule_work(&vgdev->config_changed_work);
>   }
>   
> +#ifdef CONFIG_PM_SLEEP
> +static int virtgpu_freeze(struct virtio_device *vdev)
> +{

I think you first need to call drm_mode_config_helper_suspend() [1] to 
stop DRM and save the current state.

[1] 
https://elixir.bootlin.com/linux/v6.19.10/source/drivers/gpu/drm/drm_modeset_helper.c#L179

> +	vdev->config->del_vqs(vdev);
> +	virtio_reset_device(vdev);
> +
> +	return 0;
> +}
> +
> +static int virtgpu_restore(struct virtio_device *vdev)
> +{
> +	int ret;
> +	struct virtqueue *vqs[2];
> +	struct drm_device *dev = vdev->priv;
> +	struct virtio_gpu_device *vgdev = dev->dev_private;
> +	struct virtqueue_info vqs_info[] = {
> +		{ "control", virtio_gpu_ctrl_ack },
> +		{ "cursor", virtio_gpu_cursor_ack },
> +	};
> +
> +	ret = virtio_find_vqs(vdev, 2, vqs, vqs_info, NULL);
> +	if (ret) {
> +		DRM_ERROR("failed to find virtio queues\n");
> +		return ret;
> +	}
> +
> +	vgdev->ctrlq.vq = vqs[0];
> +	vgdev->cursorq.vq = vqs[1];
> +	virtio_device_ready(vdev);

And here you have to call drm_mode_config_helper_resume() [2] to restore 
the DRM state from before the freeze.

[2] 
https://elixir.bootlin.com/linux/v6.19.10/source/drivers/gpu/drm/drm_modeset_helper.c#L227

Best regards
Thomas

> +
> +	return 0;
> +}
> +#endif
> +
>   static struct virtio_device_id id_table[] = {
>   	{ VIRTIO_ID_GPU, VIRTIO_DEV_ANY_ID },
>   	{ 0 },
> @@ -172,7 +206,11 @@ static struct virtio_driver virtio_gpu_driver = {
>   	.probe = virtio_gpu_probe,
>   	.remove = virtio_gpu_remove,
>   	.shutdown = virtio_gpu_shutdown,
> -	.config_changed = virtio_gpu_config_changed
> +	.config_changed = virtio_gpu_config_changed,
> +#ifdef CONFIG_PM_SLEEP
> +	.freeze = virtgpu_freeze,
> +	.restore = virtgpu_restore
> +#endif
>   };
>   
>   static int __init virtio_gpu_driver_init(void)

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG Nürnberg)

Re: [PATCH] drm/virtgpu: Add PM support for suspend/resume

[Morris Pan (潘泰為)]

On Wed, 2026-04-01 at 08:24 +0200, Thomas Zimmermann wrote:
> 
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
> 
> 
> Hi
> 
> Am 01.04.26 um 08:10 schrieb Morris Pan:
> > Add freeze/restore callbacks to handle system suspend/resume.
> > During freeze, delete virtqueues and reset device.
> > During restore, reinitialize virtqueues and mark device ready.
> > 
> > Signed-off-by: Morris Pan <morris.pan@mediatek.com>
> > ---
> >   drivers/gpu/drm/virtio/virtgpu_drv.c | 40
> > +++++++++++++++++++++++++++-
> >   1 file changed, 39 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.c
> > b/drivers/gpu/drm/virtio/virtgpu_drv.c
> > index a5ce96fb8a1d..fbca0a82958c 100644
> > --- a/drivers/gpu/drm/virtio/virtgpu_drv.c
> > +++ b/drivers/gpu/drm/virtio/virtgpu_drv.c
> > @@ -145,6 +145,40 @@ static void virtio_gpu_config_changed(struct
> > virtio_device *vdev)
> >       schedule_work(&vgdev->config_changed_work);
> >   }
> > 
> > +#ifdef CONFIG_PM_SLEEP
> > +static int virtgpu_freeze(struct virtio_device *vdev)
> > +{
> 
> I think you first need to call drm_mode_config_helper_suspend() [1]
> to
> stop DRM and save the current state.
> 
> [1]
> https://urldefense.com/v3/__https://elixir.bootlin.com/linux/v6.19.10/source/drivers/gpu/drm/drm_modeset_helper.c*L179__;Iw!!CTRNKA9wMg0ARbw!j0dxkuooYYkTXqgRzLyo558VesWoTL84VgkwhRczVxZ-PZlBeLg0vnY4B36rtYVRDVpGmTqVjGKJoFh7KnVelak$
> 
> > +     vdev->config->del_vqs(vdev);
> > +     virtio_reset_device(vdev);
> > +
> > +     return 0;
> > +}
> > +
> > +static int virtgpu_restore(struct virtio_device *vdev)
> > +{
> > +     int ret;
> > +     struct virtqueue *vqs[2];
> > +     struct drm_device *dev = vdev->priv;
> > +     struct virtio_gpu_device *vgdev = dev->dev_private;
> > +     struct virtqueue_info vqs_info[] = {
> > +             { "control", virtio_gpu_ctrl_ack },
> > +             { "cursor", virtio_gpu_cursor_ack },
> > +     };
> > +
> > +     ret = virtio_find_vqs(vdev, 2, vqs, vqs_info, NULL);
> > +     if (ret) {
> > +             DRM_ERROR("failed to find virtio queues\n");
> > +             return ret;
> > +     }
> > +
> > +     vgdev->ctrlq.vq = vqs[0];
> > +     vgdev->cursorq.vq = vqs[1];
> > +     virtio_device_ready(vdev);
> 
> And here you have to call drm_mode_config_helper_resume() [2] to
> restore
> the DRM state from before the freeze.
> 
> [2]
> https://urldefense.com/v3/__https://elixir.bootlin.com/linux/v6.19.10/source/drivers/gpu/drm/drm_modeset_helper.c*L227__;Iw!!CTRNKA9wMg0ARbw!j0dxkuooYYkTXqgRzLyo558VesWoTL84VgkwhRczVxZ-PZlBeLg0vnY4B36rtYVRDVpGmTqVjGKJoFh7cv1EDgQ$
> 
> Best regards
> Thomas
> 
> > +
> > +     return 0;
> > +}
> > +#endif
> > +
> >   static struct virtio_device_id id_table[] = {
> >       { VIRTIO_ID_GPU, VIRTIO_DEV_ANY_ID },
> >       { 0 },
> > @@ -172,7 +206,11 @@ static struct virtio_driver virtio_gpu_driver
> > = {
> >       .probe = virtio_gpu_probe,
> >       .remove = virtio_gpu_remove,
> >       .shutdown = virtio_gpu_shutdown,
> > -     .config_changed = virtio_gpu_config_changed
> > +     .config_changed = virtio_gpu_config_changed,
> > +#ifdef CONFIG_PM_SLEEP
> > +     .freeze = virtgpu_freeze,
> > +     .restore = virtgpu_restore
> > +#endif
> >   };
> > 
> >   static int __init virtio_gpu_driver_init(void)
> 
> --
> --
> Thomas Zimmermann
> Graphics Driver Developer
> SUSE Software Solutions Germany GmbH
> Frankenstr. 146, 90461 Nürnberg, Germany,
> https://urldefense.com/v3/__http://www.suse.com__;!!CTRNKA9wMg0ARbw!j0dxkuooYYkTXqgRzLyo558VesWoTL84VgkwhRczVxZ-PZlBeLg0vnY4B36rtYVRDVpGmTqVjGKJoFh74dj3x1M$
> GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG
> Nürnberg)
> 
> 

Hi Thomas,

Thank you very much for your detailed review and the constructive
feedback on my patch.

I am currently working on the revisions based on your comments.

Thanks again for your time and guidance.

Best regards,
Morris

Re: [PATCH] drm/virtgpu: Add PM support for suspend/resume

[Dmitry Osipenko]

Hi,

On 4/1/26 09:10, Morris Pan wrote:
> diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.c b/drivers/gpu/drm/virtio/virtgpu_drv.c
> index a5ce96fb8a1d..fbca0a82958c 100644
> --- a/drivers/gpu/drm/virtio/virtgpu_drv.c
> +++ b/drivers/gpu/drm/virtio/virtgpu_drv.c
> @@ -145,6 +145,40 @@ static void virtio_gpu_config_changed(struct virtio_device *vdev)
>  	schedule_work(&vgdev->config_changed_work);
>  }
>  
> +#ifdef CONFIG_PM_SLEEP
> +static int virtgpu_freeze(struct virtio_device *vdev)
> +{
> +	vdev->config->del_vqs(vdev);
> +	virtio_reset_device(vdev);
> +
> +	return 0;
> +}

VirtIO-GPU shouldn't be reset freely. See [1] and follow previous
hibernation-support discussions on the ML.

[1[
https://lore.kernel.org/dri-devel/20260107182745.229481-1-dongwon.kim@intel.com/

-- 
Best regards,
Dmitry

Re: [PATCH] drm/virtgpu: Add PM support for suspend/resume

[Morris Pan (潘泰為)]

On Wed, 2026-04-08 at 15:59 +0300, Dmitry Osipenko wrote:
> Hi,
> 
> On 4/1/26 09:10, Morris Pan wrote:
> > diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.c
> > b/drivers/gpu/drm/virtio/virtgpu_drv.c
> > index a5ce96fb8a1d..fbca0a82958c 100644
> > --- a/drivers/gpu/drm/virtio/virtgpu_drv.c
> > +++ b/drivers/gpu/drm/virtio/virtgpu_drv.c
> > @@ -145,6 +145,40 @@ static void virtio_gpu_config_changed(struct
> > virtio_device *vdev)
> >  	schedule_work(&vgdev->config_changed_work);
> >  }
> >  
> > +#ifdef CONFIG_PM_SLEEP
> > +static int virtgpu_freeze(struct virtio_device *vdev)
> > +{
> > +	vdev->config->del_vqs(vdev);
> > +	virtio_reset_device(vdev);
> > +
> > +	return 0;
> > +}
> 
> VirtIO-GPU shouldn't be reset freely. See [1] and follow previous
> hibernation-support discussions on the ML.
> 
> [1[
> https://lore.kernel.org/dri-devel/20260107182745.229481-1-dongwon.kim@intel.com/
>  
> 

Hi Dmitry,

Thank you for the guidance and for pointing me to that thread.

I have looked into the series you mentioned, specifically "PATCH v7
1/3: drm/virtio: Freeze and restore hooks to support suspend and
resume" (link).
I have verified that this change resolves the issue I was experiencing
in my envirronment.

I will keep an eye on that series and follow its progress. Thank you
for your time and help.

Best regards,

Morris Pan

Re: [PATCH] drm/virtgpu: Add PM support for suspend/resume

[Dmitry Osipenko]

On 4/17/26 12:40, Morris Pan (潘泰為) wrote:
> On Wed, 2026-04-08 at 15:59 +0300, Dmitry Osipenko wrote:
>> Hi,
>>
>> On 4/1/26 09:10, Morris Pan wrote:
>>> diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.c
>>> b/drivers/gpu/drm/virtio/virtgpu_drv.c
>>> index a5ce96fb8a1d..fbca0a82958c 100644
>>> --- a/drivers/gpu/drm/virtio/virtgpu_drv.c
>>> +++ b/drivers/gpu/drm/virtio/virtgpu_drv.c
>>> @@ -145,6 +145,40 @@ static void virtio_gpu_config_changed(struct
>>> virtio_device *vdev)
>>>  	schedule_work(&vgdev->config_changed_work);
>>>  }
>>>  
>>> +#ifdef CONFIG_PM_SLEEP
>>> +static int virtgpu_freeze(struct virtio_device *vdev)
>>> +{
>>> +	vdev->config->del_vqs(vdev);
>>> +	virtio_reset_device(vdev);
>>> +
>>> +	return 0;
>>> +}
>>
>> VirtIO-GPU shouldn't be reset freely. See [1] and follow previous
>> hibernation-support discussions on the ML.
>>
>> [1[
>> https://lore.kernel.org/dri-devel/20260107182745.229481-1-dongwon.kim@intel.com/
>>  
>>
> 
> Hi Dmitry,
> 
> Thank you for the guidance and for pointing me to that thread.
> 
> I have looked into the series you mentioned, specifically "PATCH v7
> 1/3: drm/virtio: Freeze and restore hooks to support suspend and
> resume" (link).
> I have verified that this change resolves the issue I was experiencing
> in my envirronment.
> 
> I will keep an eye on that series and follow its progress. Thank you
> for your time and help.

You're welcome. There is now v8 sent by Kim [2], feel free to test it
and reply with your review and/or tested-by on the patches.

[2]
https://lore.kernel.org/dri-devel/20260429204729.993669-1-dongwon.kim@intel.com/

-- 
Best regards,
Dmitry