[PATCH 3/5 v5] drm/virtio: track whether or not a context has been initiated

[Chia-I Wu]

Patch 1-4 are

Reviewed-by: Chia-I Wu <olvaffe at gmail.com>

I think we can drop patch 5 for now.


On Wed, Feb 19, 2020 at 9:56 AM Gurchetan Singh
<gurchetansingh at chromium.org> wrote:
>
> Use an atomic variable to track whether a context has been
> initiated.
>
> v5: Fix possible race and sleep via mutex (@olv)
>
> Signed-off-by: Gurchetan Singh <gurchetansingh at chromium.org>
> ---
>  drivers/gpu/drm/virtio/virtgpu_drv.h   | 2 ++
>  drivers/gpu/drm/virtio/virtgpu_ioctl.c | 8 ++++++++
>  drivers/gpu/drm/virtio/virtgpu_kms.c   | 3 +++
>  3 files changed, 13 insertions(+)
>
> diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h
> index 72c1d9b59dfe..0596d9618554 100644
> --- a/drivers/gpu/drm/virtio/virtgpu_drv.h
> +++ b/drivers/gpu/drm/virtio/virtgpu_drv.h
> @@ -209,6 +209,8 @@ struct virtio_gpu_device {
>
>  struct virtio_gpu_fpriv {
>         uint32_t ctx_id;
> +       bool context_initiated;
ctx_id and context_initialized are named hw_res_handle and created
respectively in virtio_gpu_object.  I think we should use "hw",
"id"/"handle", "initialized"/"created" more consistently.

This is just a nitpick, and does not need to be a part of this series.

> +       struct mutex context_lock;
>  };
>
>  /* virtio_ioctl.c */
> diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
> index de04f80f737d..c1a6cb4ec375 100644
> --- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c
> +++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
> @@ -44,10 +44,18 @@ void virtio_gpu_create_context(struct drm_device *dev,
>         if (!vgdev->has_virgl_3d)
>                 return;
>
> +       mutex_lock(&vfpriv->context_lock);
> +       if (vfpriv->context_initiated)
> +               goto out_unlock;
> +
>         get_task_comm(dbgname, current);
>         virtio_gpu_cmd_context_create(vgdev, vfpriv->ctx_id,
>                                       strlen(dbgname), dbgname);
>         virtio_gpu_notify(vgdev);
> +       vfpriv->context_initiated = true;
> +
> +out_unlock:
> +       mutex_unlock(&vfpriv->context_lock);
>  }
>
>  static int virtio_gpu_map_ioctl(struct drm_device *dev, void *data,
> diff --git a/drivers/gpu/drm/virtio/virtgpu_kms.c b/drivers/gpu/drm/virtio/virtgpu_kms.c
> index f7e3712502ca..424729cb81d1 100644
> --- a/drivers/gpu/drm/virtio/virtgpu_kms.c
> +++ b/drivers/gpu/drm/virtio/virtgpu_kms.c
> @@ -258,6 +258,8 @@ int virtio_gpu_driver_open(struct drm_device *dev, struct drm_file *file)
>         if (!vfpriv)
>                 return -ENOMEM;
>
> +       mutex_init(&vfpriv->context_lock);
> +
>         handle = ida_alloc(&vgdev->ctx_id_ida, GFP_KERNEL);
>         if (handle < 0) {
>                 kfree(vfpriv);
> @@ -281,6 +283,7 @@ void virtio_gpu_driver_postclose(struct drm_device *dev, struct drm_file *file)
>         vfpriv = file->driver_priv;
>
>         virtio_gpu_context_destroy(vgdev, vfpriv->ctx_id);
> +       mutex_destroy(&vfpriv->context_lock);
>         kfree(vfpriv);
>         file->driver_priv = NULL;
>  }
> --
> 2.25.0.265.gbab2e86ba0-goog
>