Re: [PATCH 02/13] vfio: Introduce a vfio_uninit_group_dev() API call

[Cornelia Huck <cohuck@redhat.com>]

On Wed, Jul 14 2021, Jason Gunthorpe <jgg@nvidia.com> wrote:

> From: Max Gurtovoy <mgurtovoy@nvidia.com>
>
> This pairs with vfio_init_group_dev() and allows undoing any state that is
> stored in the vfio_device unrelated to registration. Add appropriately
> placed calls to all the drivers.
>
> The following patch will use this to add pre-registration state for the
> device set.
>
> Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
> ---
>  Documentation/driver-api/vfio.rst            |  4 ++-
>  drivers/vfio/fsl-mc/vfio_fsl_mc.c            |  6 +++--
>  drivers/vfio/mdev/vfio_mdev.c                | 13 +++++++---
>  drivers/vfio/pci/vfio_pci.c                  |  6 +++--
>  drivers/vfio/platform/vfio_platform_common.c |  7 +++--
>  drivers/vfio/vfio.c                          |  5 ++++
>  include/linux/vfio.h                         |  1 +
>  samples/vfio-mdev/mbochs.c                   |  2 ++
>  samples/vfio-mdev/mdpy.c                     | 25 ++++++++++--------
>  samples/vfio-mdev/mtty.c                     | 27 ++++++++++++--------
>  10 files changed, 64 insertions(+), 32 deletions(-)

(...)

> diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c
> index e81b875b4d87b4..cf264d0bf11053 100644
> --- a/samples/vfio-mdev/mbochs.c
> +++ b/samples/vfio-mdev/mbochs.c
> @@ -558,6 +558,7 @@ static int mbochs_probe(struct mdev_device *mdev)
>  	return 0;
>  
>  err_mem:
> +	vfio_uninit_group_dev(&mdev_state->vdev);
>  	kfree(mdev_state->vconfig);
>  	kfree(mdev_state);
>  	return ret;
> @@ -571,6 +572,7 @@ static void mbochs_remove(struct mdev_device *mdev)
>  	vfio_unregister_group_dev(&mdev_state->vdev);
>  	kfree(mdev_state->pages);
>  	kfree(mdev_state->vconfig);
> +	vfio_uninit_group_dev(&mdev_state->vdev);

Does the location of the uninit vs the kfree matter? Even if not, it
might be good to keep it consistent.

>  	kfree(mdev_state);
>  }
>