Re: [PATCH v28 04/17] vfio: Add migration region initialization and finalize function

[Cornelia Huck]

On Fri, 23 Oct 2020 16:10:30 +0530
Kirti Wankhede <kwankhede@nvidia.com> wrote:

> Whether the VFIO device supports migration or not is decided based of
> migration region query. If migration region query is successful and migration
> region initialization is successful then migration is supported else
> migration is blocked.
> 
> Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
> Reviewed-by: Neo Jia <cjia@nvidia.com>
> Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> ---
>  hw/vfio/meson.build           |   1 +
>  hw/vfio/migration.c           | 133 
> ++++++++++++++++++++++++++++++++++++++++++
>  hw/vfio/trace-events          |   3 +
>  include/hw/vfio/vfio-common.h |   9 +++
>  4 files changed, 146 insertions(+)
>  create mode 100644 hw/vfio/migration.c

(...)

> +static int vfio_migration_init(VFIODevice *vbasedev,
> +                               struct vfio_region_info *info)
> +{
> +    int ret;
> +    Object *obj;
> +    VFIOMigration *migration;
> +
> +    if (!vbasedev->ops->vfio_get_object) {
> +        return -EINVAL;
> +    }
> +
> +    obj = vbasedev->ops->vfio_get_object(vbasedev);
> +    if (!obj) {
> +        return -EINVAL;
> +    }
> +
> +    migration = g_new0(VFIOMigration, 1);
> +
> +    ret = vfio_region_setup(obj, vbasedev, &migration->region,
> +                            info->index, "migration");
> +    if (ret) {
> +        error_report("%s: Failed to setup VFIO migration region %d: %s",
> +                     vbasedev->name, info->index, strerror(-ret));
> +        goto err;
> +    }
> +
> +    vbasedev->migration = migration;
> +
> +    if (!migration->region.size) {
> +        error_report("%s: Invalid zero-sized of VFIO migration region %d",

s/of //

> +                     vbasedev->name, info->index);
> +        ret = -EINVAL;
> +        goto err;
> +    }
> +    return 0;
> +
> +err:
> +    vfio_migration_region_exit(vbasedev);
> +    g_free(migration);
> +    vbasedev->migration = NULL;
> +    return ret;
> +}

(...)

> +void vfio_migration_finalize(VFIODevice *vbasedev)
> +{
> +    VFIOMigration *migration = vbasedev->migration;

I don't think you need this variable?

> +
> +    if (migration) {
> +        vfio_migration_region_exit(vbasedev);
> +        g_free(vbasedev->migration);
> +        vbasedev->migration = NULL;
> +    }
> +
> +    if (vbasedev->migration_blocker) {
> +        migrate_del_blocker(vbasedev->migration_blocker);
> +        error_free(vbasedev->migration_blocker);
> +        vbasedev->migration_blocker = NULL;
> +    }
> +}

(...)