Re: [PATCH 09/14] vfio: Add Error** argument to .vfio_save_config() handler

[Avihai Horon]

On 07/02/2024 15:33, Cédric Le Goater wrote:
> External email: Use caution opening links or attachments
>
>
> Use vmstate_save_state_with_err() to improve error reporting in the
> callers.
>
> Signed-off-by: Cédric Le Goater <clg@redhat.com>
> ---
>   include/hw/vfio/vfio-common.h |  2 +-
>   hw/vfio/migration.c           | 18 ++++++++++++------
>   hw/vfio/pci.c                 |  5 +++--
>   3 files changed, 16 insertions(+), 9 deletions(-)
>
> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
> index 
> 9b7ef7d02b5a0ad5266bcc4d06cd6874178978e4..710e0d6a880b97848af6ddc2e7968a01054fa122
>  100644
> --- a/include/hw/vfio/vfio-common.h
> +++ b/include/hw/vfio/vfio-common.h
> @@ -133,7 +133,7 @@ struct VFIODeviceOps {
>       int (*vfio_hot_reset_multi)(VFIODevice *vdev);
>       void (*vfio_eoi)(VFIODevice *vdev);
>       Object *(*vfio_get_object)(VFIODevice *vdev);
> -    void (*vfio_save_config)(VFIODevice *vdev, QEMUFile *f);
> +    int (*vfio_save_config)(VFIODevice *vdev, QEMUFile *f, Error **errp);
>       int (*vfio_load_config)(VFIODevice *vdev, QEMUFile *f);
>   };
>
> diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
> index 
> 2e0a79967cc97f44d9be5575c3cfe18c9f349dab..fb264c1ef57bbbde4306901e5449e0dfbd0ce3b7
>  100644
> --- a/hw/vfio/migration.c
> +++ b/hw/vfio/migration.c
> @@ -190,14 +190,19 @@ static int vfio_load_buffer(QEMUFile *f, VFIODevice 
> *vbasedev,
>       return ret;
>   }
>
> -static int vfio_save_device_config_state(QEMUFile *f, void *opaque)
> +static int vfio_save_device_config_state(QEMUFile *f, void *opaque,
> +                                         Error **errp)
>   {
>       VFIODevice *vbasedev = opaque;
> +    int ret = 0;

Nit: 0 assignment is redundant.

Thanks.

>       qemu_put_be64(f, VFIO_MIG_FLAG_DEV_CONFIG_STATE);
>
>       if (vbasedev->ops && vbasedev->ops->vfio_save_config) {
> -        vbasedev->ops->vfio_save_config(vbasedev, f);
> +        ret = vbasedev->ops->vfio_save_config(vbasedev, f, errp);
> +        if (ret) {
> +            return ret;
> +        }
>       }
>
>       qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE);
> @@ -579,13 +584,14 @@ static int vfio_save_complete_precopy(QEMUFile *f, void 
> *opaque)
>   static void vfio_save_state(QEMUFile *f, void *opaque)
>   {
>       VFIODevice *vbasedev = opaque;
> +    Error *local_err = NULL;
>       int ret;
>
> -    ret = vfio_save_device_config_state(f, opaque);
> +    ret = vfio_save_device_config_state(f, opaque, &local_err);
>       if (ret) {
> -        error_report("%s: Failed to save device config space",
> -                     vbasedev->name);
> -        qemu_file_set_error(f, ret);
> +        error_prepend(&local_err, "%s: Failed to save device config space",
> +                      vbasedev->name);
> +        qemu_file_set_error_obj(f, ret, local_err);
>       }
>   }
>
> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
> index 
> 4fa387f0430d62ca2ba1b5ae5b7037f8f06b33f9..99d86e1d40ef25133fc76ad6e58294b07bd20843
>  100644
> --- a/hw/vfio/pci.c
> +++ b/hw/vfio/pci.c
> @@ -2585,11 +2585,12 @@ const VMStateDescription vmstate_vfio_pci_config = {
>       }
>   };
>
> -static void vfio_pci_save_config(VFIODevice *vbasedev, QEMUFile *f)
> +static int vfio_pci_save_config(VFIODevice *vbasedev, QEMUFile *f, Error 
> **errp)
>   {
>       VFIOPCIDevice *vdev = container_of(vbasedev, VFIOPCIDevice, vbasedev);
>
> -    vmstate_save_state(f, &vmstate_vfio_pci_config, vdev, NULL);
> +    return vmstate_save_state_with_err(f, &vmstate_vfio_pci_config, vdev, NULL,
> +                                       errp);
>   }
>
>   static int vfio_pci_load_config(VFIODevice *vbasedev, QEMUFile *f)
> --
> 2.43.0