Re: [PATCH v3 10/17] vfio/migration: Move migration v1 logic to vfio_migration_init()

[Alex Williamson <alex.williamson@redhat.com>]

On Thu, 3 Nov 2022 18:16:13 +0200
Avihai Horon <avihaih@nvidia.com> wrote:

> Move vfio_dev_get_region_info() logic from vfio_migration_probe() to
> vfio_migration_init(). This logic is specific to v1 protocol and moving
> it will make it easier to add the v2 protocol implementation later.
> No functional changes intended.
> 
> Signed-off-by: Avihai Horon <avihaih@nvidia.com>
> ---
>  hw/vfio/migration.c  | 30 +++++++++++++++---------------
>  hw/vfio/trace-events |  2 +-
>  2 files changed, 16 insertions(+), 16 deletions(-)
> 
> diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
> index 99ffb75782..0e3a950746 100644
> --- a/hw/vfio/migration.c
> +++ b/hw/vfio/migration.c
> @@ -785,14 +785,14 @@ static void vfio_migration_exit(VFIODevice *vbasedev)
>      vbasedev->migration = NULL;
>  }
>  
> -static int vfio_migration_init(VFIODevice *vbasedev,
> -                               struct vfio_region_info *info)
> +static int vfio_migration_init(VFIODevice *vbasedev)
>  {
>      int ret;
>      Object *obj;
>      VFIOMigration *migration;
>      char id[256] = "";
>      g_autofree char *path = NULL, *oid = NULL;
> +    struct vfio_region_info *info = NULL;

Nit, I'm not spotting any cases where we need this initialization.  The
same is not true in the code the info handling was extracted from.
Thanks,

Alex

>  
>      if (!vbasedev->ops->vfio_get_object) {
>          return -EINVAL;
> @@ -803,6 +803,14 @@ static int vfio_migration_init(VFIODevice *vbasedev,
>          return -EINVAL;
>      }
>  
> +    ret = vfio_get_dev_region_info(vbasedev,
> +                                   VFIO_REGION_TYPE_MIGRATION_DEPRECATED,
> +                                   VFIO_REGION_SUBTYPE_MIGRATION_DEPRECATED,
> +                                   &info);
> +    if (ret) {
> +        return ret;
> +    }
> +
>      vbasedev->migration = g_new0(VFIOMigration, 1);
>      vbasedev->migration->device_state = VFIO_DEVICE_STATE_V1_RUNNING;
>      vbasedev->migration->vm_running = runstate_is_running();
> @@ -822,6 +830,8 @@ static int vfio_migration_init(VFIODevice *vbasedev,
>          goto err;
>      }
>  
> +    g_free(info);
> +
>      migration = vbasedev->migration;
>      migration->vbasedev = vbasedev;
>  
> @@ -844,6 +854,7 @@ static int vfio_migration_init(VFIODevice *vbasedev,
>      return 0;
>  
>  err:
> +    g_free(info);
>      vfio_migration_exit(vbasedev);
>      return ret;
>  }
> @@ -857,34 +868,23 @@ int64_t vfio_mig_bytes_transferred(void)
>  
>  int vfio_migration_probe(VFIODevice *vbasedev, Error **errp)
>  {
> -    struct vfio_region_info *info = NULL;
>      int ret = -ENOTSUP;
>  
>      if (!vbasedev->enable_migration) {
>          goto add_blocker;
>      }
>  
> -    ret = vfio_get_dev_region_info(vbasedev,
> -                                   VFIO_REGION_TYPE_MIGRATION_DEPRECATED,
> -                                   VFIO_REGION_SUBTYPE_MIGRATION_DEPRECATED,
> -                                   &info);
> +    ret = vfio_migration_init(vbasedev);
>      if (ret) {
>          goto add_blocker;
>      }
>  
> -    ret = vfio_migration_init(vbasedev, info);
> -    if (ret) {
> -        goto add_blocker;
> -    }
> -
> -    trace_vfio_migration_probe(vbasedev->name, info->index);
> -    g_free(info);
> +    trace_vfio_migration_probe(vbasedev->name);
>      return 0;
>  
>  add_blocker:
>      error_setg(&vbasedev->migration_blocker,
>                 "VFIO device doesn't support migration");
> -    g_free(info);
>  
>      ret = migrate_add_blocker(vbasedev->migration_blocker, errp);
>      if (ret < 0) {
> diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
> index a21cbd2a56..27c059f96e 100644
> --- a/hw/vfio/trace-events
> +++ b/hw/vfio/trace-events
> @@ -148,7 +148,7 @@ vfio_display_edid_update(uint32_t prefx, uint32_t prefy) "%ux%u"
>  vfio_display_edid_write_error(void) ""
>  
>  # migration.c
> -vfio_migration_probe(const char *name, uint32_t index) " (%s) Region %d"
> +vfio_migration_probe(const char *name) " (%s)"
>  vfio_migration_set_state(const char *name, uint32_t state) " (%s) state %d"
>  vfio_vmstate_change(const char *name, int running, const char *reason, uint32_t dev_state) " (%s) running %d reason %s device state %d"
>  vfio_migration_state_notifier(const char *name, const char *state) " (%s) state %s"