Re: [Qemu-devel] [PATCH v7 07/13] vfio: Add migration state change notifier

[Yan Zhao]

On Tue, Jul 09, 2019 at 05:49:14PM +0800, Kirti Wankhede wrote:
> Added migration state change notifier to get notification on migration state
> change. These states are translated to VFIO device state and conveyed to 
> vendor
> driver.
> 
> Signed-off-by: Kirti Wankhede <address@hidden>
> Reviewed-by: Neo Jia <address@hidden>
> ---
>  hw/vfio/migration.c           | 54 
> +++++++++++++++++++++++++++++++++++++++++++
>  hw/vfio/trace-events          |  1 +
>  include/hw/vfio/vfio-common.h |  1 +
>  3 files changed, 56 insertions(+)
> 
> diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
> index c01f08b659d0..e4a89a6f9bc7 100644
> --- a/hw/vfio/migration.c
> +++ b/hw/vfio/migration.c
> @@ -132,6 +132,53 @@ static void vfio_vmstate_change(void *opaque, int 
> running, RunState state)
>      }
>  }
>  
> +static void vfio_migration_state_notifier(Notifier *notifier, void *data)
> +{
> +    MigrationState *s = data;
> +    VFIODevice *vbasedev = container_of(notifier, VFIODevice, 
> migration_state);
> +    int ret;
> +
> +    trace_vfio_migration_state_notifier(vbasedev->name, s->state);
> +
> +    switch (s->state) {
> +    case MIGRATION_STATUS_ACTIVE:
> +        if (vbasedev->device_state & VFIO_DEVICE_STATE_RUNNING) {
> +            if (vbasedev->vm_running) {
> +                ret = vfio_migration_set_state(vbasedev,
> +                          VFIO_DEVICE_STATE_RUNNING | 
> VFIO_DEVICE_STATE_SAVING);
> +                if (ret) {
> +                    error_report("%s: Failed to set state RUNNING and 
> SAVING",
> +                                  vbasedev->name);
> +                }
> +            } else {
> +                ret = vfio_migration_set_state(vbasedev,
> +                                               VFIO_DEVICE_STATE_SAVING);
> +                if (ret) {
> +                    error_report("%s: Failed to set state STOP and SAVING",
> +                                 vbasedev->name);
> +                }
> +            }
> +        } else {
> +            ret = vfio_migration_set_state(vbasedev,
> +                                           VFIO_DEVICE_STATE_RESUMING);
> +            if (ret) {
> +                error_report("%s: Failed to set state RESUMING",
> +                             vbasedev->name);
> +            }
> +        }
> +        return;
> +
hi Kirti
currently, migration state notifiers are only notified in below 3 interfaces:
migrate_fd_connect, migrate_fd_cleanup, postcopy_start, where
MIGRATION_STATUS_ACTIVE is not an valid state.
Have you tested the above code? what's the purpose of the code?

Thanks
Yan

> +    case MIGRATION_STATUS_CANCELLING:
> +    case MIGRATION_STATUS_CANCELLED:
> +    case MIGRATION_STATUS_FAILED:
> +        ret = vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_RUNNING);
> +        if (ret) {
> +            error_report("%s: Failed to set state RUNNING", vbasedev->name);
> +        }
> +        return;
> +    }
> +}
> +
>  static int vfio_migration_init(VFIODevice *vbasedev,
>                                 struct vfio_region_info *info)
>  {
> @@ -152,6 +199,9 @@ static int vfio_migration_init(VFIODevice *vbasedev,
>      vbasedev->vm_state = 
> qemu_add_vm_change_state_handler(vfio_vmstate_change,
>                                                            vbasedev);
>  
> +    vbasedev->migration_state.notify = vfio_migration_state_notifier;
> +    add_migration_state_change_notifier(&vbasedev->migration_state);
> +
>      return 0;
>  }
>  
> @@ -194,6 +244,10 @@ void vfio_migration_finalize(VFIODevice *vbasedev)
>          return;
>      }
>  
> +    if (vbasedev->migration_state.notify) {
> +        remove_migration_state_change_notifier(&vbasedev->migration_state);
> +    }
> +
>      if (vbasedev->vm_state) {
>          qemu_del_vm_change_state_handler(vbasedev->vm_state);
>      }
> diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
> index 3d15bacd031a..69503228f20e 100644
> --- a/hw/vfio/trace-events
> +++ b/hw/vfio/trace-events
> @@ -148,3 +148,4 @@ vfio_display_edid_write_error(void) ""
>  vfio_migration_probe(char *name, uint32_t index) " (%s) Region %d"
>  vfio_migration_set_state(char *name, uint32_t state) " (%s) state %d"
>  vfio_vmstate_change(char *name, int running, const char *reason, uint32_t 
> dev_state) " (%s) running %d reason %s device state %d"
> +vfio_migration_state_notifier(char *name, int state) " (%s) state %d"
> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
> index f6c70db3a9c1..a022484d2636 100644
> --- a/include/hw/vfio/vfio-common.h
> +++ b/include/hw/vfio/vfio-common.h
> @@ -128,6 +128,7 @@ typedef struct VFIODevice {
>      uint32_t device_state;
>      VMChangeStateEntry *vm_state;
>      int vm_running;
> +    Notifier migration_state;
>  } VFIODevice;
>  
>  struct VFIODeviceOps {
> -- 
> 2.7.0
>