[RFC,v2,27/32] vhost+postcopy: Wire up POSTCOPY_END notify

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

Wire up a call to VHOST_USER_POSTCOPY_END message to the vhost clients
right before we ask the listener thread to shutdown.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 hw/virtio/trace-events   |  2 ++
 hw/virtio/vhost-user.c   | 30 ++++++++++++++++++++++++++++++
 migration/postcopy-ram.c |  5 +++++
 migration/postcopy-ram.h |  1 +
 4 files changed, 38 insertions(+)

On Thu, Aug 24, 2017 at 08:27:25PM +0100, Dr. David Alan Gilbert (git) wrote:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> 
> Wire up a call to VHOST_USER_POSTCOPY_END message to the vhost clients
> right before we ask the listener thread to shutdown.
> 
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

Reviewed-by: Peter Xu <peterx@redhat.com>

> ---
>  hw/virtio/trace-events   |  2 ++
>  hw/virtio/vhost-user.c   | 30 ++++++++++++++++++++++++++++++
>  migration/postcopy-ram.c |  5 +++++
>  migration/postcopy-ram.h |  1 +
>  4 files changed, 38 insertions(+)
> 
> diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
> index 065822c70a..5b599617a1 100644
> --- a/hw/virtio/trace-events
> +++ b/hw/virtio/trace-events
> @@ -1,6 +1,8 @@
>  # See docs/devel/tracing.txt for syntax documentation.
>  
>  # hw/virtio/vhost-user.c
> +vhost_user_postcopy_end_entry(void) ""
> +vhost_user_postcopy_end_exit(void) ""
>  vhost_user_postcopy_fault_handler(const char *name, uint64_t fault_address, int nregions) "%s: @0x%"PRIx64" nregions:%d"
>  vhost_user_postcopy_fault_handler_loop(int i, uint64_t client_base, uint64_t size) "%d: client 0x%"PRIx64" +0x%"PRIx64
>  vhost_user_postcopy_fault_handler_found(int i, uint64_t region_offset, uint64_t rb_offset) "%d: region_offset: 0x%"PRIx64" rb_offset:0x%"PRIx64
> diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
> index c2e55be0fd..d4461459fe 100644
> --- a/hw/virtio/vhost-user.c
> +++ b/hw/virtio/vhost-user.c
> @@ -965,6 +965,33 @@ static int vhost_user_postcopy_listen(struct vhost_dev *dev, Error **errp)
>      return 0;
>  }
>  
> +/*
> + * Called at the end of postcopy
> + */
> +static int vhost_user_postcopy_end(struct vhost_dev *dev, Error **errp)
> +{
> +    VhostUserMsg msg = {
> +        .request = VHOST_USER_POSTCOPY_END,
> +        .flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK,
> +    };
> +    int ret;
> +
> +    trace_vhost_user_postcopy_end_entry();
> +    if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
> +        error_setg(errp, "Failed to send postcopy_end to vhost");
> +        return -1;
> +    }
> +
> +    ret = process_message_reply(dev, &msg);
> +    if (ret) {
> +        error_setg(errp, "Failed to receive reply to postcopy_end");
> +        return ret;
> +    }
> +    trace_vhost_user_postcopy_end_exit();
> +
> +    return 0;
> +}
> +
>  static int vhost_user_postcopy_notifier(NotifierWithReturn *notifier,
>                                          void *opaque)
>  {
> @@ -990,6 +1017,9 @@ static int vhost_user_postcopy_notifier(NotifierWithReturn *notifier,
>      case POSTCOPY_NOTIFY_INBOUND_LISTEN:
>          return vhost_user_postcopy_listen(dev, pnd->errp);
>  
> +    case POSTCOPY_NOTIFY_INBOUND_END:
> +        return vhost_user_postcopy_end(dev, pnd->errp);
> +
>      default:
>          /* We ignore notifications we don't know */
>          break;
> diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
> index 7d0786ff04..28791cf1f1 100644
> --- a/migration/postcopy-ram.c
> +++ b/migration/postcopy-ram.c
> @@ -337,7 +337,12 @@ int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis)
>  
>      if (mis->have_fault_thread) {
>          uint64_t tmp64;
> +        Error *local_err = NULL;
>  
> +        if (postcopy_notify(POSTCOPY_NOTIFY_INBOUND_END, &local_err)) {
> +            error_report_err(local_err);
> +            return -1;
> +        }
>          if (qemu_ram_foreach_block(cleanup_range, mis)) {
>              return -1;
>          }
> diff --git a/migration/postcopy-ram.h b/migration/postcopy-ram.h
> index ecf731c689..d0dc838001 100644
> --- a/migration/postcopy-ram.h
> +++ b/migration/postcopy-ram.h
> @@ -130,6 +130,7 @@ enum PostcopyNotifyReason {
>      POSTCOPY_NOTIFY_PROBE = 0,
>      POSTCOPY_NOTIFY_INBOUND_ADVISE,
>      POSTCOPY_NOTIFY_INBOUND_LISTEN,
> +    POSTCOPY_NOTIFY_INBOUND_END,
>  };
>  
>  struct PostcopyNotifyData {
> -- 
> 2.13.5
>