Re: [Qemu-devel] [PATCH v4 10/29] vhost+postcopy: Register shared ufd with postcopy

[Marc-André Lureau]

On Thu, Mar 8, 2018 at 8:57 PM, Dr. David Alan Gilbert (git)
<address@hidden> wrote:
> From: "Dr. David Alan Gilbert" <address@hidden>
>
> Register the UFD that comes in as the response to the 'advise' method
> with the postcopy code.
>
> Signed-off-by: Dr. David Alan Gilbert <address@hidden>

Reviewed-by: Marc-André Lureau <address@hidden>


> ---
>  hw/virtio/vhost-user.c | 20 +++++++++++++++++++-
>  1 file changed, 19 insertions(+), 1 deletion(-)
>
> diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
> index 431858b219..9f74111e92 100644
> --- a/hw/virtio/vhost-user.c
> +++ b/hw/virtio/vhost-user.c
> @@ -171,6 +171,7 @@ struct vhost_user {
>      CharBackend *chr;
>      int slave_fd;
>      NotifierWithReturn postcopy_notifier;
> +    struct PostCopyFD  postcopy_fd;
>  };
>
>  static bool ioeventfd_enabled(void)
> @@ -796,6 +797,17 @@ out:
>      return ret;
>  }
>
> +/*
> + * Called back from the postcopy fault thread when a fault is received on our
> + * ufd.
> + * TODO: This is Linux specific
> + */
> +static int vhost_user_postcopy_fault_handler(struct PostCopyFD *pcfd,
> +                                             void *ufd)
> +{
> +    return 0;
> +}
> +
>  /*
>   * Called at the start of an inbound postcopy on reception of the
>   * 'advise' command.
> @@ -835,8 +847,14 @@ static int vhost_user_postcopy_advise(struct vhost_dev 
> *dev, Error **errp)
>          error_setg(errp, "%s: Failed to get ufd", __func__);
>          return -1;
>      }
> +    fcntl(ufd, F_SETFL, O_NONBLOCK);
>
> -    /* TODO: register ufd with userfault thread */
> +    /* register ufd with userfault thread */
> +    u->postcopy_fd.fd = ufd;
> +    u->postcopy_fd.data = dev;
> +    u->postcopy_fd.handler = vhost_user_postcopy_fault_handler;
> +    u->postcopy_fd.idstr = "vhost-user"; /* Need to find unique name */
> +    postcopy_register_shared_ufd(&u->postcopy_fd);
>      return 0;
>  }
>
> --
> 2.14.3
>
>



-- 
Marc-André Lureau