> -----Original Message-----
> From: dev <[email protected]> On Behalf Of Ilya Maximets
> Sent: Wednesday, January 9, 2019 10:50 PM
> To: [email protected]; Maxime Coquelin <[email protected]>;
> Michael S . Tsirkin <[email protected]>; Xiao Wang
> <[email protected]>
> Cc: Tiwei Bie <[email protected]>; Zhihong Wang
> <[email protected]>; [email protected]; Jason Wang
> <[email protected]>; [email protected];
> [email protected]; Ilya Maximets
> <[email protected]>
> Subject: [dpdk-dev] [PATCH v3 2/3] net/virtio: update memory ordering
> comment for vq notify
> 
> We're not using io ports in case of modern device even on IA.
> Also, this comment useless for other architectures.

Agree, it should be architecture neutral. 

> 
> Signed-off-by: Ilya Maximets <[email protected]>
> ---
>  drivers/net/virtio/virtqueue.h | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/virtio/virtqueue.h b/drivers/net/virtio/virtqueue.h
> index dffa03669..53aeac238 100644
> --- a/drivers/net/virtio/virtqueue.h
> +++ b/drivers/net/virtio/virtqueue.h
> @@ -437,14 +437,13 @@ virtqueue_kick_prepare_packed(struct virtqueue
> *vq)
>       return flags != RING_EVENT_FLAGS_DISABLE;
>  }
> 
> +/*
> + * virtqueue_kick_prepare*() or the virtio_wmb() should be called
> + * before this function to be sure that all the data is visible to vhost.
> + */

C11 _atomic APIs are preferred for new code, other than wmb or rmb,  could you 
work on that? 

>  static inline void
>  virtqueue_notify(struct virtqueue *vq)
>  {
> -     /*
> -      * Ensure updated avail->idx is visible to host.
> -      * For virtio on IA, the notificaiton is through io port operation
> -      * which is a serialization instruction itself.
> -      */
>       VTPCI_OPS(vq->hw)->notify_queue(vq->hw, vq);
>  }
> 
> --
> 2.17.1

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