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Date:   Tue, 2 Jun 2020 01:01:58 -0400
From:   "Michael S. Tsirkin" <mst@redhat.com>
To:     Jason Wang <jasowang@redhat.com>
Cc:     kvm@vger.kernel.org, virtualization@lists.linux-foundation.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
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        saugatm@xilinx.com, vmireyno@marvell.com,
        zhangweining@ruijie.com.cn, eli@mellanox.com
Subject: Re: [PATCH 1/6] vhost: allow device that does not depend on vhost
 worker
Message-ID: <20200602005904-mutt-send-email-mst@kernel.org>
References: <20200529080303.15449-1-jasowang@redhat.com>
 <20200529080303.15449-2-jasowang@redhat.com>
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On Fri, May 29, 2020 at 04:02:58PM +0800, Jason Wang wrote:
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index d450e16c5c25..70105e045768 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -166,11 +166,16 @@ static int vhost_poll_wakeup(wait_queue_entry_t *wait, unsigned mode, int sync,
>  			     void *key)
>  {
>  	struct vhost_poll *poll = container_of(wait, struct vhost_poll, wait);
> +	struct vhost_work *work = &poll->work;
>  
>  	if (!(key_to_poll(key) & poll->mask))
>  		return 0;
>  
> -	vhost_poll_queue(poll);
> +	if (!poll->dev->use_worker)
> +		work->fn(work);
> +	else
> +		vhost_poll_queue(poll);
> +
>  	return 0;
>  }
>

So a wakeup function wakes up eventfd directly.

What if user supplies e.g. the same eventfd as ioeventfd?

Won't this cause infinite loops?

-- 
MST