From mboxrd@z Thu Jan  1 00:00:00 1970
From: Yuanhan Liu <yliu@fridaylinux.org>
Subject: Re: [PATCH 10/12] vhost: support to kick in secondary
	process
Date: Thu, 21 Sep 2017 17:17:59 +0800
Message-ID: <20170921091759.GE2251@yliu-home>
References: <1503654052-84730-1-git-send-email-jianfeng.tan@intel.com>
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 <20170921033323.GA2251@yliu-home>
 <59f2bfc0-91ee-b276-68e3-563e5b5af89b@intel.com>
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To: "Tan, Jianfeng" <jianfeng.tan@intel.com>
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On Thu, Sep 21, 2017 at 03:04:39PM +0800, Tan, Jianfeng wrote:
> >On Fri, Aug 25, 2017 at 09:40:50AM +0000, Jianfeng Tan wrote:
> >>To support kick in secondary process, we propose callfd_pri and
> >>kickfd_pri to store the value in primary process; and by a new
> >>API, rte_vhost_set_vring_effective_fd(), we can set effective
> >>callfd and kickfd which can be used by secondary process.
> >>
> >>Note in this case, either primary process or the secondary process
> >>can kick the frontend; that is, they cannot kick a vring at the
> >>same time.
> >Since only one can work, why not just overwriting the fd? Say, you
> >could introudce some APIs like "rte_vhost_set_vring_callfd", then
> >you don't need to introduce few more fields like "callfd_pri".
> 
> That cannot address the below case:
> 1. Primary starts;
> 2. Secondary one starts; (if we overwrite it without storing it in some
> other fields)
> 3. Secondary one exits;
> 4. Secondary two starts. (primary cannot share the fd with this secondary
> process now, as this fd does not mean anything to the primary process)

I was thinking that those fds will be retrieved by the primary process
once? So thsoe it got at beginning are still valid?

	--yliu