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Date:   Tue, 5 Apr 2022 15:54:12 +0200
From:   Vincent Whitchurch <vincent.whitchurch@axis.com>
To:     Johannes Berg <johannes@sipsolutions.net>
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Subject: Re: [RFC v1 01/10] roadtest: import libvhost-user from QEMU
Message-ID: <20220405135412.GB28574@axis.com>
References: <20220311162445.346685-1-vincent.whitchurch@axis.com>
 <20220311162445.346685-2-vincent.whitchurch@axis.com>
 <7f405d8d09a83954aa3411eff8b71ee687c7ec33.camel@sipsolutions.net>
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On Thu, Mar 24, 2022 at 02:00:10PM +0100, Johannes Berg wrote:
> On Fri, 2022-03-11 at 17:24 +0100, Vincent Whitchurch wrote:
> > Import the libvhost-user from QEMU for use in the implementation of the
> > virtio devices in the roadtest backend.
> 
> So hm, I wonder if this is the sensible thing to do?
> 
> Not that I mind importing qemu code, but:
> 
>  1) the implementation is rather complex in some places, and has support
>     for a LOT of virtio/vhost-user features that are really not needed
>     in these cases, for performance etc. It's also close to 4k LOC.

Is this really a problem given that the code is imported as-is?  The
intention is not to have to make a lot of local modifications to it in
the kernel tree.  The code is stable and presumably well-tested
upstream, and upstream maintains it as a separate library (in the QEMU
source tree though) to encourage reuse.

>  2) the implementation doesn't support time-travel mode which might come
>     in handy

True, but I don't see the external time-travel controller stuff being
too useful for the kinds of tests this framework is targeting.