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Date: Fri, 23 Nov 2018 18:19:48 -0500
From: "Emilio G. Cota" <cota@braap.org>
Message-ID: <20181123231948.GB13782@flamenco>
References: <20181025172057.20414-1-cota@braap.org>
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	<874lc9hwe5.fsf@linaro.org>
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Subject: Re: [Qemu-devel] [RFC 10/48] exec: export do_tb_flush
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To: Alex =?iso-8859-1?Q?Benn=E9e?= <alex.bennee@linaro.org>
Cc: qemu-devel@nongnu.org, Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>, =?iso-8859-1?Q?Llu=EDs?= Vilanova <vilanova@ac.upc.edu>, Peter Maydell <peter.maydell@linaro.org>, Stefan Hajnoczi <stefanha@gmail.com>

On Thu, Nov 22, 2018 at 17:09:22 +0000, Alex Bennée wrote:
> 
> Emilio G. Cota <cota@braap.org> writes:
> 
> > This will be used by plugin code to flush the code cache as well
> > as doing other bookkeeping in a safe work environment.
> 
> This seems a little excessive given the plugin code could just call
> tb_flush() directly. Wouldn't calling tb_flush after scheduling the
> plugin_destroy be enough?
> 
> If there is a race condition here maybe we could build some sort of
> awareness into tb_flush as to the current run state. But having two
> entry points to this rather fundamental action seems likely to either be
> misused or misunderstood.

We have to make sure that no callback left in the generated code is
called once a plugin has been uninstalled. To me, using the same safe
work window to both flush the TB and uninstall the plugin seems the
simplest way to do this.

Thanks,

		Emilio