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Date: Fri, 14 Dec 2018 13:23:55 -0500
From: "Emilio G. Cota" <cota@braap.org>
Message-ID: <20181214182355.GA25356@flamenco>
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Subject: Re: [Qemu-devel] [RFC v2 05/38] plugin: add user-facing API
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To: Aaron Lindsay <aaron@os.amperecomputing.com>
Cc: "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>, Richard Henderson <richard.henderson@linaro.org>, Alex =?iso-8859-1?Q?Benn=E9e?= <alex.bennee@linaro.org>, Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>

On Fri, Dec 14, 2018 at 17:59:20 +0000, Aaron Lindsay wrote:
> On Dec 14 12:08, Emilio G. Cota wrote:
(snip)
> > The idea is that a plugin can "reset" itself, so that (1) all
> > its CBs are cleared and (2) the plugin can register new callbacks.
> > This would all happen in an atomic context (no vCPU running), so
> > that the plugin would miss no CPU events.
> 
> The implication being that there would not be the same possibility of
> other callbacks being called between when qemu_plugin_reset and the
> qemu_plugin_reset_cb_t callback are called as there is at plugin
> un-installation time?

The callback is needed for the same reason -- we can only guarantee
that there will be no callbacks once the current RCU read critical section
expires.

> > How does this sound?
> 
> I think what you describe is exactly what I'm interested in.

Nice. I'll work on this for v3.

Thanks,

		Emilio