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From: =?utf-8?Q?Llu=C3=ADs_Vilanova?= <vilanova@ac.upc.edu>
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Date: Thu, 18 Aug 2016 12:22:18 +0200
In-Reply-To: <20160818094720.GA4850@stefanha-x1.localdomain> (Stefan
	Hajnoczi's message of "Thu, 18 Aug 2016 10:47:20 +0100")
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Subject: Re: [Qemu-devel] [PATCH 0/6] hypertrace: Lightweight guest-to-QEMU
 trace channel
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To: Stefan Hajnoczi <stefanha@gmail.com>
Cc: qemu-devel@nongnu.org, Steven Rostedt <rostedt@goodmis.org>, Luiz Capitulino <lcapitulino@redhat.com>, lttng-dev@lists.lttng.org, Masami Hiramatsu <mhiramat@kernel.org>, Stefan Hajnoczi <stefanha@redhat.com>

Stefan Hajnoczi writes:

> On Fri, Aug 05, 2016 at 06:59:23PM +0200, Llu=C3=ADs Vilanova wrote:
>> The hypertrace channel allows guest code to emit events in QEMU (the hos=
t) using
>> its tracing infrastructure (see "docs/trace.txt"). This works in both 's=
ystem'
>> and 'user' modes. That is, hypertrace is to tracing, what hypercalls are=
 to
>> system calls.
>>=20
>> You can use this to emit an event on both guest and QEMU (host) traces t=
o easily
>> synchronize or correlate them. You could also modify you guest's tracing=
 system
>> to emit all events through the hypertrace channel, providing a unified a=
nd fully
>> synchronized trace log. Another use case is timing the performance of gu=
est code
>> when optimizing TCG (QEMU traces have a timestamp).
>>=20
>> See first commit for a full description.
>>=20
>> Signed-off-by: Llu=C3=ADs Vilanova <vilanova@ac.upc.edu>
>> ---

> CCing Steven Rostedt, Masami Hiramatsu, Luiz Capitulino, and LTTng folks
> who have all looked into host/guest tracing solutions.
[...]

Oh, I wasn't aware of that. I'm certainly interested in collaborating.


Cheers,
  Lluis