[lttng-dev] [Qemu-devel] [PATCH 0/6] hypertrace: Lightweight guest-to-QEMU trace channel

Lluís Vilanova vilanova at ac.upc.edu
Thu Aug 18 10:22:18 UTC 2016

Stefan Hajnoczi writes:

> On Fri, Aug 05, 2016 at 06:59:23PM +0200, Lluís Vilanova wrote:
>> The hypertrace channel allows guest code to emit events in QEMU (the host) using
>> its tracing infrastructure (see "docs/trace.txt"). This works in both 'system'
>> and 'user' modes. That is, hypertrace is to tracing, what hypercalls are to
>> system calls.
>> You can use this to emit an event on both guest and QEMU (host) traces to 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 and fully
>> synchronized trace log. Another use case is timing the performance of guest code
>> when optimizing TCG (QEMU traces have a timestamp).
>> See first commit for a full description.
>> Signed-off-by: Lluís Vilanova <vilanova at 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.


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