[Qemu-devel] guest clock management for testing real-time systems

[Sébastien Barthélémy]

Hello all,

In order to test and debug a linux-based real-time system, I'd like to
hook it up to a software simulator, which sadly does not run fast
enough to meet the real-time constraints.

To workaround this problem, I had the idea of running the real-time
system in guest whose clock would be controlled by the simulator,
running on the host.
Alas, I found no API for doing so with qemu. Yet, it seems qtest does
it (I found qtest_clock_step [1] etc.)

Is it possible or at least conceivable to control (and slow down) the
guest time externally? Where should I look to get some insight on that
matter?

Note that this question was asked previously [2], [3], but never answered.

[1] http://lists.nongnu.org/archive/html/qemu-devel/2012-03/msg05326.html
[2] http://lists.gnu.org/archive/html/qemu-discuss/2012-05/msg00034.html
[3] http://lists.gnu.org/archive/html/qemu-devel/2008-08/msg01109.html