Sergei Lyubski <slyub...@gmail.com> writes:
> Hi guys,
>
> My name is Sergey. My company uses QEMU for CPU performance
> simulation/evaluaton.
> Sorry, I found your emails in QEMU relatively recent commits into ram.c .
> Why ram.c . Because I see some weirdness in
> the behavior.
>
> Our goal is :
> a) To boot Linux , to launch some TEST/SPEC, to drop a few
> checkpoints.
> b) To resume execution from those checkpoints, to attach a
> performance simulator and
> to evaluate performance at the "hot" code areas.
>
> How we tried to do it .
>
> a) run QEMU with -monitor telnet options
> b) connect to QEMU with telnet
> c) after LINUX booted in QEMU monitor (telnet) executed
> migrate -d file://<FULL CKPT PATH>
> quit
> d) run QEMU with option -incoming file://<FULL CKPT PATH>
>
> Now !!
>
> If I drop the checkpoint when running on linux a long ( endless) test
> which prints on the console, everything works (!)
> and the console is properly restored.
>
> When I drop the checkpoint when the linux console is in shell prompt,
> the restoration does not work.
> I see either error message from ram_load_precopy()
> error_report("Unknown combination of migration flags: 0x%x",
> flags);
I suspect seeing the value of flags will help with any diagnosis.
>
> or
>
> the console is locked, QEMU restarts and runs (ps, top). The only
> solution is to kill
> QEMU . After that, QEMU console is distorted and requires to type
> RESET.
Are you able to attach with gdb and get a backtrace?
>
> Could you please comment on the above issues.
> If you need more info I can send you my screen shots.
> Please note that that the similar behavior is observed on both
> qemu 9.0 ( stable-9.0) and
> qemu 8.x
>
> Thanks in advance.
> Sergey Lyubskiy
--
Alex Bennée
Virtualisation Tech Lead @ Linaro
