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);
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.
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