[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] [RFC] save/restore with icount enabled.

From: Paolo Bonzini
Subject: Re: [Qemu-devel] [RFC] save/restore with icount enabled.
Date: Wed, 15 May 2013 14:50:37 +0200
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130311 Thunderbird/17.0.4

Il 15/05/2013 11:31, KONRAD Frédéric ha scritto:
> Hi,
> We are trying to do a simple save/restore on the VM with icount enabled.
> We saw that qemu_icount_bias and qemu_icount in cpus.c are not
> saved/restored,
> and icount_extra, icount_decr in CPUState neither, so the vm_clock is just
> growing normally after restoring the VM is that normal?
> We think that this is making the "replay" undeterminastic, which is bad for
> reverse execution.
> Is there a good reason for them not being saved?

No.  You can probably move icount to timers_state.  Something like
zeroing qemu_icount in cpu_disable_ticks() is required in order to save
qemu_icount_bias like the other members of timers_state.  There is even
a dummy field that you can reuse to avoid the pain of adding a
subsection to vmstate_timers. :)


> Thanks,
> Fred

reply via email to

[Prev in Thread] Current Thread [Next in Thread]