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From: Paul Brook <paul@codesourcery.com>
Subject: Re: [Qemu-devel] time inside qemu
Date: Fri, 29 Dec 2006 18:10:41 +0000
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To: qemu-devel@nongnu.org
Cc: =?iso-8859-1?q?M=E0rius_Mont=F3n?= <marius.monton@uab.cat>

On Friday 29 December 2006 17:53, M=E0rius Mont=F3n wrote:
> Hi,
>
> As I understand, OSes running inside qemu "have" notion of time: (its
> date and time works, time(1) command works, etc.).
> My question is about how qemu manages time. I need to stop and start
> again this "virtual-time".

qemu doesn't maintain virtual time, it just uses the real host time.

> I just tried with cpu_disable_ticks() and cpu_enable_ticks(). It seems
> to work partially: at least now system date and time are out of sync..

I suspect you'll find that for anything other than very coarse user (ie. us=
er=20
stop/continue) these are effectively useless.

Any benchmark/performance measurements you make inside qemu are meaningless=
=2E=20
qemu performance bears no relation whatsoever to the performance=20
characteristics of real hardware.

Paul