From: Paul Brook <paul@codesourcery.com>
To: qemu-devel@nongnu.org
Cc: Steffen Liebergeld <usenet@gmx.eu>
Subject: Re: [Qemu-devel] Re: Precise guest instruction count.
Date: Wed, 11 Mar 2009 13:13:20 +0000 [thread overview]
Message-ID: <200903111313.20980.paul@codesourcery.com> (raw)
In-Reply-To: <gp8c91$g22$1@ger.gmane.org>
> By turning of all timers in Qemu I hope to disable all timer interrupts for
> the guest. The results I get are not correct for the first time the code is
> run, but for all subsequent runs. In the first run, the instruction count
> has 12 additional instructions, which are not actually executed.
>
> What is the cause of those additional instructions?
Probably you're not reading the correct value. Like I said, for performance
reasons the counter is only valid at certain points.
Try instead implementing your timer as a peripheral.
Paul
next prev parent reply other threads:[~2009-03-11 13:13 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-09 9:38 [Qemu-devel] Precise guest instruction count Steffen Liebergeld
2009-03-09 21:56 ` Laurent Desnogues
2009-03-11 10:33 ` [Qemu-devel] " Steffen Liebergeld
2009-03-11 10:42 ` Laurent Desnogues
2009-03-11 12:53 ` Steffen Liebergeld
2009-03-11 13:13 ` Paul Brook [this message]
2009-03-10 1:55 ` [Qemu-devel] " Paul Brook
2009-03-11 11:45 ` [Qemu-devel] " Steffen Liebergeld
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