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Date: Tue, 16 Nov 2010 13:33:31 -0600
From: Anthony Liguori <anthony@codemonkey.ws>
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Subject: Re: [Qemu-devel] Re: [Try2][PATCH] Initial implementation of a mpeg1
	layer2 streaming audio driver.
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To: =?ISO-8859-1?Q?Andreas_F=E4rber?= <andreas.faerber@web.de>
Cc: =?ISO-8859-1?Q?Fran=E7ois_Revol?= <revol@free.fr>, qemu-devel@nongnu.org

On 11/16/2010 01:22 PM, Andreas Färber wrote:
> Am 15.11.2010 um 22:53 schrieb François Revol:
>
>> I'm still having a hard time getting sound to work reliably in Haiku 
>> guests regardless the output or emulated card. OTH it works perfectly 
>> in VirtualBox with almost no cpu overhead. If anyone has a clue...
>> It might be related to the use of RDTSC as primary time source, still 
>> it's the same in vbox.
>
> Did you check the time drift command line options? Iirc Gleb needed 
> some hacks for timer-related issues on Windows.

Time drift correction is only applicable to the RTC and PIT and deals 
with catching up the periodic timers.

The issue with the TSC as a time source is that it skips around during 
CPU migration.  The easiest way to work around this is to simply pin 
your guest to a single physical CPU (assuming you're using KVM).

With TCG, it depends, but you can actually end up accessing the host TSC 
in which case, your SOL because the code in QEMU that uses the host TSC 
assumes a UP host which aren't all that common anymore :-)

Regards,

Anthony Liguori

>> (does [KVM] even work on OSX ?)
>
> No.
>
> Andreas