Re: [Qemu-devel] [PATCH] -win2k-hack performance+DMA support

[Leonardo E. Reiter]

No problem... hopefully Fabrice will apply this patch to CVS soon. 
We've been testing/deploying this mechanism (every 16th interrupt) with 
Win4Lin Pro for a long time now with no disk full problems, so I can 
vouch that it's reliable (and quite fast compared to delaying on *every* 
interrupt).  As for the DMA reintroducing the problem, that's 
understandable since Fabrice didn't originally implement the 
win2k_install_hack check for the DMA callback in hw/ide.c.  It was a 
moot point since DMA didn't work with Windows 2000 anyway in QEMU CVS 
until very recently, but since it does now, it will cause problems 
unless it handles -win2k-hack as well.

- Leo Reiter

Brad Campbell wrote:
> Using todays CVS, and kqemu in user mode only I tried to install 
> Win2k-SP4 25 times all with disk full errors until I applied this patch.
> It would appear the installer will use DMA mode if it's available and 
> therefore the existing win2k-hack does not work.
>
> Using this patch 5 out of 5 installs worked perfectly.
>
> Thanks Leo :)
>
> Regards,
> Brad

--
Leonardo E. Reiter
Vice President of Product Development, CTO

Win4Lin, Inc.
Virtual Computing from Desktop to Data Center
Main: +1 512 339 7979
Fax: +1 512 532 6501
http://www.win4lin.com