Re: [Qemu-devel] enabling bus-master IDE driver

[zitu <zitu@free.fr>]

Quoting Simon Frew <thargthedestroyer@hotmail.com>:
> Running qemu with 512mb ram.  Seems to work fine, but guest o/s installation
> was very slow.  So after reading through previous posts on here I found the
> patch posted previously to enable dma for ide, and have applied that to
> ide.c
> and rebuilt qemu.  Then in windows go to device manager and see what it
> thinks
> is installed.  Device manager says I have a Intel 82371SB PCI Bus Master IDE
> controller.  So I right-click on "Primary IDE channel" and look in
> properties->advanced settings.  Transfer Mode is set to "DMA if available"
> and current transfer mode says "PIO mode".  So it still seems to be in PIO
> mode!

I have the same problem inside XP guest too. Linux guest seems really in
DMA mode, since my transfer rates go from 17MB to 47MB on a 512MB hdd image.

>
> Does that mean that the patch doesn't work?  Do I have to do something else
> to make dma work?

I think this patch is almost complete for linux and solaris guests. Some
more work/init is needed inside XP/NT/2K. Anyone around with this
knowledge ?

Zitu
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