Re: [Qemu-devel] [patch] non-blocking disk IO

[Brad Campbell <brad@wasp.net.au>]

John Coiner wrote:
> 
> Non-blocking disk IO now works for any type of disk image, not just 
> "raw" format. There is no longer any format-specific code in the patch:
> 
> http://people.brandeis.edu/~jcoiner/qemu_idedma/qemu_dma_patch.html
> 
> You might want this patch if:
>  * you run a multitasking guest OS,
>  * you access a disk sometimes, and
>  * you wouldn't mind if QEMU ran a little faster.
> 
> Why I have not got feedback in droves I do not understand ;)

I have 3 or 4 images here (of different flavours of windows from 95 -> XP) that I have base images 
about 4G and then I use qcow files to do my testing and other damaging stuff to.
With this patch qemu will not boot the qcow files but will boot the base images (I copy them and 
then try to boot to test). As soon as I patch -R && make, qemu will boot the qcow files no problems..

Let me clarify that..
qemu-img create -f qcow xp.img 4G
qemu -cdrom xp.iso -hda xp.img -boot d (Install XP from scratch)
qemu-img create -b xp.img -f qcow xp2.img
qemu -hda xp2.img

This gives me an invalid hard disk error. If I revert the patch I can boot from xp2.img with no 
issues. With or without the patch I can boot from xp.img.

I have tried installing XP with and without the patch and that works fine..

Regards,
Brad
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