[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

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

From: Juergen Keil
Subject: Re: [Qemu-devel] enabling bus-master IDE driver
Date: Fri, 5 Nov 2004 16:37:06 +0100 (CET)

> Quoting zitu <address@hidden>:
> > >
> > > Does that mean that the patch doesn't work?  Do I have to do something 
> > > 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 ?
> answering to myself... :)
> WIN_WRITEDMA_EXT & WIN_READDMA_EXT cases are not defined in hw/ide.c

Aha, and Windows uses these commands, on small HDDs <= 128GB ?

> I have no idea where to start to write a patch for these... :(
> Until these and the atapi_dma are set/defined, no dma should work IMHO.
> And this seems not to be OS dependant.
> Which means the linux figures I got were wrong ???

The *_EXT versions are apparently for HDDs with capacities >128GB, these
need 48-bit LBA addresses to access the HDD space over the 128GB mark.

I guess that Solaris/Linux uses the commands with the smaller 28-bit
LBA disk addresses for small disks with capacities <= 128GB.

An interesting experiment would be to setup a QEMU HDD image > 128GB,
then try Solaris x86/Linux with such a big disk and check if it still
works.  Probably not.

reply via email to

[Prev in Thread] Current Thread [Next in Thread]