Re: [Qemu-devel] [PATCH] add iommu version to sparc32

[Blue Swirl]

On 11/16/07, Robert Reif <address@hidden> wrote:
>
> >>Add iommu version to sparc32.  Also reset iommu after initialization.
> >>
> >>
> >
> >Should the version be tied to CPU model instead of machine type? At
> >least for Turbosparc this seems to be the case.
> >
> >
> On SMP systems the IOMMU is on the system board in a separate ASIC.  On
> single CPU systems the IOMMU is integrated into the CPU.  Without checking
> the FEH, the SS 5 was the only single CPU system that shipped with more than
> one family of CPUs (MicroSparc II and TurboSparc and they do have different
> IOMMU versions).  That could be special cased.

OK, then the machine is more correct place.

Thanks, patch applied.

> Unfortunately QEMU will allow you to specify unrealistic systems.  We
> should
> probably add allowable CPU types to specific machine types to catch this.

Well, there are plenty of things that can be unrealistic, for example
memory size. For the IOMMU case, Linux does not make any checks for
the version, same with NetBSD. I don't think it matters too much.