Re: [gentoo-user] CONFIG_IOMMU_SUPPORT???

[Joost Roeleveld <joost@antarean.org>]

On Wednesday, August 24, 2011 01:10:14 PM Mark Knecht wrote:
> On Wed, Aug 24, 2011 at 12:55 PM, Paul Hartman
> 
> <paul.hartman+gentoo@gmail.com> wrote:
> > On Wed, Aug 24, 2011 at 2:13 PM, Mark Knecht <markknecht@gmail.com> wrote:
> >> http://cateee.net/lkddb/web-lkddb/IOMMU_SUPPORT.html
> >> 
> >> which seem to indicate that I should see an IOMMU option somewhere in
> >> the drivers section of the kernel config. I do not, however, find that
> >> right now which is why I came here to ask.
> > 
> > It looks to me like the specific option CONFIG_IOMMU_SUPPORT was just
> > added for kernel 3.1, so you won't see it until then. It even mentions
> > it on the page you linked to:: "found in Linux kernels: 3.1-rc+HEAD"
> > 
> > It appears virtualbox-modules 4.1.0 doesn't check this. Maybe 4.1.2 is
> > developed against the 3.1 kernel... Maybe you should switch to the
> > latest git kernel, if you dare, or maybe you could mask the vbox
> > modules 4.1.2 and use 4.1.0 instead? I'm not a virtualbox user so I
> > have no idea if that's a reasonable suggestion or not, but I'm just
> > throwing it out there. :)
> 
> Thanks for the insights Paul. I'll roll back to a slightly earlier
> version of Virtualbox which will likely solve the problem.
> 
> Cheers,
> Mark

I just checked on my system and with Virtualbox 4.0.4, it works. (ok, it's 
older :)

# " zcat /proc/config.gz | grep IOMMU " gives:
**
# CONFIG_CALGARY_IOMMU is not set
# CONFIG_AMD_IOMMU is not set
CONFIG_IOMMU_HELPER=y
# CONFIG_IOMMU_API is not set
# CONFIG_IOMMU_STRESS is not set
** kernel = gentoo-sources-2.6.34-r6

I can succesfully run 64 and 32bit clients on this machine. CPU is Intel Xeon

On my other machine (with Virtualbox 4.0.12 and AMD Phenom CPU I get the 
following for the same command:
**
CONFIG_GART_IOMMU=y
CONFIG_CALGARY_IOMMU=y
CONFIG_CALGARY_IOMMU_ENABLED_BY_DEFAULT=y
CONFIG_AMD_IOMMU=y
CONFIG_AMD_IOMMU_STATS=y
CONFIG_IOMMU_HELPER=y
CONFIG_IOMMU_API=y
# CONFIG_IOMMU_DEBUG is not set
# CONFIG_IOMMU_STRESS is not set
** kernel = gentoo-sources-2.6.36-r5

I should probably disable some stuff, but not sure why the CALGARY got enabled 
by default.

I haven't gotten round to testing 4.1.2 yet.

--
Joost