On Wed, Sep 26, 2012 at 08:35:59AM -0600, Alex Williamson wrote:
> Hmm, that throws a kink in iommu groups. So perhaps we need to make an
> alias interface to iommu groups. Seems like this could just be an extra
> parameter to iommu_group_get and iommu_group_add_device (empty in the
> typical case). Then we have the problem of what's the type for an
> alias? For AMI-Vi, it's a u16, but we need to be more generic than
> that. Maybe iommu groups should just treat it as a void* so iommus can
> use a pointer to some structure or a fixed value like a u16 bus:slot.
> Thoughts?
Good question. The iommu-groups are part of the IOMMU-API, with an
interface to the IOMMU drivers and one to the users of IOMMU-API. So the
alias handling itself should be a function of the interface to the IOMMU
driver. In general the interface should not be bus specific.
So a void pointer seems the only logical choice then. But I would not
limit its scope to alias handling. How about making it a bus-private
pointer where IOMMU driver store bus-specific information. That way we
make sure that there is one struct per bus-type for this pointer, and
not one structure per IOMMU driver.
Joerg
--
AMD Operating System Research Center
Advanced Micro Devices GmbH Einsteinring 24 85609 Dornach
General Managers: Alberto Bozzo
Registration: Dornach, Landkr. Muenchen; Registerger. Muenchen, HRB Nr. 43632
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
