On Wed, 2012-09-26 at 15:20 +0200, Roedel, Joerg wrote: > On Tue, Sep 25, 2012 at 01:43:46PM -0600, Alex Williamson wrote: > > Joerg, any thoughts on a quirk for this? Unfortunately we can't just > > skip IOMMU groups when an alias is broken because it puts the other > > IOMMU groups at risk that might not actually be isolated from this > > device. It looks like we parse the alias info before PCI is probed, so > > maybe we'd need to call the quirk from iommu_init_device itself. > > I fear that the BIOS does everything right and device 08:04.0 is indeed > using 08:00.0 as request-id. There are a couple of devices where this > happens, usually when the vendor just took the old 32bit PCI chip, added > a transparent PCIe-to-PCI bridge to the device and sell it a PCIe. > > So the assumption that every request-id has a corresponding pci_dev > structure does not hold. I also had made that assumption in the > AMD IOMMU driver but had to add code which removes that assumption. We > should look for a way to remove that assumption from the group-code too.
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? Thanks, Alex -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/