On Tue, Jan 27, 2015 at 12:08:56AM +0000, Joerg Roedel wrote: > From: Joerg Roedel <[email protected]> > > The default domain will be used (if supported by the iommu > driver) when the devices in the iommu group are not attached > to any other domain. > > Signed-off-by: Joerg Roedel <[email protected]> > --- > drivers/iommu/iommu.c | 26 +++++++++++++++++++++++--- > 1 file changed, 23 insertions(+), 3 deletions(-) > > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c > index 34636eb..8f33ddd3 100644 > --- a/drivers/iommu/iommu.c > +++ b/drivers/iommu/iommu.c > @@ -76,6 +76,9 @@ struct iommu_group_attribute iommu_group_attr_##_name = > \ > #define to_iommu_group(_kobj) \ > container_of(_kobj, struct iommu_group, kobj) > > +static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus, > + enum iommu_domain_type type); > + > static ssize_t iommu_group_attr_show(struct kobject *kobj, > struct attribute *__attr, char *buf) > { > @@ -362,6 +365,17 @@ rename: > > kobject_get(group->devices_kobj); > > + /* > + * Try to allocate a default domain for the group, if this > + * hasn't happened yet. This is not the best place to do that, > + * it should happen in iommu_group_alloc(). But we have no > + * iommu_ops there yet, so the allocation has to happen here for > + * now. > + */ > + if (group->default_domain == NULL) > + group->default_domain = __iommu_domain_alloc(dev->bus, > + IOMMU_DOMAIN_DMA);
Having a per-group domain is wasteful for IOMMUs that only support a modest number of concurrent domains, so in reality I think we need to have one domain per IOMMU instance. Is that possible? One problem with the current per-bus approach is that __iommu_domain_alloc can't figure out which IOMMU instance corresponds to the group. Will -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
