Hi Jacob,
On 7/15/20 12:39 AM, Jacob Pan wrote:
On Tue, 14 Jul 2020 13:57:01 +0800
Lu Baolu<baolu.lu@xxxxxxxxxxxxxxx> wrote:
This adds two new aux-domain APIs for a use case like vfio/mdev where
sub-devices derived from an aux-domain capable device are created and
put in an iommu_group.
/**
* iommu_aux_attach_group - attach an aux-domain to an iommu_group
which
* contains sub-devices (for example mdevs)
derived
* from @dev.
* @domain: an aux-domain;
* @group: an iommu_group which contains sub-devices derived from
@dev;
* @dev: the physical device which supports IOMMU_DEV_FEAT_AUX.
*
* Returns 0 on success, or an error value.
*/
int iommu_aux_attach_group(struct iommu_domain *domain,
struct iommu_group *group,
struct device *dev)
/**
* iommu_aux_detach_group - detach an aux-domain from an iommu_group
*
* @domain: an aux-domain;
* @group: an iommu_group which contains sub-devices derived from
@dev;
* @dev: the physical device which supports IOMMU_DEV_FEAT_AUX.
*
* @domain must have been attached to @group via
iommu_aux_attach_group(). */
void iommu_aux_detach_group(struct iommu_domain *domain,
struct iommu_group *group,
struct device *dev)
It also adds a flag in the iommu_group data structure to identify
an iommu_group with aux-domain attached from those normal ones.
Signed-off-by: Lu Baolu<baolu.lu@xxxxxxxxxxxxxxx>
---
drivers/iommu/iommu.c | 58
+++++++++++++++++++++++++++++++++++++++++++ include/linux/iommu.h |
17 +++++++++++++ 2 files changed, 75 insertions(+)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index e1fdd3531d65..cad5a19ebf22 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -45,6 +45,7 @@ struct iommu_group {
struct iommu_domain *default_domain;
struct iommu_domain *domain;
struct list_head entry;
+ unsigned int aux_domain_attached:1;
};
struct group_device {
@@ -2759,6 +2760,63 @@ int iommu_aux_get_pasid(struct iommu_domain
*domain, struct device *dev) }
EXPORT_SYMBOL_GPL(iommu_aux_get_pasid);
+/**
+ * iommu_aux_attach_group - attach an aux-domain to an iommu_group
which
+ * contains sub-devices (for example mdevs)
derived
+ * from @dev.
+ * @domain: an aux-domain;
+ * @group: an iommu_group which contains sub-devices derived from
@dev;
+ * @dev: the physical device which supports IOMMU_DEV_FEAT_AUX.
+ *
+ * Returns 0 on success, or an error value.
+ */
+int iommu_aux_attach_group(struct iommu_domain *domain,
+ struct iommu_group *group, struct device
*dev) +{
+ int ret = -EBUSY;
+
+ mutex_lock(&group->mutex);
+ if (group->domain)
+ goto out_unlock;
+
Perhaps I missed something but are we assuming only one mdev per mdev
group? That seems to change the logic where vfio does:
iommu_group_for_each_dev()
iommu_aux_attach_device()
It has been changed in PATCH 4/4:
static int vfio_iommu_attach_group(struct vfio_domain *domain,
struct vfio_group *group)
{
if (group->mdev_group)
return iommu_aux_attach_group(domain->domain,
group->iommu_group,
group->iommu_device);
else
return iommu_attach_group(domain->domain,
group->iommu_group);
}
So, for both normal domain and aux-domain, we use the same concept:
attach a domain to a group.
Best regards,
baolu
