Hi Alex,
On 7/30/20 4:03 AM, Alex Williamson wrote:
On Tue, 14 Jul 2020 13:57:00 +0800
Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> wrote:
The iommu aux-domain api's work only when IOMMU_DEV_FEAT_AUX is enabled
for the device. Add this check to avoid misuse.
Shouldn't this really be the IOMMU driver's responsibility to test? If
nothing else, iommu_dev_feature_enabled() needs to get the iommu_ops
from dev->bus->iommu_ops, which is presumably the same iommu_ops we're
then calling from domain->ops to attach/detach the device, so it'd be
more efficient for the IOMMU driver to error on devices that don't
support aux. Thanks,
Fair enough. The vendor iommu driver always knows the status of aux-
domain support. So this check is duplicated. I will drop this patch.
Best regards,
baolu
Alex
Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
---
drivers/iommu/iommu.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 1ed1e14a1f0c..e1fdd3531d65 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2725,11 +2725,13 @@ EXPORT_SYMBOL_GPL(iommu_dev_feature_enabled);
*/
int iommu_aux_attach_device(struct iommu_domain *domain, struct device *dev)
{
- int ret = -ENODEV;
+ int ret;
- if (domain->ops->aux_attach_dev)
- ret = domain->ops->aux_attach_dev(domain, dev);
+ if (!iommu_dev_feature_enabled(dev, IOMMU_DEV_FEAT_AUX) ||
+ !domain->ops->aux_attach_dev)
+ return -ENODEV;
+ ret = domain->ops->aux_attach_dev(domain, dev);
if (!ret)
trace_attach_device_to_domain(dev);
@@ -2748,12 +2750,12 @@ EXPORT_SYMBOL_GPL(iommu_aux_detach_device);
int iommu_aux_get_pasid(struct iommu_domain *domain, struct device *dev)
{
- int ret = -ENODEV;
+ if (!iommu_dev_feature_enabled(dev, IOMMU_DEV_FEAT_AUX) ||
+ !domain->ops->aux_get_pasid)
+ return -ENODEV;
- if (domain->ops->aux_get_pasid)
- ret = domain->ops->aux_get_pasid(domain, dev);
+ return domain->ops->aux_get_pasid(domain, dev);
- return ret;
}
EXPORT_SYMBOL_GPL(iommu_aux_get_pasid);
