iommu: Prevent pasid attach if no ops->remove_dev_pasid

driver should implement both set_dev_pasid and remove_dev_pasid op, otherwise
it is a problem how to detach pasid. In reality, it is impossible that an
iommu driver implements set_dev_pasid() but no remove_dev_pasid() op. However,
it is better to check it.

Move the group check to be the first as dev_iommu_ops() may fail when there
is no valid group. Also take the chance to remove the dev_has_iommu() check
as it is duplicated to the group check.

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20241204122928.11987-2-yi.l.liu@intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 599030e1e890ba6f0fa273ddd24fd3c9b2d1de44..286b14d008b2000d13847b127c7f327ff40029ba 100644 (file)
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -3368,16 +3368,19 @@ int iommu_attach_device_pasid(struct iommu_domain *domain,
        /* Caller must be a probed driver on dev */
        struct iommu_group *group = dev->iommu_group;
        struct group_device *device;
+       const struct iommu_ops *ops;
        int ret;
 
-       if (!domain->ops->set_dev_pasid)
-               return -EOPNOTSUPP;
-
        if (!group)
                return -ENODEV;
 
-       if (!dev_has_iommu(dev) || dev_iommu_ops(dev) != domain->owner ||
-           pasid == IOMMU_NO_PASID)
+       ops = dev_iommu_ops(dev);
+
+       if (!domain->ops->set_dev_pasid ||
+           !ops->remove_dev_pasid)
+               return -EOPNOTSUPP;
+
+       if (ops != domain->owner || pasid == IOMMU_NO_PASID)
                return -EINVAL;
 
        mutex_lock(&group->mutex);