[PATCH v4 1/7] iommu: Prevent pasid attach if no ops->remove_dev_pasid

Yi Liu
2024-11-08T12:04:32Z

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.

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
---
drivers/iommu/iommu.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 13fcd9d8f2df..1c689e57928e 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -3352,17 +3352,19 @@ int iommu_attach_device_pasid(struct iommu_domain *domain,
struct iommu_attach_handle *handle)
{
/* Caller must be a probed driver on dev */
+ const struct iommu_ops *ops = dev_iommu_ops(dev);
struct iommu_group *group = dev->iommu_group;
struct group_device *device;
int ret;

- if (!domain->ops->set_dev_pasid)
+ if (!domain->ops->set_dev_pasid ||
+ !ops->remove_dev_pasid)
return -EOPNOTSUPP;

if (!group)
return -ENODEV;

- if (!dev_has_iommu(dev) || dev_iommu_ops(dev) != domain->owner ||
+ if (!dev_has_iommu(dev) || ops != domain->owner ||
pasid == IOMMU_NO_PASID)
return -EINVAL;

--
2.34.1