From: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Provide a high-level API to allow replacements of one domain with
another for specific pasid of a device. This is similar to
iommu_group_replace_domain() and it is also expected to be used
only by IOMMUFD.
Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Signed-off-by: Yi Liu <yi.l.liu@xxxxxxxxx>
---
drivers/iommu/iommu-priv.h | 2 ++
drivers/iommu/iommu.c | 73 ++++++++++++++++++++++++++++++--------
2 files changed, 60 insertions(+), 15 deletions(-)
@@ -3433,8 +3443,8 @@ EXPORT_SYMBOL_GPL(iommu_attach_device_pasid);
* The @domain must have been attached to @pasid of the @dev with
* iommu_attach_device_pasid().
*/
-void iommu_detach_device_pasid(struct iommu_domain *domain, struct device *dev,
- ioasid_t pasid)
+void iommu_detach_device_pasid(struct iommu_domain *domain,
+ struct device *dev, ioasid_t pasid)
{
struct iommu_group *group = iommu_group_get(dev);
@@ -3447,6 +3457,39 @@ void iommu_detach_device_pasid(struct iommu_domain *domain, struct device *dev,
}
EXPORT_SYMBOL_GPL(iommu_detach_device_pasid);
+/**
+ * iommu_replace_device_pasid - replace the domain that a pasid is attached to
+ * @domain: new IOMMU domain to replace with
+ * @dev: the physical device
+ * @pasid: pasid that will be attached to the new domain
+ *
+ * This API allows the pasid to switch domains. Return 0 on success, or an
+ * error. The pasid will roll back to use the old domain if failure. The
+ * caller could call iommu_detach_device_pasid() before free the old domain
+ * in order to avoid use-after-free case.
+ */
+int iommu_replace_device_pasid(struct iommu_domain *domain,
+ struct device *dev, ioasid_t pasid)
+{
+ struct iommu_group *group = dev->iommu_group;
+ int ret;
+
+ if (!domain)
+ return -EINVAL;
+
+ if (!group)
+ return -ENODEV;
+
+ mutex_lock(&group->mutex);
+ __iommu_remove_group_pasid(group, pasid);
+ xa_erase(&group->pasid_array, pasid);
+ ret = __iommu_group_attach_pasid(domain, group, pasid);
+ mutex_unlock(&group->mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL_NS_GPL(iommu_replace_device_pasid, IOMMUFD_INTERNAL);
+
/*
* iommu_get_domain_for_dev_pasid() - Retrieve domain for @pasid of @dev
* @dev: the queried device