Merge branch 'nesting_reserved_regions' into iommufd.git for-next

Nicolin Chen says:

=========
IOMMU_RESV_SW_MSI is a unique region defined by an IOMMU driver. Though it
is eventually used by a device for address translation to an MSI location
(including nested cases), practically it is a universal region across all
domains allocated for the IOMMU that defines it.

Currently IOMMUFD core fetches and reserves the region during an attach to
an hwpt_paging. It works with a hwpt_paging-only case, but might not work
with a nested case where a device could directly attach to a hwpt_nested,
bypassing the hwpt_paging attachment.

Move the enforcement forward, to the hwpt_paging allocation function. Then
clean up all the SW_MSI related things in the attach/replace routine.
=========

Based on v6.11-rc5 for dependencies.

* nesting_reserved_regions: (562 commits)
  iommufd/device: Enforce reserved IOVA also when attached to hwpt_nested
  Linux 6.11-rc5
  ...

4 files changed, 47 insertions, 27 deletions

diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c
index cd679c13752e..81e9cc6e3164 100644
--- a/drivers/iommu/io-pgfault.c
+++ b/drivers/iommu/io-pgfault.c
@@ -170,6 +170,7 @@ void iommu_report_device_fault(struct device *dev, struct iopf_fault *evt)
 		report_partial_fault(iopf_param, fault);
 		iopf_put_dev_fault_param(iopf_param);
 		/* A request that is not the last does not need to be ack'd */
+		return;
 	}
 
 	/*
diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c
index 11573a84f68a..5fd3dd420290 100644
--- a/drivers/iommu/iommufd/device.c
+++ b/drivers/iommu/iommufd/device.c
@@ -327,8 +327,9 @@ static int iommufd_group_setup_msi(struct iommufd_group *igroup,
 	return 0;
 }
 
-static int iommufd_hwpt_paging_attach(struct iommufd_hwpt_paging *hwpt_paging,
-				      struct iommufd_device *idev)
+static int
+iommufd_device_attach_reserved_iova(struct iommufd_device *idev,
+				    struct iommufd_hwpt_paging *hwpt_paging)
 {
 	int rc;
 
@@ -354,6 +355,7 @@ static int iommufd_hwpt_paging_attach(struct iommufd_hwpt_paging *hwpt_paging,
 int iommufd_hw_pagetable_attach(struct iommufd_hw_pagetable *hwpt,
 				struct iommufd_device *idev)
 {
+	struct iommufd_hwpt_paging *hwpt_paging = find_hwpt_paging(hwpt);
 	int rc;
 
 	mutex_lock(&idev->igroup->lock);
@@ -363,8 +365,8 @@ int iommufd_hw_pagetable_attach(struct iommufd_hw_pagetable *hwpt,
 		goto err_unlock;
 	}
 
-	if (hwpt_is_paging(hwpt)) {
-		rc = iommufd_hwpt_paging_attach(to_hwpt_paging(hwpt), idev);
+	if (hwpt_paging) {
+		rc = iommufd_device_attach_reserved_iova(idev, hwpt_paging);
 		if (rc)
 			goto err_unlock;
 	}
@@ -387,9 +389,8 @@ int iommufd_hw_pagetable_attach(struct iommufd_hw_pagetable *hwpt,
 	mutex_unlock(&idev->igroup->lock);
 	return 0;
 err_unresv:
-	if (hwpt_is_paging(hwpt))
-		iopt_remove_reserved_iova(&to_hwpt_paging(hwpt)->ioas->iopt,
-					  idev->dev);
+	if (hwpt_paging)
+		iopt_remove_reserved_iova(&hwpt_paging->ioas->iopt, idev->dev);
 err_unlock:
 	mutex_unlock(&idev->igroup->lock);
 	return rc;
@@ -399,6 +400,7 @@ struct iommufd_hw_pagetable *
 iommufd_hw_pagetable_detach(struct iommufd_device *idev)
 {
 	struct iommufd_hw_pagetable *hwpt = idev->igroup->hwpt;
+	struct iommufd_hwpt_paging *hwpt_paging = find_hwpt_paging(hwpt);
 
 	mutex_lock(&idev->igroup->lock);
 	list_del(&idev->group_item);
@@ -406,9 +408,8 @@ iommufd_hw_pagetable_detach(struct iommufd_device *idev)
 		iommufd_hwpt_detach_device(hwpt, idev);
 		idev->igroup->hwpt = NULL;
 	}
-	if (hwpt_is_paging(hwpt))
-		iopt_remove_reserved_iova(&to_hwpt_paging(hwpt)->ioas->iopt,
-					  idev->dev);
+	if (hwpt_paging)
+		iopt_remove_reserved_iova(&hwpt_paging->ioas->iopt, idev->dev);
 	mutex_unlock(&idev->igroup->lock);
 
 	/* Caller must destroy hwpt */
@@ -440,17 +441,17 @@ iommufd_group_remove_reserved_iova(struct iommufd_group *igroup,
 }
 
 static int
-iommufd_group_do_replace_paging(struct iommufd_group *igroup,
-				struct iommufd_hwpt_paging *hwpt_paging)
+iommufd_group_do_replace_reserved_iova(struct iommufd_group *igroup,
+				       struct iommufd_hwpt_paging *hwpt_paging)
 {
-	struct iommufd_hw_pagetable *old_hwpt = igroup->hwpt;
+	struct iommufd_hwpt_paging *old_hwpt_paging;
 	struct iommufd_device *cur;
 	int rc;
 
 	lockdep_assert_held(&igroup->lock);
 
-	if (!hwpt_is_paging(old_hwpt) ||
-	    hwpt_paging->ioas != to_hwpt_paging(old_hwpt)->ioas) {
+	old_hwpt_paging = find_hwpt_paging(igroup->hwpt);
+	if (!old_hwpt_paging || hwpt_paging->ioas != old_hwpt_paging->ioas) {
 		list_for_each_entry(cur, &igroup->device_list, group_item) {
 			rc = iopt_table_enforce_dev_resv_regions(
 				&hwpt_paging->ioas->iopt, cur->dev, NULL);
@@ -473,6 +474,8 @@ static struct iommufd_hw_pagetable *
 iommufd_device_do_replace(struct iommufd_device *idev,
 			  struct iommufd_hw_pagetable *hwpt)
 {
+	struct iommufd_hwpt_paging *hwpt_paging = find_hwpt_paging(hwpt);
+	struct iommufd_hwpt_paging *old_hwpt_paging;
 	struct iommufd_group *igroup = idev->igroup;
 	struct iommufd_hw_pagetable *old_hwpt;
 	unsigned int num_devices;
@@ -491,9 +494,8 @@ iommufd_device_do_replace(struct iommufd_device *idev,
 	}
 
 	old_hwpt = igroup->hwpt;
-	if (hwpt_is_paging(hwpt)) {
-		rc = iommufd_group_do_replace_paging(igroup,
-						     to_hwpt_paging(hwpt));
+	if (hwpt_paging) {
+		rc = iommufd_group_do_replace_reserved_iova(igroup, hwpt_paging);
 		if (rc)
 			goto err_unlock;
 	}
@@ -502,11 +504,10 @@ iommufd_device_do_replace(struct iommufd_device *idev,
 	if (rc)
 		goto err_unresv;
 
-	if (hwpt_is_paging(old_hwpt) &&
-	    (!hwpt_is_paging(hwpt) ||
-	     to_hwpt_paging(hwpt)->ioas != to_hwpt_paging(old_hwpt)->ioas))
-		iommufd_group_remove_reserved_iova(igroup,
-						   to_hwpt_paging(old_hwpt));
+	old_hwpt_paging = find_hwpt_paging(old_hwpt);
+	if (old_hwpt_paging &&
+	    (!hwpt_paging || hwpt_paging->ioas != old_hwpt_paging->ioas))
+		iommufd_group_remove_reserved_iova(igroup, old_hwpt_paging);
 
 	igroup->hwpt = hwpt;
 
@@ -524,9 +525,8 @@ iommufd_device_do_replace(struct iommufd_device *idev,
 	/* Caller must destroy old_hwpt */
 	return old_hwpt;
 err_unresv:
-	if (hwpt_is_paging(hwpt))
-		iommufd_group_remove_reserved_iova(igroup,
-						   to_hwpt_paging(old_hwpt));
+	if (hwpt_paging)
+		iommufd_group_remove_reserved_iova(igroup, hwpt_paging);
 err_unlock:
 	mutex_unlock(&idev->igroup->lock);
 	return ERR_PTR(rc);
diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h
index 017e50574f3b..5d3768d77099 100644
--- a/drivers/iommu/iommufd/iommufd_private.h
+++ b/drivers/iommu/iommufd/iommufd_private.h
@@ -325,6 +325,25 @@ to_hwpt_paging(struct iommufd_hw_pagetable *hwpt)
 	return container_of(hwpt, struct iommufd_hwpt_paging, common);
 }
 
+static inline struct iommufd_hwpt_nested *
+to_hwpt_nested(struct iommufd_hw_pagetable *hwpt)
+{
+	return container_of(hwpt, struct iommufd_hwpt_nested, common);
+}
+
+static inline struct iommufd_hwpt_paging *
+find_hwpt_paging(struct iommufd_hw_pagetable *hwpt)
+{
+	switch (hwpt->obj.type) {
+	case IOMMUFD_OBJ_HWPT_PAGING:
+		return to_hwpt_paging(hwpt);
+	case IOMMUFD_OBJ_HWPT_NESTED:
+		return to_hwpt_nested(hwpt)->parent;
+	default:
+		return NULL;
+	}
+}
+
 static inline struct iommufd_hwpt_paging *
 iommufd_get_hwpt_paging(struct iommufd_ucmd *ucmd, u32 id)
 {
diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c
index c5c14bbf723c..540437be168a 100644
--- a/drivers/iommu/iommufd/selftest.c
+++ b/drivers/iommu/iommufd/selftest.c
@@ -274,7 +274,7 @@ static int mock_domain_read_and_clear_dirty(struct iommu_domain *domain,
 	return 0;
 }
 
-const struct iommu_dirty_ops dirty_ops = {
+static const struct iommu_dirty_ops dirty_ops = {
 	.set_dirty_tracking = mock_domain_set_dirty_tracking,
 	.read_and_clear_dirty = mock_domain_read_and_clear_dirty,
 };